The Influence of Declining Air Lead Levels on Blood Lead–Air Lead Slope Factors in Children

Background: It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB–PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards.Objectives: The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature.Methods: We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994) and NHANES 9908 (1999–2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA.Results: Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0–11 years of age.Conclusion: These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies.Citation: Richmond-Bryant J, Meng Q, Davis A, Cohen J, Lu SE, Svendsgaard D, Brown JS, Tuttle L, Hubbard H, Rice J, Kirrane E, Vinikoor-Imler LC, Kotchmar D, Hines EP, Ross M. 2014. The Influence of declining air lead levels on blood lead–air lead slope factors in children. Environ Health Perspect 122:754–760; http://dx.doi.org/10.1289/ehp.1307072     

Air Lead Exposures and Blood Lead Levels within a Large Automobile Manufacturing Workforce, 1980–1985

Recent (1980–1985) trends in air lead (PbA) exposures and blood lead (PbB) levels experienced by approximately 10 000 workers employed in various stages of the automobile manufacturing process (i.e., auto assembly, lead-acid battery manufacture, foundry work, and “other” manufacturing-related operations) are described. Between 1980–1985, the mean PbB levels of assembly, battery, foundry, and “other” workers decreased by 28, 24, 3, and 27%, respectively, to 16.6, 23.6, 15.9, and 11.8 μg Pb/dl. Workers in the following job categories experienced the highest annual mean PbB levels: paste machine operators (battery plants), solder-grinders (assembly plants), and crane operators (foundries). During the same period, median 8-h Time Weighted Average PbA exposures (μg Pb/m³) in assembly plants, battery plants, and foundries decreased by 10, 12, and 20%, respectively, to 8.1, 13.6, and 10.9 μg/m³.     

Distribution of Thallium and Lead in Children’s Blood

? Mean whole blood concentrations for lead and thallium were determined by atomic absorption spectrophotometric analysis for children residing in Newark, NJ. Frequency distributions for the various concentration ranges for both metals were recorded. There is no noticeable correlation between the lead and thallium content of whole blood, which suggests that exposure to and/or absorption of these substances are different.     

Predictors of Blood Lead in Children in Chennai,India (2005–2006)

Abstract

Lead has been phased out of gasoline in India since 2001. However, elevated blood lead levels continue to be reported, and little is known about the predictors of lead exposure. The purpose of this study was to examine the lead burden and identify possible predictors of blood lead among children in Chennai, India after the phase-out of leaded gasoline. Subjects were children from twelve schools in Chennai. Venous blood was collected and analyzed for lead. Demographic, environmental, and nutritional information was collected using questionnaires administered to the primary caregiver. Generalized estimating equations were used to assess predictors of blood lead. We found that lead exposure remains elevated among children four or more years after the phase-out of lead from gasoline. Industrial activity, water storage vessels, and lower socio-economic status are predictors of elevated blood lead in this population, but additional work is required to better define preventable risk factors.     

Association between Bone Turnover,Micronutrient Intake,and Blood Lead Levels in Pre-and Postmenopausal Women,NHANES 1999–2002

Background

Blood lead levels (BLLs) have been shown to increase during periods of high bone turnover such as pregnancy and menopause.

Objectives

We examined the associations between bone turnover and micronutrient intake with BLLs in women 20–85 years of age (n = 2,671) participating in the National Health and Nutrition Examination Survey, 1999–2002.

Methods

Serum bone-specific alkaline phosphatase (BAP) and urinary cross-linked N-telopeptides (NTx) were measured as markers of bone formation and resorption, respectively. Lead was quantified in whole blood. The association between tertiles of BAP and NTx, and BLLs was examined using linear regression with natural log_-transformed BLLs as the dependent variable and interpreted as the percent difference in geometric mean BLLs.

Results

In adjusted analyses, mean BLLs among postmenopausal women in the upper tertiles of NTx and BAP were 34% [95% confidence interval (CI), 23%–45%] and 30% (95% CI, 17%–43%) higher than BLLs among women in the lowest tertiles of NTx and BAP, respectively. These associations were weaker, but remained statistically significant, among premenopausal women (NTx: 10%; 95% CI, 0.60%–19%; BAP: 14%; 95% CI, 6%–22%). Within tertiles of NTx and BAP, calcium intake above the Dietary Reference Intake (DRI), compared with below the DRI, was associated with lower mean BLLs among postmenopausal women but not premenopausal women, although most of the associations were not statistically significant. We observed similar associations for vitamin D supplement use.

Conclusions

Bone resorption and bone formation were associated with a significant increase in BLLs among pre-and postmenopausal women.     

Prenatal Cigarette Smoking and Smokeless Tobacco Use Among Alaska Native and White Women in Alaska, 1996–2003

Objective To examine trends in prenatal cigarette smoking and smokeless tobacco use among Alaska Native (AN) and white women in Alaska. Methods Using 1996–2003 data from the population-based Pregnancy Risk Assessment Monitoring System, we determined trends in self-reported prenatal tobacco use among AN and white women and used chi-square tests and multiple variable logistic regression analysis to identify maternal factors associated with prenatal tobacco use. Results Over the study period, prevalence of any tobacco use during pregnancy declined by 27% among AN women (from 55.8 to 40.9%) (P < 0.0001) and by 17% among white women (from 18.8 to 15.6%) (P < 0.0001). In 2003, among AN women the prevalence of self-reported smokeless tobacco use was 16.9%, cigarette smoking was 25.7%, and any tobacco use was 40.9%; corresponding values for white women were 0.4, 15.0, and 15.6%, respectively. Western Alaska had the highest prevalence of tobacco use. Conclusion The prevalence of tobacco use decreased between 1996 and 2003, but remained higher among AN women than white women, especially for smokeless tobacco. Support for cessation interventions targeting pregnant women should be made a public health priority in Alaska. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.     

Environmental Pollution and Blood Lead Levels in Nigeria: Who is Unexposed?

Abstract

While blood lead levels (BLLs) in many western countries have progressively declined since 1976, in Nigeria high BLL continue to be documented not only in exposed workers but also in "unexposed" control subjects. The problem of environmental lead exposure has hitherto gone unaddressed by both researchers and health policy makers in Nigeria despite the immense public health importance. Continued high BLLs in Nigeria cast doubt on researchers' ability to find real "unexposed control subjects" in future studies, and point to the importance of controlling environmental lead exposures.     

Patterns of Cigarette and Smokeless Tobacco Use Before, During, and After Pregnancy Among Alaska Native and White Women in Alaska, 2000–2003

Objective To examine patterns of cigarette and smokeless tobacco use before, during, and after pregnancy among Alaska Native (AN) and white women living in Alaska. Methods We used data from the 2000–2003 population-based Pregnancy Risk Assessment Monitoring System to describe patterns of self-reported prenatal tobacco use among AN and white women. We used multiple variable logistic regression analysis to identify maternal factors associated with quitting and relapse. The final sample included 5,458 women. Results During 2000–2003, the prevalence of any tobacco use before pregnancy was twofold higher among AN women than among white women (60.0 vs. 27.5%), and the prevalence of any tobacco use during pregnancy and after pregnancy were each nearly threefold higher. Of the 25.8% (SE 0.9) of white women who smoked before pregnancy, 49.0% (SE 2.1) reported that they quit during pregnancy and of those, 41.1% (SE 2.9) relapsed postpartum. Of the 38.5% (SE 0.9) of AN women who smoked before pregnancy, 35.7% (SE 1.4) quit, and of those 57.0% (SE 2.4) relapsed. Of the 14.2% of AN women who chewed tobacco before pregnancy, 15.7% (SE 1.7) quit, and of those, 52.9% (SE 5.9) relapsed. Conclusion During 2000–2003, the prevalence of tobacco use was two to three times higher among AN women than among white women before, during, and after pregnancy. In addition, AN women had lower quit rates and higher relapse rates than white women. Comprehensive, culturally appropriate tobacco control approaches targeting AN women are needed to increase cessation during pregnancy and to decrease relapse.     

Patterns of Children’s Blood Lead Screening and Blood Lead Levels in North Carolina, 2011–2018—Who Is Tested,Who Is Missed?

Background: No safe level of lead in blood has been identified. Blood lead testing is required for children on Medicaid, but it is at the discretion of providers and parents for others. Elevated blood lead levels (EBLLs) cannot be identified in children who are not tested.Objectives: The aims of this research were to identify determinants of lead testing and EBLLs among North Carolina children and estimate the number of additional children with EBLLs among those not tested.Methods: We linked geocoded North Carolina birth certificates from 2011–2016 to 2010 U.S. Census data and North Carolina blood lead test results from 2011–2018. We estimated the probability of being screened for lead and created inverse probability (IP) of testing weights. We evaluated the risk of an EBLL of ≥3μg/dL at <30 months of age, conditional on characteristics at birth, using generalized linear models and then applied IP weights to account for missing blood lead results among unscreened children. We estimated the number of additional children with EBLLs of all North Carolina children using the IP-weighted population and bootstrapping to produce 95% credible intervals (CrI).Results: Mothers of the 63.5% of children (402,002 of 633,159) linked to a blood lead test result were disproportionately young, Hispanic, Black, American Indian, or on Medicaid. In full models, maternal age ≤20y [risk ratio (RR)=1.10; 95% confidence interval (CI): 1.13, 1.20] or smoking (RR=1.14; 95% CI: 1.12, 1.17); proximity to a major roadway (RR=1.10; 95% CI: 1.05, 1.15); proximity to a lead-releasing Toxics Release Inventory site (RR=1.08; 95% CI: 1.03, 1.14) or a National Emissions Inventory site (RR=1.11; 95% CI: 1.07, 1.14); and living in neighborhoods with more housing built before 1950 (RR=1.10; 95% CI: 1.05, 1.14) or before 1940 (RR=1.18; 95% CI: 1.11, 1.25) or more vacant housing (RR=1.14; 95% CI: 1.11, 1.17) were associated with an increased risk of EBLL, whereas overlap with a public water service system was associated with a decreased risk of EBLL (RR=0.85; 95% CI: 0.83, 0.87). Children of Black mothers were no more likely than children of White mothers to have EBLLs (RR=0.98; 95% CI: 0.96, 1.01). Complete blood lead screening in 2011–2018 may have identified an additional 17,543 (95% CrI: 17,462, 17,650) children with EBLLs ≥3μg/dL.Discussion: Our results indicate that current North Carolina lead screening strategies fail to identify over 30% (17,543 of 57,398) of children with subclinical lead poisoning and that accounting for characteristics at birth alters the conclusions about racial disparities in children’s EBLLs. https://doi.org/10.1289/{"type":"entrez-protein","attrs":{"text":"EHP10335","term_id":"372009720","term_text":"EHP10335"}}EHP10335     

Tobacco Use and Cessation Among Pregnant Alaska Natives from Western Alaska Enrolled in the WIC Program, 2001–2002

Objectives This study examined the rate of tobacco use (cigarette smoking and smokeless tobacco [ST]) at three time points: during the 3 months before pregnancy, during pregnancy, and at 6 weeks postpartum among Alaska Native women residing in the Y-K Delta region of Western Alaska. Methods A retrospective, non-randomized observational cohort design was utilized. The sample consisted of 832 Alaska Natives (mean maternal age = 26.2 years, average length of gestation = 3.8 months) seen at their first prenatal visit and enrolled in the women, infant, and children (WIC) program at the Yukon-Kuskokwim Delta Regional Hospital in Bethel, Alaska, during a 2-year-period (2001–2002). Tobacco use was assessed using an interview format at the first prenatal and at the 6-week postpartum visits. Results The rates of any tobacco use were 48% (95% CI 45%, 52%) 3 months before pregnancy, 79% (95% CI 76%, 82%) during pregnancy, and 70% (95% CI 67%, 74%) at 6 weeks postpartum. The proportion of women using ST changed significantly (P < 0.001) over the three time points (14%, 60%, and 61%, respectively) as well as the proportion of women who smoked cigarettes (P < 0.001) (40%, 42%, and 19%, respectively). Conclusions This study documents the high rate of tobacco use, particularly ST use, during pregnancy among Alaska Native women. Development of tobacco use prevention and cessation interventions during pregnancy for Alaska Native women is warranted.     

Prevalence of Chronic Disease and Their Risk Factors Among Iranian,Ukrainian, Vietnamese Refugees in California, 2002–2011

Little is known about how the health status of incoming refugees to the United States compares to that of the general population. We used logistic regression to assess whether country of origin is associated with prevalence of hypertension, obesity, type-II diabetes, and tobacco-use among Iranian, Ukrainian and Vietnamese refugees arriving in California from 2002 to 2011 (N = 21,968). We then compared the prevalence among refugees to that of the Californian general population (CGP). Ukrainian origin was positively associated with obesity and negatively with smoking, while the opposite was true for Vietnamese (p < 0.001). Iranian origin was positively associated with type-II diabetes and smoking (p < 0.001). After accounting for age and gender differences, refugees had lower prevalence of obesity and higher prevalence of smoking than CGP. Individually, all refugee groups had lower type-II diabetes prevalence than CGP. Grouping all refugees together can hide distinct health needs associated with country of origin.