The Evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program studied the effectiveness of the housing intervention performed in reducing the blood lead of children at four post-intervention times (6-months, 1-year, 2-years, and 3-years). A repeat measures analysis showed that blood lead levels declined up to three-years post-intervention. The results at each successive collection time were significantly lower than at the previous post-intervention time except for the difference between the levels at two and three years. At two-years post-intervention, geometric mean blood lead levels were approximately 37% lower than at pre-intervention. Children with pre-intervention blood lead levels as low as 10 μg/dL experienced substantial declines in blood lead levels. Previous studies have found substantial improvements only if a child's pre-intervention blood lead level was above 20 μg/dL. Individual interior lead hazard control treatments as grouped by Interior Strategy were not a significant predictor of post-intervention blood lead levels. However, children living in dwellings where exterior lead hazard control interventions were done had lower blood lead levels at one-year post-intervention than those living in dwellings without the exterior interventions (all other factors being equal), but those differences were only significant when the mean exterior paint lead loading at pre-intervention was about the 90th percentile (7.0mg/cm(2)). This observation suggests that exterior lead hazard control can be an important component of a lead hazard control plan. Children who were six to eleven months of age at pre-intervention had a significant increase in blood lead at one-year post-intervention, probably due to other exposures.
This study is an examination of the effect of lead hazard control strategies on children's blood lead levels immediately after an intervention was conducted as part of the US Department of Housing and Urban Development's Lead-Based Paint Hazard Control Grant Program. Fourteen state and local government grantees participated in the evaluation. The findings indicated an overall average reduction in the blood lead levels of 869 children soon after the implementation of lead hazard controls. However, 9.3% of these children (n=81) had blood lead increases of 5 μg/dL or more. Data routinely collected as part of the evaluation, as well as additional information supplied by the individual programs, were used to determine potential reasons for these observed increases in blood lead. A logistic regression analysis indicated that three principal factors were associated with the blood lead increases: the number of exterior deteriorations present in the child's home (prior to intervention), the educational level of the female parent or guardian of the child, and the child's age. The statistical analysis did not find evidence that children living in households that either did not relocate or relocated for less than the full work period were significantly more likely to have a blood lead increase equal to or greater than 5 μg/dL than children living in households that fully relocated. Statistical analyses also did not reveal any single interior strategy to be more or less likely than others to be associated with a blood lead increase of 5 μg/dL or more.
Arsenic residues in the communities surrounding former smelters remain a public health concern, especially for infants and children. To evaluate environmental exposure among these children, a population-based cross-sectional study was conducted in the vicinity of a former copper smelter in Anaconda, Montana. A total of 414 children less than 72 months old were recruited. First morning voided urine samples and environmental samples were collected for arsenic measurements. The geometric mean of speciated urinary arsenic was 8.6 microg/liter (GSD = 1.7, N = 289). Average arsenic levels of different types of soil ranged from 121 to 236 microg/g and were significantly related to proximity and wind direction to the smelter site. The same significant relationship was observed for interior dust arsenic. Speciated urinary arsenic was found to be significantly related to soil arsenic in bare areas in residential yards (P < 0.0005). In general, elevated excretion of arsenic was demonstrable and warranted parents' attention to reduce exposure of their children to environmental arsenic.
Urinary arsenic concentration has been used generally for the determination of exposure, but much concern has been raised over the most appropriate expression for urinary arsenic levels. In this study, we examined the influence of various adjustments of expressing urinary arsenic data. All children who were less than 72 mo of age and who were potty trained were invited to participate in the present study. Urine, soil, and dust samples Were collected, and arsenic measurements were made. The geometric mean of speciated urinary arsenic among children who provided first-voided urine samples on 2 consecutive mornings was 8.6 mu g/l (geometric standard deviation = 1.7, n = 289). Speciated urinary arsenic was related significantly to soil arsenic in bare areas (p <.0005). Use of a single urine sample versus the average of two first-voided urine samples collected on 2 consecutive mornings did not significantly alter the relationship between environmental arsenic and urinary arsenic levels. Furthermore, none of the adjustments to urinary concentration improved the strength of correlation between urinary arsenic and soil arsenic levels. Concentration adjustments may not be necessary for urinary arsenic levels obtained from young children who provide first-void samples in the morning.
The final clean-up of residential lead abatement projects in federally-supported housing, as well as in other housing in a number of states, must meet surface dust lead clearance levels expressed as μg of lead per square foot. These clearance levels were established because hand-to-mouth ingestion of lead-contaminated dust is recognised as a major pathway through which many children are exposed. A dilemma exists because many floors in housing undergoing abatement are carpeted and the established clearance levels are generally not recommended for use on carpets. These clearance levels are also used as 'action levels' to determine whether exposure reduction activities are needed. The US Environmental Protection Agency is currently in the process of issuing standards for hazardous levels of lead in interior dust and bare soil under Title X of the Housing and Community Development Act of 1992, ‘The Residential Lead-Based Paint Hazard Reduction Act of 1992’. An effort to develop a potential surface dust lead clearance level for carpets was made using an existing vacuum dust collection method that has previously been shown to be a reliable indicator of childhood lead exposure. This method was designed for use on carpeted and non-carpeted surfaces. Using data from the Cincinnati Soil Lead Abatement Demonstration Project, the suggested floor-dust lead level where an estimated 95% of the population of children would be expected to have blood lead values below the national goal of 10 μg dL−1, was more than an order of magnitude lower than the current floor-dust lead clearance level of 1080 μg m−2 (100 μg ft−2). Further comparisons of blood lead and carpet lead levels in other parts of the country should be performed before a risk-based lead loading clearance level is established.