Window replacement and residential lead paint hazard control 12 years later.

Window replacement is a key method of reducing childhood lead exposure, but the long-term effectiveness has not been previously evaluated. Windows have the highest levels of interior lead paint and dust compared to other building components. Our objective was to conduct a follow-up study of residential window replacement and lead hazard control 12 years after homes were enrolled in an evaluation of the HUD Lead Hazard Control Grant Program, sampling settled lead dust in housing in four cities (n=189 homes). Previous work evaluated lead hazard controls up to 6 years after intervention using dust lead measurements and two years after intervention using both dust and blood lead data. But the earlier work could not examine the effect of window replacement over the longer time period examined here: 12 years. The individual homes were assigned to one of three categories, based on how many windows had been replaced: all replacement, some replacement, or non-replacement. Windows that were not replaced were repaired. We controlled for covariates such as site, housing condition, presence of lead paint, and season using longitudinal regression modeling. Adjusted floor and sill dust lead geometric mean dust lead loadings declined at least 85% from pre-intervention to 12 years after the intervention for homes with all replacement windows, some windows replaced and no windows replaced. Twelve years after intervention, homes with all replacement windows had 41% lower interior floor dust lead, compared to non-replacement homes (1.4 versus 2.4 µg/ft2, p<0.001), and window sill dust lead was 51% lower (25 versus 52 µg/ft2, p=0.006) while controlling for covariates. Homes with some windows replaced had interior floor and window sill dust lead loadings that were 28% (1.7 versus 2.4 µg/ft2, p=0.19) and 37% (33 versus 52 µg/ft2, p=0.07) lower, respectively, compared to non-replacement homes. The net economic benefit of window replacement compared to window repair (non-replacement) is $1700-$2000 per housing unit. Homes in which all windows were replaced had significantly lower lead dust. New windows are also likely to reduce energy use and improve home value. Lead-safe window replacement is an important element of lead hazard control, weatherization, renovation and housing investment strategies and should be implemented broadly to protect children.

Longevity of the effectiveness of interim soil lead hazard control measures and influencing factors.

A 7-year follow-up was conducted to determine factors associated with the longevity of interim soil lead hazard control measures that had been applied to housing in the Cleveland OH area. The approach involved (1) visual determination of the treatment integrity, (2) collection of information regarding 14 factors that may contribute to longevity of treatment integrity and (3) collection of one composite soil sample from treated areas with visual failure at each house and another composite sample from areas without visual failure. For the 200 houses studied, an average of 4 different soil areas were treated. For 96% of these areas, the treatments used were: (1) re-seeding, (2) mulch/wood chips and (3) gravel. Of a total of 191,034 ft(2) of treated soil areas observed, less than one-third, i.e. 59,900 ft(2) (31.3%) exhibited visual failure at the time of follow-up. Hazard control method and the presence/absence of shade were the only factors found to significantly affect visual failure rates. Of the three most commonly used control measures, the lowest visual failure rate was for re-seeding, 29.1% after a mean of 7.3 years; for non-shaded areas, which had been re-seeded, the failure rate was 22.2% compared to 35.7% for shaded areas. At 116 of the 193 houses (60%) that had both visually failed and visually non-failed treated soil areas, the geometric mean soil lead concentration was higher in the failed areas (p=0.003). The actual difference was only 13% with most levels equal to or exceeding 400 ppm. However, when compared to the US EPA limit for bare soil in other residential areas (1200 ppm) the percent equal to or exceeding the limit was much higher in the visually failed areas, 33.1%, than in areas where such failure was not observed, 22.0%.

Lead loadings in household dust in Delhi, India.

Lead in household dust is dangerous to children who ingest lead from playing close to the ground, and having frequent hand-to-mouth contact. Although there have been several investigations of lead levels in India in air, blood and new paint, the literature is sparse on the levels of lead in household dust. This study analyzed 99 samples of dust taken from bare floors and 49 samples of dust taken from windowsills in a cross-section of Delhi, India houses for lead loadings. The arithmetic mean of lead loading for floor samples and windowsill dust samples was found to be 36.24 microg/ft(2) and 129.5 microg/ft(2), respectively. The geometric mean of dust lead loading for floor and interior windowsill samples was found to be 19.7 microg/ft(2) and 75.5 microg/ft(2), respectively. Comparing the results with US geometric mean dust lead levels from a national cross-section of US housing, which in 2000 were 1.1 microg/ft(2) and 9.4 microg/ft(2) on floors and windowsills, respectively as reported by Jacobs et al. (2002) suggests that the lead content of the dust in Delhi homes is much higher than that in the national data in the US and that the levels pose a hazard to children. Practical Implications The present study is first of its kind in this part of the world. In the context of ongoing efforts to eliminate lead from paints worldwide this research will help the scientists and policy makers in assessing the Children's exposure to lead in developing country as well. Since more than one half of the housing units tested had at least one dust lead sample exceeding US health-based standards, health care providers and public health officials need to give attention to possible lead poisoning in Delhi children. Routine blood lead screening of children should follow recommended public health practice for children at risk. Additional larger-scale studies are needed in Delhi and elsewhere to determine how representative these findings are and to attempt to delineate the sources of the high dust lead which are expected to vary depending on the location. Knowledge of the sources is needed to appropriately allocate resources. From other studies performed in India it is likely that lead-based paint is one of the sources and its continued use should be discontinued.

Health hazards by lead exposure: evaluation using ASV and XRF.

Globally, of many toxic heavy metals, lead is the most widely used for various purposes, resulting in a variety of health hazards due to environmental contamination. Lead in the workplace enters the workers through inhalation of lead-contaminated air, by ingestion, and sometimes through dermal exposure. Furthermore, exposure outside the workplace can occur from inhalation of lead-contaminated air, ingestion of lead-contaminated dust and soil, consumption of lead polluted water, lead adulterated food and lead supplemented medicine. In the present study, an evaluation of blood lead was carried out with the aid of a 3010 B lead analyser, based on the principle of anodic stripping voltametry (ASV), and environmental lead in paint, soil and dust samples by a field portable X-ray fluorescence (XRF) analyser. This revealed a high incidence of lead toxicity in most of the lead-based industrial workers in the four facilities tested in India and high levels of lead in the environmental samples. Developed countries have complied with the global standards for regulating environmental lead poisoning in the workplace, eliminating to some degree excessive exposure to lead. A developing country, such as India, can tackle this problem by implementing national and international policies. The US Occupational Safety and Health Administration (OSHA) and Environmental Protection Agency (EPA) regulations, which are of prime importance, or similar regulations, can be adapted for use in India and implemented to minimize lead exposure and to reduce the resultant health hazards.

Effectiveness of lead-hazard control interventions on dust lead loadings: findings from the evaluation of the HUD Lead-Based Paint Hazard Control Grant Program.

From 1994 to 1999, the Evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program studied the intervention experiences of over 2800 homes in 11 states in the USA. Each interior intervention was categorized as (in order of increasing intensity) (a) cleaning/spot painting; (b) complete repainting; (c) complete repainting plus window treatments; (d) window abatement plus treatments to other components; (e) abatement of all lead-based paint hazards; or (f) abatement of all lead-based paint. Complete dust testing and environmental data were available for 1034 and 278 dwellings through 12 and 36 months postintervention, respectively. Strategies ranging from complete repainting to window abatement plus other treatments reduced geometric mean preintervention windowsill and floor dust lead loadings up to 36 months postintervention (reductions for complete repainting, from 16 to 5 microg/ft2 on floors and 182 to 88 microg/ft2 on sills; for window abatement plus other treatments, 27-8 microg/ft2 on floors and 570-124 microg/ft2 on sills). Full abatement reduced windowsill and floor loadings from baseline to 12 months postintervention [95-6 microg/ft2 on floors and 518-30 microg/ft2 on sills (data were not available for this strategy at 36 months)]. Window lead-hazard abatement was the most effective measure to reduce dust lead loadings on windows, but this treatment would need to be performed in conjunction with treatments to floors as well as exterior and soil treatments for the most effective control of dust lead on floors.