Estimating the national burden of mild intellectual disability in children exposed to dietary lead in China

The effects of lead as a dietary pollutant remain a global public health concern that needs urgent resolution. Children are highly susceptible to the adverse outcomes of lead pollution, as even low levels of lead may cause irreversible damage to intellectual development. Since several sources of lead exposure are present in the environment, it is necessary to identify the attributable burden of lead-related diseases arising from different exposure sources. In the present study, we used epidemiological data from studies around the nation to estimate the burden of mild intellectual disability (MID) attributed to lead exposure sources by using disability-adjusted life years (DALYs). To this end, a dose-response approach was used and a model comprising three components was established: exposure, dose-response, and DALYs module. In Chinese children aged 0-6 years, blood lead levels (BLLs) of 5.34 +/- 3.09 mu g/dL resulted in a MID incidence rate of 12.84 cases per 1000 children, with an estimated burden of disease (BoD) of 42.23 DALYs per 1000 children. Owing to dietary lead exposure, 36.64 healthy life years per 1000 children were lost, which was notably higher than the outcomes associated with exposure from other sources. This was consistent with the result that dietary exposure was the main contributor to children's lead exposure, accounting for 86.76%. According to the regional distribution based on the existing literature, the areas in China with higher BLLs were Heilongjiang, Shanxi, and Jiangxi. Our findings provided the information for lead risk management decisions and policies making.