LEFT: Smog obscures the Forbidden City in Beijing in September 2005. Credit: Brian Jeffery Beggerly/Flickr. RIGHT: Smog hangs over Connaught Place in New Delhi in November 2006. Credit: Ville Miettinen/Flickr.

Take a deep breath. Hold it. Now, release. Breathing is an amazing bodily function, one that is fundamental to life and an act that we do both automatically and conscientiously. Though we are acutely aware of changes in our breathing–too fast, too shallow, too loud–most people give little thought to what is in the air we breathe.

With an estimated 3.4 million deaths annually attributed to outdoor air pollution, this lack of awareness is concerning. To better understand the linkages between air quality and human heath, a group of the world’s leading scientists convened by the Environmental Performance Index at Yale University came together to review the latest science on air pollution and explore how the next generation of air quality indicators can be made more useful for policy purposes.

Linking scientific data to policies to improve air quality is hard to do. One reason is that it is difficult to attribute ambient air pollution to specific sources of pollution. For example, forecasting for ozone requires complex scientific modeling, making it difficult to attribute to regional or global sources. Measuring how pollutants change over space and time is also tricky, especially when it comes to understanding how air pollution moves across cities and within neighborhoods. Depending upon where you live, air quality data may not be available in real time (if they’re available at all, see this interactive map we put together showing availability of reported air quality data to the World Health Organization). More often than not, especially in developing countries, data are reported in yearly smoothed-out averages and can obscure daily spikes from human activity (rush hour, for example) that most impact health.

Click on the image below to access an interactive infographic about the gaps in data and understanding for four air pollutants that impact human health (particulate matter, ozone, mercury and persistent organic pollutants) and what is needed to design next-generation indicators to address them:

To better understand these linkages, the scientists focused on some of the most deadly air pollutants, including ozone and particulate matter (PM), which cause respiratory illness, and persistent organic pollutants (POPs) and mercury, which affect human health through food chains and degrade ecosystems. These pollutants are caused by urbanization and industrialization, and are, for the most part, naked to the human eye. Most of these pollutants are not regularly monitored in most of the world, particularly in areas that are urbanizing and developing the fastest. Not enough attention is given to advocating for stricter monitoring and clean-up of these pollutants.

Although there is a plethora of ongoing research on air pollution, these data are not collected and communicated in a meaningful way for policy-makers to take much needed action. For example, air quality indices that are used to communicate health exposures to PM or ozone do not tell a city mayor what sources are largely responsible for the pollution. Should the mayor tackle emissions arising from motor vehicles, or should environmental ministries mandate better scrubbers on power plants? The available indicators generated from ground-based monitoring stations do not link to the sources of pollution, making action challenging.

Another common problem we found across each indicator is the need for more and better data. However, many countries lack the capacity or financial resources to install and maintain costly ground-based monitoring stations or networks. Here’s where the data revolution, low-cost environmental sensors, and improved mobile technology can allow for crowd-sourced data to help fill in some of the data gaps, especially in developing countries that are in “information-poor.”

At the same time, we must make sure that people are aware of air pollution issues that affect their everyday lives, which is why we developed the interactive data visualization above to raise awareness about air pollution and the need for new indicators to measure air quality. The aim of these interactive data visualizations, produced by a team of student designers and programmers, is to help educate people about the air we breathe by answering key questions: Where do air pollutants come from? What are the risks and impacts? How do we measure these factors? And, what do we do to address data gaps?

Ultimately, the goal is to help policy-makers make better decisions about air quality as it relates to important drivers such as agriculture, land use change, urban form, and economic growth. Check out the interactive to learn more about what is in the air, how it affects your health, and what can be done to achieve the ‘next generation’ indicators for policy action.

To view the interactive on the website of Yale’s Environmental Performance Index click here.