Combining polar organic chemical integrative samplers (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms

Polar organic chemical integrative samplers (POCIS) are valuable tools in passive sampling methods for monitoring polar organic pesticides in freshwaters. Pesticides extracted from the environment using such methods can be used to toxicity tests. This study evaluated the acute effects of POCIS extracts on natural phototrophic biofilm communities. Our results demonstrate an effect of POCIS pesticide mixtures on chlorophyll a fluorescence, photosynthetic efficiency and community structure. Nevertheless, the range of biofilm responses differs according to origin of the biofilms tested, revealing spatial variations in the sensitivity of natural communities in the studied stream. Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment.

Research highlights
► Polar organic chemical integrative samplers (POCIS) were used for monitoring polar organic pesticides in a contaminated river.
► The acute effects of POCIS extracts were tested on natural phototrophic biofilm communities.
► POCIS pesticide mixtures affected chlorophyll a fluorescence, photosynthetic efficiency and community structure.
► Biofilm responses differed according to origin of the biofilms tested, revealing variations in the sensitivity of natural communities.
► Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment.