Hormesis Associated with a Low Dose of Methylmercury Injected into Mallard Eggs

• Published in: Archives of environmental contamination and toxicology 2012, Vol.62 (1), p.141-144
• Main Authors: Heinz, Gary H., Hoffman, David J., Klimstra, Jon D., Stebbins, Katherine R., Kondrad, Shannon L., Erwin, Carol A.
• Format: Article
• Language: English
• Subjects: Animal reproduction; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Birds; Chloride; Chlorides; Contamination; Control equipment; Dose-Response Relationship, Drug; Ducks - physiology; Earth and Environmental Science; Ecotoxicology; Ecotoxicology, biological effects of pollution; Eggs; Embryos; Environment; Environmental Chemistry; Environmental Health; Environmental Pollutants - administration & dosage; Environmental Pollutants - toxicity; Environmental testing; Females; Food chains; Fundamental and applied biological sciences. Psychology; General aspects; Hatching; Hormesis; Indicator organisms; Low concentrations; Mercury; Methylmercury; Methylmercury Compounds - administration & dosage; Methylmercury Compounds - toxicity; Monitoring/Environmental Analysis; No-Observed-Adverse-Effect Level; Ovum - drug effects; Pollution; Random Allocation; Soil Science & Conservation; Studies; Success; Toxicity
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-011-9680-0

We injected mallard ( Anas platyrhynchos ) eggs with methylmercury chloride at doses of 0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 μg mercury/g egg contents on a wet-weight basis. A case of hormesis seemed to occur because hatching success of eggs injected with 0.05 μg/g mercury (the lowest dose) was significantly greater (93.3%) than that of controls (72.6%), whereas hatching success decreased at progressively greater doses of mercury. Our finding of hormesis when a low dose of methylmercury was injected into eggs agrees with a similar observation in a study in which a group of female mallards was fed a low dietary concentration of methylmercury and hatching of their eggs was significantly better than that of controls. If methylmercury has a hormetic effect at low concentrations in avian eggs, these low concentrations may be important in a regulatory sense in that they may represent a no-observed adverse effect level (NOAEL).