This issue of the journal includes three papers that touch on relations among socioeconomic status (SES), health, and air quality. Jerrett et al considered whether SES differentials in Hamilton, Ontario, modify the temporal relations between daily mortality and either coefficient of haze (COH) or SO2. Martins et al did a similar analysis with respect to PM10 in Sao Paulo, Brazil. The third paper, by Gouveia et al, also involved Sao Paulo but examined cross sectional relations between several pollutants and infant birth weight.
Inequitable distribution of environmental impacts within a city or region may raise issues of "environmental justice", but it may also be possible to get additional insights into the implied health relations by probing a little deeper into the nature and origins of such differential impacts.