title: Toxicity of herbicides in highway runoff.
abstract: Previous field monitoring at two highway sites found highway-applied herbicides in storm water runoff at maximum concentrations ranging from 10 microg/L for glyphosate and diuron to as high as 200 microg/L for oryzalin. To determine whether these herbicides at these concentrations can cause any toxicity to aquatic organisms, a standard toxicity study was conducted. Storm water was collected along Highway 37, Sonoma County, California, USA, and the herbicides isoxaben, oryzalin, diuron, clopyralid, and glyphosate were spiked into the storm water at the highest concentrations observed during the five previous field-monitoring campaigns. Three different toxicity studies were conducted and the results showed the following: No significant reduction in reproduction or increase in mortality relative to the control for an 8-d Ceriodaphnia (water flea) toxicity test; no significant increase in mortality or decrease in biomass compared to the control during a 7-d Pimephales (fish) toxicity test; and, in a 96-h Selenastrum (algae) toxicity test, both the 10-microg/L diuron treatment and the combined 50-microg/L isoxaben plus 200-microg/L oryzalin treatment produced significant (p < 0.05) reductions in algal growth compared to the controls, although the 30-microg/L clopyralid or 10-microg/L glyphosate treatments did not exhibit any toxic effects.
authors.affiliation: Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Xinjiang
authors.initials: X
authors.lastname: Huang
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fong
authors.forename: Linda
authors.initials: L
authors.lastname: Deanovic
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Young
mesh_terms: D000818:Animals; D001549:Benzamides / Q000633:toxicity; D003621:Daphnia; D004136:Dinitrobenzenes / Q000633:toxicity; D004237:Diuron / Q000633:toxicity; D004553:Electric Conductivity; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes; D005998:Glycine / Q000031:analogs & derivatives / Q000633:toxicity; D006540:Herbicides / Q000737:chemistry / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000737:chemistry; D010848:Picolinic Acids / Q000633:toxicity; D011891:Rain; D013424:Sulfanilamides / Q000633:toxicity; D013696:Temperature; D018675:Toxicity Tests / Q000379:methods; D014867:Water; D014872:Water Movements; D014874:Water Pollutants, Chemical; D000097797:Glyphosate
chemical_list: D001549:Benzamides; D004136:Dinitrobenzenes; D004237:Diuron; D005998:Glycine; D006540:Herbicides; D010710:Phosphates; D010848:Picolinic Acids; D013424:Sulfanilamides; D014867:Water; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C011767:clopyralid; C012465:oryzalin; C057467:isoxaben