Another factor strongly linked to socioeconomic status is the quality of one’s physical environment (Adler and Newman, 2002; Evans and Kantrowitz, 2002). U.S. data indicate that substandard housing, crowding, elevated noise levels, limited ability to regulate temperature and humidity, and exposure to noxious pollutants and allergens (including lead, smog, particulates, and dust mites) are all common in poor, segregated communities (Been, 1997; Bullard, 1994; Evans and Saegert, 2000; Mohai and Bryant, 1992, 1998; Pearlin et al., 2001). For both adults and children, increased respiratory and other health problems result from residing near hazardous waste sites (Dolk et al., 1998; Goldberg et al., 1999), residential exposure to air pollution (Keeler et al., 2002; Pope et al., 2002; Thurston and Ito, 2001), and deteriorated housing conditions (Peat et al., 1998; Rauh et al., 2002). However, the exact contribution of such environmental conditions to racial and ethnic differences in health status, and the extent to which they add to other socioeconomic effects or possibly explain them, is still unclear.
Although socioeconomic status is strongly linked to health, many research questions remain about the nature of this linkage and the contribution of socioeconomic status to racial and ethnic health differences.
Research Need 6: Clarify the degree to which socioeconomic status accounts for racial and ethnic differences in health outcomes over the life course.
Some differences are not explained by socioeconomic status, or even run counter to the expected. Would better measures of education, or other aspects of status, provide clarification? Would incorporating measures of earlier socioeconomic status, perhaps status prior to immigration, explain more of the differences? Is better modeling needed of presumed nonlinear relationships? What differences in health outcomes would still not be explained even if all these questions could be answered? The possibility that the effects of socioeconomic factors are misestimated because of differential survival by race and ethnic group also requires consideration.
One complication is that dimensions of socioeconomic status are not identical in their effects on racial and ethnic health differences. Analysts need to know the most appropriate aspect of status to consider—income, wealth, education, or occupation. Health differences by race or ethnicity will look different if one or the other indicator is controlled. Policy makers need to know which aspect of status matters most. It makes a great deal of difference to policy whether differences are largely due to income, in which case increasing the income of the poor gains greater weight from its possible