Blood lead (Pb) levels: further evidence for an environmental mechanism explaining the association between socioeconomic status and psychophysiological dysregulation in children.
OBJECTIVE
The authors recently reported that blood lead (Pb) was a significant mediator for the positive association between socioeconomic status (SES) and peripheral vascular responses to acute stress in children (B. B. Gump et al., 2007). The present study considers the possibility that Pb may also mediate an association between SES and cortisol responses to acute stress.


METHODS
Early childhood Pb exposure was tested as a mediator for cross-sectional associations between SES and cortisol responses.


METHODS
The primary outcome was cortisol responses to acute stress in 9.5-year-old children (N = 108).


RESULTS
Lower family income was associated with significantly greater cortisol levels following an acute stress task. A mediational analysis confirmed that Pb was a significant mediator for this association.


CONCLUSIONS
These results reaffirm the importance of considering the chemical environment as well as social and psychological environment when evaluating psychophysiological effects of low SES.
Gump
Brooks B
BB
Department of Psychology, SUNY Oswego, Oswego, NY 13126, USA. gump@oswego.edu
Reihman
Jacki
J
Stewart
Paul
P
Lonky
Ed
E
Granger
Douglas A
DA
Matthews
Karen A
KA
D000223:Adaptation, Psychological / Q000502:physiology; D001143:Arousal / Q000502:physiology*; D002648:Child; D004781:Environmental Exposure; D005260:Female; D006306:Health Surveys; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007854:Lead / Q000097:blood*; D007855:Lead Poisoning / Q000503:physiopathology* / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D009518:New York; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D055500:Resilience, Psychological; D012931:Social Environment; D012959:Socioeconomic Factors; D013223:Statistics as Topic
D007854:Lead; D006854:Hydrocortisone