Prevalence of lead poisoning among artisanal gold miners in French Guiana in 2022

Abstract Objectives Lead poisoning is a major public health problem worldwide. In French Guiana, a French overseas territory in South America, several studies have highlighted the massive lead impregnation of the local population, but the risk factors have not yet been fully elucidated. People working in informal gold mining share part of their lifestyle with French Guianese communities. The aim of this was therefore to estimate the level of lead poisoning in this population and the factors associated with it. Methods This cross-sectional descriptive study was based on data collected by questionnaire and blood sampling. Persons working in informal gold mines were enrolled on the logistic rear bases on the Surinamese and Brazilian sites of the bordering rivers. Blood lead levels were measured on dry blood spots (50 µl). Using a threshold of 100 μg.L −1 , single and multiple regressions were used to assess the associated factors. Results Among the 526 persons included, the median age was 38 years and 73.5% were men. The prevalence of lead poisoning was 44.7 % (95%CI=40.4%-49.0%). The factors associated with a BLL over 100 μg.L-1 were: amount of time spent in gold mining (OR=1.31 [1.09-1.58], occupation with mud exposure (OR=1.67 [1.13-2.48]), working in the Southwestern region (OR=2.09 [1.34-3.27]) and consuming game (OR=1.58 [1.06-2.36]). Conclusion The people working on gold mining sites are highly exposed to lead poisoning. The risk factors are suggestive of environmental contamination and differ from those suspected in the population of French Guiana. Research in context Evidence before study Lead poisoning has a major impact on health. Although, its risk factors are well known in the Western world, they are different in the Amazon. In French Guiana, a French overseas territory in South America, lead poisoning is very common in the local population, but the risk factors are still poorly understood. So far, the suspected sources of lead poisoning are the bioaccumulation of lead in cassava flour, lead contained in hunting ammunition, lead used to weigh the fishing nets, and lead spills from used lead batteries. Added value of this study This study shows, for the first time, the high lead impregnation of the population living and working on illegal gold mining sites in French Guiana. Although some aspects of their lifestyles are shared with the local population, the risk factors we observed were different from those commonly hypothesized. We found that length of time spent in gold mining, specific geographic areas and activities in close contact with mud were significantly associated with lead poisoning. Implications of all the available evidence The contrast between the factors associated with lead poisoning in the local population and in the population working at the gold mining sites allows to propose new hypotheses and research questions to be proposed about potential sources of contamination, for example related to local geology.