Headlines - Setting New Guidelines for Managing Lead Exposure

Lead is subject to a specific scientific approach: first, by recognizing that its toxicity is threshold-free (any dose has an effect on health)—a concept generally reserved for carcinogenic and mutagenic effects—and second, by defining an internal toxicological reference value (TRV) (blood lead level) rather than an external dose absorbed by the body.This approach leads to a policy of reducing lead exposure to the lowest possible level at the time in question. Thus, the High Council for Public Health (HCSP) has set two targets for 2017:

• a reduced average (geometric) blood lead level for the French population to 12 μg/L

• 98% of blood lead levels below 40 μg/L (instead of 50 μg/L observed in 2008–2009).

It proposes that screening efforts be prioritized for two populations: children and women who are pregnant or planning to become pregnant within the next 6 months. It specifies two blood lead levels, to be updated every 10 years, to determine the course of action:

• a rapid intervention level of 50 μg/L, replacing the 100 μg/L threshold in effect until now

• a vigilance level of 25 μg/L.

It proposes contamination levels in exposure environments that should trigger screening for childhood lead poisoning: 300 mg(Pb)/kg(Soil) in soil, 70 μg/m² in household dust, and 20 μg/L in water. These values correspond to an expected blood lead level of 50 μg/L or higher in approximately 5% of children. When the expected blood lead level exceeds the 25 μg/L vigilance threshold in at least 5% of children frequenting public spaces (corresponding to 100 ppm in soil), it proposes conducting a risk assessment based on the European Food Safety Authority’s internal TRL of 12 μg/L (blood lead level corresponding to a one-point decrease in IQ in young children) to determine management measures. Concentrations in household dust between 25 μg/m² and 70 μg/m² should lead to hygiene and dietary recommendations. This opinion, which has been anticipated since the ANSES report on lead toxicity (2), will change policy regarding the fight against lead poisoning.