Biomonitoring Study among People Living near Abandoned Metal Mines in Southern France

After more than 100 years of past industrial mining activity in the Gard department (Southern France), significant pollution of soils with lead, arsenic and cadmium has been observed. To better understand the exposure of neighboring populations, Santé publique France (the French Public Health Agency) conducted a population biomonitoring study. The objectives were to measure the biological exposure levels, to identify the key factors of exposure and to propose appropriate measures to reduce human exposure. The study took place in a sensitive context with significant media pressure.A cross-sectional study was conducted among the general population and participation was on a voluntary basis. Different data was collected: biological samples (blood for lead and urines for arsenic and cadmium), questionnaire on eating habits and lifestyles, environmental samples in soils and house dust. The levels of lead, arsenic and cadmium were quantified and a generalized linear model was used to determine the risk factors. Santé publique France relied on a multidisciplinary external advisor committee to translate the results into appropriate operational measures. The committee completed the process by interviewing various stakeholders (elected officials, local authorities, associations and residents' representatives).The participation rate was 23.5% (651/2774). Nearly a quarter had an over-exposure of arsenic and 13% of cadmium. Blood lead levels were not different from those observed in the French population. In addition to the expected key factors (age, sex, alcohol and tobacco consumption), biological levels were influenced by pollutant concentrations in soils and the consumption of certain local products. Pollutants in dust were not correlated with biological levels. However, the frequency of home cleaning was associated with a decrease in biological levels (lead, arsenic). Collective and individual proposals for exposure reduction were formulated.