Expert perspectives on exposure-response functions for urban health policy: Lessons from a UBDPolicy workshop

Policy-makers require robust, quantitative evidence in order to better align urban and transport planning practices with public health goals. Epidemiologically derived exposure-response functions can quantify the association between urban health determinants and human health outcomes. They are therefore a crucial input in quantitative health risk assessments, providing to policy-makers actionable evidence on how healthier, more sustainable cities may be achieved. The Urban Burden of Disease Policy (UBDPolicy) project convened a two-day workshop to discuss recent developments, ongoing challenges, and future directions for exposure-response functions and their application to quantitative health risk assessment. The workshop discussions centred around air pollution, transport noise, non-optimal temperature, greenspace and physical activity as primary pathways through which urban and transport planning impact human health. Based on this workshop, we provide an expert-guided perspective on how to enhance both our conceptual understanding of exposure-response functions and their practical application in urban health risk assessment. We also identify pathway-specific as well as cross-cutting (e.g., quantifying multiple exposures, need for population sub-group evidence) research needs relevant to environmental health more broadly. We propose several future research directions as an agenda for advancing urban environmental health.