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.

Environmental causes of violence.

Violent and anti-social behavior is usually attributed to social factors, including poverty, poor education, and family instability. There is also evidence that many forms of violent behavior are more frequent in individuals of lower IQ. The role of exposure to environmental contaminants has received little attention as a factor predisposing to violent behavior. However a number of environmental exposures are documented to result in a common pattern of neurobehavioral effects, including lowered IQ, shortened attention span, and increased frequency of antisocial behavior. This pattern is best described for children exposed to lead early in life, but a similar pattern is seen upon exposure to polychlorinated biphenyls and methyl mercury. Although not as extensively studied, similar decrements in IQ are seen upon exposure to arsenic and secondhand smoke (SHS) exposure. Prenatal and postnatal SHS exposure is also associated with increased rates of conduct disorder and attention deficit hyperactivity. Recent evidence suggests that temporal trends in rates of violent crime in many nations are consistent with earlier preschool blood lead trends, with a lag of about 20 years. These ecologic correlations are consistent with many controlled studies suggesting that lead-exposed children suffer irreversible brain alterations that make them more likely to commit violent crimes as young adults. If this pattern is true for lead and other contaminants, the most effective way to fight crime may be to prevent exposure to these contaminants.

Trends in preschool lead exposure, mental retardation, and scholastic achievement: association or causation?

This study shows that 1936-1990 preschool blood lead trends explain 65% of the 1948-2001 variation in USA mental retardation (MR) prevalence, 45% of the 1953-2003 variation in the average scholastic achievement test (SAT) verbal score, and 65% of the 1953-2003 variation in the average SAT math score. These temporal relationships are characterized by best-fit time lags (highest R(2) and t-value for blood lead) consistent with lead-induced cognitive damage in the first year of life: a 12-year lag for school-age MR, and a 17-year lag for SAT scores. Recent shifts in age-specific MR prevalence are consistent with recent trends in preschool blood lead. SAT and MR trends by race are consistent with racial differences in how 1960s slum clearance affected childhood exposure to severe lead paint hazards. SAT trends by Hispanic origin are consistent with an especially sharp fall in preschool blood lead in New York City since 1970.

Monetary benefits of preventing childhood lead poisoning with lead-safe window replacement.

Previous estimates of childhood lead poisoning prevention benefits have quantified the present value of some health benefits, but not the costs of lead paint hazard control or the benefits associated with housing and energy markets. Because older housing with lead paint constitutes the main exposure source today in the US, we quantify health benefits, costs, market value benefits, energy savings, and net economic benefits of lead-safe window replacement (which includes paint stabilization and other measures). The benefit per resident child from improved lifetime earnings alone is $21,195 in pre-1940 housing and $8685 in 1940-59 housing (in 2005 dollars). Annual energy savings are $130-486 per housing unit, with or without young resident children, with an associated increase in housing market value of $5900-14,300 per housing unit, depending on home size and number of windows replaced. Net benefits are $4490-5,629 for each housing unit built before 1940, and $491-1629 for each unit built from 1940-1959, depending on home size and number of windows replaced. Lead-safe window replacement in all pre-1960 US housing would yield net benefits of at least $67 billion, which does not include many other benefits. These other benefits, which are shown in this paper, include avoided Attention Deficit Hyperactivity Disorder, other medical costs of childhood lead exposure, avoided special education, and reduced crime and juvenile delinquency in later life. In addition, such a window replacement effort would reduce peak demand for electricity, carbon emissions from power plants, and associated long-term costs of climate change.

Understanding international crime trends: the legacy of preschool lead exposure.

This study shows a very strong association between preschool blood lead and subsequent crime rate trends over several decades in the USA, Britain, Canada, France, Australia, Finland, Italy, West Germany, and New Zealand. The relationship is characterized by best-fit lags (highest R2 and t-value for blood lead) consistent with neurobehavioral damage in the first year of life and the peak age of offending for index crime, burglary, and violent crime. The impact of blood lead is also evident in age-specific arrest and incarceration trends. Regression analysis of average 1985-1994 murder rates across USA cities suggests that murder could be especially associated with more severe cases of childhood lead poisoning.

Validation of a 20-year forecast of US childhood lead poisoning: Updated prospects for 2010.

We forecast childhood lead poisoning and residential lead paint hazard prevalence for 1990-2010, based on a previously unvalidated model that combines national blood lead data with three different housing data sets. The housing data sets, which describe trends in housing demolition, rehabilitation, window replacement, and lead paint, are the American Housing Survey, the Residential Energy Consumption Survey, and the National Lead Paint Survey. Blood lead data are principally from the National Health and Nutrition Examination Survey. New data now make it possible to validate the midpoint of the forecast time period. For the year 2000, the model predicted 23.3 million pre-1960 housing units with lead paint hazards, compared to an empirical HUD estimate of 20.6 million units. Further, the model predicted 498,000 children with elevated blood lead levels (EBL) in 2000, compared to a CDC empirical estimate of 434,000. The model predictions were well within 95% confidence intervals of empirical estimates for both residential lead paint hazard and blood lead outcome measures. The model shows that window replacement explains a large part of the dramatic reduction in lead poisoning that occurred from 1990 to 2000. Here, the construction of the model is described and updated through 2010 using new data. Further declines in childhood lead poisoning are achievable, but the goal of eliminating children's blood lead levels > or =10 microg/dL by 2010 is unlikely to be achieved without additional action. A window replacement policy will yield multiple benefits of lead poisoning prevention, increased home energy efficiency, decreased power plant emissions, improved housing affordability, and other previously unrecognized benefits. Finally, combining housing and health data could be applied to forecasting other housing-related diseases and injuries.