A novel look at racial health disparities: the interaction between social disadvantage and environmental health.
OBJECTIVE
We explored the notion that social disadvantage increases vulnerability to the health effects of environmental hazards. Specifically, we examined (1) whether race modifies the association between blood lead and blood pressure and (2) whether socioeconomic status (SES) plays a role in this modifying effect.


METHODS
Using the National Health and Nutrition Examination Survey (2001-2008) and linear regression, we estimated the association between blood lead and blood pressure. Using interactions among race, SES, and lead, we estimated this association by levels of social disadvantage.


RESULTS
Black men and women showed a 2.8 (P < .001) and 4.0 (P < .001) millimeters mercury increase in SBP, respectively, for each doubling of blood lead. White adults showed no association. This lead-SBP association exhibited by Blacks was primarily isolated to Blacks of low SES. For example, poor but not nonpoor Black men showed a 4.8 millimeters mercury (P < .001) increase in SBP for each doubling of blood lead.


CONCLUSIONS
Our results suggest that social disadvantage exacerbates the deleterious health effects of lead. Our work provides evidence that social and environmental factors must be addressed together to eliminate health disparities.
Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109, USA. mhicken@umich.edu
Margaret T
MT
Hicken
Gilbert C
GC
Gee
Jeffrey
J
Morenoff
Cathleen M
CM
Connell
Rachel C
RC
Snow
Howard
H
Hu
D000328:Adult; D044383:Black People / Q000706:statistics & numerical data; D001794:Blood Pressure; D004522:Educational Status; D004781:Environmental Exposure / Q000706:statistics & numerical data; D004782:Environmental Health / Q000706:statistics & numerical data*; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D007854:Lead / Q000097:blood; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D011203:Poverty / Q000706:statistics & numerical data; D044469:Racial Groups / Q000706:statistics & numerical data*; D012737:Sex Factors; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American
D007854:Lead