Delayed neurotoxicity in monkeys exposed developmentally to methylmercury

Journal Article · · Neurotoxicology (Park Forest South, Illinois); (USA)

OSTI ID:6748052

Rice, D C ^[1]

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1. Bureau of Chemical Safety, Health and Welfare Canada, Ottawa, Ontario (Canada)

Five monkeys (Macaca fascicularis) were dosed from birth to 6.5-7.0 years of age with 50 micrograms/kg/day of mercury as methylmercuric chloride. Blood mercury levels were 0.6-0.9 ppm throughout most of the period of dosing. Blood mercury levels declined rapidly after cessation of dosing to levels below 0.01 ppm. When these monkeys were approximately 13 years old, some individuals displayed clumsiness during routine exercise. This observation was examined by cage-side observation and independent clinical neurological assessment by two staff veterinarians. Fine motor performance was assessed by timing retrieval of raisins from recessed grids. Treated monkeys took longer to retrieve raisins than age-matched controls. Clinical neurological assessment revealed apparent insensitivity to touch and pin-prick in mercury-exposed monkeys, and exposed monkeys were clumsier and slower in the exercise cage. These results indicate that overt signs of toxicity can be manifested long after exposure to methylmercury has ceased.

• OSTI ID: 6748052
• Journal Information: Neurotoxicology (Park Forest South, Illinois); (USA), Journal Name: Neurotoxicology (Park Forest South, Illinois); (USA) Vol. 10:4; ISSN 0161-813X; ISSN NRTXD
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BEHAVIOR
ENVIRONMENTAL EXPOSURE
MAMMALS
MERCURY COMPOUNDS
METHYLMERCURY
MONKEYS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
PRIMATES
SENSITIVITY
TOXICITY
VERTEBRATES