The distribution of blood concentrations of lead (Pb), cadmium (Cd), chromium (Cr) and manganese (Mn) in residents of the German Ruhr area and its potential association with occupational exposure in metal industry and/or other risk factors

In this population-based cohort we found evidence that working in metal industry was predictive for having elevated blood Pb and Mn concentrations. However, the 95th percentiles of all investigated metals were not significantly influenced by metal-related occupations. The present study is supportive for gender-specific reference values to limit occupational exposure to Mn and Pb. The strong influence of smoking on blood Cd hinders establishing reference values.