Human developmental neurotoxicity of methylmercury: impact of variables and risk modifiers.
Methylmercury (MeHg) is a widespread environmental and food toxicant which has long been known to affect neurodevelopment in both humans and experimental animals. Risk assessment for MeHg is mainly based on human data coming from the massive episodes of poisoning in Japan and Iraq, as well as from large scale epidemiological studies concerning childhood development and neurotoxicity in relation to in utero exposure in various fish eating communities around the world. Despite the extensive literature and research, the threshold dose for MeHg neurotoxic effects is still unclear, in particular when it comes to subtle effects on neurobehaviour. In this article clinical and epidemiological findings concerning the neurodevelopmental toxicity of MeHg are reviewed. Much attention is focussed on the potential impact of factors, such as diet and nutrition, gender, pattern of exposure and co-exposure to other neurotoxic pollutants, which may modulate MeHg toxic effects. These factors, together with the notion that some symptoms may ensue or exacerbate with aging, contribute to the difficulties in the definition of safe levels for developmental exposure.
Castoldi
Anna F
AF
Toxicology Division, University of Pavia, Via Palestro 26, 27100 Pavia, Italy. anna.castoldi@fsm.it
Johansson
Carolina
C
Onishchenko
Natalia
N
Coccini
Teresa
T
Roda
Elisa
E
Vahter
Marie
M
Ceccatelli
Sandra
S
Manzo
Luigi
L
D000818:Animals; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D020262:Mercury Poisoning, Nervous System / Q000453:epidemiology / Q000503:physiopathology*; D008767:Methylmercury Compounds / Q000506:poisoning*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D018570:Risk Assessment; D012307:Risk Factors
D004785:Environmental Pollutants; D008767:Methylmercury Compounds