by Nadia Colombi
figures by Daeun Jeong
edited by Jennifer Sun
Air pollution contributes to roughly 7 million deaths worldwide every year. It is among the leading avoidable causes of disease and death globally, and the world’s largest environmental health risk. Furthermore, it is a cause of global health inequities, disproportionately affecting women, children, the elderly, and low-income populations.
Working collectively to implement air quality standards that are robust and enforceable presents an opportunity to drastically improve public health at the global scale, since air pollution knows no borders. Fortunately, many of the strategies we need to make major strides in global air quality management have already been developed and implemented in countries on the pioneering edge of effective air pollution regulation and management.
The recent Global Assessment of Air Pollution Legislation by the United Nations Environmental Program (UNEP) was created to distill this knowledge into a set of best practices in air quality legislation and management. To achieve this, the report conducted a rigorous analysis of national air quality legislation and its effectiveness at improving air quality across UN member states. The report highlights current global shortcomings in efforts to reduce air pollution (Figure 1), but more importantly, it illustrates opportunities for improving air quality across nations.
What exactly do we mean by “air pollution”?
Air pollution refers to substances in the atmosphere that have a detrimental effect on humans and other living organisms. It is an umbrella term that includes things like soot and ozone, which can irritate the eyes and throat as well as damage the lungs when exposed acutely in large quantities or in smaller amounts chronically. These substances are relatively short-lived (<1 year) in the atmosphere and directly impact air quality. However, air pollutants can also include greenhouse gasses such as carbon dioxide and methane, which are less relevant to human health in the near term but contribute to climate change, which has long-term impacts on air quality, human health, and the environment.
Scientists lump these relatively short-term and long-term pollutants with such different properties together because they are interconnected. For example, climate change leads to rising sea levels, more extreme weather, heat-related deaths, increased transmission of infectious diseases, and hot and stagnant conditions that can exacerbate the negative impact of local air pollution. Additionally, fires, which will become more frequent in certain regions due to climate change, can lead to higher levels of black carbon and particulate matter, both of which are hazardous to human health.
What can countries do to ensure improved air quality?
While the UN Global Assessment of Air Pollution Legislation acknowledges that there is no “one-size-fits-all” blueprint for developing robust air quality legislation that can be generalized for all countries, it highlights the commonalities between approaches that have been historically successful in alleviating air pollution. Below, we illustrate five key recommendations outlined in the report (Figure 2).
- Regulate the air we breathe
The exposure to pollution in the air we breathe (ambient air) results from a wide range of social and economic behaviors such as vehicle use, industry, energy production and population density. While high emissions contribute to poor air quality, certain types of environmental conditions can also exacerbate the effects of pollution by allowing it to accumulate without ventilation. A famous example of this is Los Angeles, which is situated in a coastal lowland area surrounded by mountains on the east. Cool ocean air blows from the west and acts like a lid on top of the warm and sunny basin, trapping in both warm air and pollution. This exacerbates the population’s exposure to high levels of emissions produced within the large city.
Thus, the report argues that in addition to reducing emissions, it is crucial to impose limits on the amount of pollution present in the air breathed by a population by adopting ambient air quality standards (AAQS). Regulating air pollution through AAQS provides a more direct link to health-relevant human exposures to air pollution than the volume of pollutant emitted by particular sources.
- Frame air quality laws in terms of public health
Effectively reducing emissions and curbing air pollution is challenging and financially burdensome for both industry and public authorities. If the legal definition of “air pollution” is narrow, those responsible for reducing it will often push back on the scope of their responsibilities.
The U.S Clean Air Act, cited by some legal experts as the most powerful environmental law in the world, is the primary law governing air pollution in the U.S. The law defines air pollution as “any air pollutant that may endanger public health or welfare”. While the influence of the fossil fuel industry in U.S elections has led to challenges in using the Clean Air Act to regulate greenhouse gas emissions, its public health-oriented framing led to a 78% reduction in the combined emissions of six common hazardous pollutants. The benefit of this framing has been recognized and adopted by other countries, such as China, Japan, and Korea, leading to large reductions in East Asian pollution and the implementation of carbon pricing.
- Hold institutions accountable
Successfully reducing air pollution necessitates standards to be enforceable, which includes continuous monitoring and modeling of ambient air. To ensure that standards are being met, emitters should be required to regularly report air pollution concentrations to a public authority or government agency.
If standards are not being met, there should be a legal basis for those responsible to be held accountable. This can include requirements for the responsible party to escalate remediation actions, report their plan for achieving standards, or make emergency plans for addressing dangerous pollution levels. More strict measures may include imposing daily fines, shutting the offending company down, or even prosecution, as is regularly done in China.
- Ensure that the process is public and participatory
Implementation of air quality law is supported by citizen empowerment. Providing the public with information on the current state of air pollution is an essential component of any air quality policy – particularly because air pollution is not always visible. Since air quality information can be highly technical, this report argues that the best way to disseminate information is to adopt official air quality indices (AQI) that are accessible and easy to interpret. Opportunities for citizen participation in air-quality plan-making and monitoring can be provided, for example, through public comment periods for new environmental laws and “citizen science” initiatives (e.g. Argentina, United States).
Finally, when certain communities are being disproportionately impacted by poor air quality, there should be a legal mechanism for those communities to take action. A particularly robust example of this is seen in Indonesia, where air quality laws explicitly enshrine the right of communities to file class-action lawsuits in cases of environmental pollution.
- Keep up with the latest science
A robust system of air quality governance includes a clear air quality law review and revision process. This is because evidence about national air quality grows and changes over time through monitoring, as does scientific understanding about the effects of air pollution. Air quality law revision is inevitable in a system in which air quality law is focused on public health objectives. Legislative review and revision provides an opportunity for knowledge-sharing and continual improvement of air quality law to reflect current knowledge. Building a regular process for updating air quality standards into the air quality governance system can effectively facilitate this process.
Following these approaches can have a far-reaching impact on public health
The multifaceted nature of air pollution and its wide-ranging sources, emitters, and regulatory structures makes robust air quality legislation particularly challenging. The report discussed here does not provide a single blueprint for all nations to achieve better air quality. Furthermore, while it acknowledges the role that global economic inequities play in the ability of individual countries to implement effective air quality legislation, it does not attempt to solve those inequities. Instead, by highlighting legislative approaches that have been successful at reducing air pollution, it provides a roadmap for countries with adequate resources to ensure that their air quality legislation accomplishes what it is set out to do: reduce air pollution. Because pollution crosses national borders, ensuring that countries reduce their contribution to air pollution provides an opportunity to greatly improve public health at a global scale.
The author would like to thank Lyssa Freese for her feedback on the content of this article.
Nadia Colombi is a third-year Ph.D. student in the Earth and Planetary Science program at Harvard University. You can find her on twitter as @nkcolombi
Daeun Jeong is a fourth-year Ph.D. student in the Biological and Biomedical Sciences program at Harvard University.