In this Special Issue of Science, four Reviews and a Policy Forum explore the intersections of science, health, and policy related to the air we breathe, tackling topics including how air pollution is monitored, what impacts it has on human health, how those impacts are felt most by populations with fewer resources, and what changes we can make to the built environment to secure clean air.
In one Review, Wei Huang and colleagues discuss the new air quality guidelines from the World Health Organization (WHO) and related challenges in improving air quality and health. Wealthy countries have robust air pollution data, they note, while Low- and Middle-Income Countries (LMICs) lack infrastructure for such monitoring. Advances in satellite technology and air pollution modeling can help bridge these data gaps, but economic disparities persist, hindering LMICs from mitigating air pollution risks effectively. Huang et al. stress the urgency of implementing air pollution intervention policies with measurable indicators and developing evidence-based risk communication strategies for timely protection of vulnerable populations. A second Review, by Joshua Apte and Chirag Manchanda, explores high-resolution urban air pollution mapping. Two of the most popular mapping methods, mobile monitoring and low-cost sensor networks, have complementary strengths in measuring urban air quality, say the authors. Mobile monitoring captures pollutants at fine spatial scales and informs control strategies, while sensor networks provide temporal resolution at multiple locations. In a third Review, Daniel Mork and colleagues examine the impact of government policies on disparities in air pollution exposure in the US. They highlight the burden of air pollution borne by marginalized communities, partly due to a legacy of racist and exclusionary policies. To better analyze these complex relationships, Mork emphasizes the need for data that links policies, environmental exposures, socioeconomic factors, and health outcomes. In a fourth Review, Lidia Morawska and colleagues discuss the importance of ventilation and indoor air quality, drawing lessons from the COVID-19 pandemic. They emphasize the need for clean indoor air to reduce infection risks and improve general well-being. The authors review seven key findings on improving indoor air quality through new monitoring and ventilation approaches. "In addition to negative health consequences and fear, the pandemic has revealed that there are major deficits in terms of clean air supply to indoor spaces," write the authors. "An improvement in this situation is urgently needed, not only to reduce the risk of infection by airborne pathogens but also for general well-being."
Lastly, in a Policy Forum, Alastair Lewis and colleagues show that despite increasing evidence and awareness about the harmful impacts of air pollution, many countries continue to have weak air quality policies. Lewis et al. argue that current legal requirements need to evolve to effectively achieve clean air. According to the authors, raising the ambition of air quality policies isn't just about meeting WHO standards but also fostering a flexible regulatory environment where science, law, and policy can accelerate progress toward global clean air goals.
