Temporal and spatial trends in sediment contaminants associated with toxicity in California watersheds

Autor: Bryn M. Phillips, Ronald S. Tjeerdema, Katie Siegler, Jennifer P. Voorhees, Brian S. Anderson
Rok vydání: 2015
Předmět:
Zdroj: Environmental Pollution. 206:1-6
ISSN: 0269-7491
DOI: 10.1016/j.envpol.2015.06.028
Popis: California's Stream Pollution Trends program (SPoT) assesses long-term water quality trends, using 100 base-of-the-watershed sampling sites. Annual statewide sediment surveys from 2008 to 2012 identified consistent levels of statewide toxicity (19%), using the freshwater amphipod Hyalella azteca. Significant contaminant trends included a decrease in PCBs, stable concentrations of metals and PAHs, and a statewide increase in detections and concentrations of pyrethroid pesticides. The pyrethroid pesticide bifenthrin was detected in 69% of samples (n = 410). Detection of toxicity increased in a subset of samples tested at a more environmentally relevant test temperature (15 °C), and the magnitude of toxicity was much greater, indicating pyrethroid pesticides as a probable cause. Pyrethroid toxicity thresholds (LC50) were exceeded in 83% of samples with high toxicity. Principal components analysis related pyrethroids, metals and total organic carbon to urban land use.
Databáze: OpenAIRE