Fate and ecotoxicity of the new antifouling compound Irgarol 1051 in the aquatic environment

• Published in: Water research (Oxford) Vol. 34; no. 14; pp. 3523 - 3530
• Main Authors: Okamura, H, Aoyama, I, Liu, D, Maguire, R.J, Pacepavicius, G.J, Lau, Y.L
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2000; Elsevier Science
• Subjects: Animal, plant and microbial ecology; antifouling compound; Applied ecology; Applied sciences; Biological and medical sciences; Biological and physicochemical phenomena; Crustacea; Degradation; degradation product; Earth sciences; Earth, ocean, space; Ecosystems; ecotoxicity; Ecotoxicology, biological effects of pollution; Engineering and environment geology. Geothermics; Exact sciences and technology; fate; Fundamental and applied biological sciences. Psychology; herbicide; Herbicides; Irgarol 1051; Marine and brackish environment; Natural water pollution; Pollution; Pollution, environment geology; Seto Inland Sea Japan; Toxicity; transformation; Water treatment and pollution; Asia; Japan; degradation product; fate; M1; Irgarol 1051; herbicide; Seto Inland Sea Japan; transformation; antifouling compound; ecotoxicity; Biodegradation; Marine environment; Pollutant behavior; Toxicity; Pesticides; Antifouling paint; Water pollution; Antioxidant; Degradation product; Herbicide; Organic compounds; Seawater
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(00)00095-6

Residue analyses and ecotoxicity assessment were conducted on the new antifouling compound Irgarol 1051 (2-methylthio-4-
tert-butylamino-6-cyclopropylamino-
s-triazine) and its degradation product M1 (2-methylthio-4-
tert-butylamino-6-amino-
s-triazine) in order to delineate the environmental fate and impact of Irgarol 1051 on the aquatic ecosystem. For the first time, the Irgarol degradation product (M1) was positively identified in environmental samples. During the 1998 Irgarol survey, concentrations of M1 (up to 1870 ng/l) were generally higher than those of Irgarol in the coastal waters of the Seto Inland Sea in Japan, suggesting a greater environmental persistence for M1 than for the parent compound Irgarol 1051 in the aquatic ecosystem. Ecotoxicity testing revealed that Irgarol 1051 and M1 were moderately toxic to a marine bacterium and the four crustaceans tested, but were highly toxic to some algae and higher plants. In the root elongation inhibition bioassay, M1 showed a phytotoxicity at least 10 times greater than that of Irgarol and six other triazine herbicides (terbutryn, terbutylazine, terbumeton, simetryn, atrazine and simazine). These results strongly suggest that both Irgarol 1051 and its persistent degradation product M1 may potentially affect and/or damage the primary producer community in aquatic ecosystems. To safeguard the aquatic ecosystem from the damaging impact of micro contaminants, it is recommended that, besides monitoring for the target parent compound, major degradation products should also be included in environmental surveys. Otherwise, there is a risk of underestimating the ultimate impact of a particular toxicant on the environment.