An experimental ecotoxicological study and its application to the behavioural study of organic mercury (CH 3HgCl) in the environment: influence of temperature and pH

• Published in: Chemosphere (Oxford) Vol. 49; no. 10; pp. 1399 - 1405
• Main Authors: Jahanbakht, S, Livardjani, F, Jaeger, A
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2002; Elsevier
• Subjects: Agnatha. Pisces; Air; Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Biological and medical sciences; Biological and physicochemical phenomena; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Engineering and environment geology. Geothermics; Exact sciences and technology; Fish; Fishes; Food Chain; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Hydrogen-Ion Concentration; Mercury - analysis; Mercury - chemistry; Methylmercury; Methylmercury Compounds; Models, Theoretical; Natural water pollution; Pollution; Pollution, environment geology; Sediment; Temperature; Tissue Distribution; Water; Water Pollutants - analysis; Water treatment and pollution; Water; pH; Fish; Sediment; Air; Methylmercury; Biodegradation; Sediment water interaction; Ecotoxicology; Pollutant behavior; Toxicity; Temperature effect; Air water interface; Indicator; Aquatic environment; Vertebrata; Medium effect; Mineralization; Pisces; Volatilization; Mercury Organic compounds; Water pollution; Gas exchange; Biological accumulation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(02)00506-4

Laboratory experiments were carried out to study the influence of temperature (24, 28 and 30 °C) and pH (1–10) on organic mercury (CH 3HgCl) transfer and accumulation in an experimental ecotoxicological model. We followed the evolution of CH 3HgCl in a basic model (water+air) by varying temperature and pH. In a second step, we completed the model by adding sediment and fish. We added CH 3HgCl to water at the beginning of each experiment which was repeated at least three times. Results demonstrated that mercury was released from methylmercury into the air regardless of water pH and its concentration in the air increased with increasing pH. By contrast, in presence of sediment, almost all the mercury was fixed onto the sediment and no mercury was traced in air or in water. Interestingly, in the presence of sediment, the life span of fish under methylmercury exposure lasted longer despite their higher mercury body level content at their death. These results indicate that water is a bad exposure indicator for aquatic pollution. In case of chronic pollution, sediments, fish and aquatic plants are more appropriate indicators.