The specific physiology and behaviour of children makes them particularly vulnerable to chemical exposure. Specific studies must therefore be conducted to understand the impact of pollution on children’s health. Human biomonitoring is a reliable approach for exposure assessment, and hair, allowing the detection of parent chemicals and metabolites, and covering wider time windows than urine and blood is particularly adapted to study chronic exposure. The present study aims at assessing chemical exposure and investigating possible determinants of exposure in children living in Luxembourg.

Hair samples were collected from 256 children below 13 y/o and tested for 153 compounds (140 pesticides, 4 PCBs, 7 BDEs and 2 bisphenols). Moreover, anthropometric parameters, information on diet, residence, and presence of pets at home was collected through questionnaires. Correlations, regressions, t-tests, PLS-DA and MANOVAs, were used to investigate exposure patterns.

Twenty-nine to 88 (median = 61) compounds were detected per sample. The highest median concentration was observed for BPA (133.6 pg/mg). Twenty-three biomarkers were detected in ≥95% of the samples, including 13 in all samples (11 pesticides, BPA and BPS). Exposure was higher at younger ages (R² = 0.57), and boys were more exposed to non-persistent pesticides than girls. Presence of persistent organic pollutants in most children suggests that exposure is still ongoing. Moreover, diet (e.g. imazalil: 0.33 pg/mg in organic, 1.15 pg/mg in conventional, p-value<0.001), residence area (e.g. imidacloprid: 0.29 pg/mg in urban, 0.47 pg/mg in countryside, p-value = 0.03), and having pets (e.g. fipronil: 0.32 pg/mg in pets, 0.09 pg/mg in no pets, p-value<0.001) were identified as determinants of exposure.

The present study demonstrates that children are simultaneously exposed to multiple pollutants from different chemical classes, and confirms the suitability of hair to investigate exposure. These results set the basis for further investigations to better understand the determinants of chemical exposure in children.

儿童的特殊生理和行为使他们特别容易受到化学物质的影响。因此，必须进行具体研究以了解污染对儿童健康的影响。人体生物监测是一种可靠的暴露评估方法，头发可以检测母体化学物质和代谢物，覆盖比尿液和血液更广的时间窗，特别适用于研究慢性暴露。本研究旨在评估化学暴露并调查生活在卢森堡的儿童暴露的可能决定因素。

收集了 256 名 13 岁以下儿童的头发样本，并测试了 153 种化合物（140 种农药、4 种多氯联苯、7 种溴化二苯醚和 2 种双酚）。此外，通过问卷调查收集了人体测量参数、饮食信息、居住地和家中宠物的存在情况。相关性、回归、t 检验、PLS-DA 和 MANOVA 用于研究暴露模式。

每个样品检测到 29 到 88 种（中位数 = 61）化合物。观察到 BPA 的最高中值浓度 (133.6 pg/mg)。在 ≥95% 的样品中检测到 23 种生物标志物，包括所有样品中的 13 种（11 种农药、BPA 和 BPS）。年轻时的接触率较高（R ² = 0.57），男孩比女孩更容易接触到非持久性杀虫剂。大多数儿童中存在持久性有机污染物表明接触仍在进行中。此外，饮食（例如，抑霉唑：有机 0.33 pg/mg，常规 1.15 pg/mg，p 值<0.001），居住区（例如吡虫啉：城市 0.29 pg/mg，农村 0.47 pg/mg，p-值 = 0.03）和养宠物（例如氟虫腈：宠物为 0.32 pg/mg，无宠物为 0.09 pg/mg，p 值<0.001）被确定为暴露的决定因素。

本研究表明，儿童同时暴露于来自不同化学类别的多种污染物，并证实了头发适合调查暴露。这些结果为进一步调查以更好地了解儿童化学品暴露的决定因素奠定了基础。