Effect-based nationwide surface water quality assessment to identify ecotoxicological risks.

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Water Quality Assessment

Background:

• Standard chemical monitoring often misses toxic effects in surface waters.
• There is a critical need for effect-based monitoring strategies using bioassays to detect environmental risks.

Purpose of the Study:

• To conduct a nationwide, effect-based water quality assessment of surface waters.
• To identify and rank ecotoxicological risks across various surface water bodies.

Main Methods:

• Deployed passive samplers (silicone rubber, polar organic chemical integrative samplers) and conducted in-situ daphnia tests at 45 locations.
• Extracted accumulated compounds from samplers and exposed them to a battery of in vivo and in vitro bioassays.
• Compared bioassay responses to effect-based trigger values to identify risks.

Main Results:

• Bioassay responses were detected in all tests, with trigger values exceeded in 9 out of 21 assays.
• Effect-based assessment successfully ranked locations by ecotoxicological risk.
• No correlation was found between land use and identified ecotoxicological risks.

Conclusions:

• Effect-based water quality assessment effectively prioritizes sites based on ecotoxicological risks.
• This method identifies hazardous compounds not typically listed as priority substances.
• It offers a cost-effective alternative to extensive chemical analysis at low-risk sites.