Knowledge gaps regarding the potential role of pesticides in the loss of agricultural biodiversity worldwide and mixture-related issues hamper proper risk assessment of unintentional impacts of pesticides, rendering essential the monitoring of wildlife exposure to these compounds. Free-ranging mammal exposure to legacy (Banned and Restricted: BRPs) and currently used (CUPs) pesticides was investigated, testing the hypotheses of: (1) a background bioaccumulation for BRPs whereas a “hot-spot” pattern for CUPs, (2) different contamination profiles between carnivores and granivores/omnivores, and (3) the role of non-treated areas as refuges towards exposure to CUPs. Apodemus mice (omnivore) and Crocidura shrews (insectivore) were sampled over two French agricultural landscapes (n = 93). The concentrations of 140 parent chemicals and metabolites were screened in hair samples. A total of 112 compounds were detected, showing small mammal exposure to fungicides, herbicides and insecticides with 32 to 65 residues detected per individual (13–26 BRPs and 18–41 CUPs). Detection frequencies exceeded 75% of individuals for 13 BRPs and 25 CUPs. Concentrations above 10 ng/g were quantified for 7 BRPs and 29 CUPs (in 46% and 72% of individuals, respectively), and above 100 ng/g for 10 CUPs (in 22% of individuals). Contamination (number of compounds or concentrations) was overall higher in shrews than rodents and higher in animals captured in hedgerows and cereal crops than in grasslands, but did not differ significantly between conventional and organic farming. A general, ubiquitous contamination by legacy and current pesticides was shown, raising issues about exposure pathways and impacts on ecosystems. We propose a concept referred to as “biowidening”, depicting an increase of compound diversity at higher trophic levels. This work suggests that wildlife exposure to pesticide mixtures is a rule rather than an exception, highlighting the need for consideration of the exposome concept and questioning appropriateness of current risk assessment and mitigation processes.
Awareness of the adverse effects of exposure to pollutant mixtures, possibly much more severe than individual chemicals, has drawn attention towards the necessity of using multi-residue methods to obtain the most possible comprehensive information on exposome. Among the different biological matrices used for exposure assessment, hair enables to detect the largest number of chemicals, including many classes such as persistent pollutants, hydrophilic metabolites and metals. Most biomonitoring studies are however focused on a limited number of pollutants and only give a partial information on exposure. Combining several multi-residue methods, the present study aimed at assessing the exposure of a population to an extensive variety of chemicals by hair analysis. One hair sample was collected from each participant (55 children and 134 adults). Samples were analysed with three different multi-residue methods, targeting, respectively, 152 organic pollutants (pesticides, PCBs, bisphenols, PBDEs), 62 polycyclic aromatic hydrocarbons (PAHs) and metabolites, nicotine and cotinine and 36 metals. From 33 to 70 organic chemicals were detected in each child’s hair sample, and from 34 up to 74 in adults. From 7 to 26 PAH were detected per child, and 7 to 21 in adults. Twenty-three to 27 metals were detected per child and 21 to 28 per adult. The highest median concentration were observed for zinc (143 μg /mg in children; 164 μg /mg in adults), bisphenol A (95.9 pg/mg in children; 64.7 pg/mg in adults) and nicotine (66.4 pg/mg in children; 51.9 pg/mg in adults). The present study provides the most comprehensive exposure assessment ever and highlights the simultaneous exposure to multiple classes of pollutants in the general population. The results support the use of multi-residue methods for future studies on exposure-associated effects, to document exposome and better consider the effect of chemical mixtures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.