Comparative effect of oral ingestion of methyl mercury on chicks and rats
Two experiments with day-old chicks and one experiment with weanling rats were conducted to determine: (1) whether low levels of mercury found in some feedstuffs would result in hazardous accumulations of mercury in their tissues, and (2) the effects of feeding various dietary levels of methyl mercury to chicks and rats. Data show that feeding animal protein (fish meal) containing higher than normal levels of mercury did not result in the concentration of mercury in poultry tissues that exceeded FDA guideline levels. In fact, breast muscle concentration of mercury averaged only 0.1 p.p.m. even when the fish meal made up 17% of the diet. Significant amounts of mercury were deposited in the feathers of the test birds. At 16.9 p.p.m. dietary mercury as methyl mercuric chloride, all chicks succumbed to mercury toxicity by 17 days of age. Total mercury dose was 28.3 mg./kg. body weight. At this level of dietary mercury, brain, liver, and breast tissue of chicks at death contained 19, 47, and 15 p.p.m., respectively. Within limits, tissue concentrations of mercury were proportional to dietary levels. During a 21-day depletion period, chicks excreted an average of 0.66% of the total body burden of mercury per day. Thus biological half-lives can be calculated to average about 97 days for all dietary levels. Rats fed diets containing 16 p.p.m. mercury did not show outward signs of toxicity until the 6th week of treatment. Liver and brain mercury levels in rats fed 16 p.p.m. mercury averaged 26 and 12 p.p.m., respectively. Male rats generally had higher tissue levels of mercury than females. In general, rats tolerated the highest level of dietary methyl mercury for a longer period of time than chicks which consumed three times as much mercury and deposited less mercury in their tissues.
- Research Organization:
- National Oceanic and Atmospheric Administration, College Park, MD
- OSTI ID:
- 5482904
- Journal Information:
- Poult. Sci.; (United States), Journal Name: Poult. Sci.; (United States) Vol. 52:2; ISSN POSCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL HALF-LIFE
BIRDS
BODY
BODY BURDEN
BRAIN
CENTRAL NERVOUS SYSTEM
CHICKENS
COMPARATIVE EVALUATIONS
DIGESTIVE SYSTEM
DISTRIBUTION
DOSE-RESPONSE RELATIONSHIPS
FEATHERS
FOWL
GLANDS
INGESTION
INTAKE
LIVER
MAMMALS
MAXIMUM PERMISSIBLE EXPOSURE
MERCURY COMPOUNDS
METHYLMERCURY
MUSCLES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
ORGANS
RATS
RODENTS
SAFETY STANDARDS
SEX DEPENDENCE
STANDARDS
TISSUE DISTRIBUTION
TOXICITY
VERTEBRATES