Mapping your way to better health


There’s a new tool in California that can tell you how dirty your neighborhood is compared to the rest of the state. It’s called Cal EnviroScreen, and zip codes with the worst ozone, particulate matter, diesel exhaust and other contamination are shaded a deep indigo on a state map, where as the cleanest are white or light sea foam green. Many of California’s dirtiest zip codes are in the Central Valley, like West Fresno, where KQED reports that children play in a park built on top of a Superfund site, farmers spray pesticides on their fields, and semi trucks zoom up and down a highway.

Cal EnviroScreen, developed by California’s Office of Environmental Health Hazard Assessment, isn’t designed to simply add insult to injury; many residents of polluted communities already know how bad it is. “This tool was to try and look at (a) community as a whole rather than a specific site or chemical,” says toxicologist George Alexeeff, the head of the state’s Office of Environmental Health Hazard Assessment, who told KQED that regulators often miss the big picture. “What about those areas that seem to be suffering from multiple sources of pollution?”

Plotting pollution by zip code. Blue=more polluted. White=less polluted.

The idea is to identify the state’s most contaminated communities (which are often among the poorest and most ethnically-diverse) so that regulators can divvy up and spend cleanup money for maximum benefit. Cal EnviroScreen was developed in tandem with the state’s new cap-and-trade law, and clean-up projects will be funded by companies that exceed carbon emission standards. Under cap-and-trade, emitters receive allowances for 90 percent of their carbon dioxide emissions, but must buy the last 10 percent at an auction. A bill passed last year requires that 25 percent of the proceeds be spent on reducing pollution or mitigating impacts of climate change in disadvantaged communities that “already face disproportionate impacts from substandard air quality in the form of higher rates of respiratory illness, hospitalizations and premature death,” reports The Sacramento Bee.

However, some people worry that the map will make the most polluted communities unattractive to businesses and prospective home-buyers by drawing even more attention to their plight. Communities often fight Superfund designation for similar reasons.

“This would be like hanging a sign at the county or the city limits saying, hey, don’t even think about doing business here,” Vito Chiesa, Chair of Stanislaus County board of Supervisors, told KQED.

But others say people in the most polluted areas already know how bad things are, and it doesn’t do much good to hide that.

“The notion that the way to prevent negative economic consequences from pollution is to avoid acknowledging the problem makes no sense,” write Ryan Young and Rey León in an opinion piece for The Modesto Bee. “Rather than redlining communities, (Cal EnviroScreen) identifies green investment zones. And it's backed by a real mechanism that will bring investment dollars to these communities.”

Some business are concerned that by documenting polluted areas and noting their (often high) rates of afflictions like asthma and low birth weight, Cal EnviroScreen implies a causal link between the two whether or not a connection has been scientifically proven. In a letter to the California EPA, Cynthia Cory, director of environmental affairs for the California Farm Bureau Federation, said the new maps "incorrectly portray that the adverse health conditions in a community are a result of direct exposure from pollution."

But there is increasing interest in proving this kind of causal relationship: The budding field of Geomedicine seeks to combine mapping and computer software with environmental hazards and health effects. In addition to programs like Cal EnviroScreen, there are devices like the Asthmapolis inhaler, which is equipped with a Bluetooth-like device that tracks where you take a puff, helping identify what places are likely to trigger an attack. It was conceptualized by Epidemiologist David Van Sickle, who was frustrated by how hard it was to figure out what exactly triggers an asthma attack, and piloted by patients outside of Sacramento.

California appears to be one of Geomedicine’s proving grounds: the Loma Linda University Medical Center near Los Angeles will soon launch software designed by software company Esri that maps patient health with toxins in their home environment. The maps also show grocery stores, parks, and soup kitchens, so health workers can share convenient places to find healthy meals or get exercise with patients. You can visit Esri’s website now, plug in your zip code, and check out your area’s heart attack rate and see local emitters of toxic chemicals.

This type of mapping isn’t new — the American Lung Association releases an annual ranking and map of air quality around the country, for example — but what is new is the direct connection to doctors and the effort to better document the link between environmental hazards and health.

As Ethan Berke, a family physician and spatial epidemiologist at Dartmouth Medical School in Hanover, N.H., told The Washington Post, “Place should be a vital sign.”

Emily Guerin is the assistant online editor at High Country News.

Screenshot of Cal EnviroScreen courtesy California Office of Environmental Health Hazard Assessment.

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