Long‐term dietary exposure to lead in young children living in different European countries
EFSA Supporting Publications
Long-term dietary exposure to lead in children aged 1 up to 14 years living in 12 different European countries was estimated using daily food consumption patterns and mean lead concentrations in various food commodities. Food consumption data were all categorised according to a harmonised system to allow for linkage with lead concentration data in a standardised way. Two different models were used for the calculations: the beta-binomialnormal (BBN) model and the observed individual means (OIM)
... vidual means (OIM) model. For both models the lower bound exposure ranged from 0.4 to 1.7 µg/kg bw per day for median consumers. For 99th percentile consumers however the exposure differed between the two models with a lower bound exposure ranging from 0.7 to 4.1 µg/kg bw per day with the BBN model and 0.9 to 7.9 µg/kg bw per day with the OIM model. Upper bound exposures were on average a factor 1.8 higher for both models. Exposures on a body weight basis were higher in younger compared to older children. To assess the long-term exposure to lead in European children, a model, such as the BBN model, that corrects for the within-person variation is the preferred method to be used. The OIM method results in an overestimation of the percentage of the population exceeding a provisional tolerable weekly intake which is of relevance for risk management decisions. 1 EFSA-Q-2009-00837. Accepted for Publication on 5 May 2010. 2 Current affiliation is "National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands". Another important advantage of the BBN model is that it can model covariates, such as age. This is important when assessing the exposure in children, because it is known that the exposure decreases with age, as shown for lead in this report. Ignoring the effect of age on the exposure when present may result in imprecise estimates of exposure and thus to wrong conclusions. However, models that correct for the within-person variation can only be used when the condition of normality of the transformed positive daily exposure distribution is met. This should always be checked when using these models to assess the long-term exposure to food chemicals. Methodological issues of an exposure study linking different national food consumption databases with one "European" lead concentration database were addressed in the discussion.