Triazine herbcides: Ecological risk assessment in North American surface waters

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:369978

Solomon, K R ^[1]

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1. Univ. of Guelph (Canada)

The triazine herbicides are some of the most widely used pesticides in North America. Some are found in surface waters in North America and risks to aquatic ecosystems are a possible concern. This paper presents the results of a comprehensive aquatic ecological risk assessment conducted using probabilistic risk assessment techniques. The assessment of exposure data concentrated on Midwestern us watersheds, the area of greatest triazine use in North America and showed that concentrations of some triazines rarely exceeded 20 {mu}g/L in rivers, streams, and reservoirs. The effects assessment showed that phytoplankton were the most sensitive organisms to triazines followed, in decreasing order of sensitivity, by macrophytes, benthic invertebrates, zooplankton and fish. Distribution analysis of sensitivity to atrazine showed 10th percentile of 37 {mu}g/L for LC50s in all organisms and 5.4 {mu}g/L for LC50s in algae and plants. Simazine showed 10th percentiles of 188 {mu}g/L for LC50s in all organisms and 27 {mu}g/L for LC50s in aquatic plants. Comparisons of the exposure and effects distributions showed low probabilities of exceeding the 10th percentiles of the sensitivity distributions. These results will be discussed in relation to the mechanism of action of these substances and other stressors in the environment.

• OSTI ID: 369978
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
55 BIOLOGY AND MEDICINE
BASIC STUDIES
ALGAE
AQUATIC ECOSYSTEMS
ENVIRONMENTAL EFFECTS
HERBICIDES
INVERTEBRATES
ORGANIC CHLORINE COMPOUNDS
PESTICIDES
PHYTOPLANKTON
PLANT GROWTH
RISK ASSESSMENT
RIVERS
STREAMS
SURFACE WATERS
TOXICITY
TRIAZINES
WATER POLLUTION
WATERSHEDS
ZOOPLANKTON