Environmental dissipation of fungicide triphenyltin acetate and its potential as a groundwater contaminant

The effects of various factors on fungicide triphenyltin acetate dissipatio n in selected soil types were studied; temperature is clearly the most impo rtant factor of these. Residues of this fungicide in Fangtzupo clay loam an d Lanyang loam incubated at 30 degreesC for 32 days (water content 100, 70, or 40% of field capacity) were 25% of the original amounts. In soil sample s incubated at 10, 30, or 40 degreesC with 100% field capacity water conten t, residues were 80, 26, and 5.5% for Fangtzupo soil, respectively, and 83, 26, and 7.0% for Lanyang soil, respectively. No significant difference in dissipation rate was found between sterilized and unsterilized soil, sugges ting that microbial degradation is not an important factor in this process. Rapid degradation rates were observed-half-lives of 8.3 to 19.4 days in Fa ngtzupo clay loam and 8.0 to 16.3 days in Lanyang loam at temperatures rang ing from 30 to 40 degreesC (soil water content of 100, 70, and 40% of field capacity). Significant increases in half-life (approximately 150 days) occ urred at lower temperatures (10 degreesC) in both soil types. The potential of triphenyltin acetate to contaminate groundwater was tested using the be havior assessment and groundwater pollution-potential models. Results indic ate that the leaching rate of the fungicide is very slow (1.0 cm day(-1)) u nder normal conditions. (C) 2001 Academic Press.