Air quality regimes struggle to catch up as science evolves and policy ambitions are too limited, researchers say

A lack of coordination between legal, policy and scientific thinking risks “wasting an opportunity” to improve air quality, concludes new environmental law research co-led by a UCL academic.

In their Science In their paper, ‘Harnessing science, policy and law to secure clean air’, Professors Eloise Scotford (UCL School of Law), Alastair Lewis (University of York) and Delphine Misonne (UCLouvain Saint-Louis, Brussels) review recent research and highlight the significant risks to global air quality.

Despite significant advances in air quality legislation and policy in some parts of the world in recent decades, scientific evidence indicates that air pollution at ever lower concentrations is causing health harm, making clean air increasingly urgent but increasingly difficult to achieve.

Research shows that for many national regulatory regimes, raising the ambition of air quality policies and outcomes is not simply a matter of raising legal standards to the level of the World Health Organization’s air quality guidelines.

Aware of this complexity, researchers stress the need to move from political ambition to policy implementation, through the agile integration of scientific, political and legal knowledge.

“Once-in-a-generation transitions, if not accompanied by consideration of air quality impacts and coordinated regulatory updates, could lead to wasted opportunities,” they say in their paper.

The researchers highlight several areas where coordinated action is needed: setting standards; choosing which pollutants to legislate on; setting targets to reduce pollution and keep it within certain levels; urban planning, including consideration of the impact of air pollution on disadvantaged communities and ethnic minority groups; and coordinating policymaking at local, national and supranational levels.

One of those problems—deciding which pollutants to regulate—is that relatively few pollutants have been the subject of clean air laws over the past four decades, but they may need to be expanded to better represent the current state of the science in terms of toxicology and harm.

The problem, they say, is that “standards set by law are typically created only when the scientific evidence of harmful effects is deemed compelling by legislators,” leading to “common pollutants” such as the very fine particles known as PM2.5 being commonly regulated today. Because they are cheap and easy to measure, PM2.5 has become the “de facto variable” in health studies, they say.

But they add: “There is probably merit in setting limit values ​​for black carbon, ultrafine particles, formaldehyde or subcomponents of fine particles such as secondary organic aerosols; however, each of these still needs to accumulate the weight of evidence to become legal requirements.”

To help counter this bias, researchers are calling for “exploratory” observations of air pollution, following the precautionary principle, “ideally” coupled with research funding to encourage them.

Another key element in ensuring that air quality policies are feasible and implemented is coordination of policy development.

The benefits of reducing air pollution and greenhouse gas emissions have “long been recognized by the scientific community, but there is also an underappreciated need for legal and regulatory coordination,” the researchers say in their paper.

They cite the example of low-carbon aviation fuels, saying that carbon regulation alone “does not guarantee better air quality.”

The climate commitment to adopt low-carbon fuels can only succeed in reducing pollution if there are “parallel, internationally agreed regulatory requirements to reduce nitrogen oxide and particulate emissions from engines,” they say.

In the conclusion of their paper, the researchers state: “To advance the debate, we argue that expanding the space for dynamic regulatory development at the science-law-policy interface is an important avenue to accelerate the achievement of global clean air goals.”