Looking for Environmental Justice Through the Smog

Smog fills the air around a traffic jam on the New Jersey Turnpike. Photo: bk via Flickr Creative Commons (CC BY-SA 2.0).

Reporter’s Toolbox: Looking for Environmental Justice Through the Smog

By Joseph A. Davis

There are lots of environmental justice stories in the United States. Now, an updated and newly sharpened data tool can help journalists find and understand more of them.

You may have heard Toolbox rant previously about the early iterations of the U.S. Environmental Protection Agency’s EJScreen data tool. Now EJScreen is out in version 2.3 and it cuts through the smog.

EJScreen maps out many kinds of pollution data and overlays it with demographic data indicating where disadvantaged and vulnerable communities are located. It shows where pollution is harming Black, Latino and poor people. In more recent years, it has been the prototype of other models used in distributing federal aid.

 

What’s new

The latest update of EJScreen includes NO2 (nitrogen dioxide) pollution. It’s an underappreciated pollutant — if only because there’s chemistry involved. Actually, it’s one of the six “criteria pollutants” under the Clean Air Act. Those are the ones that must be controlled because of their direct harm to human health.

NO2 directly harms lung health by causing conditions like asthma. But in the summer it also combines with other chemicals to cause photochemical smog, which also harms lungs. EJScreen did not previously include NO2 data.

The new version also includes for the first time data on public drinking water systems that are not in compliance with the Safe Drinking Water Act health standards.

Another change is to show proximity to Superfund hazardous waste sites by using areal, or geographic, extent instead of just points on the map.

These and other changes have accumulated in recent years. They are enumerated in this timeline.

 

Where the data comes from

It’s always worth remembering that the foundation of the EJScreen tool is data from the EPA’s Toxics Release Inventory. TRI is the foundation for lots of other pollution data. Because it goes way back in time, it is useful for looking at historical trends. TRI itself has changed and evolved over the years.

 

The headline for this newest EJScreen release

is the addition of satellite data from NASA,

which estimates average annual NO2

levels at the census tract level.

 

The headline for this newest EJScreen release, which came out in July 2024, is the addition of satellite data from the National Aeronautics and Space Administration. It uses data from the Ozone Monitoring Instrument on NASA’s Aura satellite (combined with computer models) to estimate average annual NO2 levels at the census tract level.

Now that NASA is on the team, we wonder if there may not be opportunities to add other data from Earth-observing satellites to EJScreen.

In any case, the data from these instrumental and government sources is likely to be reliable. Check anyway.

 

How to use the data smartly

It’s worth remembering that environmental justice is not an abstraction — and not just a number. The information you get from EJScreen ultimately is about the daily lives of real people.

Nitrogen oxides pollution, for example, comes from cars and trucks. NO2 is an oxide of nitrogen. The reason your car needs a catalytic converter is to remove nitrogen oxides and some other air pollutants from exhaust emissions.

Car and truck pollution is worse near big roads and freeways — and you may have noticed that many underserved populations live in housing near the freeway. Their higher incidence of respiratory ailments is one result.

In any data project, it’s always worth remembering that you need to report the human impact and meaning of the numbers. Groundtruth everything you can. Pick up the phone. Go out and talk to people.

[Editor’s Note: For more environmental justice tools and related coverage, also be sure to check out our Topic on the Beat: Environmental Justice page and get environmental justice headlines from EJToday.]

Joseph A. Davis is a freelance writer/editor in Washington, D.C. who has been writing about the environment since 1976. He writes SEJournal Online's TipSheet, Reporter's Toolbox and Issue Backgrounder, and curates SEJ's weekday news headlines service EJToday and @EJTodayNews. Davis also directs SEJ's Freedom of Information Project and writes the WatchDog opinion column.

---

* From the weekly news magazine SEJournal Online, Vol. 9, No. 35. Content from each new issue of SEJournal Online is available to the public via the SEJournal Online main page. Subscribe to the e-newsletter here. And see past issues of the SEJournal archived here.