PBBs analysis

This method was first described by Fernandez (1975, 1978) and has been adopted as an officially recommended analytical method for PbB analysis by the working group... 

Simple correlational analysis of the NHANES II data by Harlan (1988) and Harlan et al. (1985) revealed statistically significant associations between PbB levels and systolic and diastolic blood pressure for both men and women, aged 12-74 years. Statistical analyses controlling for a number of other potentially confounding factors (e.g., age, race, and body mass index), however, indicated significant associations between PbB level and blood pressure only for the men. Based on these analyses, the effect of PbB concentration on blood pressure was estimated to be an increase in blood pressure of 7 mm Hg at PbB levels between 14 and 30 pg/dL. 

A study of 398 male and 133 female civil servants in London, England, measured blood pressure, PbB, and serum creatinine concentration the study found no correlation between blood pressure and PbB after adjustment for significant covariates, including sex, age, cigarette smoking, alcohol intake, and body mass index in a stepwise multiple regression analysis (Staessen et al. 1990). 

The above study was replicated later with 75 asymptomatic black children, 3-7 years old, of uniformly low socioeconomic status (Hawk et al. 1986 Schroeder and Hawk 1987). Backward stepwise multivariate regression analysis revealed a highly significant negative linear relationship between Stanford-Binet IQ scores and contemporary PbB levels over the entire range of 6-47 pg/dL (mean,... 

According to the investigators, the lack of association with lead rank indicated that the effect of lead was due to current rather than past lead exposure. The probability that a child was hyperactive increased significantly with increasing PbB levels (as PbB percentile rank within age group). The probability of speech impairment, however, was not related to blood lead levels. Linear regression analysis... 

Analysis of the unadjusted data showed that all postnatal blood lead levels were inversely associated with Full Scale IQ measured at age 10 however, only the associations involving PbB level at ages 10 years,... 

A later analysis (Emhart et al. 1987) related PbB levels obtained at delivery (maternal and cord blood) and at 6 months, 2 years, and 3 years of age to developmental tests (MDI, PDI, Kent Infant Development Scale [KID], and Stanford-Binet IQ) administered at 6 months, 1 year, 2 years, and 3 years of age, as appropriate. After controlling for covariates and confounding risk factors, the only significant associations of blood lead with concurrent or later development were an inverse association between maternal (but not cord) blood lead and MDI, PDI, and KID at 6 months, and a positive association between 6-month PbB and 6-month KID. The investigators concluded that, taken as a whole, the results of the 21 analyses of correlation between blood lead and developmental test scores were "reasonably consistent with what might be expected on the basis of sampling variability," that any association of blood lead level with measures of development was likely to be due to the dependence of both PbB and... 

In a historical cohort mortality study of 1,990 primary lead smelter workers, an SMR of 2.04 for mortality from renal cancer was calculated (Selevan et al. 1985). The cohort consisted of workers who had worked at least 1 year, with at least 1 day of employment at the smelter between 1940 and 1965. The cohort had been heavily exposed to lead and in 1976 the PbB levels averaged 56.3 pg/dL. Exposures to cadmium and arsenic were generally minor. A follow-up study of this cohort was conducted from 1977 through 1988 (Steenland et al. 1992). Analysis of the follow-up study revealed an excess of kidney cancer, particularly in the high-lead group (SMR 2.39). Although, as the authors indicate, the study is... 

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