Grant: Project Grant

How male and female babies grow and respond to their prenatal environment is different. Vulnerability to environmental pollution appears to be sex-specific, however; the reason for the disproportionate impact of pollution remains unknown. With only a small percentage of plastics being recycled each year, plastic pollution is currently a global environmental problem. Larger macroplastics in both the ocean and on land are subjected to breakdown through natural weathering and mechanical degradation, leading to the formation of smaller particles termed microplastics (<5 mm) and nanoplastics (<1 um). Our team recently reported that the effects of maternal exposure to nanoplastics in utero and postnatally were dependent on fetal sex. For example, male fetuses exposed to nanoplastics showed an increase in pro-inflammatory markers in the brain while females showed a decrease in thyroid hormones. We also found nanoplastics exposure resulted in several changes to areas of the brain that were dependent on sex. Several of these brain areas show a sex chromosome effect in the mouse, motivating our use of a transgenic mouse model that uncouples sex chromosomes (XX vs XY) and sex hormones (ovaries vs testes). The goals of this proposal are to use cutting edge imaging technologies (ultrasound, computed tomography, magnetic resonance) and assessments of social and communicative behaviours to develop a complete understanding of how sex development contributes to vulnerability to plastics pollution. We will also test an environmental enrichment intervention to determine if it will alleviate some of the deficits in fetal development following plastics exposure. This work has the potential to significantly improve pregnancy outcomes and identify groups most adversely impact by some of our most prominent environmental pollutants.