Car dependency and US environmental health research: a long drive from motonormativity to planetary health

The US National Institute of Environmental Health Sciences (NIEHS) has advanced understanding of traffic-related air pollution and its health impacts. Yet the research funder has not recognised car dependency itself as a structural environmental exposure that shapes population health through multiple environmental pathways beyond air quality, including traffic injuries, noise, heat, and greenhouse gas emissions. The US public health research enterprise, and the NIEHS in particular, should encourage environmental health researchers to apply their expertise to car dependency, a societal status quo with far-reaching implications for environmental justice, population health, and planetary health. Planetary health provides a useful framework for this reorientation, urging researchers to study population health and climate-related consequences together rather than in isolation. Doing so will require the NIEHS to adopt a broader conception of health-related outcomes than it has traditionally applied, including population-level health effects-which might differ in direction from individual-level counterparts-and indicators of climate change mitigation and adaptation. Given its methodological breadth and cross-disciplinary tradition, the environmental health research community is well-positioned to lead this effort.