Acute exposure to groundwater contaminants mixture of nitrate, atrazine and imidacloprid impacts growth kinetics of poultry cecal microbiomes and significantly decreases Caco-2 cell viability

Abstract

Atmospheric deposition, and agricultural runoff or erosion events have substantially contributed to groundwater pollution throughout the USA. This can become troublesome in states like Wisconsin where 68% of the population rely on groundwater for their drinking water source. As such, exposome research must account for the complexity and frequency of environmental exposures. This study aimed to elucidate chemical-biological interactions and adverse outcome pathways associated with an environmentally relevant mixture of agricultural chemicals detected in Wisconsin groundwater via in vitro and in silico methodologies. Using in vitro models, we determined that a ternary mixture of environmentally relevant concentrations of nitrate, atrazine and imidacloprid resulted in an overt decline in growth rate to the poultry cecal microbiome compared to each chemical singularly. Further, there was a decrease in Caco-2 cell viability in various two-chemical combinations. In silico methods analyzed contaminants detected in Wisconsin groundwater wells from across the state and prioritized two groundwater wells as potential for health concerns. Prioritized chemicals in these groundwater wells were linked to nine gene targets and several adverse outcome pathways. In all, the results demonstrated that there is chemical-biological interaction between these model organisms agricultural and chemical mixtures at real world exposure concentrations. HighlightsO_LIin silico methods were able to predict potential adverse effects for communities utilizing these groundwater wells C_LIO_LI8 out of 9 chemicals prioritized with in silico tools were herbicides C_LIO_LIA ternary mixture of nitrate, imidacloprid and atrazine resulted in a decline in growth rate for poultry cecal microbiome C_LIO_LICaco-2 cells significantly impacted by two-chemical combinations but not ternary mixtures C_LI