Lenwood Hall

By Lenwood W. Hall and Ronald D. Anderson

The objective of this study was to summarize and map bifenthrin sediment and water column monitoring data from California waterbodies (2001–2017) and determine where detected bifenthrin concentrations were reported and potential toxicity to aquatic biota may exist. Bifenthrin sediment data based on targeted sampling in depositional areas were available for more sites (982) than water column data (716 sites), and sediment sites had a lower percent of nondetected concentrations (36%) when compared with water values (77%). Comparison of results from three ambient sediment toxicity tests from sediment sites and six ambient toxicity tests from water sites showed no toxicity from 43% of the sediment sites and 65% of the water sites. A comparison of sediment measurements with acute toxicity data from two test species (Hyalella azteca and Chironomus tentans) showed no toxicity at 80–99.5% of the sites. Bifenthrin total water concentrations compared with a proposed 2015 chronic criterion of 0.01 ng/L showed no exceedances at 77% of the sites. Due to the conservative assumptions used in this analysis, bifenthrin ecological risk to aquatic life in California water bodies from both sediment exposure based on only targeted sampling from depositional areas and water column exposures based on using only total concentrations (not the bioavailable phase) is generally judged to be low statewide.

Part of the book: Spatial Analysis, Modelling and Planning