Human exposure to pollutants is normally monitored by measurement of potentially harmful chemicals in the air. But in May 26 Lancet, Jan Staessen and colleagues from the Environment and Health Study Group, Studiecoördinatiecentrum, Leuven, Belgium suggest that biomarkers are a better way to detect environmental exposure to pollutants because they can measure possible biological effects before overt disease develops.

Staessen et al recruited 200 17-year-old adolescents from a rural control area and from two suburbs polluted by a lead smelter and two waste incinerators and measured sexual maturation and a set of biomarkers in blood and urine samples. Sexual maturation was delayed in children living near the waste incinerators and biomarkers of renal dysfunction (cystatin-C and β₂ microglobulin) were positively correlated with blood lead levels. Biomarkers of DNA damage (8-hydroxy-deoxyguanosine) were positively correlated with urinary metabolites of polycyclic aromatic hydrocarbons and volatile organic compounds (Lancet, 2001,...