Input, flux, and persistence of six select pesticides in San Francisco Bay

International Journal of Environmental Analytical Chemistry
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Abstract

Temporal patterns of pesticide inputs to San Francisco Bay were identified and correlated with timing of application and transport mechanism. Fluxes were calculated from measured concentrations and estimated flow. Persistence of the pesticides under typical riverine or estuarine conditions were estimated from laboratory experiments. Simazine was detected most frequently and had the highest flux into the Bay, which could be explained by its continuous use and long half-life. In comparison, diazinon was detected at lower concentrations and had a lower flux which corresponded to its lower use and shorter half-life. The order-of-magnitude lower fluxes of carbofuran and methidathion corresponded to their lower use and expected hydrolysis. Molinate was detected at the highest concentration but its flux was lower than expected, considering its very high use and persistence in the laboratory experiments. Additional loss of molinate is likely to occur from volatilization and photodegradation on the rice fields. Although thiobencarb had the second highest use, it had the lowest flux of the six pesticides, which can be attributed to its loss via hydrolysis, photodegradation, volatilization, and sorption to sediments. Fluxes into San Francisco Bay were equal to or greater than those reported for other estuaries, except for the Gulf of Mexico.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Input, flux, and persistence of six select pesticides in San Francisco Bay
Series title International Journal of Environmental Analytical Chemistry
DOI 10.1080/03067310701619014
Volume 87
Issue 13-14
Year Published 2007
Language English
Contributing office(s) California Water Science Center, Toxic Substances Hydrology Program
Description 15 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title International Journal of Environmental Analytical Chemistry
First page 897
Last page 911
Country United States
State California
City San Francisco
Other Geospatial San Francisco Bay