Elevated temperature impact on toxicological effects of pesticides, antimicrobials and their mixtures to duckweed Lemna minor

Anthropogenic chemical pollution has the potential to pose one of the largest environmental threats to humanity, but global understanding of the issue remains fragmented. Water pollution becomes alarming since anthropogenic activity results in the contamination of water bodies with various contaminants, which in turn reduces ecosystem functioning and poses human health risks. Pesticides and pharmaceutical and personal care products (PPCPs) stand out for their widespread occurrence and highly diverse biological effects and are considered as emerging contaminants (ECs). Despite frequent detection in surface waters, the mixture effects of these emerging contaminants on the aquatic organisms remain unclear. In addition, there is a need to understand how changing environmental factors impact on joint effects of emerging contaminants as they often occur in the environment. To address the knowledge gap of the effects of emerging contaminants and their mixtures in a changing climate, we aimed to test the elevated temperature effect on mixed exposures of frequently detected pesticide Terbuthylazine (TBA) and antimicrobial Triclosan (TCS) to duckweed Lemna minor. Duckweeds L.minor were exposed to TBA and TCS individually and in mixtures (TCS+TBA) under different temperature regimes (23˚C and 27˚C). L.minor morphological indicators (frond area), biochemical indicators as well as oxidative stress damage were measured. Results showed elevated temperature exacerbated negative effects of terbuthylazine, triclosan and their mixture.