Second-Hand Smoke Exposure at Home in the United States; Minorities' Diminished Returns

Educational attainment and poverty status are two strong socioeconomic status (SES) indicators that protect individuals against exposure to second-hand smoke. Minorities' Diminished Returns (MDRs), however, refer to smaller protective effects of SES indicators among ethnic minority groups such as Hispanics and Blacks, compared to non-Hispanic Whites. This study explored ethnic differences in the effects of educational attainment and poverty status on second-hand smoke exposure in the homes of American adults.

This cross-sectional study included 18,274 non-smoking adults who had participated in the Population Assessment of Tobacco and Health (PATH; 2013). The independent variables were educational attainment and poverty status. The dependent variable was second-hand smoke exposure at home. Age and region of residence were the covariates. Ethnicity was the moderator.

Overall, individuals with a higher educational attainment (odds ratio [OR] = 0.76, 95% CI = 0.74-0.79) and those who lived out of poverty (OR = 0.56, 95% CI =0.51-0.62) had lower odds of second-hand smoke exposure at home. Hispanic ethnicity showed significant interactions with both SES indicators, suggesting that the protective effects of education and poverty on second-hand smoke exposure at home are smaller for Hispanics (ORs for interaction with education and poverty status = 1.30 and 1.26, P < 0.05) than for Non-Hispanics.

In the US, high SES Hispanics remain at high risk of exposure to second-hand smoke at home despite a high education and income. High SES better reduces environmental exposures for non-Hispanic than for Hispanic individuals.