Work

The impact of lead exposure on idiopathic developmental intellectual disability: A shifting burden from children to older adults (1990–2021)

Year: 2025

Type: article

Abstract: BACKGROUND: Lead is the primary environmental risk factor for cognitive impairment. However, the lead exposure-related cognitive burden across the life cycle remains unclear. We estimate the burden of idiopathic developmental intellectual disability (IDID) attributable to lead exposure at global, regional, and national levels for all age groups from birth onward, with a focus on children and older adults. METHODS: The age-specific disability-adjusted life years (DALYs) and age-standardized DALYs rate (ASDR) were examined using the Global Burden of Disease 2021. Average annual percentage change was applied to assess ASDR temporal trends. Correlation analyses, health inequality analyses, and frontier analyses were used to estimate the impact of socio-demographic index (SDI) on DALYs. The Bayesian age-period-cohort model combined with Integrated Nested Laplace Approximations framework was applied to predict IDID changes. RESULTS: In 2021, there were 2.38 million DALYs of IDID attributable to lead exposure across the entire life cycle. The highest number of DALYs (0.77 million) and ASDR (38.20/100,000) were found in children aged 0-14 years, but these have declined since 1990, especially among males in high SDI region. However, the number of DALYs and ASDR among adults aged ≥ 70 years increased sharply, which increased from 4836.52 (95 % uncertainty interval [UI], 1622.03-9348.03) and 2.35 (95 % UI, 0.80-4.54) per 100,000 in 1990-78297.55 (95 % UI, 2708.52-189584.79) and 9.79 (95 % UI, 0.34-23.74) per 100,000 in 2035, respectively. This trend was most pronounced among females in low SDI region. Global inequalities in DALYs of IDID attributable to lead exposure among adults aged ≥ 70 years are widening. CONCLUSIONS: The lead exposure-related IDID burden has declined among children since 1990, demonstrating substantial global progress in childhood lead governance. However, the burden has increased substantially among those aged ≥ 70 years as aging intensifies, with particular concern for elderly females in low SDI region.

Source: Ecotoxicology and Environmental Safety

DOI: 10.1016/j.ecoenv.2025.119176