title: Methylmercury contamination of laboratory animal diets.
abstract: In the midst of research focusing on the neurodevelopmental effects of mercury vapor in rats, we detected significant levels of mercury (30-60 ng/g) in the blood of nonexposed control subjects. We determined that the dominant form of the mercury was organic and that the standard laboratory chow we used in our vivarium was the source of the contamination. The dietary levels were deemed of potential biologic significance, even though they might have fallen below the limits of measurement specified by the supplier. All investigators employing animals in research must assess such potential contamination because dietary agents may alter a) conclusions based on intentionally administered doses, b) outcomes by interacting with other agents that are the primary focus of the research, and c) outcomes of research unrelated to the toxic effects of experimentally administered agents.
authors.affiliation: Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA. bernard_weiss@urmc.rochester.edu
authors.forename: Bernard
authors.initials: B
authors.lastname: Weiss
authors.forename: Sander
authors.initials: S
authors.lastname: Stern
authors.forename: Elsa
authors.initials: E
authors.lastname: Cernichiari
authors.forename: Robert
authors.initials: R
authors.lastname: Gelein
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000831:Animals, Newborn; D015986:Confounding Factors, Epidemiologic; D035061:Control Groups; D004032:Diet; D004785:Environmental Pollutants / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood; D005260:Female; D005396:Fish Products; D005506:Food Contamination; D008297:Male; D008767:Methylmercury Compounds / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D004785:Environmental Pollutants; D008767:Methylmercury Compounds