Published: Oct. 1, 2009 By

Neighborhood with smog

African Americans, single mothers live in the most polluted areas, researcher finds

African Americans and single mothers with young children compose a disproportionate share of the population living in the most polluted neighborhoods in America, a University of Colorado sociologist has found.

This and other confirmation of environmental inequality among racial groups contradicts a landmark study claiming that the significance of race had declined. And the prevalence of single mothers in polluted areas, the scholar says, highlights the need for more study of gender-related environmental inequality.

Liam Downey, an associate professor of sociology, has been studying environmental inequality for more than a decade. Employing modern analytical tools such as geographic information systems—or GIS—Downey has advanced scholars’ understanding of who lives in the nation’s most polluted areas.

Downey’s work was recognized at this year’s annual meeting of the American Sociological Association. CU’s chair of sociology describes Downey as a “rising star within environmental sociology.”

In a paper published last year in the journal Sociological Perspectives, Downey and graduate student Brian Hawkins used data from the 2000 U.S. Census and the Environmental Protection Agency to determine which racial groups live in the areas with the worst industrial air pollution and whether their incomes affect their toxic exposure.

They found that African Americans in the United States are exposed to toxic concentrations of air pollution 1.45 times greater than the second-most environmentally “burdened” group.

Low-income, predominantly black neighborhoods and households suffer a much higher pollution burden than do any other neighborhood or household type that Downey studied.

Additionally, blacks are exposed to toxic concentrations 2.52 times greater than Asian Americans, whose neighborhoods are, on average, the cleanest of those Downey studied.

In fact, as Downey’s paper notes, blacks experience such a high air-pollution burden that black households with incomes of $50,000 to $60,000 live in neighborhoods that are, on average, more polluted than the average neighborhood of white households with incomes less than $10,000.

“I think that’s a very important finding,” Downey says.

Downey’s study of race, income and environmental inequality has also yielded surprising results that, he says, “defy simple explanation.” For instance, in a study of U.S. metropolitan areas, Downey found that African-Americans, Hispanics, Pacific Islanders, Native Americans and Asian Americans are each the most pollution burdened-group in some metropolitan areas and the least pollution-burdened group in other metropolitan areas.

Downey’s research also contradicts the claims of noted sociologist William Julius Wilson, whose book “The Declining Significance of Race” argued that blacks’ “life chances” were more constrained by socio-economic class than by race. Wilson’s book has been widely cited but controversial since it appeared in 1978.

However, Downey’s focus extends beyond race and class. He and Hawkins have also found that regardless of race, single-mother families with young children are significantly over-represented in the nation’s most polluted neighborhoods.

This inequality also exists across income levels and in three separate pools of data: in large metropolitan areas, in highly polluted metropolitan areas and across the country as a whole.

The average female-headed family lives in a neighborhood 1.13 times more toxic than the average male-headed family, and 1.36 times more toxic than the average married-couple family, Downey found.

While there’s a good deal of research on environmental inequality among racial groups, there’s relatively little research on gender-related environmental inequality, Downey notes.

He finds that dearth of study ironic because “Single mothers led much of the environmental-justice activism that led to this research.” Further, young children in single-parent families are particularly susceptible to pollution. And the less money a family has, the less it’s able to provide children with good health care.

Not only does the over-representation of single-parent families in hazardous neighborhoods have serious public-health implications, it also has potentially serious educational and labor-market implications, he notes.

All of that, Downey suggests, means that environmental-inequality researchers should broaden their focus beyond race and income.

For the studies on single-parent and racial environmental inequality, Downey used GIS to merge population data from the U.S. Census Bureau with environmental hazard data from the EPA’s Risk-Screening Environmental Indicators project.

The RSEI provides toxicity-weighted air pollutant concentration data for industrial facilities that meet several EPA requirements, including using more than 10,000 pounds of at least one of 600 specified toxic chemicals annually. Thus, Downey used GIS and the RSEI to estimate air-pollution concentration values for every census tract in the continental United States.

“I think one of my main contributions is how I use GIS to link pollution data to population data,” Downey says.

The American Sociological Association seems to concur. For a series of articles published between 2004 and 2008, Downey won the ASA Environment and Technology Section’s Outstanding Publication Award. That work includes his studies of racial environmental inequality, single-mother families and pollution and earlier work exploring the extent of environmental inequality.

Downey received the award in San Francisco in August. “I am absolutely thrilled to be receiving this award and hope that this significant recognition of my work prompts other researchers to further examine the factors that shape environmental inequality in the United States.”

Downey also thanked his department for its support.

The award is “terrific recognition of Liam’s substantial long-term contributions,” says Richard Rogers, chair of sociology. “This recognition further underscores the fact that Liam is a rising star within environmental sociology. CU-Boulder is fortunate indeed to have him!”

Having enlarged the scope of understanding of environmental inequality, Downey is pursuing new lines of inquiry. For instance, he is currently collaborating with Kyle Crowder, a distinguished professor of sociology at the University of North Carolina at Chapel Hill and one of the nation’s leading experts on residential mobility.

Studying residential mobility from 1987 to 2005, Downey and Crowder have found that blacks are only slightly less likely than whites to leave polluted neighborhoods but that the neighborhoods that blacks tend to move to are much more polluted than ones that whites move to.

Some, but not all, of this difference in mobility can be explained by African Americans’ lower income.

“This suggests that residential discrimination is likely an important factor affecting environmental inequality,” Downey says, “but we don’t know that for certain.”