Agnieszka ( Sorokowska
email: sorokowska@gmail.com

Agata Groyecka
email: agata.groyecka@gmail.com

Frackowiak, T., Lansford, J. E Maciej Karwowski
email: maciek.karwowski@gmail.com

Tomasz Frackowiak
email: tomasz.frackowiak@uwr.edu.pl

Jennifer E Lansford
email: lansford@duke.edu

Khodabakhsh H Ahmadi
email: kh_ahmady@yahoo.com

Ahmad M Alghraibeh

Richmond Aryeetey
email: raryeetey@ug.edu.gh

Anna Bertoni
email: anna.bertoni@unicatt.it

Karim Bettache
email: karim.bettache@monash.edubandar

Auteur De Correspondance)

Cetinkaya, H Lei Chang
email: chang@umac.mo

Domínguez Espinosa

King Saud

Sheyla Blumen
email: sblumen@pucp.edu.pe

Marta Błażejewska
email: blazejewska.m@gmail.com

Tiago Bortolini
email: tbortolini@gmail.com

Katarzyna Cantarero
email: kcantarero@swps.edu.pl

Felipe Nalon Castro
email: castrofn@gmail.com

Hakan Cetinkaya
email: cetinkayah@ankara.edu.tr

Bin-Bin Chen
email: chenbinbin@fudan.edu.cn

Diana Cunha
email: diicunha@gmail.com

Daniel David
email: daniel.david@ubbcluj.rocluj-napocaromania

Oana A David
email: oanadavid@psychology.rocluj-

Alejandra Del Carmen
email: alejandra.domiguez@ibero.mxciudad

Silvia Donato
email: silvia.donato@unicatt.it

Daria Dronova
email: dariadronova@yandex.ru

Jitka Fialová
email: jitka.fialova@natur.cuni.cz

Maryanne Fisher
email: mlfisher.99@gmail.com

Evrim Gulbetekin
email: evrimg@akdeniz.edu.tr

Hamamcıoğl U Akkaya
email: hamamcioglu.a@hotmail.com

Peter Hilpert
email: p.hilpert@surrey.ac.uk

Raffaella Iafrate
email: raffaella.iafrate@unicatt.it

Mariana Iesyp

Ivan Franko
email: ivana.hromatko@ffzg.hr

Bawo James
email: bawojames@yahoo.com

Feng Jiang
email: fengjiang0205@gmail.com

Charles Obadiah

Grete Kjelvik
email: kjelvik@ntnu.no

Amos Laar
email: alaar@ug.edu.gh

Fívia De

Araújo Lopes

Guillermo Macbeth
email: guimacbeth@hotmail.com

Nicole M Marcano
email: nmarcano@gmail.com

Rocio Martinez

Norbert Mesko
email: meskonorbert@me.com

Natalya Molodovskay

Khadijeh Moradi Qezeli

Alexandra Mühlhauser
email: alexandra.muehlhauser@gmail.com

Jean Carlos Natividade
email: jeannatividade@gmail.com

Joseph Ntayi
email: ntayius@yahoo.com

Elisabeth Oberzaucher
email: elisabeth.oberzaucher@univie.ac.at

Ojedokun Adekunle Ajasin
email: oluyinka.ojedokun@aaua.edu.ng

Akungba- Akoko Nigeria

Mohd Sofian

Bin Omar- Fauzee
email: dromarfauzee@yahoo.com

Ike E Onyishi
email: ikeonyishi@yahoo.com

Anna Paluszak
email: anna.paluszak@uwr.edu.pl

John D Thomas Pierce
email: piercej@philau.edu

Jefferson

Urmila Pillay
email: upillay@gmail.com

Global study of social odor awareness

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N.

Introduction

Olfaction plays an important role in human social communication [START_REF] Stevenson | An Initial Evaluation of the Functions of Human Olfaction[END_REF], including multiple domains in which people often rely on their sense of smell in the social context. For example, odors influence assessments of one's attractiveness [START_REF] Roberts | Body Odor Quality Predicts Behavioral Attractiveness in Humans[END_REF] and personality [START_REF] Sorokowska | Does Personality Smell? Accuracy of Personality Assessments Based on Body Odour: Does personality smell?[END_REF], they enhance the proneness to displaying prosocial behaviors [START_REF] Baron | The sweet smell of... helping: Effects of pleasant ambient fragrance on prosocial behavior in shopping malls[END_REF] and can influence social desirability [START_REF] Regenbogen | Behavioral and neural correlates to multisensory detection of sick humans[END_REF].

The importance of the sense of smell in the social context can however vary across individuals. Odor awareness reflects the extent to which people are affected by odors in everyday life and their metacognition of olfactory sensations [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF]. In existing olfactory awareness scales [START_REF] Cupchik | Sensitivity to the cognitive and affective qualities of odours[END_REF][START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF][START_REF] Croy | Individual significance of olfaction: Development of a questionnaire[END_REF] much attention is paid to social odors (e.g., "Do you notice the smell of people's breath or sweat?", "Do you pay attention to the perfume, the aftershave or deodorant other people use?"). An odor-oriented person pays much attention to odors in everyday life and is likely to feel positive or negative affect as a result of exposure to certain odors. Higher awareness might intensify the emotions resulting from exposure to a partner's odor [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF]. Further, it is suggested that odors play an important role in attachment and romantic relationships [START_REF] Schaal | Variability and invariants in early odour preferences: comparative data from children belonging to three cultures[END_REF][START_REF] Cupchik | Sensitivity to the cognitive and affective qualities of odours[END_REF]. For example, sense of smell aids selection of heterozygous mates [START_REF] Winternitz | Patterns of MHCdependent mate selection in humans and nonhuman primates: a meta-analysis[END_REF]. At the same time, romantic love reduces women's attention to body odors obtained from men other than their current partner, which is considered as evidence for love being an emotion helping intimate partners to maintain their relationship [START_REF] Lundström | Romantic love modulates women's identification of men' s body odors[END_REF].

In addition to certain individual variation, social odor responsiveness and awareness seems to vary between cultures [START_REF] Ferdenzi | Affective dimensions of odor perception: A comparison between Swiss, British, and Singaporean populations[END_REF][START_REF] Ferdenzi | Children's Awareness and Uses of Odor Cues in Everyday Life: A Finland-France Comparison[END_REF][START_REF] Schleidt | A cross-cultural study on the attitude towards personal odors[END_REF][START_REF] Saxton | Sex differences in olfactory behavior in Namibian and Czech children[END_REF][START_REF] Seo | Attitudes toward olfaction: A cross-regional study[END_REF]. The cultural differences in attitudes towards odors seem to appear early in development as they are observable also in children (Ferdenzi et al., 2011[START_REF] Ferdenzi | Children's Awareness and Uses of Odor Cues in Everyday Life: A Finland-France Comparison[END_REF][START_REF] Saxton | Sex differences in olfactory behavior in Namibian and Czech children[END_REF]. Nevertheless, to date, only a few cross-cultural studies on odor awareness exist; additionally, they usually cover a small number of countries which limits possible Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. and Germans, and recalled more odors pertaining to "social" category than members of other cultures [START_REF] Seo | Attitudes toward olfaction: A cross-regional study[END_REF]. Still, it is not clear why such results are observed and whether cross-cultural differences would be also present between members of other cultures. We aimed to address these gaps in the current study.

Country-level factors

As olfaction plays a role in proxemics and interpersonal distancing [START_REF] Ferdenzi | Children's Awareness and Uses of Odor Cues in Everyday Life: A Finland-France Comparison[END_REF][START_REF] Seo | Attitudes toward olfaction: A cross-regional study[END_REF], the first factor that could potentially affect social olfactory awareness on the country level is whether the culture is described as contact or noncontact [START_REF] Hall | The hidden dimension[END_REF][START_REF] Mazur | A c c e p t e d M a n u s c r i p t 32[END_REF][START_REF] Sussman | Influence of culture, language, and sex on conversational distance[END_REF]). Yet, the contact-noncontact grouping seems to be more anecdotal than evidencebased (see [START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF], since no clear criteria for such division have been examined and described. A factor related to proxemics in this context is population density. Living in populous sites may increase the closeness and frequency of social contacts and enhance the exposure to odors in everyday life [START_REF] Cleaveland | Diseases of humans and their domestic mammals: pathogen characteristics, host range and the risk of emergence[END_REF][START_REF] Jones | Global trends in emerging infectious diseases[END_REF]. In addition, through mere exposure, it could also increase a person's familiarity with odors in different social contexts, influencing olfactory perception [START_REF] Ferdenzi | Variability of affective responses to odors: culture, gender, and olfactory knowledge[END_REF] and awareness of social odors.

Second of the country-level variables is temperature, because it has been shown to be related to preferred social proximity, perception of social exclusion, focus on relationships and interpersonal communication [START_REF] Zhong | Cold and lonely does social exclusion literally feel cold?[END_REF][START_REF] Ijzerman | Temperature perceptions as a ground for social proximity[END_REF][START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF].

Thus, indirectly, temperature may influence exposure to social odors and their relative importance, since engagement in olfaction-related activities is associated with odor awareness (Martinec Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. [START_REF] Nováková | Effects of diversity in olfactory environment on children's sense of smell[END_REF][START_REF] Nováková | Engagement in olfaction-related activities is associated with the ability of odor identification and odor awareness[END_REF]Martinec Nováková and Vojtušová Mrzílková, 2016). For example, odor exposure in children predicts (Martinec Nováková and Vojtušová Mrzílková, 2016) and even increases [START_REF] Nováková | Effects of diversity in olfactory environment on children's sense of smell[END_REF] their olfactory awareness. Further, from the physiological point of view, temperature is related to sweating and thus to more intense body odor, to which people from countries with higher average temperature are more exposed. This could also change body odor-related behaviors and perception of social odors. Intensified body odor can be seen as a stronger stimulus in communication, but on the other hand it may be commonly masked by fragranced cosmetics, and the use of odorants can affect people's body odor and the way they are perceived by others [START_REF] Sorokowska | Body odor based personality judgments: the effect of fragranced cosmetics[END_REF]; but see [START_REF] Lenochová | Psychology of fragrance use: perception of individual odor and perfume blends reveals a mechanism for idiosyncratic effects on fragrance choice[END_REF].

Socio-economic status, is one of the factors that might differentiate odor awareness similarly to its hypothesized influence on preferred social distance [START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF]. On a countrylevel, this variable can be expressed in the Human Development Index (HDI), which reflects a country's gross national income per capita, average life expectancy, and expected education levels.

However, because incomes within one country can vary greatly even in countries with high HDI, we need to consider socio-economic status from both individual and country-level perspectives. Potential mechanisms of influence of socio-economic status on olfactory awareness are discussed below, in the section describing individual-level variables.

Individual factors

Besides exploring country-level characteristics ascribed to the entire populations, the aim of this paper is to establish links between individual factors and social odor awareness; among these gender is one of the most salient ones. Women value odors more than men in mating [START_REF] Havlicek | He sees, she smells? Male and female reports of sensory reliance in mate choice and non-mate choice contexts[END_REF][START_REF] Herz | Differential use of sensory information in sexual behavior as a function of gender[END_REF][START_REF] Herz | Sex differences in response to physical and social factors involved in human mate selection: The importance of smell for women[END_REF], and outside mating contexts [START_REF] Havlicek | He sees, she smells? Male and female reports of sensory reliance in mate choice and non-mate choice contexts[END_REF],

suggesting their relatively higher odor awareness in the social context. Further, odor awareness is Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

A c c e p t e d M a n u s c r i p t 16 linked to female-stereotyped activities in childhood and adulthood [START_REF] Nováková | Engagement in olfaction-related activities is associated with the ability of odor identification and odor awareness[END_REF].

Nevertheless, although the gender difference in olfactory performance is quite well documented (yet, not pertaining to all odor-related tasks, for a review see [START_REF] Doty | Sex differences and reproductive hormone influences on human odor perception[END_REF], still little is known about gender effect in the context of attention paid to social odor cues.

Another individual factor, potentially related to odor awareness, is age. Some studies find odor awareness to be correlated with olfactory abilities [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF], and olfactory acuity changes with age [START_REF] Sorokowska | Changes of olfactory abilities in relation to age: odor identification in more than 1400 people aged 4 to 80 years[END_REF]. Specifically, people below 20 years of age and above 60 years of age score lower in identification tests than people aged 20-60. The relative decline in odor identification after age 60 is broadly described and refers to an immense percentage of society [START_REF] Larsson | Odor Identification in Old Age: Demographic, Sensory and Cognitive Correlates[END_REF][START_REF] Doty | The influences of age on olfaction: A review[END_REF]. Prior to age 20, olfactory skills are known to increase as a function of experience and cognitive development [START_REF] Ferdenzi | Variability of affective responses to odors: culture, gender, and olfactory knowledge[END_REF]. Due to the impairment of smell abilities with age and in line with some previously published data (e.g., [START_REF] Dematte | Individual variability in the awareness of odors: Demographic parameters and odor identification ability[END_REF], we hypothesize that older participants will display lower odor awareness also in the social context (but see [START_REF] Croy | Individual significance of olfaction: Development of a questionnaire[END_REF].

Both low levels of education and material situation can affect personal hygiene [START_REF] Cleland | Maternal education and child survival in developing countries: The search for pathways of influence[END_REF][START_REF] Kuusela | Oral hygiene habits of 11-year-old schoolchildren in 22 European countries and Canada in 1993/1994[END_REF][START_REF] Ilika | Personal hygiene practice and school-based health education of children in Anambra State, Nigeria[END_REF]. Because odor awareness is related to behaviors such as avoidance of people with an unpleasant smell, paying attention to odorants or noticing other people's sweat or breath [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF], people who are exposed to strong, unpleasant social odorants in their everyday life are likely to become accustomed and pay less attention to them. Consequently, they may score lower on measures of social odor awareness. As odor identification has been shown to be influenced by education [START_REF] Larsson | Demographic and cognitive predictors of cued odor identification: evidence from a population-based study[END_REF][START_REF] Liu | Performance on a smell screening test (the MODSIT): A study of 510 predominantly illiterate Chinese subjects[END_REF], it is likely that education alters also odor awareness through an indirect connection with olfactory acuity [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF]. On the other hand, people in a non-industrialized society of Tsimane' were found to have lower thresholds of odor detection [START_REF] Sorokowska | Olfaction and Environment: Tsimane' of Bolivian Rainforest Have Lower Threshold of Odor Detection Than Industrialized German People[END_REF], while hunter-gathers from Malaysia exhibited notably developed ability to identify odors [START_REF] Majid | Hunter-Gatherer Olfaction Is Special[END_REF]. These exceptional olfactory abilities could probably be due to Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. horticulture. Yet, because our sample comprises mostly industrialized societies where sense of smell is no longer used for hunting or foraging, we hypothesize that better education and higher socioeconomic status will be positively correlated with social odor awareness.

Further, higher exposure to interpersonal odors is likely to vary with subjectively preferred interpersonal distance, as detecting other people's odor is related to closer contact [START_REF] Schleidt | A cross-cultural study on the attitude towards personal odors[END_REF][START_REF] Ferdenzi | Children's Awareness and Uses of Odor Cues in Everyday Life: A Finland-France Comparison[END_REF]. Consequently, people who feel more comfortable in personal or intimate contact use their sense of smell more frequently and actively in the social context, which, in turn, makes them more likely to be odor-aware than people who prefer greater interpersonal distance.

Relatedly, they could often rely on odors during social judgements. Preferred social distance is, however, known to vary both as a function of cultural and individual differences, so it is important to control it for each participant individually [START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF].

Generally, despite the growing body of literature on differences in olfactory performance or hedonic preferences across the globe, we still do not know which aspects of the culture affect olfactory awareness. Further, while affective responses to specific odors are known to vary and reflect familiarity with the stimuli [START_REF] Ferdenzi | Variability of affective responses to odors: culture, gender, and olfactory knowledge[END_REF], little is known about the subjective importance of social odors in everyday life across different countries. In order to cover the broad spectrum of variables potentially correlated with odor awareness, it is crucial to conduct a study on a large sample, including participants from various geographic regions. Therefore, we conducted a large-scale analysis of data collected from 10,794 participants from 52 study sites all over the world. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. Korea, Canada, Kenya, Austria, United Kingdom, South Korea, Italy). In some countries, in addition to locations specified above, the research was conducted during individual visits in participants' homesthis was done, for example, in Kazakhstan, China, Croatia, Hungary. Further, we used chainreferral method (snowball sampling)in all participating countries the researchers invited friends and family members of the participants, their acquaintances, and their students to take part in the study.

Finally, some samples included also parents of children taking part in a different project (USA), and participants recruited through online and journal announcements (Italy and USA).

All participants were naïve to the hypotheses of the study, they completed the questionnaires independently and individually. The data collection was a part of a larger project-the participants took part also in a study on interpersonal distance preferences [START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF], and in some countries, married participants completed additional questionnaires on their marital satisfaction [START_REF] Hilpert | The associations of dyadic coping and relationship satisfaction vary between and within nations: A 35-nation study[END_REF][START_REF] Sorokowski | Marital satisfaction, sex, age, marriage duration, religion, number of children, economic status, education, and collectivistic values: Data from 33 countries[END_REF].

-----------Table 1 Here -----------

Measures and Procedure

The data were collected by co-authors and their respective research teams. All respondents took part in the study voluntarily and provided written consent prior to participation. They were not compensated for their participation. Participants completed paper-and-pencil questionnairesthe original version of the questionnaire was in English, but in all non-English speaking countries, the questions were translated to the native language by researchers fluent in English and a given language using backtranslation procedures [START_REF] Brislin | Back-translation for cross-cultural research[END_REF].

The social odor awareness questionnaire applied in this study comprised items from the Odor Awareness Scale [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF]. The participants did not complete the full scale, instead, we Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. A c c e p t e d M a n u s c r i p t 20 selected 6 items related to perception of odors in interpersonal situations, i.e., "Do you pay attention to the perfume, the aftershave or deodorant other people use?"; "How important is it to you that your partner has a pleasant smell?"; "Do you notice the smell of people's breath or sweat?"; "When someone has an unpleasant body odor, does that make you find him or her unattractive?"; "When someone has a pleasant body odor, so you find him or her attractive?"; "You are in a public space sitting close to someone who has an unpleasant smell. Do you look for another seat if possible?". In all questions, we used original response scales and verbal descriptors. The range of possible results was between 6 and 30 points. The reliability of this scale in the whole sample was good (Cronbach's  =

.80), similarly as reliability within-countries (min  = .53 [Bulgaria], max  = .87 [South Korea], median  = .76), with only two countries reliability estimated as below .60 (Bulgaria,  = .53, Saudi

Arabia,  = .59).

In addition to participants' report on gender and age, we measured their education level quantified as "1no formal education, 2primary school, 3secondary school, 4high school or technical college, 5bachelor or masters degree". The material situation was rated on a 5-point scale, from "1much better than average in my country" to "5much worse than average in my country".

Further, the participants declared their preferred interpersonal distance to (a) a stranger, (b) an acquaintance, and (c) a close person. Answers were given on a distance (0-220 cm) scale anchored by two human-like figures, labeled A for the left one and B for the right one. Participants were asked to imagine that he or she is Person A. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. As individuals were nested within countries, we analyzed data using multilevel regression models (aka hierarchical linear models). We started with a baseline (empty) model to estimate the variability of the social olfactory awareness in the social context across countries. In the next model, we included individual-level variables: gender, age, the level of education, self-reported material situation and preferred interpersonal distance. In the third and final model, we added country-level predictors: HDI, population density (log-transformed) and average temperature. We compared the models using -2 log likelihood (-2LL) statistics and Akaike Information Criterion (AIC), with lower values in both cases indicating better models. In all models, we controlled for nesting participants within countries and estimated fixed effects of Level-1 (Individuals) and Level-2 (Countries) variables using a maximum likelihood estimator.

-----------Table 2 Here -----------

Results

Table 1 summarizes the main characteristics of each site and Table 2 shows the questionnaire results

for men and women. Our main analyses were conducted by means of a series of multilevel regression models. As illustrated in Table 3, the baseline model showed that there was substantial variability in self-reported sense of smell in the social context at both individual and country levels. Intra-class correlation coefficient (ICC) demonstrated that 29% of the sense of smell's variability was associated with country-level, while 71% of the variance was located at the level of individuals.

In Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. In Model 3 we included country-level predictors: HDI, average temperature and logtransformed population density. None of these variables, however, were statistically significant predictors of self-reported social olfactory awareness. Similarly, adding these predictors into the model did not improve it as compared to Model 2 and illustrated by higher value of AIC.

-----------Table 3 Here -----------

Discussion

The Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. The results suggest that individual differences play an important role in social odor awareness, i.e., in aspects of odor awareness that are related to non-verbal communication between humans. We found three statistically significant predictors of odor awarenessgender, age and education in the largest international sample to date. Our findings on gender concur with previous research on the attitudes towards the sense of smell. Women consider olfaction more important than men in self-report questionnaires related both to sexual [START_REF] Herz | Differential use of sensory information in sexual behavior as a function of gender[END_REF][START_REF] Herz | Sex differences in response to physical and social factors involved in human mate selection: The importance of smell for women[END_REF][START_REF] Havlicek | He sees, she smells? Male and female reports of sensory reliance in mate choice and non-mate choice contexts[END_REF] and to non-sexual contexts [START_REF] Havlicek | He sees, she smells? Male and female reports of sensory reliance in mate choice and non-mate choice contexts[END_REF]. Further, [START_REF] Croy | Individual significance of olfaction: Development of a questionnaire[END_REF] showed that female respondents judged the sense of smell as being more important in their lives than male respondents. As mentioned in the Introduction, also in a previous cross-cultural study conducted in four countries, women indicated a higher interest in the sense of smell than men [START_REF] Seo | Attitudes toward olfaction: A cross-regional study[END_REF]. Our study extends all these findings by showing that female olfactory awareness in the social context was higher than male across 44 countries. The predictive value of education is less obvious, yet also consistent with our hypothesis. Education could be associated with higher expenses on personal hygiene and, therefore, more attention paid to pleasantness of body odors. Further, more educated people might be more aware of their sense of smell and its importance and be more aware of different olfactory cues. The case of age is, however, more complicated. [START_REF] Croy | Individual significance of olfaction: Development of a questionnaire[END_REF] found that the importance of the sense of smell remains relatively unchanged throughout the life-span, and we observed a slight, albeit statistically significant decrease in social olfactory awareness associated with aging. It is possible that either the previous results were specific to one culture, or that olfactory awareness in the social context is somewhat different from general odor awareness, as measured by [START_REF] Croy | Individual significance of olfaction: Development of a questionnaire[END_REF].

It should be highlighted that our findings on social olfactory awareness in 44 countries are consistent with well characterized age-and gender-related differences in olfactory abilities. Studies on various aspects of olfactory perception show that women outperform men in tasks like odor memory and identification, and in the social context, they rely on body odor to a greater extent while evaluating a potential partner [START_REF] Brand | Sex differences in human olfaction: Between evidence and enigma[END_REF][START_REF] Doty | Sex differences and reproductive hormone influences on human odor perception[END_REF][START_REF] Ferdenzi | Variability of affective responses to odors: culture, gender, and olfactory knowledge[END_REF]. Our results revealed the same pattern. Further, we observed that social olfactory awareness decreases with Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

A c c e p t e d M a n u s c r i p t 24 age, and it is known that so does olfactory performance [START_REF] Doty | Sex differences and reproductive hormone influences on human odor perception[END_REF][START_REF] Sorokowska | Changes of olfactory abilities in relation to age: odor identification in more than 1400 people aged 4 to 80 years[END_REF]. Lower olfactory abilities in older people might result from, among others, cumulative damage to the olfactory epithelium from repeated infections, or a variety of neurodegenerative diseases [START_REF] Doty | Sex differences and reproductive hormone influences on human odor perception[END_REF]. The findings on age-and gender-dependent olfactory abilities and our data seem to suggest that people with a better sense of smell use it in more ways and are more aware of odors than those with lesser smell ability [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF], especially in the social context. Still, it needs to be highlighted that studies regarding odor awareness in relation to olfactory performance produce mixed results (see [START_REF] Smeets | The Odor Awareness Scale: A New Scale for Measuring Positive and Negative Odor Awareness[END_REF][START_REF] Dematte | Individual variability in the awareness of odors: Demographic parameters and odor identification ability[END_REF]. Odor awareness, a metacognitive measure, and various aspects of odor perception (assessed by various psychophysical tests) are not equivalent. Nevertheless, our data suggest that, at least in the social context, odor awareness could be subject to influence of biological factors, like it is in the case of olfactory sensitivity [START_REF] Gross-Isseroff | Evidence for genetic determination in human twins of olfactory thresholds for a standard odorant[END_REF]. Further, preference for certain odors, especially those of other people, can be genetically determined [START_REF] Havlicek | MHC-correlated mate choice in humans : A review[END_REF][START_REF] Janeš | Infuence of MHC on odour perception of 43 chemicals and body odour[END_REF][START_REF] Havlicek | MHC-correlated mate choice in humans : A review[END_REF][START_REF] Janeš | Infuence of MHC on odour perception of 43 chemicals and body odour[END_REF][START_REF] Milinski | Evidence for MHC-correlated perfume preferences in humans[END_REF]. Therefore, it is possible that subjective importance of social odors is also dependent on some innate, genetic factors (like HLAhuman leukocyte antigen).

Understanding the interplay between genetic and environmental factors is, however, really complicated in all studies involving human subjects. In addition to genetics, olfactory sensitivity is impacted in complex ways by environment [START_REF] Calderón-Garcidueñas | Urban air pollution: Influences on olfactory function and pathology in exposed children and young adults[END_REF][START_REF] Doty | Genetic and environmental influences on odor identification ability in the very old[END_REF][START_REF] Guarneros | Mexico City Air Pollution Adversely Affects Olfactory Function and Intranasal Trigeminal Sensitivity[END_REF][START_REF] Hudson | Effect of air pollution on olfactory function in residents of Mexico City[END_REF][START_REF] Knaapila | Self-Ratings of Olfactory Function Reflect Odor Annoyance Rather than Olfactory Acuity[END_REF], and odor awareness, however defined, must take this into account. Additionally, there are experience-and learning-mediated effects on different aspects of odor perception (e.g., [START_REF] Distel | Perception of everyday odors-correlation between intensity, familiarity and strength of hedonic judgement[END_REF][START_REF] Schaal | Variability and invariants in early odour preferences: comparative data from children belonging to three cultures[END_REF][START_REF] Schaal | Emerging chemosensory preferences: another playground for the innate-acquired dichotomy in human cognition[END_REF]. This potential influence of personal history is particularly interesting, as studies show that learning and experience can shape also olfactory awareness. Parental reports of the children's odor exposure predicted their offspring's odor awareness, in preschool children (Martinec Nováková and Vojtušová Mrzílková, 2016) and in young adults [START_REF] Nováková | Engagement in olfaction-related activities is associated with the ability of odor identification and odor awareness[END_REF]. Despite difficulties in determining whether the sources of such findings are biologically-or environmentally-driven, these data further Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. In our global study, we examined three country-level predictors, but we did not find any of them statistically significant. However, 30% of the variability in social odor awareness was assigned to the level of country. If national wealth, temperature, and population density do not account for the variability in social odor awareness, the question as to which country-level factors are related to importance of odors in social contexts remains unanswered. There are several cultural factors not addressed in this study that could be taken into account while considering odor awareness. Some of them, for example cultural values, might be difficult to quantify, and therefore it seems challenging to measure them in survey research. As discussed above, apart from culture, there are also climaterelated indices (e.g. humidity or air pollution) that may be related to olfactory performance and hence odor awareness [START_REF] Calderón-Garcidueñas | Urban air pollution: Influences on olfactory function and pathology in exposed children and young adults[END_REF]. In the light of the current research, the issue of culture-and climate-related predictors of attention paid to odors remains an open question to be addressed in future investigations, that could include also, e.g., less industrialized societies.

There are certain limitations of the current study. The sample sizes were generally too small to be fully representative for participating cultures, and they were often samples of conveniencesnowball sampling was frequently used as a method of recruitment. However, all coauthors were instructed to recruit participants from as diverse socioeconomical backgrounds as possible, and the samples were to be balanced in terms of age, gender, and education level. However, we used different methods of recruitment in different locationswe had no standard recruitment procedure.

Nevertheless, this is the first study on odor awareness that involves such a large number of diverse cultures and despite certain limitations, our findings expand the knowledge on predictors of odor awareness in social interactions.

In summary, our study revealed that individual characteristics are more strongly related than country-level factors to self-reported odor awareness in social contexts. Although people from different countries differ from one another substantially in social odor awareness, the main Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N. Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N.

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  A c c e p t e d M a n u s c r i p t 17 environmental pressures that promoted olfaction as a useful sense for hunting, fishing, gathering and

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  approved by the ethical board of the Institute of Psychology, University of Wroclaw (and other ethical committees in countries where additional approvals were necessary). The work was performed in accordance with the Declaration of Helsinki for Medical Research involving Human Subjects. All participants provided written, informed consent prior to their inclusion in the study.ParticipantsThe sample in this investigation comprised 10,794 individuals: 4896 men and 5855 women (43 participants decided not to disclose their gender, they were excluded from further analyses involving this variable). Participants' age ranged from 17 to 88 years, with M = 39.62 and SD = 11.71.Participants lived in 44 countries and 52 sitesas there were multiple sites in Brazil (3), India (3), Nigeria (3), and Turkey (3). The study sites included: Argentina, Austria, Brazil (Natal), Brazil (Porto Alegre), Brazil (Rio de Janeiro), Bulgaria, Canada, China, Colombia, Croatia, Czech Republic, Estonia, Germany, Ghana, Greece, Hong Kong, Hungary, India (Chennai), India (Bangalore), India (Guwahati), Indonesia, Iran, Italy, Kazakhstan, Kenya, Malaysia, Mexico, Nigeria (Benin), Nigeria (Enugu), Nigeria (Ondo), Norway, Pakistan, Peru, Poland, Portugal, Romania, Russia, Saudi Arabia, Serbia, Slovakia, South Korea, Spain, Sweden, Switzerland, Thailand, Turkey (Ankara), Turkey (Antalya), Turkey (Sivas), Uganda, Ukraine, United Kingdom, and USA.The participants were recruited by investigators in their respective countries. In most study locations, the participating groups comprised both a community sample and a student sample. Community samples were recruited in neighborhoods of large markets and shopping malls, neighborhoods of university facilities, local administration offices, public parks and other city facilities, and among members of vocational courses conducted at different universities (for example in Hungary, Peru, Norway, Poland, Saudi Arabia, Ghana, Brazil, Nigeria, the Netherlands, Ukraine, Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018 Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.A c c e p t e d M a n u s c r i p t 19

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  05, both ps < .001) and explained 3% of Level-1 variance. Consistent with our predictions, women had higher social olfactory awareness than men (B = 0.90, SE = 0.09, p < .001), and olfactory awareness decreased with age (B = -0.02, SE = 0.004, p < .001) and increased with educational level obtained (B = 0.23, SE = 0.05, p < .001). It was not related, however, to reported material conditions of participants (B = -0.08, SE = 0.05, p = .15) and their preferred interpersonal distance (B = -0.0003, SE = 0.001, p = .82).

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  that individual-level factors (including personal history) might modulate odor awareness more than culture-level variables.

  N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  . (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N., Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

  Olfaction plays an important role in human social communication, including multiple domains in which people often rely on their sense of smell in the social context. The importance of the sense of smell and its role can however vary inter-individually and culturally. Despite the growing body of literature on differences in olfactory performance or hedonic preferences across the globe, the aspects of a given culture as well as culturally universal individual differences affecting odor awareness in human social life remain unknown. Here, we conducted a large-scale analysis of data collected from 10,794 participants from 52 study sites from 44 countries all over the world. The aim of our research was to explore the potential individual and country-level correlates of odor awareness in the social

	Abstract
	M a n u s c r i p t
	A c c e p t e d
	12

, Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d. context. The results show that the individual characteristics were more strongly related than countrylevel factors to self-reported odor awareness in different social contexts. A model including individual-level predictors (gender, age, material situation, education and preferred social distance) provided a relatively good fit to the data, but adding country-level predictors (Human Development Index, population density and average temperature) did not improve model parameters. Although there were some cross-cultural differences in social odor awareness, the main differentiating role was played by the individual differences. This suggests that people living in different cultures and different climate conditions may still share some similar patterns of odor awareness if they share other individual-level characteristics. Keywords: odor awareness; olfaction; smell; culture Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018

  Our research aimed at exploring a number of potential individual and country-level correlates of odor awareness in the social context. This is the first to date global research focused on social odors, providing data from a large number of cultures about potential individual-and cultural-level factors related to the importance of the sense of smell and role of odors in the social context.

Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018

  The participant was asked to rate how close a Person B could approach, so that he or she would feel comfortable in a conversation with Person B. The participants marked the distance at which Person B should stop on the scale below the figures (see[START_REF] Sorokowska | Preferred Interpersonal Distances: A Global Comparison[END_REF] for details of the method). Based on the participants' reply, we calculated mean preferred

	interpersonal distance for each person. In addition, we analyzed country-level variables: population
	density (United Nations population density report; United Nations, 2013), and average, yearly
	temperature in a given study site (provided by respective coauthors), and the Human Development
	Index (HDI; UNDP, 2013)

Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018

Table 1 .

 1 Summary of descriptive statistics

	Country / Study Site Argentina Austria Brazil Brazil Brazil Bulgaria	City / study sites Parana Vienna Natal Porto Alegre Rio de Janeiro Blagoevgrad	Sample size 201 200 240 140 100 102	% Females 65% 43% 42% 26% 42% 38%	Age 32.31 M 26.59 35.58 33.34 43.16 M SD M Education SD 11.16 3.91 0.96 9.73 4.12 0.61 9.59 4.44 0.82 8.39 4.86 0.37 a n u s c r i p t Material situation Mean preferred distance M SD M SD 2.74 0.49 58.64 22.80 2.73 0.66 68.93 23.77 2.51 0.69 81.42 36.74 2.26 0.60 73.00 32.34 11.74 4.62 0.72 2.27 0.63 75.60 23.84 38.35 8.95 4.65 0.77 3.04 0.20 62.81 8.72	HDI M 0.81 0.90 0.73 0.73 0.73 0.78	Population density M 14.52 100.19 22.93 22.93 22.93 66.62	Average temperature M 19.00 11.50 26.00 20.00 24.00 10.00
	Canada China Colombia Croatia Czech Republic Estonia Germany Ghana	Halifax Shanghai, Beijing Santa Maria Zagreb Prague Tartu Dresden A c c e p t e d 68 63% 38.43 10.15 365 53% 37.00 6.06 100 59% 41.10 11.81 614 51% 44.75 11.65 167 52% 36.48 15.93 146 66% 42.93 12.30 154 60% 31.59 13.39 Legon, Accra 103 50% 40.42 9.53	4.66 4.19 3.83 3.97 4.19 4.48 4.26 4.24	0.48 1.03 1.07 0.98 0.71 0.78 0.71 1.06	2.79 2.47 2.77 2.67 2.86 2.89 3.41 2.03	1.04 0.74 0.74 0.75 0.79 0.74 0.99 0.75	87.75 63.36 87.93 91.54 82.95 94.41 69.18 81.36	40.40 43.92 28.66 22.15 23.05 26.16 31.21 28.26	0.91 0.70 0.72 0.81 0.87 0.85 0.92 0.56	3.42 141.69 40.78 76.73 133.82 28.80 232.53 101.72	7.60 15.09 26.00 11.00 8.00 5.00 9.40 26.00
												35

, Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d. Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018

Table 2 .

 2 Means and Standard Deviations of the Results obtained by Men and Women across

	Participating Sites
		Men			Women			Overall
	Country
		M	N	SD	M	N	SD	M	N	SD
	Argentina	21.39 71	4.39	23.72	130 4.15	22.90 201	4.37
	Austria	22.69 115 3.82	21.76	85	3.46	22.30 200	3.69
	Brazil (Natal) Brazil (Porto Alegre) Brazil (Rio de Janeiro) Bulgaria Canada China	M 21.71 137 3.36 24.46 103 3.04 24.26 58 3.58 24.52 63 2.01 14.64 25 3.11 a n u s c r i p t 22.41 100 4.33 22.00 237 21.62 37 3.44 23.71 140 21.55 42 4.23 23.12 100 26.00 39 2.58 25.09 102 14.25 43 3.30 14.40 68 18.63 131 4.38 18.37 153 4.11 18.49 284	3.80 3.38 4.08 2.34 3.22 4.23
	A c c e p t e d
										39

, Cetinkaya, H., Chang, L., Chen, B.-B., Cunha, D., David, D., David, O. A., Dileym, F. A., Domínguez Espinosa, A. d.

Acknowledgements

The authors thank Paul Oburu for collecting data in Kenya. Downloaded from https://academic.oup.com/chemse/advance-article-abstract/doi/10.1093/chemse/bjy038/5045948 by University of the Sunshine Coast user on 28 June 2018

Funding

This work was supported by the Polish Ministry of Science and Higher Education Iuventus Plus grant # IP2014 043773 to AS. Data collection in Saudi Arabia was funded by Deanship of Scientific Research at King Saud University through research group No (RG-1439-012).

Conflict of interest

The authors declare no conflict of interest. Andero Teras is a Founder, CEO and Event Marketing Manager of Mõttemaru OÜ but that there are no conflicts of interests with this study.

Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K.

Version postprint

Comment citer ce document : Sorokowska, A. (Auteur de correspondance), Groyecka, A., Karwowski, M., Frackowiak, T., Lansford, J. E., Ahmadi, K., Alghraibeh, A., Aryeetey, R., Bertoni, A., Bettache, K., Blumen, S., Baejewska, M., Bortolini, T., Butovskaya, M., Cantarero, K., Castro, F. N.


S Jurjanz
email: stefan.jurjanz@univ-lorraine.fr

C Collas

M L Lastel

X Godard

H Archimède

G Rychen

M Mahieu

C Feidt

Evaluation of soil intake by growing Creole young bulls in common grazing systems in humid tropical conditions

Keywords: soil intake, beef cattle, tethering, stocking rate, pasture allowance Implications

Soil is the main matrix which contributes to the transfer of environmental pollutants to animals and consequently into the food chain. In the French West Indies, chlordecone, a very persistent organochlorine pesticide, has been widely used on banana growing areas and this process has resulted in a long-term pollution of the corresponding soils. Domestic outside-reared herbivores are exposed to involuntary soil intake, and tethered grazing commonly used in West Indian systems can potentially favour their exposure to chlordecone. Thus, it appears necessary to quantify to what extent grazing conditions will influence soil intake. This experiment consisted of a cross-over design with two daily herbage allowance (DHA) grazed alternatively. Six young Creole bulls were distributed into two groups (G1 and G2) according to their BW. The animals were individually tethered and grazed on a restrictive (RES) or non-restrictive (NRES) levels of DHA during two successive 10-days periods. Each bull progressed on a new circular area every day. The two contrasting levels of DHA (P < 0.001) were obtained via a different daily grazing surface area (RES: 20 m 2 /animal, NRES: 31 m 2 /animal; P < 0.01) offered to the animals by the modulation of the length of the tethering chain (RES: 1.9 m, NRES: 2.6 m). These differences in offered grazing areas resulted in DHA of 71 and 128 g DM/kg BW 0.75 , respectively for RES and NRES treatments. As expected, the animals grazing on the reduced area realized a lower daily dry matter intake (DMI) (RES: 1.12 kg/100 kg BW, NRES: 1.83 kg/100 kg BW; P < 0.05) and present a lower organic matter digestibility (RES: 0.67, NRES: 0.73; P < 0.01) than NRES ones, due in part to the shorter post-grazing sward surface height (RES: 3.3 cm, NRES: 5.2 cm; P < 0.01) of their grazing circles. Soil intake was estimated on an individual level based on the ratio of the marker titanium in soil, herbage and faeces. Grazing closer to the ground, animals on RES treatment ingested a significantly higher proportion of soil in their total DMI (RES: 9.3%, NRES: 4.4%; P < 0.01). The amount of ingested soil in the diet was not significantly different between the two treatments (RES: 98 g/100 kg BW, NRES: 78 g/100 kg BW; P > 0.05) due to the lower DMI of RES compared with NRES treatment.

Introduction

Feeding management of pasture for domestic herbivores presents lots of nutritional, economic and environmental advantages. These include grass being a well-balanced and cheap source of nutrients [START_REF] Peyraud | Ideal concentrate feeds for grazing dairy cows responses to supplementation in interaction with grazing management and grass quality[END_REF], maintaining natural and marginal grasslands, and contributing to animal welfare [START_REF] Burow | Effect of grazing on the cow welfare of dairy herds evaluated by a multidimensional welfare index[END_REF]. However, grazing also enhances soil intake by herbivores (soil particles on vegetation, root intake, [START_REF] Abrahams | Soil ingestion by sheep grazing the metal enriched floodplain soils of Mid-Wales[END_REF] resulting in an increased exposure to gastrointestinal parasites [START_REF] Stromberg | Fourth Ostertagia workshop: nematode parasites of importance to ruminant livestock[END_REF] and environmental contaminants [START_REF] Laurent | Contamination des sols -Transferts des sols vers les animaux[END_REF]. Although ingested soil may be a source of mineral nutrients for animals [START_REF] Thornton | Soil ingestiona major pathway of heavy metals into livestock[END_REF], several studies pointed out soil as being one of the main matrices for pollutants transfer to outside-reared animals [START_REF] Beresford | The importance of soil adhered to vegetation as a source of radionuclides ingested by grazing animals[END_REF][START_REF] Fries | Transport of organic environmental contaminants to animal products[END_REF][START_REF] Matscheko | Application of sewage sludge to arable land-soil concentrations of polybrominated diphenyl ethers and polychorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls, and their accumulation in earthworms[END_REF]. Lipophilic properties of the persistent organic pollutants are responsible for their adsorption on soil components, which enables soil to retain and accumulate pollutants in the horizon surface longer than the other matrices (also called memory effect) [START_REF] Jones | Organic contaminants in Welsh soils: polynuclear aromatic hydrocarbons[END_REF][START_REF] Duarte-Davidson | Screening the environmental fate of organic contaminants in sewage sludge applied to agricultural soils: II. The potential for transfers to plants and grazing animals[END_REF]. Therefore, the exposure of free range animals to pollutants is closely linked to the amount of soil ingested which can be particularly high for some ruminants, up to 14% of the daily dry matter intake (DMI) in cattle [START_REF] Fries | Soil ingestion by dairy cattle[END_REF], and up to 30% of DMI in sheep [START_REF] Thornton | Soil ingestiona major pathway of heavy metals into livestock[END_REF] reported on pastures in very extensive temperate systems. Several authors reported that soil-bound persistent organic pollutants such as polychlorinated biphenyls in lactating goats [START_REF] Feidt | Relative bioavailability of soil-bound polychlorinated biphenyls in lactating goats[END_REF] and piglets (Delannoy et al., 2015), but also for chlordecone (CLD) in piglets (Bouveret et al., 2013) and growing lambs [START_REF] Jurjanz | Relative bioavailability of soil-bound chlordecone in growing lambs[END_REF] are highly bioavailable and fully absorbed in the digestive tract. Consequently, an accurate quantification of soil intake is required to evaluate the risk for food safety.

The French West Indies suffer from extensive pollution with CLD, a polycyclic ketone pesticide used until 1993 to fight against banana black weevil (Cosmopolites sordidus). The transfer of this pesticide into the food chain may engender severe damages on human health (Cabidoche et al., 2009; Multigner et al., 2016). Post-tethered grazing is a practice commonly used in Caribbean Islands where 20% to 30% of animal producers manage a limited number of animals which are grazing on non-standard pasture areas (e.g. tethered at roadsides, on cane or banana field borders, in fallow areas or in orchards). However, when these practices are carried out on a limited area they can result in limited daily herbage allowance (DHA) and herbage losses due to trampling and deposition of faeces. Such reduced herbage offer would usually result in animals grazing closer to the soil, favouring greater soil intake. Most studies on soil intake by domestic herbivores were performed in temperate grazing conditions (Healy 1968; Fries et al., 1982; Jurjanz et al., 2012). Meanwhile, no data are available for humid tropical Caribbean conditions or for post-tethered cattle to evaluate soil intake in these specific grazing systems. Indeed, the high grass production enhanced usually high stocking rates which could increase the risk of soil intake. This is a real difference to studies on soil intake in more or less extensive strip grazing systems in temperate [START_REF] Fries | Soil ingestion by dairy cattle[END_REF][START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF] or arid regions [START_REF] Kirby | Soil-ingestion rates of steers following brush management in central Texas[END_REF]. These studies identified in temperate conditions sward height and herbage allowance as main variation factors of soil intake. These farm-like factors are probably also relevant for tropical conditions even if the precise effect on soil intake of reduced herbage offer by tethered grazing and high stocking rates remains unknown.

The following trial aimed to evaluate the soil intake of posttethered growing Creole bulls grazed in tropical conditions in order to evaluate the risk for exposure to soil-bound pollutants in these systems. Feed allowance was the variation factor studied using two contrasted levels of DHA (restrictive (RES) and non-restrictive (NRES)). These two DHA levels were achieved adapting daily surface area (DSA) offered to the animals according to pre-grazing sward surface height (SSH) (controlled factor). Daily herbage allowance and DSA variations were obtained by different chain lengths between the post and animal's neck. The assumption can be made that the restrictive DHA could result in a higher soil intake for RES than NRES animals grazing a non-restrictive DHA. The first hypothesis is that the restrictive DHA could make that RES animals graze closer to the ground which would increase direct or indirect soil intake. The second hypothesis is that the low DSA associated to the restrictive DHA could favour trampling and intake of dirty herbage by RES animals. Finally, the third hypothesis assumes that the NRES level would lead to similar soil intakes than those reported in temperate conditions but RES level would increase this intake in an extent to be determined.

Material and methods

The experiment was conducted in farm-like conditions in accordance to the European Union and national legislation on animal care.

Treatments and experimental design

The experiment was performed at the Experimental Station 'Duclos' of the French INRA Institute (Petit-Bourg, Guadeloupe, France) (16°12'04.8'N, 61°39'53.4'W; altitude: 111 m) from 25 February to 5 April 2015). Six weaned bulls of the breed Creole of Guadeloupe (Bos taurus) alternatively received either a restrictive DHA of 71 g DM/kg BW 0.75 or a higher daily herbage allowance of 128 g DM/kg BW 0.75 . These DHA measured 2 cm above the ground level, corresponded to less than, or a satisfying level in respect to the requirements of moderate cattle growth (INRA, 2010). These two treatments were tested in a cross-over design during two successive 10-days periods (Period 1 from 18 to 27 March, Period 2 from 27 March to 5 April 2015) (Figure 1). Samples of herbage and faeces were taken during the last 5 days of each period. Animals were post-tethered and constrained by a chain from their neck to a post to graze in a limited circular area. Minimum and maximum temperature was on average 19.6 ± 0.2 and 28.1 ± 0.2°C during period 1, and 20.3 ± 0.4 and 27.9 ± 0.2°C during period 2 (mean ± SE). Mean daily rainfall was 2.15 ± 0.75 and 6.80 ± 2.85 mm for periods 1 and 2, respectively (mean ± SE).

Animals and pre-experimental period

The six bulls were born between 5 May and 9 July 2014 at the INRA station 'Gardel' (Le Moule, Guadeloupe, France). After weaning, the animals were accustomed on a neighbouring plot covered by the same herbage type to tethered grazing in a pre-experimental period from 25 February to 17 March 2015. This period allowed estimation of the daily herbage allowances for RES and NRES treatments and to calibrate surfaces offered to the animals at the experimental conditions. The young bulls were divided into two groups (G1 and G2) depending on age (G1: 9.0 ± 0.1 and G2: 9.3 ± 0.7 months old; mean ± SE) and body weight (BW) determined by a barymetric ribbon (G1: 174.7 ± 11.3 kg; G2: 152.3 ± 15.8 kg; mean ± SE). The first group was assigned to the RES treatment in period 1 and to the NRES treatment in period 2, and vice versa for the second group.

Grazing management Animals were tethered grazed on a Para grass pasture (Brachiaria mutica) divided into two plots for each experimental period. The two plots were mown beforehand to 3 cm on two different dates to ensure the same time of regrowth and identical vegetation stage for measurements. A mineral fertilization of 100 kg/ha (NPK 27-9-18) was applied on both plots after the mowing. Every morning at 0800 h, each young bull was offered fresh herbage by moving its post on a new area to control daily herbage allowance and limit intake fluctuations (Figure 2). Posts were spaced 9.20 m from each other to avoid any contamination of a grazing circle by faeces of another individual (for intake measurements). The two contrasted levels of DHA (RES: 71 g DM/kg BW 0.75 ; NRES: 128 g DM/kg BW 0.75 ) were attained by variation of the daily surface offered to the animals, modulated by animal neck-to-post chain length. Daily surface allowance was individually calculated using the average SSH and a regression of the corresponding SSH-herbage mass. Sward surface height was measured in the next circle to be grazed by animals, every day before moving them into this circle. Sward surface height herbage regression between SSH and herbage mass was realized during the pre-experimental period using a large range of SSH, to estimate the available herbage mass in grazing circles (see 'Vegetation characteristics' section).

Vegetation characteristics

Sward surface height and herbage mass were simultaneously recorded from 6 to 31 March 2015 in several 30 × 30 cm quadrats (900 cm 2 ), randomly selected in both plots in a large range of SSH (3.5 to 27.5 cm) out of areas reserved for grazing circle in order to establish the SSH-herbage mass regression. One measure of SSH per quadrat was measured using a herbometer (Herbometre ® , Arvalis, Paris, France), following which herbage inside each quadrat was cut with a lawn-mower (Isio, Lithium-Ion Technology; Bosch, Renningen, Germany) to 2 cm above ground level. Herbage was weighed and one sample per quadrat was dried for 48 h at 60°C to determine herbage DM content and then calculate herbage mass and establish the SSH-herbage mass regression. Fifteen pre-grazing SSH measurements were made in each grazing circle before the animals entered so that chain length could be determined using the SSH-herbage mass regression according to the targeted restrictive and normal DHA. Post-grazing SSH was also measured every day from 15 random points per circle. Herbage was sampled twice daily during the last 5 days of each period near each grazing circle in order to not interfere with the herbage allowance provided by the circle, using the previously described methodology (cutting at 2 cm of the ground level with a lawn-mower). Samples were washed in water at 30°C with detergent (TFD4 at 3%) to remove soil particles, then weighed and dried at 60°C until constant weight to determine DM content. These DM values allowed to calculate a posteriori the estimate the daily herbage mass offered to each animal. The 10 samples for each animal and period were combined in equal proportions to form one per animal and per period for analysis of organic matter (OM), ash (incineration at 550°C during 6 h) and CP contents (Dumas method, AOAC Official Method 990.03, AOAC International, 2005) by URZ laboratory (INRA Guadeloupe, France, using a 'Rapid N Cube' by Elementar Analysensysteme GmbH) and for titanium (Ti) content (Inductively Coupled Plasma Mass Spectrometry method, Limit of quantification LOQ = 5 mg Ti/kg DM; see 'Soil intake' section) by laboratory UT2A (Ultra Traces Analyses d'Aquitaine, Pau, France).

Dry matter intake Daily DMI was estimated for each animal for the last 5 days of each period (23 to 27 March for period 1 and 1 to 5 April for period 2) as:

DMI = OMI 100=OMh
where OMh is the OM content (in %) of ingested herbage, and OMI the OM intake calculated as follows:

OMI = FO= 1 À OMD ð Þ
where FO is the faecal output over 24 h expressed in OM, calculated with the dry weight of faeces over 24 h and the faecal OM content, and OMD the OM digestibility of the diet expressed as a decimal value. The proportion of ingested soil can reduce the estimated DM digestibility of the diet and can affect the corresponding daily DMI [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF].

To avoid this bias we first calculated the daily OMI, then added the proportion of ash ingested to obtain the daily DMI for each cattle. Faeces were collected once a day every morning after animals moved into a new grazing circle. One faecal sample was taken from each individual, taking care to avoid vegetal or soil contamination. Remaining daily faecal samples were collected from each animal and weighed for faecal output estimation. The five daily faecal samples of each animal were pooled in identical proportions to one sample per animal and per period, each of which were weighed and dried at 60°C (until constant weight) to determine contents of DM, OM, ash, CP and Ti using the methods described above for grass samples. Organic matter digestibility was estimated from faecal CP content according to [START_REF] Boval | Evaluation d'indicateurs fécaux pour prédire la digestibilité et et les quantités ingérées de Dichanthium sp par des bovins créoles[END_REF]:

OMD = 0:983 À 4:002=faecal CP; in which faecal CP is expressed in g=kg DM
Intense rain prevented the collect of faeces the 3rd April so daily intake was measured during only 4 days at the second period.

Soil intake

During each of the 5 measurement days of each period, three soil samples (top 5 cm depth) were carried out with an auger in each grazing circle. In order to avoid damage to herbage before grazing which could favour soil intake, this sampling was carried out when animals had left the circle. Gravel and pieces of vegetation were removed from samples and the three daily samples were pooled to an individual daily pool. Then, 300 g of each daily sample were pooled to form one soil sample per animal and per period, which was wet sieved, dried at 60°C (until constant weight) to determine DM and Ti content (method previously described for herbage samples). Soil intake rate (SiR) was calculated as a percentage of DMI according to [START_REF] Beyer | Estimates of soil ingestion by wildlife[END_REF]:

SiR % of thetotally ingested DM ð Þ = Tih À Tif + DMD Tif ð Þ = DMD Tif À Tis + Tih ð Þ
where Tih, Tif and Tis are the Ti contents in herbage, faeces and soil, respectively. DMD is the DM digestibility of the diet estimated as follows:

DMD = OMD qOM ð Þ+ 0:57 qMM ð Þ
where OMD is the previously calculated value with the [START_REF] Boval | Evaluation d'indicateurs fécaux pour prédire la digestibilité et et les quantités ingérées de Dichanthium sp par des bovins créoles[END_REF] equation, qOM and qMM are the faecal proportions of organic and mineral matter, respectively, expressed as decimal values, and 0.57 is the average ash digestibility in beef cattle according to [START_REF] Wagner | Influence of recycling beef cattle waste on indigestible residue accumulation -Environmental Protection Technology Series[END_REF]. Soil intake amount (SiA) was then individually calculated using DMI and the proportion of soil in the DM. [START_REF] Healy | Ingestion of soil by dairy cows[END_REF][START_REF] Smith | The intake of lead and associated metals by sheep grazing mining-contaminated floodplain pastures in mid-Wales, UK: I. Soil ingestion, soil-metal partitioning and potential availability to pasture herbage and livestock[END_REF][START_REF] Abrahams | The importance of ingested soils in supplying fluorine and lead to sheep grazing contaminated pastures in the peak district mining area of Derbyshire, UK[END_REF]. As Ti absorption in animals is negligible, any faecal Ti can be attributed to ingested soil.

Statistical analyses

Statistical analyses were performed using R software (version 3.2.3) (R Development Core Team, 2016). Herbage (grazing management, herbage quality), soil (Ti content) and animal (OMI and DMI, soil intake) variables were tested using linear mixed models with treatment and period as fixed effects, and individual as a random effect. Individual animals were used as the experimental unit. Normality of residuals was checked using Shapiro-Wilk tests. The levels of studied factors were compared by the means using the 'glht' function of 'multcomp' package (Tukey's correction) (P < 0.05).

Results

Vegetation characteristics

The treatment effect of the DSA per animal (RES: 19.8 m 2 v. NRES: 30.9 m 2 ; P < 0.01) was reached using different individually chain lengths (RES: 1.92 m v. NRES: 2.57 m; P < 0.01). As expected, this resulted in significantly different daily herbage allowances between RES and NRES treatments (3.24 v. 5.90 kg DM/animal; 1.98 v. 3.60 kg DM/100 kg BW; 71 v. 128 g DM/kg BW 0.75 ; P < 0.001) meaning that animals on RES treatment were offered a lower DHA than those on NRES treatment. The period did not affect the DSA nor DHA (Table 1).

The six animals of the two treatments were entered into grazing circles that contained the same pre-grazing SSH (8.44 cm; P > 0.05). The post-grazing SSH were significantly higher for NRES than RES treatment (5.20 v. 3.27 cm; P < 0.01), but also for second v. first period (respectively 4.76 and 3.71 cm; P < 0.05). On the contrary, the pre/post-grazing Table 1 Grazing management and sward characteristics for both treatments (RES, NRES) and periods (P1, P2) SSH differential did not differ whatever treatment or period was considered (4.20 cm; P > 0.05; Table 1). Sward quality was similar between treatments (DM: 161 g/kg, OM: 882 g/kg DM, ash: 119 g/kg DM, CP: 170 g/kg DM) and periods, except for DM and Ti contents which were higher in period 1 than in period 2 (P < 0.01; Table 1).

Herbage intake Daily faecal output, expressed in OM, did not significantly differ between RES and NRES animals (0.61 kg OM/animal, 0.37 kg OM/100 kg BW). On the contrary, OMD of the diet was significantly higher in the NRES treatment in comparison with the RES treatment (0.73 v. 0.67; P < 0.01). As expected, daily OMI was significantly higher for NRES than for RES treatment (2.62 v. 1.59 kg OM/animal, 1.61 v. 0.99 kg OM/ 100 kg BW; P < 0.05; Table 2) and the daily DMI presents the same variations with a significant difference according to the treatment (2.97 v. 1.80 kg DM/animal, 1.83 v. 1.12 kg DM/ 100 kg BW; P < 0.05; Table 2).

Soil intake

The Ti content in soil did not vary significantly whatever the treatment and the period (3813 mg/kg DM; P > 0.05; Table 3) even if animals progressed every day to a new grazing circle. The Ti content in faeces from RES bulls was nearly double in comparison with samples from NRES ones (945 v. 563 mg/kg DM; P < 0.01), and was higher in period 1 than in period 2 (846 v. 662 mg/kg DM; P < 0.05).

Restrictive animals presented a lower DMD than NRES bulls (0.66 v. 0.71; P < 0.01). The low DHA level (71 g/kg BW 0.75 ) offered to RES animals resulted in a more than two times higher SiR (9.3 v. 4.4% DM; P < 0.01) than the one obtained with the higher DHA level (128 g/kg BW 0.75 ) offered to NRES animals. This strong effect of the tested treatment on the proportion of ingested soil was not significant when the SiA was considered (P = 0.14), regardless of the way of expression that is per animal or per 100 kg of BW (144 g DM/animal, 88 g DM/100 kg BW; P > 0.05; Table 3).

Discussion

Daily dry matter intake and variation factors Restrictive animals showed a lower DMI than animals on NRES treatment regardless of the period. This result should be considered with the significantly higher DHA for NRES than RES animals (+1.62 kg DM/100 kg BW, Table 1) and also with their higher OMD (+0.06, Table 2), as there was no faecal output Table 2 Body weight, daily organic matter intake (OMI) and dry matter intake (DMI) for both treatments (RES, NRES) and periods (P1, P2) Table 3 Soil intake rate (SiR) and daily soil intake amount (SiA) for both treatments (RES, NRES) and periods (P1, P2) difference between RES and NRES animals (Table 2). Dry matter intake represents 57% and 51% of the offered DM (i.e. at 2 cm over the ground level) for RES and NRES bulls, respectively. Post-grazing SSH was shorter for RES than NRES treatment but in line with the ones reported in temperate conditions in dairy cows [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF]. The pre/post-grazing SSH differential did not differ significantly between the two treatments because of the relatively high mean square error. Therefore, the DMI differential observed between treatments is mainly due to differences in the offered DSA. However, these post-grazing SSH differences could partially explain the OMD difference between the two treatments. Contrary to NRES animals, RES bulls ingested a part of the plants closer to the ground which is a more fibrous and less digestible part of the Para grass with a relatively high stem proportion.

Soil intake

The SiR was significantly higher for RES than NRES animals, but this effect was not significant regarding the daily SiA as DMI is significantly lower for RES than NRES animals (RES: 9.3% of 1.8 kg DMI/day; NRES: 4.4% of 2.97 kg DMI/day).

The lack of knowledge on soil intake by tethered young bulls in tropical grazing systems limits comparison of these results with those of literature. Some studies were performed in temperate grazing systems with different types of animals (breed, physiological state, etc.). In lactating dairy cows in intensive strip grazing systems, [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF] reported a significant interaction between DHA and sward type with higher soil intake for dairy cows which were offered a low (20 kg DM/cow per day above ground level; pure perennial ryegrass: 3% of 14.7 kg DMI/day, perennial ryegrass-white clover mixture: 5.8% of 14.1 kg DMI/day) compared with a medium DHA (35 kg DM/cow per day above ground level; 1% of 17 kg DMI/day for both sward types). Soil intake rate that we observed for NRES growing bulls in our experiment (4.4% DMI) is close to the rate for dairy cows grazing a high DHA without any supplement (4.9% DMI), but also similar to the average soil intake by dairy cows grazing a low DHA (4.4% DMI) compared with the results of [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF]. On the contrary, SiR in DMI that we observed for RES growing animals in our experiment (9.3% DMI) is higher than all the rates reported by [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF] whatever the treatment. This difference outlined the originality of this study which can be explained by the used animal type (meat v. dairy breed), physiological state (growing v. lactating), sward type (specific leaf area, sward structure, digestibility), grazing management (post v. strip) and pedoclimatic conditions (tropical v. temperate). [START_REF] Fries | Soil ingestion by dairy cattle[END_REF] reported generally lower soil intakes for heifers and dry cows which ingested from 1.38 ± 0.33% to 2.43 ± 0.50% of soil in their DMI (mean ± SE) when they were on pasture with a feed supply. Thus, soil intakes measured in our experiment were higher but experimental conditions were different as our growing bulls did not receive any supplementation at pasture. When ruminants are grazing closer to the ground surface and when high stocking rates are used, much higher SiR have been reported. These practices are mainly reported in sheep. [START_REF] Field | The intake of soil by grazing sheep[END_REF] reported from 0.4% to 14% DMI, [START_REF] Green | Factors affecting the transfer of radionuclides to sheep grazing on pastures reclaimed from the sea[END_REF] up to 13% and even up to 30% DMI by [START_REF] Thornton | Geochemistry applied to agriculture[END_REF]. [START_REF] Abrahams | The importance of ingested soils in supplying fluorine and lead to sheep grazing contaminated pastures in the peak district mining area of Derbyshire, UK[END_REF] evidenced the greatest amounts of soil ingested (in sheep) by slow herbage growth, high appetite (i.e. nutritional needs) of animals and higher rainfall. Indeed climate and temperature influence several factors as pasture allowance and quality but also the amount of soil adhered on plants by raindrop splashing or animal trampling [START_REF] Green | Factors affecting the transfer of radionuclides to sheep grazing on pastures reclaimed from the sea[END_REF][START_REF] Smith | The intake of lead and associated metals by sheep grazing mining-contaminated floodplain pastures in mid-Wales, UK: I. Soil ingestion, soil-metal partitioning and potential availability to pasture herbage and livestock[END_REF]. The grazing management, decided by the farmer, would determine stocking rate and grazing intensity (i.e. the percentage of leaves removed or eaten). This may increase soil loading on plants and plant covering and in this way influence the amount of soil in the diet [START_REF] Rafferty | Seasonal variations in the transfer of 137 Cs and 40 K to pasture grass and its ingestion by grazing animals[END_REF][START_REF] Hinton | Soil contamination of plant surfaces from grazing and rainfall interactions[END_REF][START_REF] Abrahams | Soil ingestion by sheep grazing the metal enriched floodplain soils of Mid-Wales[END_REF].

Shorter post-grazing SSH for RES than NRES treatment highlights a closely to the ground grazing for RES animals which implies increased soil intake in comparison with higher SSH. Plants are exposed to soil particles deposition onto their surface by wind transport in arid conditions [START_REF] Sehmel | Particle and gas dry deposition: a review[END_REF], raindrop splash [START_REF] Mazurak | Detachment of soil particles in simulated rainfall[END_REF] or soil disturbance by mechanical equipment or livestock activities as trampling [START_REF] Li | An experimental study on mass loading of soil particles on plant surfaces[END_REF][START_REF] Rafferty | Seasonal variations in the transfer of 137 Cs and 40 K to pasture grass and its ingestion by grazing animals[END_REF]. In our conditions, trampling seems to be very relevant, especially on ferrosol present on the experimental site, as this clay-rich soil can easily take up humidity and adhere on plants. Thus, young bulls with the shorter chains ingested more soil, in proportion to their DMI, than animals with longer chains. Consequently, the daily allocated surface influences herbage losses or contamination due to trampling or deposition of faeces.

Implications for rearing and exposure risk to environmental pollutants RES animals received 55% of the amount of herbage daily allocated to NRES ones, which was designed to allow the satisfaction of NRES animals' nutritional needs and avoid a close to the ground grazing which can favour soil intake. Consequently, RES animals could not completely satisfy their requirements, due to a lower daily DMI, and would have to stay longer in these restrictive grazing conditions (i.e. 71 g DM/ kg BW 0.75 ) to achieve their growth and attain their completion BW. This extended rearing duration exposes them to an absolute soil intake higher than for NRES animals. Based on literature (Bouveret et al., 2013; Jurjanz et al., 2014) soil intake by animals observed during our experiment would result in CLD contamination when the animals would have grazed on polluted areas.

Our study confirmed that herbage allowance is a major determinant under the experimental conditions imposed. It would be interesting to deal with herbage allowance effect in depth to determine the type of relation (linear, quadratic) between soil intake and herbage availability. This determination would allow the herbage threshold to be established in order to minimize soil intake in Caribbean conditions and thereby also the risk of exposure to soil-bound contaminants. Moreover, this relationship would allow the quantification of the increase in soil intake enhanced by less optimal grazing conditions. Thus, these results suggest to avoid practicing a restricted DHA for Creole cattle reared in contaminated areas in order to reduce their risk of CLD exposure. [START_REF] Hinton | Soil contamination of plant surfaces from grazing and rainfall interactions[END_REF] developed a mathematical model to predict how practices of grazing management can decrease soil ingestion by animals on pastures in Switzerland. They predicted that a reduction of soil intake of 50% needs to reduce grazing pressure of 2.5 times. In our conditions, soil intake was reduced by 19% (from 159 to 129 g/day) by increasing DHA up to 182% (70.6 v. 128.5 kg DM per kg BW 0.75 ) and DSA up to 156% (from 19.8 to 30.9 m 2 ).

Regarding grazing management, a SSH higher than 5 cm is proposed by [START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF] to prevent a closeto-the-ground grazing on temperate pastures. Although unusual in Caribbean conditions, a feed supply at pasture is another way to reduce soil intake [START_REF] Fries | Soil ingestion by dairy cattle[END_REF][START_REF] Jurjanz | Soil intake of lactating dairy cows in intensive strip grazing systems[END_REF].

Thus, the high soil intake shown in this study, especially under a restrictive DHA can beand should bereduced by different management factors available. The quantification of their effects need further studies to improve knowledge and finally to limit as much as possible soil intake.

Figure 1

 1 Figure 1 Cross-over design and main measurements. RES = restrictive treatment, NRES = non-restrictive treatment, DHA = daily herbage allowance, DSA = daily surface area.

Figure 2

 2 Figure2Grazing management of the two groups of tethered young bulls (G1: animals A1 to A3, and G2: animals A4 to A6) during the ten days (period 1: D1 to D10, period 2: D11 to D20) of each experimental period.

RES

  = restricted; NRES = non-restricted; P1 = period 1; P2 = period 2; OM = organic matter; OMD = organic matter digestibility. a,b Values within a row with different superscripts differ significantly at P < 0.05. Signification of P-values for tested effects was *0.05 and **0.01.

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Acknowledgements

The experiment was partially funded by Plan National Chlordécone 3 (CHLORDEL project). The authors thank warmly J. Fleury, F. Pommier, F. Nimir and F. Labirin from INRA PTEA, S. Calif and T. Silou from INRA URZ, as well as Y. Le Roux from UR AFPA for statistical advice and D. J. Beriro from British Geological Survey for English proofreading.