LAUSR

ABSTRACT We describe analyses to estimate the global burden of disease associated with methylmercury (MeHg). An intelligence quotient < 70, indicating intellectual disability (ID), was selected as the critical disease, maternal hair Hg concentration during pregnancy selected as the critical exposure biomarker, and a dose‐effect relationship of an 0.18 point IQ reduction per &mgr;g/g increase in maternal hair Hg was assumed, based on a meta‐analysis. A systematic review was conducted to obtain country‐specific data on the distribution of maternal hair Hg concentrations. The country‐specific incidence of MeHg‐associated ID was calculated, and a random effects model was used to impute the incidence for countries for which no exposure data could be found. The global burden of MeHg‐associated ID was quantified in terms of Disability‐Adjusted Life Years (DALYs) using the World Health Organization (WHO) Global Health Estimates methodology, and presented by 14 subregions. In 2015, the global total for MeHg‐associated cases of ID was 226,655; 210,074 of these cases (93%) were mild cases of ID. The highest rate of ID (6 cases per 100,000 population) was found in the Americas D subregion. The global DALY estimate was 1,963,869. The Western Pacific B subregion contributed the most to this total (696,417), although the Americas D subregion had the greatest rate (54 DALYs per 100,000 population). The burden of disease associated with MeHg is therefore highly subregion‐dependent even in areas that are geographically related. The priority given to reducing this burden can therefore be expected to vary considerably by subregion depending on other health needs. HighlightsDiet is the primary pathway for exposure to methylmercury (MeHg).Prenatal exposure to MeHg causes impaired cognitive development.Globally, MeHg causes nearly 250,000 cases of intellectual disability per year.MeHg associated intellectual disability represents nearly 2 million DALYs globally.The Western Pacific B subregion accounts for more than one third of the DALY.