DC Has Higher Per-Capita Cancer Risk In Its Air Than Any of the 50 States

Government estimates of toxic chemical concentrations in local air indicate that residents of the District of Columbia face an additional cancer risk from toxic chemicals in outdoor air that is more than 700 times higher than the goal set by Congress a decade ago, the Environmental Defense Fund (EDF) announced today. DC has a higher per-capita cancer risk in its air than any of the 50 states. Maryland ranked fourth, with an air cancer risk more than 500 times Congress’ goal.

The newly released government figures are based on 1990 data and represent the first-ever estimate of which toxic chemicals, in what amounts, are in local communities’ air. EDF took the government figures and calculated the associated health risks for each community. The 1990-based government estimates come with official cautions about their use, and several accuracy checks showing close comparability with measurements as recent as 1997.

The District of Columbia shows a higher per-capita cancer risk in its air than any of the 50 states, despite having virtually no major industrial facilities. Car and truck traffic and the Ronald Reagan National Airport were its main sources of air toxics.

“The numbers show that cars, trucks, and small businesses tend to be responsible for much more of the air’s toxicity than is generally recognized,” said EDF attorney David Roe. Of the air cancer risk calculated by EDF for the District of Columbia, 67% is from mobile sources and 16% from small-business ‘area’ sources, with the remaining 17% from industrial ‘point’ sources. “Up to now, lack of information has meant lack of attention to some of the biggest causes of toxic air,” Roe said.

EDF is using its widely acclaimed Scorecard website (www.scorecard.org) to make this information on air toxics publicly available on the internet. “For the first time since the Clean Air Act passed 30 years ago, people can now learn about toxic chemicals in their own local air, and can see how well the law has or has not been protecting them,” said EDF scientist Dr. Bill Pease, Scorecard’s creator and chief designer. Visitors to the website simply type in a zip code to get the local facts.

Simultaneously, EDF has also added local information on the six so-called ‘criteria’ air pollutants (ozone, sulfur dioxide, particulates, etc.) to its Scorecard website. The health implications of those pollutants are shown as well, based on 1998 measurements. Criteria pollutants are widely monitored; air toxics are not.

The unprecedented information about air toxics at the local level comes from the US Environmental Protection Agency’s Cumulative Exposure Project (CEP), which made estimates of the concentrations of 148 separate chemicals in the air of every census tract in the continental US. (A census tract is a small area with 4000 to 5000 residents. The US includes over 60,000 census tracts.) EPA released the CEP results to a limited public in December 1998, after EDF and others requested it under the Freedom of Information Act. EDF then added health risk calculations and incorporated all the data into Scorecard.

EPA has cautioned that CEP results are based on modeling, rather than direct measurements, and that the modeling uses 1990 data. Comparisons with the handful of more recent, measured results for air toxics that are available from eight states, some as recent as 1997, show that CEP estimates are generally comparable, with underestimation a bigger problem than overestimation. Scorecard shows all comparisons. “The CEP estimates from EPA cast a lot of light onto what’s been a very dark subject, but they aren’t the ultimate word,” said Dr. Pease.