Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review.
OBJECTIVE
To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity.


METHODS
A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO).


RESULTS
Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value.


CONCLUSIONS
There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.
Risk Sciences and Public Policy Institute, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, United States of America (USA).
Mary C
MC
Sheehan
Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA .
Thomas A
TA
Burke
Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA .
Ana
A
Navas-Acien
Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA .
Patrick N
PN
Breysse
Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA .
John
J
McGready
Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA .
Mary A
MA
Fox
D000328:Adult; D015415:Biomarkers / Q000097:blood; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D014943:Global Health; D006197:Hair / Q000737:chemistry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008767:Methylmercury Compounds / Q000009:adverse effects / Q000032:analysis*; D020258:Neurotoxicity Syndromes / Q000209:etiology; D011247:Pregnancy; D045483:Rivers; D017747:Seafood / Q000009:adverse effects / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000009:adverse effects / Q000032:analysis*; D055815:Young Adult
D015415:Biomarkers; D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical