Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

from streams in watersheds with agricultural, urban, and mixed land use (Gilliom,
Barbash et al. 2006).
About 40 pesticide compounds accounted for most detections in water, fish, or bed
sediment. Twenty-four pesticides and one degradate were each detected in more than
10% of streams in agricultural, urban, or mixed land use settings. These 25 pesticide
compounds include 11 herbicides used most heavily in agriculture during the study
period (plus the atrazine degradate, deethylatrazine); 7 herbicides used extensively for
non-agricultural purposes; and 6 insecticides used in both agricultural and urban settings.
Three of those insecticides were chlorpyrifos, diazinon, and malathion. Thirteen
organochlorine pesticide compounds, including historically used parent pesticides and
their degradates and by-products, were each found in more than 10% of fish or bedsediment
samples from streams draining watersheds with either agricultural, urban, or
mixed land use (Gilliom, Barbash et al. 2006).
Additionally, more frequent detections and higher concentrations of insecticides occur in
sampled urban streams (Gilliom, Barbash et al. 2006). Diazinon, chlorpyrifos, carbaryl,
and malathion nationally ranked 2 nd , 4 th , 8 th , and 15 th among pesticides in frequencies of
outdoor applications for home- and garden use in 1992 (Whitmore, Kelly et al. 1992).
These same insecticides accounted for the most insecticide detections in urban streams.
Diazinon and carbaryl were the most frequently detected and were found at frequencies
and levels comparable to those for the common herbicides. Historically used insecticides
were also found most frequently in fish and bed sediment from urban streams. The
highest detection frequencies were for chlordane compounds, dichloro-diphenyltrichloroethane
(DDT) compounds, and dieldrin. Urban streams also had the highest
concentrations of total chlordane and dieldrin in both sediment and fish tissue. Chlordane
and aldrin were widely used for termite control until the mid-to-late 1980s. Their
agricultural uses were restricted during the 1970s.
Chlorpyrifos and diazinon were commonly used in agricultural and urban areas from
1992-2001 and prior to the sampling period. About 13 million lbs of chlorpyrifos and
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