Every Breath You Take

Fuel for thought. A better measure of exposure to jet fuel shows that some military personnel may be at increased risk for adverse health effects from breathing noxious fumes. In this issue, Steve Wing, an associate professor of epidemiology in the School of Public Health at the University of North Carolina at Chapel Hill, and colleagues investigate environmental injustice in North Carolina's swine industry by analyzing the location and characteristics of confined animal feeding operations (CAFOs) for hogs in relation to racial, economic, and water source factors [EHP 108:225-231]. Using data for census block groups (corresponding to areas of approximately 500 households), Wing and colleagues investigated hog production according to three variables: incidence of poverty, racial composition, and dependence on well water. Cities with 1990 populations greater than 100,000 and counties known to not border areas with CAFOs were excluded, leaving 4,177 block groups with a combined estimated population of 4.9 million people for analysis. For comparison, the distribution for each variable was divided into quintiles of increasing incidence of poverty, nonwhite population, and well use. For example, the lowest poverty quintile referred to the fifth of the block groups with the lowest incidence of poverty, whereas the highest poverty quintile referred to the fifth of the block groups with the highest incidence of poverty. Wing and colleagues found that increasing prevalence of hog production was associated with increases in all three variables. While the increasing percentages of nonwhite people and poverty each related strongly to the location of hog facilities, it was the combination of these two variables that was most strongly associated with large numbers of CAFOs. Both the number of CAFOs and the steady state live weight (calculated as a function of the number of each type of hog and their corresponding weight) rose steadily with quintiles of the distribution for each variable. Over 800 hog operations were found in areas corresponding to the fourth and fifth quintiles of the poverty distribution, compared to only 43 hog operations in the first. Furthermore, almost half of all CAFOs were located in block groups where 85% or more of the households rely on wells as their primary source ofwater. Wing and colleagues found that corporate operations were more concentrated in poor and nonwhite areas than were independent operations. Recent growth of corporate operations paralleled by declines in independent operations suggests that the environmental injustices associated with hog production in …