Contribution to the assessment of exposure to indoor pesticides in France
Contribution à l’évaluation de l’exposition d’enfants franciliens aux pesticides dans l’environnement intérieur : cas particulier des insecticides organophosphorés
Résumé
Pesticides are widely used for agricultural, industrial and residential purposes. This causes concern for animals, humans and ecosystems. The non-dietary exposure of populations has not been well studied, especially in France. In this context, we focused on indoor environment and cutaneous contamination by selected pesticides and tried to determine the internal exposure to some organophosphorus (OP) insecticides. This work was conducted in three phases. First, we selected and developed the measurements and questionnaires to perform the study. A series of questionnaires were created, gathering sociodemographic information, data on the environment of the houses studied and on lifestyles and probable sources of pesticide exposure (pesticide use habits, description of the products used) of the subjects. Selected measurements were indoor air measurement, cutaneous residues assessed by means of hand wipes and urinary dialkylphosphates, metabolites common to numerous OP insecticides. Analytical methods (gas and high performance liquid chromatography combined with selective detectors) were chosen, adapted and validated in collaboration with the INERIS laboratories. A selection of various insecticides, herbicides and fungicides was made, according to their use, their toxicity and their remanence. The second phase was the application of this protocol to an adult population (n=41) occupationally exposed or non-occupationally exposed to pesticides. Measurements were taken at the workplace of gardeners, florists and veterinary workers and at home for nonoccupationally exposed subjects. OPs, organochlorine and propoxur insecticides, as well as some herbicides and fungicides, were detected in the air of every type of premises and on the hands of every group of subjects. In our sample, gardeners and florists were mostly exposed to methyl-OPs, and veterinary workers to ethyl-OPs. The general population was exposed to the same pesticides, but at somewhat lower levels. Urinary metabolites of OP insecticides did not significantly differ between the different exposed groups. This work allowed us to assess the feasibility of our study design. The third part of this work consisted in studying the non-dietary exposure to pesticides of children aged 6-7 years, attending school in three predetermined areas in the Ile-de-France region. Our hypothesis was that the type of housing and housing environment could influence children’s exposure to pesticides. We recruited 73 children living in houses and 57 living in apartments. In addition to the measurements already described, house dust was also sampled for approximately 50% of the households. A garden, a cat and/or a dog were present in 55.5% and 29% of the households, respectively. At least one pesticide product was present in 94% of the homes, mostly insecticides. During the year preceding the study, 87% of the parents reported the use of at least one pesticide product, mostly insecticide (average quantity of 2.5 products used). More than 25% of the parents mentioned at least one professional pest-control operation at home. Lindane, alpha-HCH and propoxur were the most frequently detected compounds in indoor air (in 88%, 49%, and 44% of the samples, respectively). Due to the great number of non quantifiable values, non parametric statistics were performed. Air and hand OP levels were significantly correlated, whereas no correlation was observed with urinary DAP levels. Propoxur levels in air and on hands were also significantly correlated. The sampling season, type of housing and ventilation were predictors of lindane and alpha-HCH air concentrations. Ventilation, use of insecticides against head lice and the presence of a garden were significantly associated with air concentrations of OP insecticides. The sampling season, type of housing and plants inside the home were associated with levels of hand OP contamination of the children. Termiticide treatment, the presence of a cat or a dog and use of insecticide against head lice for the child studied significantly influenced urinary dialkylphosphate concentrations. To conclude, the study design and the measurements we chose allowed us to describe nondietary exposure to various urban populations in the Ile-de-France region. The factors that seem to influence this exposure suggest new orientations for future studies, to better define which subjects are overexposed.
L’expologie est le nom proposé1 pour traduire le terme anglais « exposure assessment ». Un article récent de Wallace LA., un des « pères fondateurs » de l’expologie, tire le bilan des implications de ce concept [6]. Pour l’auteur, cette nouvelle discipline scientifique est apparue, il y a 20 ans, dans le but d’évaluer l’exposition humaine aux polluants environnementaux. Le principe fondamental de cette nouvelle science est de « mesurer là où sont les personnes ». Un premier principe a été le développement de dispositifs de prélèvements petits, légers et silencieux. Un second principe a été de mesurer la charge corporelle, pour déterminer la relation entre l’exposition et la dose. Le développement de ces outils a mis en évidence que les sources de pollution étaient disséminées, proches des personnes et échappant à toute réglementation. Ce constat a remis en cause la vision que l’on pouvait avoir dans les années 1970, à savoir une pollution d’origine industrielle provenant des cheminées d’usine et se répandant dans les milieux environnants. Le biomonitoring humain (BMH), ou biosurveillance, est un outil d’identification, de contrôle et de prévention de l’exposition des populations aux substances chimiques.
Domaines
Sciences de l'environnement
Origine : Publication financée par une institution
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