Predicting blood lead levels from current and past environmental data in Europe.

ABSTRACT

The present case study on lead in Europe illustrates the use of the Integrated Monitoring Framework Strategy to assess the health outcome of environmental pollution by evaluating the associations between lead in various environmental compartments (air, soil, dust, drinking water and diet) and lead concentrations in blood (B-Pb) for various age-related sub-populations. The case study was aimed to investigate whether environmental, exposure and biomonitoring data at general population level, covering all EU member states, could be integrated. Although blood lead has been monitored extensively in Europe, consistent datasets are not yet available. Data diverge with regard to objectives, regional scale, sampling years, gender, age groups and sample size. Significant correlations were found between B-Pb and the concentrations of Pb in air and diet. The significant decrease of the Pb in air over time from 0.31 µg/m(3) (P95 0.94; n=98) prior to 1990 to 0.045 µg/m(3) (P95 0.11; n=256) in 2007 (latest observations included) (Δ=-85%) corresponds to a decline in B-Pb by 48% and 57% in adult women and adult men, respectively. For pre-school children a more shallow decline in B-Pb of 16% was calculated over the same period. Similarly, the reduction in Pb-dietary intake from on average 68.7 µg/d (P95 161.6; n=19) in 1978 to 35.7 µg/d (P95 82.3; n=33) in the years post 2000 (Δ=-48%) is paralleled by a decline in B-Pb of 32, 33 and 19% in adult women, primary- and pre-school children, respectively. Insufficient data exist for other age groups to calculate statistically significant correlations. Although regression models have been derived to predict B-Pb for different sub-populations in Europe based on Pb concentrations in air and soil as well as dietary intake, it is concluded that the available data are insufficient to accurately predict actual and future simultaneous exposure to Pb from various environmental compartments, and as a consequence the health impact of Pb for various target populations at EU scale. At least due to data availability, air Pb remains the best predictor of B-Pb in the population. However, lead emission sources have largely been reduced and inhalation of lead in air is not causal to B-Pb levels. Therefore, there is a need of adequate data for Pb in soil and house dust, and in diet and drinking water as these are causal exposure sources with a longer Pb half-life than air. An extended and more harmonized surveillance system monitoring B-Pb, especially in children, is urgently required in order to identify, quantify and reduce still remaining sources of Pb exposure.