Frantz Rowe

The case for contact tracing apps and values dilemmas: a privacy paradox in a neo-liberal world International Journal of Information Management

Keywords: Five relevant keywords Contact tracing apps, Privacy paradox, freedom of movement, technology of the self, health Five relevant keywords Contact tracing apps, Privacy paradox, freedom of movement, technology of the self, health

Contact tracing as an extreme case of the privacy paradox : which values?

Present benefits : freedom of movement, not morally responsible Future risks : privacy, habituation to security policies and health In crisis situations, contact tracing apps contribute to self-disciplining French government plays on the paradox and downplays long term concerns Abstract: Contact tracing apps are presented as a solution, if not the solution, to curb pandemics in the Covid-19 crisis. In France, despite heated public institutional debate on privacy related issues, the app was presented by government as an essential benefit for protecting health and lives, thus avoiding both politicians and citizens to feel morally responsible and looking guilty, and as essential to recover our freedom to move. However we argue that, while detection of cases have still not been reported after 10 days and one million app downloads -a situation comparable to Australia who launched its app a month before -, the adoption of the app generates important risks to our informational privacy, surveillance and habituation to security policies. It also may create discrimination, distrust and generate other health problems such as addiction and others as 5G technology continues to be deployed without prior impact studies. Finally the smartphone app against covid epidemics appears as an extreme case of the privacy paradox where the government plays on the immediate benefits and downplays long-term concerns while inducing a technology of self. Contact tracing apps may become an emblematic case for digital transformation and value changes in the western world.

« No contact tracing, no lockdown lifting » said Dr Véran, the French government Health Minister, on May 6th at the Senate debate on the "stop-covid" app. The power of this crisp formula seemed clear : the app is a means to the end of reconquering our freedom of movement. Yet it was ambiguous and senators rejected it then before approving it on may 27 th . The ambiguity resorts to a debate on values where individual privacy is at risk of being crushed and where surveillance is looming, an important issue in a country who puts liberty first on its motto. In France, as in many countries, the idea of building a mobile app that would inform a smartphone user if she/he crossed the way of contagious individuals has led the French government to add this protection method to the traditional contact tracing method by human investigation that is generally used when an epidemic develops. In general, contact tracing methods enable the State to identify contagious individuals, notably presymptomatic and asymptomatic ones, and isolate them before they spread the pandemic further. With the smartphone app method, they would be informed that they crossed someone who was contagious if they stayed more than 15 minutes at less than one meter from one another, so not respecting the "social distancing" protection rule. They can be informed up to 15 days after the encounter as the disease may take time to develop. Such contacts happen in many situations, especially in public transportation or with relatives or good friends who may ignore for a moment that they have Covid-19.

The app potentially offers several advantages over the traditional method for contact tracing. The latter rests on traditional snowballing interviews with infected people to identify who they interacted with in the past days. Specifically, tracing cost is much lower if individuals are automatically detected as prospective cases. Most importantly, an app can help identify more quickly and more comprehensively the infected individuals who were in contact with a person if both were carrying their smartphones with the app. It is estimated that on average the method is three days faster than the traditional method assuming that the tracking brigades are not overwhelmed. These advantages are key when an epidemic moves fast and has severe consequences, such as a potentially huge death toll and social and economic crisis [START_REF] Ferretti | Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing[END_REF]. At the time we write France has had nearly 30,000 deaths due to covid-19 and 22 other countries have started develop a similar app. For example Austria and Australia launched their apps a couple of months before but despite the benefits the launch was considered a failure. Beyond technical reasons that may explain this negative outcome, and from which France and other following countries could learn, concerns for privacy may still prevail in France where a culture on data privacy has been built for more than 40 years and prevent this identification and preventative method to be a success.

In this opinion paper we will first present conditions for the app to be effective. We then highlight the value dilemmas. In particular we notice that it provides an original illustration of the privacy paradox [START_REF] Kokolakis | Privacy attitudes and privacy behaviour: A review of current research on the privacy paradox phenomenon[END_REF]. The French government and people value privacy, but in the current crisis, they may prefer immediate benefits. Consequently they expose themselves to hacking risks and surveillance related to technology vulnerability and monitoring. We then highlight that this calculus is influenced by the public debate at institutional level and interpret technology and responsibility in a Foucauldian perspective as a technology of self in a neo-liberal world. In the fourth section we then give our opinion which largely overlaps with that of La Quadrature du Net, a French organization similar to Freedom on The Net. We highlight that not only privacy would be harmed, but risks such as potential surveillance and habituation to security policies, discrimination, distrust and generate other health problems in the long-term may develop. We conclude with practical and research implications.

CRITICAL CONDITIONS FOR THE EFFECTIVENESS OF THE APP

Numerous conditions are critical to predict that the mobile app method of infected individuals identification will be effective. Notably : 1) Correct information qualifying individuals as infected and contagious requires that population be tested and that tests are not error-prone, 2) High likelihood that when a contagious person meets or crosses another person an infected person both parties have a smartphone, 3) A very high proportion of smartphone users download the app. That these conditions be all met is very unlikely. The first condition would require a testing capacity that France did not have before mid-may. With testing capacity clearly below one million per week how can we control at individual level the infection and/or contagious level of a 67 million population? On May 27, th at parliament, Dr Véran presented findings of a recent study indicating that 46% of presystematic individuals contribute to the reproduction of the disease as an argument in favor of the app [START_REF] Ferretti | Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing[END_REF]. But the effectiveness of the app presupposes that the health system and a corresponding IS records who is infected and when infection occurred. We can still cross the way of people who are contagious and have not been tested precisely because a large share of infected individuals are still asymptomatic and ignore it. The second condition can be met if the population is largely equipped with smartphones and if all those in contact in their daily encounters carry their smartphones. This is unlikely even if in France 77% of the population is equipped with a smartphone (LQdN, 2020a). In fact, while when people travel, they take their phone with them in order to face any uncertainty related to traffic jam or delays on public transportation, when at destination, at their office or at their relatives they may keep their phone in a jacket or a bag and visit people or colleagues or go to meetings without them. Thus, people do not always carry their smartphones with them and this makes the traditional method of contact tracing still necessary. The third condition is that a significant share of smartphone owners may want to trade a potentially higher safety for themselves and others for their higher vulnerability to security breaches when they allow Bluetooth and subsequent privacy issues. However wishing to limit these issues, in France, unlike other countries (e.g. Norway), government chose Bluetooth against geolocation by GPS. Being more cost efficient and, if effective, of interest as a complementary means for isolating contagious people and increasing individual and public health, the app does not come without short-term and long-term risks of privacy and surveillance. Maybe for some this will be a real tradeoff while for others privacy is long gone with the digital and e-commerce [START_REF] Spiekermann | E-privacy in 2 nd generation Ecommerce: privacy preferences versus actual behavior[END_REF]; they enjoy knowing that their friends and whoever else knows what they do. In sum, for those, private life has gone public with the internet.

Like cell phones, the tracing app offers both positive externalities (any individual is better protected from a health viewpoint when others also have it if they keep their phones with them) and negative externalities (the more others activate Bluetooth in high population density areas such as malls or public transportation, the greater the risk of malevolent action for those who have bad intentions have it on already). However from a public policy viewpoint the value of positive externalities grows exponentially only when a very large share of the population has adopted the app and claim has been made at Parliament on May 27 th by Cédric O, Secretary of State that a threshold of 56% of the population is sufficient, absent of masks, lockdown and tests to curb the pandemics1 . Contrary to what Dr Véran and Mr O claimed, the conclusions from one of the most advanced epidemiological study taking into account the benefit of a contact tracing smartphone app [START_REF] Ferretti | Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing[END_REF] neither meant that, without the app, lock-down would continue, nor that other preventative measures should be dropped but that an app similar to what was proposed by the Oxford team would help control the disease. However the team noted that "The app should be one tool among many general preventative population measures such as physical distancing, enhanced hand and respiratory hygiene, and regular decontamination. » (ibidem).

A SOCIETAL CHOICE: VALUES DILEMMAS, RESPONSIBILITY AND NEO-LIBERAL THINKING A privacy paradox : data privacy vs freedom and health

The dilemma(s) we face are about the values that we choose [START_REF] Rowe | Being critical is good, but better with philosophy! From digital transformation and values to the future of IS research[END_REF]. Most of the time these dilemmas are treated within an organization or a profession (e.g. RFID tags for librarians in various management processes concern efficiency and security vs privacy (Thornley & al., 2011), but they are rarely exposed at the level of a nation with impact on everyone's life. While privacy is a fundamental human right, freedom to move and safety are also fundamental. The dilemmas here are not only between health and privacy [START_REF] Harari | The world after coronavirus[END_REF], between freedom to move and data security and privacy, but also between who and what to protect. Contact tracing apps may bring higher health safety for others, and particularly for the elderly (since mortality of those infected by covid-19 essentially affects people over 65), and would contribute to allow the economy to restart, as emphasized by Dr Véran, for the risk of overwhelming the health system would diminish. Under the circumstances health professionals would also reduce their own risk of becoming infected. Presented like this, the privacy breaches risk may look minor and the two sides of the dilemma do not weigh equally. Otherwise put the covid crisis may be a nice illustration of the privacy paradox which states that we generally value privacy, but when we have an opportunity we are ready to trade it for something else [START_REF] Kokolakis | Privacy attitudes and privacy behaviour: A review of current research on the privacy paradox phenomenon[END_REF]. This feeling may be even confirmed when one looks at the public debate on privacy issues and the efforts apparently made to surface privacy issues and mitigate corresponding risks. In France, in Germany, in the UK, in Belgium and in most western countries privacy issues related to the design of these « stop-covid » app have seemingly been addressed both at technical level and at institutional level. Technically and from an IS viewpoint, while many countries around the world have developed mobile apps for contact tracing, the design features have fueled heated typical IS debates regarding whether stored data should be decentralized or centralized, which data should be stored and more largely, about data governance. Regarding governance, the French government rejected the idea that the algorithm for identification of an infected contact be developed by Apple or Google or any foreign company. It made it an issue of national sovereignty to try to regain trust of citizens who may otherwise fear that their personal and health data may be monetized by tech giants.

Turning to institutional level, France and many other European countries are very sensitive to privacy issues [START_REF] Miltgen | Cultural and generational influences on privacy concerns: A qualitative study in seven European countries[END_REF] and privacy is protected by law. For instance, long before the advent of GDPR, the Commission Nationale Informatique et Libertés (CNIL) was set up in 1978 in France, to protect our digital privacy. Furthermore the right to be forgotten was applied in France long before GDPR (2010). Despite the declared State of Urgency/Emergency the government chose to bring the debate in front of parliament and could not proceed without the legal advice (although not binding) of CNIL who finally gave a favorable recommendation for the stop-covid app on May 26 th and for the Information Systems that were set up also for contact tracing when following the traditional method. It did so after considering that : 1) no personal data would be collected from the app without being encrypted and anonymized, 2) the exchange protocol named Robert would not be based on Apple or Google technology but developed by INRIA, the National Research Institute that specializes on computing and automation.

Who is morally responsible?

The French government and people value privacy, but in the face of human suffering and losses due to health, they may opt for the immediate benefits of the app: freedom to move and not having to feel morally responsible and looking guilty of as politicians rejecting a technique that could save lives. However, this choice is made at the expense of privacy; even if in France geolocation with GPS was rejected for this reason. In fact, bluetooth technology is notoriously fraught with data breaches, and data breach vulnerability considered a risk to data privacy [START_REF] Culnan | How ethics can enhance organizational Privacy: Lessons from the Choicepoint and TJX Data Breaches[END_REF]. The privacy paradox is more multifarious and complex than it seems [START_REF] Kokolakis | Privacy attitudes and privacy behaviour: A review of current research on the privacy paradox phenomenon[END_REF]. Privacy itself and related policy is also heavily influenced by political choices related to various stakeholders' interests [START_REF] Introna | Privacy in the information age : Stakeholders, Interests and Values[END_REF]. Here it is not exactly a calculus between the expected loss of privacy and the immediate gain of information disclosure [START_REF] Dinev | An extended privacy calculus model for e-commerce transactions[END_REF][START_REF] Xu | The personalization privacy paradox: An exploratory study of decision making process for location-aware marketing[END_REF] that the government think people will make, but a calculus taking into account their need for freedom to move and their feelings about moral responsibility and guilt due to the evolution of the pandemics. For government and parliament representatives themselves the calculus may be a between reducing their risk of looking inactive and bearing similar moral responsibility (with higher social pressure since their decisions are public) if the pandemics is less controlled than in countries where the app has been adopted on the one hand; and being attacked for pursuing a surveillance policy and infringing upon data privacy on the other hand.

A technology of the self in a neo-liberal world

However, even if taking account stakeholders' interest we may still at this stage conclude that the two sides of the dilemma do not weigh equally. So why this fuss about privacy? Isn't it over with the dilemma? My own opinion and that of many other digital specialists in France is that, while the "stop-covid" app has been released in France like many other apps in the world pursuing the same contact tracing goal, and whatever the design choices they embedcentralized as in France and the UK or decentralized as in Germany, independent from Apple and Google as in the UK and in France or not, using GPS or bluetooth -these apps are more dangerous than they seem and the values dilemmas persist. Not only is privacy endangered and we move towards a surveillance society, but long term health risk are also significant if the app is widely accepted. To control the pandemics with this app people would voluntarily request to be tested and would self quarantine. By making the choice of voluntary rather than compulsory adoption of the app the government reinforces self-discipline in the population. Because it is necessary to carry smartphones close to our body to make the detection process and calculation of distance more effective, we argue that this contact tracing app can be interpreted as a technology of the self in a neo-liberal thinking, included in governmentality [START_REF] Foucault | About the Beginning of the Hermeneutics of the Self[END_REF][START_REF] Lemke | The Birth of Bio-Politics'' -Michel Foucault's Lecture at the Colle ge de France on Neo-Liberal Governmentality[END_REF], a biopower self-disciplining our bodily behavior and reinforcing self-discipline in a Foucauldian sense [START_REF] Leclercq-Vandelannoitte | Interrelationships of identity and technology in IT assimilation[END_REF], but also creating long-term risks including for society and for our health.

AN OPINION INFORMED BY A LA QUADRATURE DU NET AND LONGER-TERM CONCERNS

My humble opinion is very similar to that of La Quadrature du Net (LQdN), an independent association that generally defends privacy and fights against trends towards the advent of a surveillance society, but also goes further in that it considers other long term negative consequences such as health and exclusion/discrimination consequences related to more intense smartphone use.

In its opinion LQdN approves the position of CNIL who expressly demanded that government demonstrate the practical utility of stop-covid, while regretting that, given its illusory benefits, CNIL did not purely and simply asked the French government « to stop this dangerous and useless project and gets lost in the false debate about deceptive warrants to delineate the use of the app » (LQdN, 2020b). On april 14th LQdN sent to parliament its own arguments against post-covid. The main argument is that we can very cautiously agree to limit our freedoms ONLY when there are strong proven benefits, which is not currently the case and will not be, because, as we explained above, stop-covid effectiveness is very uncertain essentially due to a) too low predicted app and smartphone use 2 and b) too low data quality related to false positives (i.e. being informed that someone we crossed was contagious when this person was not (to reduce this risk people will have to enter a QR code in the app) or when the person (e.g. a doctor) was already informed prior to the encounter and protected herself and false negatives (e.g. not identifying the risk in the absence of sufficient disease testing capacity and due to not detecting beyond one meter as in France). From an ethical viewpoint CNIL considered that collected data will be fitting the definition of data minimisation regarding data privacy. Data minimisation means that data collection should be adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed. However, given our previous remark, we would argue that data minimisation is not met for multiple reasons: there will be multiple false positive/negative (relevance), the scope of data collection is too large and too loosely defined (purpose) 3 , the analysis and future use of biometric data are not properly addressed (adequation) 4 . With regards to health safety 2 Detection of cases have still not been reported after four days its launch on june 2 nd and one million app downloads -a situation comparable to Australia who launched its app a month before France. In Australia with 6 million downloads only one case was detected! 3 Scope at best is unclear and not well delineated. On the one hand there are three applications in charge of fighting the pandemics at national level in France : 1) « Stop-covid » on the smartphone that notifies a potential risk to the user. 2) « SI-DEP » (Système d'Informations de DEPistage) that records all the results of labs who test COVID-19 and whose purpose is to make sure that all positive cases are taken care of. 3) « Contact-COVID » whose purpose is to identify the contacts of a covid-19 case and to make sure that each and everyone has been called, informed, tested and coached. Stop-covid is not related to the other two apps (no triangulation). On the other hand, concerns remain at the portfolio of applications level : 1) any « Contact-Covid » and « SI-DEP » even if anonymized can be hacked. In short the privacy risk of stop-covid itself may not be considered important, but this risk should be assessed for any contact tracing application like contact-covid. In this respect little is known about how contact-covid is operated. 2) It remains that increased surveillance, habituation to security policy, health issues related to more permanent carrying of smartphone and addiction are serious risks specifically related to stop-covid with little predicted effectiveness if we examine the conditions for its success. Source : https://solidarites-sante.gouv.fr/soins-et-maladies/maladies/maladies-infectieuses/coronavirus/toutsavoir-sur-le-covid-19/article/contact-covid-et-si-dep-les-outils-numeriques-du-depistage-covid-19 4 Strangely the law says nothing for instance about thermal cameras that have already been installed at CDG airport. Normally those who have high temperature should then have their temperature confirmed LQdN adds that the stop-covid app may even prove counter-effective either with people feeling safe when they are not and stop behaving cautiously5 or with people hiding their symptoms in fear that they be discriminated.

Interestingly, not only short-term benefits are illusory, but negative long term risks abound, not only for privacy. LQdN (LQdN, 2020a) notes three types of risks for our freedom:

-People could be discriminated if the app was to be compulsory or if social pressure towards adoption becomes too high; a particular case of discrimination being access to blood testing being conditioned by its adoption (On this first type of risk CNIL felt that government had taken appropriate measures hence its final favorable recommendation); -Increased surveillance will be facilitated if the app is adopted by a large share of the population ; and anonymity is simply impossible as it runs counter to the very objective of the app which is to inform targeted persons. Hence the need for pseudonyms which can not be very effective against malevolent action [START_REF] Bonnetain | Le traçage anonyme, dangereux oxymore : Analyse de risques à destination des non-spécialistes[END_REF] and individual surveillance. -Habituation to security policies that curtail our freedoms and social acceptability of digital surveillance based on the blind belief of technology as solutions to social problems.

I do not wish to paint a bleak picture of the situation but the very last argument can be completed in two ways. First, the haste to develop contact tracing apps evokes pure technological solutionism that runs completely against all socio-technical lessons from IS and other socio-technical disciplines. It is not hard to guess that the tech industry and government are not innocent in this state of affairs. As LQdN (2020a) notes this is sad because there are much more important actions for government to undertake including to fight pandemics and its consequences, .

Second, such smartphones tracing apps would inevitably reinforce the ubiquitous use of smartphones in the population who is not educated to the complexity of the dark side of IT [START_REF] D'arcy | Reflecting on the 'Dark Side' of information technology use[END_REF], pushing them to carry them permanently on the body. Why inevitably? Even if the app is not massively adopted, this announcement sends the signal that in order to combat risks the government and society must be digitally oriented and this exerts pressure towards adoption and use. What will happen when technologies that are also highly contentious like 5G come without impact studies? It is notorious that adolescents are already prone to some forms of problematic smartphone dependency [START_REF] Gentina | Effects of materialism on problematic smartphone dependency among adolescents: The role of gender and gratifications[END_REF]. Do we want them to turn into real addicts and not let them be able to discern what could be suitable for them in their daily life and inevitably beyond? More importantly adolescents are unaware about privacy issues and such apps reinforce the message that personal data do not belong to you, that tracking trips is not problematic and legitimizes that this can be done by any government.

IMPLICATIONS FOR RESEARCH AND PRACTICE

and be tested if necessary. If positive this information will be added to SI-DEP. It does not say much about the myriad of sub-contactors who work on such a centralized system albeit the three apps are separate and who could also lead to data leaks. Source : https://www.legifrance.gouv.fr/eli/loi/2020/5/11/PRMX2010645L/jo/texte

As academics in our multiple activities we have an important role to play to contribute to better public project decisions like these who are critical both on the short-term and on the long-term. Our first role is to raise awareness on the situation by offering an hopefully different yet interesting interpretation. Then, it is to act more directly to contribute to relevant efforts by teaching and research in a way which is suited to the evolving situation.

Contact tracing apps may become an emblematic case for digital transformation and value changes in the western world. We see the contact tracing as an original if not extreme case of the privacy paradox [START_REF] Kokolakis | Privacy attitudes and privacy behaviour: A review of current research on the privacy paradox phenomenon[END_REF] because in studies of the informational privacy paradox a) smartphones apps, or b) location data have rarely been studied ( [START_REF] Egelman | Choice architecture and smartphone privacy: there's a price for that[END_REF] and [START_REF] Zafeiropoulou | Unpicking the privacy paradox: can structuration theory help to explain location-based privacy decisions?[END_REF] being exceptions) and because here the dilemma is not at the level of an executive, an organization or a profession, but at the level of all countries who are launching such apps and potentially to the world! In such context no active personal information disclosure is used contrary to the vast majority of the privacy paradox literature; only metadata about our location and having been in contact or not with an infected person is monitored. What is activated through self-discipline are the opening of Bluetooth and the consent to be tested and to self-quarantine if the person crossed someone infected. However it is voluntary and at all the stages of the process citizens are made responsible for their health and public safety, an important issue in governmentality: if this stop-covid preventative method for avoiding to spread the disease is not effective government won't be to blame, people will be responsible. Our interpretation is that, consciously or not, the government plays on the immediate benefits and downplays long-term risks in the equation considered by the privacy paradox while inducing self-discipline. As a consequence this case is also an opportunity to research changing bodily behavior of stop-covid adopters [START_REF] Chughtai | Taking the human body seriously[END_REF][START_REF] Leclercq-Vandelannoitte | Interrelationships of identity and technology in IT assimilation[END_REF] and assess risks if the app lives long enough.

Unfortunately for the reasons we explained in the first section of this paper, this tactic is not even going to be effective from a public health viewpoint. For our academic community, fighting solutionism in this context requires developing awareness of ethical concerns and calls for future research on the ethics of digital governance [START_REF] Markus | Obstacles on the Road to Corporate Data Responsibility, in Big Data Is Not a Monolith: Policies, Practices and Problems[END_REF]) (e.g. on conditions where data sharing would be really useful (and there are plenty such as the project of health data hub which is about the sharing of health data to help discover new treatments for all sorts of deadly and rare disease). It also suggests insisting on every occasion on our socio-technical identity as a discipline and introducing some moral philosophy or ethics into IS curricula [START_REF] Markus | POETs and Quants: Ethics education for data scientists and managers. 3 rd RICK workshop of Information and Organization[END_REF]. As suggested above there is a need to study institutions (government, parliament, justice) and industry actors positions and interests and not to focus only on the smartphone app. Beyond data governance of this app, various socio-technical systems should be studied, included the traditional contact tracing systems such as contact-covid and how it is enacted with stakeholders. Beyond the opposition between the market (Big tech companies) and the State, community governance ought to be considered.

While there is a tradition of research tracks on privacy in most IS conferences, it is important that related problems be not treated only technically (e.g. How to respect confidentiality or anonymity when one collects personal data?) but to truly address both a) values dilemmas including by providing some philosophical background with a critical theoretical stance when possible [START_REF] Introna | Privacy in the information age : Stakeholders, Interests and Values[END_REF]) and b) risks and negative consequences related to the design (e.g. Thornley & al., 2011;[START_REF] Solove | A taxonomy of privacy[END_REF]. Most importantly ethical concerns should not be last or a supplement to the design but integrated from the beginning with equal power to those in charge of enforcing it to those with a more technical profile, regardless of whether "privacy by design" has been claimed as is the case with the INRIA team who is responsible for the app development. Regarding adoption decisions, equal importance should be given to risks (Gibb & al., 2011;[START_REF] Introna | Privacy in the information age : Stakeholders, Interests and Values[END_REF] and ethics [START_REF] Mingers | Towards ethical information systems: the contribution of discourse ethics[END_REF] as it is to strategic alignment, profitability, ease of use and usefulness.

Finally, we fear that youngsters will get used to no privacy even more than now and will let surveillance generalize by industry itself with no precaution. Intelligent agent and smartphone providers are already jumping on the opportunity [START_REF] Brewster | Exclusive : Warning over Chines mobile giant Xiaomi recording millions of people's private web and phone use[END_REF]. Future generations must protect data privacy which took French and Europeans 40 years to build! However it is our task to also educate them to defend their privacy and be critical when receiving appealing commercial offers and invited to participate to local and national governments projects.

CONCLUSION

As IS specialists our temptation, and sometimes our trap, is to contribute to the main ongoing and visible debate about what design feature is best and there are always pros and cons for any application and needs in our changing world. But we should also step back and interrogate these apparent needs and strive to see the ethical or moral dilemmas that are often hidden or not really addressed because opponents voices are unheard; covered by those disproportionally richer, vocal and influential and whose interest is to present technology as the solution to our problems. The world we build with technologies incorporates irreversible trends that are part of the digital transformation. We can not make choices for others but we can inform society when we see the dangers and make more conscious choices when we face dilemmas such as the apparent one between privacy and health [START_REF] Harari | The world after coronavirus[END_REF]. Opting systematically for the latest technology does not necessarily means progress but could mean being under influence. Although hardly hit by covid-19 Belgium decided all the more courageously to only use the traditional contact tracing method.

As INRIA researchers team note [START_REF] Bonnetain | Le traçage anonyme, dangereux oxymore : Analyse de risques à destination des non-spécialistes[END_REF], the first article of CNIL has not aged a bit: "IT must serve each citizen [. . . ]. It must undermine neither human identity, nor human rights, nor private life, nor individual or public freedoms ».

This claim is based on the report to the NHS(Hinch & al.,

2020) co-signed by many of the members of the Oxford team who published in Science[START_REF] Ferretti | Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing[END_REF]. However the Science publication is far more cautious.

This argument has also been used by the French government for masks. However people are not stupid : it is not because they put their seat belt on that they speed up.


Gilles-Eric Seralini

Gerald Jungers

Toxic compounds in herbicides without glyphosate

Keywords: glyphosate, glyphosate-free herbicide, Roundup, polycyclic aromatic hydrocarbons, heavy metals, toxicity Highlights AMPA aminomethyl phosphonic acid, G glyphosate, GBH glyphosate-based herbicides, GC gas chromatography, HPLC High performance liquid chromatography, ICP Inductively coupled plasma method, MS mass spectrometry, PAH polycyclic aromatic hydrocarbons, ppb part per billion

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

We previously demonstrated the toxicity of some glyphosate-based herbicidal formulations (GBH) in vitro, not only in cell cultures [START_REF] Richard | Differential effects of glyphosate and roundup on human placental cells and aromatase[END_REF] but also in vivo on mammals over the short term [START_REF] Cassault-Meyer | An acute exposure to glyphosate-based herbicide alters aromatase levels in testis and sperm nuclear quality[END_REF] and in chronic long-term studies at ppb doses in the diet [START_REF] Seralini | Answers to critics: why there is a long-term toxicity due to NK603 Roundup-tolerant genetically modified maize and to a Roundup herbicide[END_REF][START_REF] Seralini | Republished study: long-term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize[END_REF]. This was a focus for an intense debate (Duke, 2018;[START_REF] Portier | Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC[END_REF][START_REF] Tarazona | Glyphosate toxicity and carcinogenicity: a review of the scientific basis of the European Union assessment and its differences with IARC[END_REF][START_REF] Davoren | Glyphosate-based herbicides and cancer risk: a post-IARC decision review of potential mechanisms, policy and avenues of research[END_REF], but it was more recently confirmed and explained that it was induced by compounds of the formulations other than glyphosate [START_REF] Lopes | Toxicity induced by glyphosate and glyphosate-based herbicides in the zebrafish hepatocyte cell line (ZF-L)[END_REF]Hao et al., 2019). We conducted in vivo transcriptomic, proteomic and metabolomic studies (Mesnage et al., 2015[START_REF] Mesnage | Multiomics reveal non-alcoholic fatty liver disease in rats following chronic exposure to an ultra-low dose of Roundup herbicide[END_REF]. In vitro, oxidative stress, mitochondrial dysfunction, apoptosis, membrane disruption [START_REF] Benachour | Glyphosate formulations induce apoptosis and necrosis in human umbilical, embryonic, and placental cells[END_REF], estrogen and androgen receptors blockade as well as aromatase disruption [START_REF] Richard | Differential effects of glyphosate and roundup on human placental cells and aromatase[END_REF]Gasnier et al., 2009) were demonstrated in hepatic, kidney, placental and embryonic human cells. In vivo, liver, kidneys, and hormone-dependent organs such as mammary glands and thyroid were affected by these cellular and endocrine disruptions. Proteins disturbed were involved in organonitrogen metabolism and fatty acid β-oxidation. Proteome disturbances reflected peroxisomal proliferation, steatosis, and necrosis.

Metabolomic studies confirmed lipotoxic conditions and oxidative stress [START_REF] Mesnage | Multiomics reveal non-alcoholic fatty liver disease in rats following chronic exposure to an ultra-low dose of Roundup herbicide[END_REF]. In vivo at the transcriptomic level, alterations in gene expression indicated fibrosis, necrosis, phospholipidosis, mitochondrial membrane dysfunction and ischemia (Mesnage et al., 2015b, EH). These findings confirm the histological and electron microscopic observations, as well as blood and urine biochemistry [START_REF] Seralini | Republished study: long-term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize[END_REF].

All these effects were caused by long-term consumption of formulations from 0.1 ppb, in which we identified by mass spectrometry oxidized petroleum residues and toxic heavy metals [START_REF] Mesnage | Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity[END_REF]Defarge et al., 2018).

The effects (including endocrine disruption) were not caused by glyphosate alone at the same level [START_REF] Defarge | Evaluation of the cytotoxic effects of glyphosate herbicides in human liver, lung, and nerve[END_REF]. We originally demonstrated the differential toxicity between glyphosate and its formulations marketed as Roundup, the most widely used herbicide in the world [START_REF] Richard | Differential effects of glyphosate and roundup on human placental cells and aromatase[END_REF].

We found that Roundup contained formulants that were 1000 times more toxic, and at a lower threshold more endocrine disrupting than glyphosate, but these formulants were declared as inert by the manufacturer and their identity was kept confidential by regulatory bodies. Therefore the scientific debate was centred mostly on glyphosate alone [START_REF] Bai | Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination[END_REF][START_REF] De Araujo | Glyphosate and adverse pregnancy outcomes, a systematic review of observational studies[END_REF]Van Bruggen et al., 2017), even if numerous authors used glyphosate formulations but interpreted the results as glyphosate effects (Mesnage et al., 2015). None of the above-mentioned cytologic and pathological effects seen from Roundup exposure were observed in studies using glyphosate alone at the ppb level, but in studies using the formulations, all these effects were documented. However there is still a need to measure multi-generational effects of these herbicides [START_REF] Landrigan | The need for independent research on the health effects of glyphosate-based herbicides[END_REF].

Due to the world debate on health, food and environmental toxicology, glyphosate was replaced in formulations for private use only in some countries, mostly by pelargonic and acetic acid that were declared in 2019. Thus we carefully undertook an analysis of the formulations in which these new products were dissolved, to check the potential toxicity in water and food of the new residues. We focused mainly on petroleum (PAHs) and numerous heavy metals with an extensive study on this issue. These products are still in some instances called Roundup, but the marketing has been changed to imply that the herbicides are more natural, since they no longer contain glyphosate.

Materials and Methods

Materials

Out of 16 glyphosate-free labelled herbicides available on the French market for gardeners in 2019, plus one marketed in Germany and 3 in Poland, 14 samples were selected for their authorization numbers, manufacturer or distribution company, or references of lots and dates of manufacturing. All were carefully numbered A-N and their respective contents, in terms of declared active principles, were listed (Table 1). To ensure the accuracy and reproducibility of the data, in particular for adequate replications, standard deviations and coefficients of variations, all measurements were performed in laboratories accredited by COFRAC, the French accreditation body.

ICP-MS for essential minerals and metals

Inductively coupled plasma mass spectrometry (ICP-MS) was used according to the norm NF IN ISO 17292-2. For essential minerals, calcium, magnesium, phosphorus, potassium, and sodium were detected; for metals or metalloids, other minerals, aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, chromium, cobalt, copper, iron, gallium, germanium, hafnium, indium, lithium, lead, manganese, molybdenum, nickel, niobium, palladium, rhenium, selenium, silicon, silver, strontium, tantalum, tellurium, thallium, tin, titanium, tungsten, vanadium, zinc, and zirconium were assayed (see Table 2).

Mineralization of water was adapted from the norm NF EN ISO 15587-2; the mineralization was performed by evaporation with addition of nitric acid. A self-control matrix followed the mineralization protocol. The analysis of a range blank and the calibration range were accomplished; this was controlled by an independent standard with the acceptance criterion range of +/-10%. Other independent standards were analyzed every 10-15 samples with an acceptance criterion of +/-20%; at the end of the measurements, low-end standards were analyzed.

HPLC and fluorescence detections for glyphosate and AMPA

High performance liquid chromatography (HPLC) followed by final stack derivatization and fluorescence detection (F22, all method DIN 38407-22) was performed for G and its main metabolite aminomethyl phosphonic acid (AMPA).

GC-MS for HAP

The international normalized method DIN 38407-39 was applied, including gas chromatography and mass spectrometry (GC-MS) for HAP measures. First, PAHs in water were extracted with cyclohexane. The extract was concentrated by evaporation. The PAHs were then separated by gas chromatography on capillary columns with suitable stationary separation phases and identified and quantified by mass spectrometry. The products assayed were acenaphthene, acenaphthylene, anthracene, benzo(A)anthracene, benzo(A)pyrene, benzo(B)fluoranthene, benzo (G,H,I)perylene, benzo(K)fluoranthene, chrysene, dibenzo(A,H)anthracene, fluoranthene, fluorene, indeno(1,2,3-C,D)pyrene, naphthalene, phenanthrene, and pyrene (Table 2).

Herbicidal activity

Six squares of 14 cm2 of Poa annua L. in vegetative state (10-20 blades of grass/cm2) were treated once in triplicate, simultaneously in spring in a field in Normandy. These products are for gardens to remove weeds. Herbicides were diluted as per the manufacturers' instructions. To optimize the effects in a short time and on a small surface, we poured homogeneously 50 ml on each square. Their active principles are used alone similarly as controls: i.e. acetic acid 6%, and pelargonic acid at the same final intermediate concentration as declared in samples E and K, i.e. 24%. Since pure pelargonic acid was dissolved first with 70% alcohol which reached a final 3% concentration of alcohol in the dilution, negative controls were water and water with 3% alcohol. At 3h and 24h after treatments, the grass was observed (see results); then the remaining plants were carefully cut and weighed. The effects on soil were observed after 3, 4 and 6 weeks.

10

Results

Following glyphosate prohibition for private use, we obtained a representative sampling of new herbicides declared as glyphosate-free, marketed in European Union since 2019 (Table 1). Some are still called Roundup, which previously contained glyphosate, but are now composed of new declared active principles -mainly pelargonic acid for around 65% of the available products, in which it was found to be present in highly variable concentrations (3.1-72%). It is present in pelargoniums but for herbicidal use is chemically synthesized. The next most common new declared active principle was acetic acid; it is present in vinegar at around the same concentration (6%). Less frequently, the declared active ingredients were caprylic and capric acids. These are respectively octanoic and decanoic acids. They are found in some plants like coconut and in goat's milk but can also be chemically synthesized. In one instance, benzalkonium chloride was present, in a product sourced from Poland. This is a mixture of a benzyl structure with carbon chains of different lengths; it is known as a detergent with antiseptic or biocide activity provoking cell membrane disruptions and is also used in petroleum. Some of these compounds are sold by Bayer, which has acquired Monsanto, historically the main marketer of glyphosate-based herbicides. However, the products used for this research were marketed by different companies, also indicated in Table 1.

All compounds measured are listed in Table 2 and the results detailed below.

Essential minerals concentrations

Essential minerals concentrations were highly variable in the herbicides tested, from <5 to 497 mg/L (Table 3). Only manganese was below detectable levels; copper was quantifiable only in one instance (Table 4). Potassium was by far the element found at the highest levels, reaching 0.3-0.4 g/L. Sodium was the element found at the second highest level, at half the level of potassium, followed by calcium, phosphorus, and low levels of magnesium.

Metals

Out of the 35 metals investigated, only 8 were detected in the mg/L range (Table 4), except arsenic. Silicon was by far the metal present at the highest levels, with a maximum of 36 mg/L (in H); in general there was 7 times less nickel; then titanium, iron, copper, lead, zinc, and silver were present at levels less than 10 mg/L. The herbicide with the highest level of heavy metals was C with 39 mg/L; it was also the only one containing titanium. Arsenic was specifically detected in the μg/L range from 6.33-20.9 in half of the pesticides (see summary table 6).

PAHs

In total, 16 PAHs were detected in the 16 herbicides investigated, from wellknown markers of PAH to reference carcinogens. They were <10 μg/L only in 2 samples, but then reached 28.1-2430 μg/L in the 12 others (Table 5). The herbicide with the highest level of PAH presence was K, with fluorene reaching 2100 μg/L. Herbicides E and K had a maximal dose of PAHs of over 2 mg/L and were from the same company in France and Poland, called Compo, with different authorization numbers. The class of PAHs found at the second highest levels were phenanthrene, naphthalene, and chrysene, which were detected at around a 10 times lower level (see column Total A-N, Table 5). Others include the reference carcinogen benzo(A)pyrene, which reached quantifiable levels in a third of the new herbicides. Acenaphthylene, acenaphthene, benzo(A)anthracene, fluoranthene and pyrene constituted the third sub-group, measuring between 100-300 μg/L in total.

Totals and main compounds in pesticides

To facilitate comparisons, Table 6 summarizes the totals of metals, PAHs and essential minerals and presents the detailed results by pesticide for arsenic, but also G and its metabolite AMPA. This is because arsenic is measured on a different scale from other metals. 7 pesticides out of 14 contained quantifiable levels of arsenic. G and AMPA were also not declared but were surprisingly found in 2 pesticides at low levels in comparison to their previous uses in herbicides for which they are the declared active ingredient (around 400 g/L).

Even so, the 2 pesticides had a difference of more than 21 times in G + AMPA.

However, they had the same authorization number (L and M) and thus should contain the same composition of all chemical products. In both cases, caprylic and capric acids were the only chemicals declared. For C and E also, 2 different lots of the same authorization number were measured, but the results were different in each case (see Raw Data). There was no obvious correlation between essential minerals and metals or PAHs.

Toxicities for metals and PAHs

A simple observation can be made of the maximal levels of metals observed in the herbicide formulations of this study, in comparison to the norms of toxicities (Table 7A). The so-called toxicity thresholds in water are indicated according to at least one national or international agency (AFSSA, ANSES, EPA, as a result these metals can be considered the most toxic in the present study.

For PAHs, since all the compounds measured, except for anthracene, exceeded the toxicity threshold, and because most of them are considered carcinogens, a column was added showing the ratio between the maximal levels found in this study in the samples indicated and the toxicity thresholds. We observed that benzo(A) pyrene and benzo(A) anthracene were present at levels around 3-7 thousand times higher than their respective norms; a majority reached important levels, according to this criterion.

Herbicidal effects

Fig. 1A shows the herbicidal effects after 3 or 24h provoked by 4 compounds:

since acetic and pelargonic acids are the compounds present at the highest levels, the herbicides containing these were tested once in comparison to their declared active principles alone at similar concentrations. Water was used as a control. The results clearly showed that all products and their declared active principles were highly toxic for plants and were similarly toxic 3h after the spreading. Acetic acid (6%) and pelargonic acid (24%), also known as nonanoic acid, are respectively white vinegar or pelargonium extracts and were thus diluted in water. They proved as efficient in herbicidal activity as the formulated herbicides containing PAHs and heavy metals after 3h; truly little living grass was remaining on the soil after 24h (Fig. 1B). Then the grass was cut and weighed. No difference was observed between treatments: almost all Poa annua L. was killed (> 90%) in comparison to controls. After 21 days, the grass has re-grown only on the water-treated squares. Acetic acid prevented subsequent re-growth better than pelargonic acid. Therefore the herbicides do not need the toxic PAHs and metal residues to exercise their herbicidal activity.

Discussion

It was important for this study to have access to a representative sampling of all new herbicides declared as G-free and available on the market for private use since 2019 (Table 1). Before that time, G-based herbicides were the most common pesticides (US EPA, 2017). An intense scientific, legal, political, and social debate throughout the world has centred on G toxicity [START_REF] Bai | Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination[END_REF] because this compound was the declared active ingredient in the herbicide formulations by the manufacturers, even if other substances in the commercialized formulations are more toxic [START_REF] Benachour | Glyphosate formulations induce apoptosis and necrosis in human umbilical, embryonic, and placental cells[END_REF]. G in isolation has thus been the substance regulated over the long term by environmental and health agencies since its first use in 1974 (Duke, 2018). The same reasoning has been applied since the Second World War for all pesticides: only the declared chemical alone is tested over the long term; long-term toxicity studies of formulated pesticides are not compulsory. In fact, G has never been used alone in fields but only in formulations, which are mixtures containing in general around 40% G (Mesnage et al., 2015b).

However, in many marine and terrestrial ecosystems the formulations have been demonstrated to be much more toxic than their declared active principles [START_REF] Marc | Pesticide Roundup provokes cell division dysfunction at the level of CDK1/cyclin B activation[END_REF]Mesnage et al., 2015b). The remaining 60% of the products in formulations are generally declared as safe, inert, and confidential, and as adjuvants allowing the active principle's cell penetration and/or stability. For instance, they are claimed to help spraying. Their own toxicity in the environment and the food chain has been rarely debated. Between 2013-2018, we demonstrated by mass spectrometry the presence of poly-ethoxylated tallowamines such as chemical detergents, other petroleum-derived residues, and 5 heavy metals in G-based herbicide formulations [START_REF] Mesnage | Ethoxylated adjuvants of glyphosate-based herbicides are active principles of human cell toxicity[END_REF]Defarge et al., 2018). These present their own long-term toxicities to plants and the ecosystem, including to mammals [START_REF] Seralini | Republished study: long-term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize[END_REF] and humans [START_REF] Love | Effects on aquatic and human health due to large scale bioenergy crop expansion[END_REF]IARC, 2017).

Then the question arose of the content of the formulations of G-free new formulated products. We screened in total 35 heavy metals, 16 polycyclic aromatic hydrocarbons (PAHs), and essential minerals (Table 2). These were tested by specific mass spectrometry associated with gas chromatography or inductively coupled plasma methods in the formulations.

The essential minerals (Table 3) did not reach toxic levels. These K, Na, P, Ca, Mg ions do not appear to be present in herbicide formulations at levels that could kill plants, and they could even stimulate growth [START_REF] Nath | NPKS uptake, sensing, and signaling and miRNAs in plant nutrient stress[END_REF][START_REF] Raddatz | Coordinated Transport of Nitrate, Potassium, and Sodium[END_REF].

It is a different situation for non-nutritive, potentially toxic metals. Ti, Ni, Pb, Ag, Fe and As appear to be the most toxic over the long term, for humans and environment in general, as they were detected well over the admissible level in drinkable water. For instance, Pb [START_REF] Vorvolakos | There is no safe threshold for lead exposure: Α literature review[END_REF], Ni [START_REF] Das | Primary concept of nickel toxicity -an overview[END_REF]Ti (Fage et al., 2016) were found at several hundred to a thousand times the chronic toxicity levels; and this could well intoxicate gardeners, soils, and the environment. Metalloids or metals like Si, Ni, Ti, Fe and Pb, five of the elements detected at the highest levels, are increasingly commonly used as nanoparticles in pesticides, to accelerate cell penetration and toxicity [START_REF] Baker | Nanoagroparticles emerging trends and future prospect in modern agriculture system[END_REF]. Due to their stability and new chemical properties, they could also play this negative role in the ecosystem [START_REF] Jaiswal | Detrimental Effects of Heavy Metals in Soil, Plants, and Aquatic Ecosystems and in Humans[END_REF] and human health, including in the endocrine [START_REF] Rana | Perspectives in endocrine toxicity of heavy metals -a review[END_REF] and nervous systems [START_REF] Zeng | Children with health impairments by heavy metals in an e-waste recycling area[END_REF]. Since these are not declared nor assessed for long-term toxicity, they could cause new environmental problems. Many of the gardeners to whom these new herbicides are targeted could think these are natural due to the commercial claims made for acetic and pelargonic acids by the retailers having special formations for this communication. Private vegetable gardens will be sprayed, and all the compounds described in this study can enter the food chain. The variability in herbicide compositions concerning these elements and PAHs evidences the differential production methods used for pesticide manufacture.

PAHs are well established carcinogens, like the detected benzo(A)pyrene (Verma et al., 2012), and their hidden presence at levels up to the mg/ml range appears abnormal in these garden products for consumers. Their presence in petroleum residues at fluctuating concentrations may indicate that pesticide formulants come from petroleum wastes. In conjunction with heavy metals, a synergic toxicity is possible. They could form many hazardous metabolites.

Moreover, all these compounds form toxic mixtures having possible combined effects on the long term, for instance significant perturbations in blood and tissue redox profiles (Fountoucidou et al., 2019), inducing several diseases.

Even very low doses of toxics below regulatory limits should be measured for real exposure assessments [START_REF] Tsatsakis | New challenges in risk assessment of chemicals when simulating real exposure scenarios; simultaneous multi-chemicals' low dose exposure[END_REF].

To check if any of these chemicals add significant short-term efficacy in herbicidal properties, we compared the effects of the formulated pesticides on Poa annua L. to the effects of their declared active principles at the same concentrations. This plant is one of the most common, that may be considered as a weed in gardens. These herbicides are designed for gardeners. People can remove it between edible plants in vegetable gardens, and thus can contaminate the food chain. We noticed no detectable difference, for instance, between acetic acid at 6% in vinegar and acetic acid at 6% in formulated pesticides; the first was being sold as vinegar at considerably cheaper prices in the same supermarkets, with obviously less environmental impact due to its biodegradability. The use of acetic and pelargonic acids alone as herbicides could be recommended, which would avoid toxic formulants present in commercial formulations.

However, all of the detected PAHs and heavy metals could be used as biocides by themselves over the long term; but they have not been declared, in violation of the conclusion of the Court of Justice of the European Union (CJUE, 2019).

This could have also been concluded from our previous studies with G-based herbicides [START_REF] Defarge | Evaluation of the cytotoxic effects of glyphosate herbicides in human liver, lung, and nerve[END_REF](Defarge et al., , 2018)), and the policy of pesticide production has apparently not changed with G removal.

Traces of G were even found at different levels in two formulated pesticide products with the same authorization number. In another case the authorization numbers were the same but different contaminants were found.

This shows that the methods of formulation manufacturing are not controlled or reproducible; and this impacts the feasibility of scientific assessment of the long-term toxicity of formulated pesticides in general.

In conclusion, all the toxic compounds discovered in this study may have potential interactive effects such as synergism, antagonism or additivity in environment or living organisms, where they are known to bioaccumulate.

They can even be toxic by themselves. This is because the complete formulation is employed in the field, and not only the declared active principle which to date is studied alone for long term toxicity purposes. Table 1. Ten different samples used in this work and their declared active principles available on the French market for gardeners in 2019, plus one German and 3 Polish herbicides used for comparisons. The % of each declared active principle on the label is indicated. Immediately at treatment (0h), and 3 or 24h after, Poa annua L. was observed.

Figures and Tables

Metals

The treatments are: A Roundup (sample A) at recommended dilution containing 6% acetic acid, B acetic acid 6% in water, C Clairland (sample E) containing 24% pelargonic acid, D pelargonic acid 24% dissolved in water with ethanol first (3% final), E water, F water with 3% ethanol.

  Fig. 1A. Time effects of herbicides and of their declared active principles.

Fig. 1B .

 1B Fig. 1B. Grass weight (g) after 24h on the surfaces treated for 24h. The

  INERIS, NIH, WHO), but are classical values. This reveals that As reached two times the norm, Zn 16 times, Fe 38 times, and then Ag, Cu, Pb, Ni and Ti respectively reach 100, 170, 200, 1382, and 7800 times the admitted threshold;

  Future work on pesticide toxicity for regulatory assessments should include the study of full commercial formulations including declared and non-declared ingredients. disrupt aromatase activity in human cells below toxic levels. Int. J. Environ. Res.

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	pesticides. Tox. Rep. 5, 156-163.
	Duke, S.O., 2018. The history and current status of glyphosate. Pest. Manag. Sci. 74,
	1027-1034. https://doi: 10.1002/ps.4652.
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	10.1016/j.toxlet.2019.09.015
	Gasnier, C., Dumont, C., Benachour, N., Clair, E., Chagnon, M.C., Seralini, G.E.,
	2009. Glyphosate-based herbicides are toxic and endocrine disruptors in
	human cell lines. Toxicology 262, 184-191.

Fage, S.W., Muris, J., Jakobsen, S.S., Thyssen, J.P., 2016. Titanium: a review on exposure, release, penetration, allergy, epidemiology, and clinical reactivity.

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Tsatsakis, A., Kouretas, D.A., 2019

. Mixture of routinely encountered xenobiotics induces both redox adaptations and perturbations in blood and tissues of rats after a long-term low-dose exposure regimen: The

Table 2 .

 2 All compounds assayed in pesticides. Measurements were performed according to accredited norms in the European Union for ICP-MS (essential minerals, metals), GC-MS (PAHs), or HPLC (G, AMPA).

	Sample	Herbicide name	Declared active principle %	Authorization	Holder
	A B	Roundup Speed Evergreen Monsanto Herbatak Contact Fertiligene Scotts Jade	Acetic acid	6 6	2130153 2130153	Monsanto technology LLC SCOTTS France SAS
	C	Biocontrole Starnet Jardin d'Eden Jade		52	2170243	JADE
	D	Herbatak Express garden Scotts Jade		52	2170243	JADE
	E	Clairland Herbistop Compo		24	2140121	COMPO France SAS
	F	Clairland express Herbistop spray Compo		3.1	2160115	COMPO France SAS
	G	Solabiol Beloukha Garden SBM	Pelargonic acid	52	2170243	JADE
	H	Neudorff Finalsan W.Neudorff		19	2170355	W.Neudorff GmbH KG
	I	Roundup Evergreen Belchim Germany		52	Nr 008529-62	Belchim Crop Protection
	J	Target Poland		72	MRiRW nrR-140/2017	Target SA
	K	Compo Poland		24	MRiRW nrR-34/2016	Compo Poland
	L M	Solabiol Herbiclean SBM Solabiol Herbiclean SBM	Caprylic and Capric Acids	3 3	2140167 2140167	SBM Life Science SAS SBM Life Science SAS
	N	Bros Poland	Benzalkonium Chloride 1.25 2JFA-40VN-G008 BJWH	Bross Sp. Zo.o.sp.k

Table 3 . Essential minerals found in pesticides in mg/L. Table 4. Minerals, metals, metalloids found in pesticides in mg/L.

 3 Arsenic is indicated in Table6in μg/L. Aluminium, Antimony, Arsenic,Barium, Beryllium, Bismuth, Cadmium, Chromium, Cobalt, Gallium, Germanium, Hafnium, Indium, Iron, Lead, Lithium, Mercury, Molybdenum, Nickel, Niobium, Palladium, Rhenium, Selen ium, Silic on, Silver, Strontium, Tantalum, Thallium, Tin, Titanium, Tellurium, Tungsten, Vanadium, Zinc, Zirconium. Calcium, Copper, Magnesium, Manganese, Phosphorus, Potassium, Sodium.

	Essential minerals: Polycyclic aromatic hydrocarbons: Acenaphthene, Acenaph thylene, Anthracene, Benzo (A) -
	anthracene, Dibenzo(A,H)Anthracene, Benzo(A)Pyrene, Benzo(B)Fluoranthene,
	Benzo(G,H,I)Perylene, Benzo(K)Fluoranthene, Chrysene, Fluoranthene, Fluorene, Indeno(1,2,3	-
	C,D)Pyrene, Naphthalene, Phenanthrene, Pyrene.
	Herbicides: Glyphosate, AMPA.

Metals:

16.35 <10 23.4 <2.5 26.05 <10 17.75 <2.5 <2.5 <2.5 139.25 potassium 14.6 15 389.05 376.5 44.6 <10 420.7 <2.5 307.5 83.5 41 <2.5 <2.5 <2.5 1692.45 sodium 175.3 107 54.2 91 103.6 31.9 10.7 10 27.7 8.45 105 <5 <5 161 885.85 Total 265.8 190 482.15 497 176.35 31.9 464.6 19 361.25 91.95 163.75 <5 <5 161 2904.75 Table 5. PAHs found in pesticides in μg/L.

	Metals mg/L	A	B	C		D	E	F		G	H	I	J	K	L		M	N	TOTAL A-N
	copper	<5	< 0.005	6.8		<0.25	<5	<5		<5	<5	<5	<0.25 <0.25 <0.25 <0.5	<0.25	6.8
	iron	<5	<5	7.7		<0.5	<5	<5		<5	<5	<5	<0.5	<0.5	<0.5	<0.5	<0.5	7.7
	lead	2	<0.01	2		<0,5	1	<0,5		1	<0,5 <10	<0.5	<5	<0.5	<0.5	<0.5	6.00
	nickel	<5	<0.005	<5		<5	<0.25 <0.25 <0.25 <0.25	<5	13.82 <0.25 <0.25 <0.25 <0.25	13.82
	silicon	12.1	11	8.8		<2.5	<2.5	7		6.8	36	6.9	<5	<5	<2.5	<2.5	5.35	93.95
	silver	<5	<0.01	1		<0.5	<0.5 <0.5		<0.5	<0.5 <0.5 <0.5	<0.5	<0.5	<0.5	<0.5	1.00
	titanium	<5	<0.005	7.8		<0.25	<5	<5		<5	<5	<5	<0.25 <0.25 <0.25 <0.25 <0.25	7.8
	zinc	<5	<5	4.9		<0.5	<5	<1		<5	<5	<5	<0.5	<0.5	<1		<1	<0.5	4.9
	Total	14,1	11	39		<5	1	7		7.8	36	6.9	13.82	<5	<2.5	<2.5	5.35	141.97
	PAH µg/L		A	B	C	D	E	F	G	H	I	J	K	L	M	N Total A-N
	acenaphthene		<5 <5 88 <2 79.5 <10 <2	<5 nm nm nm <10 <10	3	170.5
	acenaphthylene		<5 <5 <15 <2 210 <10 <2	<5 <2 <2	10 <10 <10 <3	220
	anthracene		2.9 <5 20 <2 26.5 <10 <2	<5 <2	6	11 <10 <10 <3	66.4
	benzo(A)anthracene	<5 < 5 <15 2.5 37 11	4	<5 <2 11	67 <10 <10 <3	132.5
	dibenzo(A,H)anthracene <5 <5 <15 <2 33 <10 <2	<5 <2 <2 <10 <10 <10 <3	33
	benzo(A)pyrene		6.4 <5 <15 2.3 30.5 <10 <2	<5 <2 <2	17 <10 <10 <3	56.2
	benzo(B)fluoranthene	<5 <5 <15 9.3 24.5 <10 6	<5 <2 16	22 <10 <10 <3	77.8
	benzo(G,H,I)perylene	<5 <5 <15 <2 29.5 <10 <2	<5 <2 <2	12 <10 <10 <3	41.5
	benzo(k)fluoranthene	<5 <5 <15 <2 <15 < 10 <2	<5 <2 9.1 <10 <10 <10 <3	9.1
	chrysene		5.6 <5 <15 9.6 279.5 10 4.7 <5 <2 11	28 <10 <10 <3	348.4
	fluoranthene		11 7.1 <15 14 38 20 5.5 <5 8.9 3.8 55 <10 <10 <3	163.3
	fluorene		2.2	5 660 3.3 1127 <10 3.3 <5 12 21 2100 <10 <10 <3	3933.8
	indeno(1,2,3-C,D)pyrene <5 <5 <15 <2 39.5 <10 <2	<5 <2 <2	11 <10 <10 <3	50.5
	naphthalene		2.1 <5 24 <2 230.5 <10 <2	25 <2 <2 <10 <10 <10 69	350.6
	phenanthrene		16 10 76 30 62 26 5.3 8.4 16 49	71 <10 <10	6	375.7
	pyrene		8.7	6 <15 4	33 17 2.9 <5 6.1 <2	26 <10 <10 <3	103.7
	Total PHA	54.9

28.1 868 75 2280 84 31.7 33.4 43 126.9 2430 <10 <10 78 6133 Table 6. Summary of main compounds and comparisons in pesticides

	Samples Declared active	Metals	Arsenic	PAH	Glyphosate +	Essential
		principles	mg/L	µg/L	µg/L	AMPA	minerals
						µg/l	mg/L
	A	acetic	14.1	6.33	54.9	<50	265.8
	B	acid	11	<5	28.1	nm	190
	C		39	16.69	868	<500	482.15
	D		<5	<5	75	<50	497
	E		1	7.21	2280 <500	176.35
	F	pelargonic	7	<5	84	nm	125.25
	G	acid	7.8	20.9	31.7	nm	464.6
	H		36	16.3	33.4	nm	19
	I		6.9	6.68	43	nm	361.25
	J		13.82	<5	126.9 <50	91.95
	K		<5	<5	2430 <500	163.75
	L	capric and	<2.5	5.13	<10	86	<5
	M	caprylic acids	<2.5	<5	<10	1850	<5
	N	benzalkonium	5.35	<5	78	<500	161
		chloride

. nm: not measured.

Table 7A . Comparisons of maximal levels of metals found in pesticides and norms for toxicities.

 7A Max: maximum level observed in this study in the samples indicated in the right column; Toxicity: toxicity threshold determined by at least one national or international agency including AFSSA, ANSES, EPA, INERIS, NIH, WHO or scientific reviews in a few cases cited in discussion; K: carcinogen; K?: probable or possible carcinogen; nd: not determined.

Tin


Raïssa-Marie Chevrot

Carmen M Schröder
email: carmen.schroder@chru-strasbourg.fr

Sous-dochead Le sommeil de l'enfant Surtitre mise au point Décryptages et recommandations sur le sommeil des enfants et des adolescents

Keywords: enfant, développement, pédiatrie, rythme circadien, sommeil

Les troubles du sommeil de l'enfant sont une plainte fréquente, que ce soit en consultation de protection maternelle et infantile, de pédiatrie ou de pédopsychiatrie. Il convient de prendre le sujet en considération au vu des conséquences notables que ces troubles peuvent avoir sur l'enfant et son entourage. Les causes organiques ayant été exclues, une bonne connaissance de la physiologie du sommeil et des rythmes permettra au professionnel de la petite enfance d'aider efficacement les parents à instaurer des habitudes favorables à un bon sommeil chez leur enfant.

TEG1 Nous savons aujourd'hui que les premières années de vie du jeune enfant sont déterminantes sur bien des plans : aussi bien affectif que cognitif ou comportemental. Les conséquences d'un mauvais sommeil du bébé et de l'enfant sont donc non négligeables en raison de ses répercussions immédiates sur la qualité de vie de l'enfant et sa famille, mais également à long terme. Une bonne compréhension des troubles du sommeil de l'enfant doit inclure trois dimensions indissociables (médicale, éducative et psychologique) afin de permettre une orientation thérapeutique adaptée [START_REF] Schröder | Insomnie de l'enfant[END_REF][START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF].

T1 Phases et cycles

TEG1 Le sommeil correspond à une baisse de l'état de conscience qui sépare deux périodes d'éveil. Il est caractérisé par une perte de vigilance, une diminution du tonus musculaire et une conservation partielle de la perception sensitive [3].

TEG1 Nous distinguons globalement deux types de sommeil : le sommeil calme et le sommeil agité chez le nouveau-né, qui se transforment vers l'âge de 3 mois en sommeil lent et sommeil paradoxal, tels que retrouvés chez l'adulte. Durant le sommeil lent, la fréquence de l'activité cérébrale est ralentie, les mouvements du corps persistent mais les mouvements oculaires disparaissent. Pendant le sommeil paradoxal, l'activité cérébrale est plus proche de celle de l'éveil. En revanche, on observe une atonie musculaire et des mouvements rapides des yeux derrière les paupières, facilement observable chez le nourrisson et le jeune enfant.

TEG1 Ces phases se répartissent au cours de la nuit en cycles de sommeil séparés entre eux par des périodes de micro-éveils et se suivent un peu comme les wagons d'un train 1 . En début de nuit, nous constatons une prépondérance du sommeil lent profond, très important pour la récupération et les apprentissages, d'où l'expression populaire selon laquelle « les heures avant minuit comptent double ». En revanche, en deuxième partie de nuit, le sommeil paradoxal prédomine. Ainsi nous aurons plus tendance à nous souvenir de ses rêves si nous nous réveillons au cours de cette phase. Chez l'adulte, quatre à six cycles s'alternent généralement au cours de la nuit. Chez l'enfant, ces cycles seront plus nombreux mais aussi plus courts.

T2 Dormir, pour quoi faire ?

Les fonctions du sommeil sont multiples et nombres d'entre elles sont aujourd'hui encore en cours d'étude. Néanmoins le rôle du sommeil a pu être démontré dans les domaines suivants : maturation cérébrale, cognition (attention, mémoire, apprentissage, performances scolaires, etc.), humeur (régulation psychique et émotionnelle, irritabilité, agressivité, dépression, etc.), comportement (hyperactivité motrice, somnolence, etc.), métabolisme (croissance, repos métabolique et élimination des déchets, apparition d'une obésité, etc.), sécrétions hormonales (hormone de croissance, notamment), immunité (vulnérabilité aux infections…).

Encadré flottant

Sommeil et mémoire

L'imagerie cérébrale permet d'observer que durant le sommeil, une réactivation des mêmes réseaux neuronaux que ceux qui ont été activés durant l'apprentissage d'une tâche en journée a lieu. En plus, l'apprentissage d'une tâche a été corrélé à la qualité du sommeil de la nuit précédente. Enfin, le sommeil aidant également à l'oubli des informations non pertinentes, les informations seyantes paraissent souvent plus claires le lendemain d'une bonne nuit, d'où l'expression « la nuit porte conseil ». Le sommeil permet donc un renforcement et une consolidation des acquis.

Sur 1 colonne à droite en bas de première page

Encadré flottant

Sommeil et émotions

Les troubles du sommeil jouent sur la réactivité émotionnelle, l'impulsivité, l'humeur et la capacité de régulation de nos émotions positives et négatives. Cela est principalement dû au fait que les régions cérébrales responsables de la régulation émotionnelle (en particulier le cortex préfrontal et l'amygdale) sont très sensibles à la privation de sommeil. Si un enfant ne dort pas bien ou pas assez, il montre alors le lendemain des signes d'une dysrégulation émotionnelle : irritabilité, pleurs, émotivité, etc. Sur 1 colonne en haut à gauche en deuxième page T1 Zoom sur l'enfant TEG1 La régulation du sommeil se fait via deux mécanismes : homéostatique (augmentation progressive du besoin de sommeil avec le temps passé éveillé) et circadien (rythmicité sur vingtquatre heures).

La mise en place d'un rythme veille-sommeil se fait grâce à l'intervention de synchroniseurs externes appelés Zeitgeber ("donneurs de temps" littéralement). Il s'agit surtout de l'information venant de l'alternance lumière-obscurité [START_REF] Schröder | Physiologie du sommeil et des rythmes biologiques[END_REF], mais aussi de l'activité physique, des prises alimentaires, des contacts sociaux, etc. Ceux-ci vont influencer l'horloge interne et permettre au rythme veillesommeil de se caler sur le cycle du jour et de la nuit. Les parents prennent donc part à cette régulation par les comportements réguliers qu'ils mettent en place pour accompagner le sommeil de leur enfant et favoriser ses capacités d'auto-apaisement (voir plus loin "Comment aider un petit enfant à dormir ?"). TEG1 D'autre part, la rythmicité du sommeil intervient dans la structuration des autres rythmes circadiens [START_REF] Czeisler | Human sleep: its duration and organization depend on its circadian phase[END_REF] : cardiaque, respiratoire, hormonaux (hormone de croissance, hormones thyroïdiennes, cortisol, métabolisme glucidique, etc.). La caractéristique circadienne du sommeil s'acquiert de manière assez homogène chez l'être humain, et vers l'âge de 3 mois environ, les rythmes circadiens (notamment le rythme de sécrétion de la mélatonine, hormone de la nuit, et le rythme de la température centrale) sont en place.

TEG1 En revanche, la durée totale quotidienne de sommeil nécessaire à chaque individu est, quant à elle, très variable -voilà pourquoi de nouvelles recommandations reconnaissent des fourchettes acceptables plus larges pour chaque âge (figure 1) [START_REF] Hirshkowitz | National Sleep Foundation's sleep time duration recommendations: methodology and results summary[END_REF]. Chez les nouveau-nés, il y aura d'emblée des courts et longs dormeurs, ce trait étant héritable des parents. De la même façon, le chronotype, c'est-à-dire la préférence pour" se coucher tôt/lever tôt" ou "se coucher tard/lever tard", comparé à ses pairs, peut être marqué très tôt 2 : on parlera alors de chronotype du matin ou chronotype du soir.

T1 Évolution du sommeil avec l'âge

TEG1 L'organisation du sommeil est majeure durant les deux premières années de vie, et particulièrement durant les six premiers mois [START_REF] Thirion | Le sommeil, le rêve et l'enfant[END_REF]. Ses caractéristiques évoluent considérablement pour répondre à des besoins et fonctions spécifiques. Son architecture se modifie, accompagnant la structuration des autres rythmes, comme nous l'avons vu plus haut.

TEG1 Le nouveau-né à terme oscille entre quatre états de vigilance différents de ceux de l'adulte : la veille calme (assez rare), la veille agitée, le sommeil calme et le sommeil agité (phase dans laquelle il s'endort, d'où ses pleurs). Le rythme est de type ultradien, c'est-à-dire que les périodes de veille et de sommeil (séquences de trois à quatre heures) sont indépendantes de l'alternance du jour et de la nuit, de la lumière et de l'obscurité.

TEG1 La répartition jour/nuit du sommeil et l'apparition d'une période de sommeil continue la nuit va se mettre en place progressivement, normalement avant 6 mois. À cet âge, la journée est alors encore ponctuée de trois périodes de sieste, schématiquement une le matin et deux l'après-midi (figure 2) [START_REF] Schröder | Les troubles du sommeil de l'enfant[END_REF]. La durée des cycles de sommeil augmente, tandis que les éveils intra-sommeil diminuent.

TEG1 Entre 6 mois et 4 ans, le temps total de sommeil diminue petit à petit. Vers 3 ans, le sommeil devient uniquement nocturne en raison de la disparition des siestes. Néanmoins, celles-ci peuvent parfois être encore nécessaires à l'enfant jusqu'à 5 ou 6 ans sans que cela soit pathologique. L'absence de sieste entraînant un déficit relatif en sommeil lent profond, il y aura en quelque sorte un rattrapage de ce type de sommeil en début de nuit. Donc à ce moment-là, on observera plus d'épisodes de parasomnies, dont le somnambulisme, les terreurs nocturnes ou les éveils confusionnels, qui sont des troubles du sommeil bénins de cette phase de développement. Cette période voit également apparaître la problématique liée au coucher. L'enfant redoute la séparation et va aussi tester la solidité des limites instaurées par ses parents. Enfin, les éveils multiples en seconde partie de nuit ne seront pas rares et sont physiologiques. Pour donner un exemple, le fait d'avoir quatre, cinq réveils par nuit vers l'âge de 18 mois est considéré comme physiologique. Ces réveils ne posent un problème que si l'intervention des parents est nécessaire à l'enfant pour se rendormir.

TEG1 Chez l'adolescent, nous voyons apparaître une tendance physiologique au retard de phase (coucher et réveil plus tardifs) liée entre autres à une moindre sensibilité à la lumière du matin et à une sécrétion plus tardive du pic de la mélatonine. Ce phénomène physiologique est accentué par le comportement des adolescents et notamment leur exposition aux écrans, mais également par la surcharge de travail qui peut leur incomber et les difficultés psychologiques inhérentes à cette période de transition. La privation de sommeil qui en découle peut donner lieu à une somnolence diurne et avoir d'importantes répercussions sur les performances scolaires, l'humeur, le comportement et même le métabolisme puisqu'une privation précoce de sommeil est un facteur de risque d'obésité. La privation chronique de sommeil dans cette tranche d'âge est donc véritablement un problème de santé publique [START_REF] Yavuz-Kodat | Sommeil et rythmes de vie à l'adolescence[END_REF].

T1 Et si l'enfant ne dort pas ?

Conscients de l'enjeu d'un bon sommeil tant pour l'enfant que pour son entourage, la question des troubles du sommeil mérite un intérêt tout particulier. Cette problématique est un motif de consultation fréquent dont l'étiologie peut être multiple et variée [START_REF] Schröder | Insomnie de l'enfant[END_REF][START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF][START_REF] Dauvilliers | Les troubles du sommeil. 3e éd. Issy-les[END_REF][START_REF] Brion | Prise en charge de l'insomnie[END_REF]. Afin de dépister des troubles du sommeil, des questionnaires validés existent en français [START_REF]Le sommeil de 0 à 18 ans. Échelles de dépistage des troubles du sommeil de l'enfant. 15 mai[END_REF] et peuvent servir d'orientation.

T2 Insomnie

TEG1 Plainte la plus fréquente, l'insomnie se caractérise chez l'enfant par un refus d'aller se coucher, une difficulté à s'endormir ou encore des réveils nocturnes nécessitant une intervention parentale [START_REF] Schröder | Insomnie de l'enfant[END_REF]. Elle est parfois d'origine organique : douleurs, médicaments, maladies spécifiques, allergies dont celle aux protéines de lait de vache, syndrome d'apnées obstructives du sommeil ou syndrome des jambes sans repos. En revanche, dans la majorité des cas, l'insomnie est comportementale (irrégularité des rythmes, nécessité de la présence parentale à l'endormissement, manque de limites, etc.). Ses principales répercussions sur l'enfant sont les troubles du comportement et les troubles attentionnels, voire la somnolence diurne, mais il ne faut pas négliger son impact sur l'équilibre et le fonctionnement familial. Il est donc important d'intervenir tôt pour éviter la chronicisation.

TEG1 Rappelons aussi qu'il existe une grande variabilité liée aux besoins de sommeil (deux à trois heures d'écart par rapport à la norme pour l'âge ne sont pas considérées comme pathologiques) et aux préférences circadiennes des enfants (plutôt couche-tôt ou couche-tard). La notion de sommeil pathologique sera donc fonction des répercussions sur le fonctionnement diurne et de la clinique.

TEG1 En France, le site du réseau Morphée est une source précieuse de documents ressources pour parents et professionnels, élaborés par des spécialistes du sommeil, où plus de détails et de conseils pratiques sur le sommeil de l'enfant et de l'adolescent peuvent être trouvés [START_REF]Le sommeil de 0 à 18 ans[END_REF].

T2 Parasomnies

Les parasomnies sont des évènements nocturnes généralement bénins, survenant tout au long de l'enfance, mais tout particulièrement entre 3 ans et l'âge de la puberté. Nous distinguons les parasomnies du sommeil lent profond (plutôt en première partie de nuit) des parasomnies du sommeil paradoxal (les cauchemars, survenant plutôt en fin de nuit) [START_REF] Schröder | Insomnie de l'enfant[END_REF][START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF]. Lors des épisodes de parasomnies du sommeil lent profond, le cerveau a en quelque sorte un fonctionnement "hybride", c'est-à-dire qu'une partie s'est éveillée mais qu'une autre est encore endormie. Bien que ces épisodes puissent être assez spectaculaires, l'intervention d'un tiers n'est pas nécessaire et, à défaut, doit se faire en douceur. Mieux vaut attendre que l'enfant se réveille et sécuriser son environnement (fenêtres, objets contondants, etc.).

T2 Troubles du sommeil et du neurodéveloppement

TEG1 Une prévalence plus élevée des troubles du sommeil et des rythmes circadiens a été retrouvée dans certaines catégories de population, notamment chez les enfants avec trouble du spectre de l'autisme [START_REF] Poirot | Sommeil, rythmes et psychiatrie[END_REF]. De nombreuses études suggèrent, au-delà des hypothèses étiologiques, que ceux-ci pourraient avoir un rôle dans les symptômes majeurs de l'autisme (cognitifs et comportementaux) [START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF].

TEG1 Il existe également une association entre le trouble du déficit de l'attention avec ou sans hyperactivité (TDAH), trouble fréquent du neurodéveloppement, et les troubles du sommeil. Mais attention : les symptômes diurnes d'une privation de sommeil liée à une insomnie peuvent se confondre avec ceux du TDAH (inattention, hyperactivité motrice pour lutter contre la somnolence, etc.). L'insomnie peut aussi en elle-même aggraver les symptômes du TDAH. Enfin, le traitement de ce trouble (par psychostimulants) peut être à l'origine de difficultés d'endormissement, bien que l'on constate plus souvent une amélioration des troubles du sommeil comorbides lorsque le TDAH est traité [START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF].

T1 Comment aider un petit enfant à bien dormir ?

Les parents ont un rôle décisif dans l'apprentissage et la mise en place des rythmes de leur enfant. Pourtant, l'évidence ne tombe pas toujours sous le sens et nombre d'idées reçues ou de conseils grand public peuvent culpabiliser un père ou une mère dans ses tentatives d'aider son enfant à bien dormir.

T2 Rituels et régularité TEG1 À force d'entraînement, les rythmes s'ancrent et s'installent. Il est donc important, après avoir repéré le moment où l'enfant manifeste les premiers signes de fatigue (bâillements, paupières lourdes, enfant bougon, irritable, etc.), de ne pas tarder à le mettre au lit et d'instaurer des horaires de coucher réguliers. En effet, dès l'âge de 1 mois, la régularité de ces horaires, des prises alimentaires et des interactions avec son entourage aide le bébé dans la mise en place et la synchronisation de ses rythmes.

TEG1 La présence d'un rituel avant le coucher permet à l'enfant de vivre ce moment de transition veille-sommeil en étant rassuré par la présence de ses parents, tout en favorisant sa propre capacité d'auto6apaisement. Il convient donc d'éviter en fin de soirée les jeux et activités excitantes ou l'exposition aux écrans, qui stimuleront l'enfant au moment où il a besoin de se calmer. Ce rituel ne doit pas être trop long car il s'agit d'un moment de transition. Concrètement, il peut s'agir d'un de soins (change…) ou de câlins suivi d'une histoire, d'une berceuse (à adapter en fonction de l'âge) avant de coucher l'enfant dans son lit pour le laisser s'y endormir seul. Il s'agit là d'un véritable apprentissage qui peut prendre plusieurs jours ou semaines. Ces moments sont souvent difficiles pour les parents, qui doivent accepter que leur enfant pleure parfois au départ, le temps qu'il apprenne à s'endormir sans aide. Dans le cas où l'enfant ne s'endort pas seul mais dans les bras, en poussette ou en voiture, il aura besoin lors de ses éveils nocturnes de retrouver les mêmes conditions d'endormissement, et donc d'être bercé, pour pouvoir replonger dans le sommeil [START_REF] Schröder | Insomnie de l'enfant[END_REF][START_REF] Schröder | Troubles du sommeil et des rythmes circadiens en psychiatrie de l'enfant et de l'adolescent[END_REF].

T2 Réveils nocturnes : mon enfant a-t-il faim ?

Quand l'enfant se situe dans les courbes de croissance physiologiques, l'alimentation nocturne n'est plus nécessaire après 6 mois environ, les repas de la journée étant suffisants. Souvent, la crainte que l'enfant se réveille à cause de la faim pousse les parents à donner un biberon ou une tétée pour rendormir le bébé. Se met alors en place un cercle vicieux car ces repas entretiennent justement les éveils nocturnes (mise en route du système digestif, distension vésicale, humidité, voire débordement des couches -mais également "programmation" des réveils nocturnes les nuits suivantes, via l'activation des horloges du système digestif). Nous avons vu plus haut les autres causes de réveils nocturnes comme les douleurs liées à une maladie ou une poussée dentaire, ou encore l'anxiété. Celles-ci, normalement, restent passagères. Rappelons que chez le nouveau-né et durant plusieurs semaines, des pleurs peuvent survenir en sommeil agité et durer plusieurs minutes 3 .

T2 Siestes

Concernant les siestes diurnes, mieux vaut qu'elles se fassent à la lumière du jour légèrement atténuée, ou dans une pénombre relative, afin d'éviter la confusion avec l'obscurité totale de la nuit dans la mise en place des rythmes. Ainsi, la lumière peut jouer son rôle de synchroniseur externe.

T1 Qu'en est-il pour les adolescents ?

Souvent malmené durant cette période de la vie, un bon sommeil est pourtant capital, notamment en raison de sa participation à la régulation émotionnelle. Pour le préserver au mieux, il convient d'éviter les comportements "antisommeil" : exposition aux écrans en fin de soirée, consommation de tabac ou d'excitants (soda, thé, café, etc.), pratique sportive tardive [START_REF] Brion | Prise en charge de l'insomnie[END_REF]. La régularité reste de mise en termes de prise alimentaire et d'horaires de coucher, ce qui est souvent la principale difficulté. Les rattrapages de nuits blanches par des grasses matinées, par exemple, provoquent un retard de phase et désorganisent les rythmes. Un réveil le week-end légèrement plus tardif, mais pas plus de deux heures par rapport au lever de semaine, et possiblement une courte sieste en début d'aprèsmidi permettront de se remettre sur pied sans perturber l'équilibre fragile du sommeil nocturne.

T1 Conclusion

Le sommeil est capital pour les parents comme pour les enfants, chez lesquels se mettent en place de nombreux mécanismes physiologiques fondamentaux. En prendre soin revient à s'occuper de la famille tout entière. Mais aussi permettre le développement le plus harmonieux possible des enfants. Pour ceux qui souffrent d'un handicap ou d'un trouble neurodéveloppemental, le sommeil permet d'améliorer considérablement leur développement, leur qualité de vie, et de prévenir l'épuisement de leur entourage. Un personnel de santé bien informé de la physiologie et des pathologies du sommeil pourra, à partir d'une écoute bienveillante et de conseils simples, aider les parents à résoudre la majorité des troubles. Dans le cas contraire, une orientation vers un spécialiste afin de rechercher une cause médicale sera nécessaire.

Notes Figures

Schro_fig1

Figure 1. Recommandations sur la durée quotidienne de sommeil par âge (d'après [START_REF] Hirshkowitz | National Sleep Foundation's sleep time duration recommendations: methodology and results summary[END_REF]).

©Figure 2 .

 2 Figure2. Maturation des rythmes veille-sommeil (d'après[START_REF] Schröder | Les troubles du sommeil de l'enfant[END_REF]).

L'image du train et des wagons est d'usage courant pour expliquer aux enfants d'âge scolaire le fonctionnement et l'organisation du sommeil. Pour des ressources éducatives à destination des enseignants, voir Apprendre le sommeil à l'école. Avec Mémé Tonpyj. https://memetonpyj.fr/.

À noter qu'un nouveau-né court dormeur aura plus de phases d'éveil et donc de pleurs, ce qui peut s'avérer difficile à vivre pour les parents.

Des éveils sont physiologiques au cours de la nuit à cet âge : ils peuvent passer inaperçus si l'enfant sait se rendormir seul. En revanche si les parents interviennent immédiatement aux premiers pleurs de l'enfant, il sera complètement réveillé, la possibilité de s'autoapaiser ne lui étant pas laissée.