Water shortage is a major concern of climate change that increases the use of reclaimed wastewater for irrigation. Active pharmaceuticals that are excreted from individuals, or from the industry, are frequently detected in reclaimed wastewater in minute concentrations. The anticonvulsant drug carbamazepine is such an environmentally ubiquitous compound. Besides irrigation water, carbamazepine is also detected in the entire agroecosystem, including irrigated soil and edible produce, and humans consuming such produce.
Carbamazepine risks the health of human fetuses when provided at therapeutic doses to pregnant mothers. Yet, it is unclear whether it can pursue similar effects at very low concentrations by environmental exposure. To explore this possibly, chick and mouse embryos have been chosen as two complementary model organisms. Since early chick embryos are similar to mammalians, yet they develop in eggs, toxic effects were directly analysed in a controlled system without maternal influences. On the other hand, as mouse embryos develop in utero, pregnant mice have been exposed to environmental levels of carbamazepine via their drinking water in order to examine whether it can approach the embryos and affect their development.
Using morphological, cellular, molecular and imaging strategies, we revealed that direct application of carbamazepine into chick embryos, or indirect exposure of mice embryos to carbamazepine through their mothers, compromises the embryonic morphology and growth in a dose- and stage- dependent manner. These results call for in-depth risk analysis to ensure that the environmental presence of pharmaceuticals is not causing irreversible ecological and public-health damages.