Exploring persistent racial/ethnic disparities in lead exposure among American children aged 1-5 years: results from NHANES 1999-2016.

OBJECTIVE: The aim of this study was to determine whether long-standing racial disparities in lead exposure still exists for children age 1-5 years old. We examined if blood lead levels were higher among non-Hispanic Black children and others compared to non-Hispanic White children. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) from 1999-2016 were used. Geometric mean blood lead levels (BLLs) were compared by race/ethnicity using log-transformed simple linear regression. Associations between race and elevated BLL were assessed using weighted Chi-square tests. Log-transformed multiple weighted linear regression was used to assess what factors affected BLLs. RESULTS: A total of 6772 children were included in this study. In 1999-2000, the geometric mean BLL for non-Hispanic Black children was 3.08 µg/dL, compared to 2.03 µg/dL for non-Hispanic White children (p = 0.01). The difference in geometric mean BLL between non-Hispanic Black children and non-Hispanic White children continued to be statistically significant in later years (all p < 0.05) until 2015-2016 (0.89 µg/dL vs 0.74 µg/dL, p = 0.17). Log-transformed linear regression showed that being non-Hispanic Black and having low family income were independently associated with higher BLL. CONCLUSION: Although lead exposure in the general population continued to decline for all racial/ethnic groups, non-Hispanic Black children still had higher BLL than non-Hispanic White children. In more recent years, the racial/ethnic gap was lesser but persisted. Racial/ethnic disparity in childhood BLL could be partially explained by socio-economic factors.

Association between blood lead levels and blood pressure in American adults: results from NHANES 1999-2016.

The aim of this study was to investigate the association between blood lead level (BLL) and hypertension in adults when lead exposure for the general population is low. The study used data from the US National Health and Nutrition Examination Survey (NHANES) 1999-2016. Participants aged 20 to 79 years were included in our study. Weighted multiple linear regression and logistic regression were conducted to test the association between BLL and systolic/diastolic blood pressure and hypertension status, respectively, while controlling for age, gender, race/ethnicity, body mass index, income level, and education. A total of 30,467 participants were included in this study. There was no association between BLL and hypertension status for the overall sample. Among those who were not taking antihypertensive medication, after adjusting for covariates, systolic blood pressure was positively correlated with BLL in non-Hispanic Whites (P = 0.004) and non-Hispanic Blacks (P = 0.0005), but not Hispanics (P = 0.07) nor Others (P = 0.37). The relationship between diastolic blood pressure and lead levels was also significant in non-Hispanic Whites and non-Hispanic Blacks. This study showed that higher BLL was associated with higher systolic and diastolic blood pressure in some population groups, but not associated with hypertension status.