Pamela A. Meyer

Trends in Blood Lead Levels and Blood Lead Testing Among US Children Aged 1 to 5 Years, 1988–2004

OBJECTIVES. To evaluate trends in childrens blood lead levels and the extent of blood lead testing of children at risk for lead poisoning from national surveys conducted during a 16-year period in the United States. METHODS. Data for children aged 1 to 5 years from the National Health and Nutrition Examination Survey III Phase I, 1988–1991, and Phase II, 1991–1994 were compared to data from the survey period 1999–2004. RESULTS. The prevalence of elevated blood lead levels, ≥10 μg/dL, among children decreased from 8.6% in 1988–1991 to 1.4% in 1999–2004, which is an 84% decline. From 1988–1991 and 1999–2004, childrens geometric mean blood lead levels declined in non-Hispanic black (5.2–2.8 μg/dL), Mexican American (3.9–1.9 μg/dL), and non-Hispanic white children (3.1 μg/dL to 1.7 μg/dL). However, levels continue to be highest among non-Hispanic black children relative to Mexican American and non-Hispanic white children. Blood lead levels were distributed as follows: 14.0% were <1.0 μg/dL, 55.0% were 1.0 to <2.5 μg/dL, 23.6% were 2.5 to <5 μg/dL, 4.5% were 5 to <7.5 μg/dL, 1.5% were 7.5 to <10 μg/dL, and 1.4% were ≥10 μg/dL. Multivariable analysis indicated that residence in older housing, poverty, age, and being non-Hispanic black are still major risk factors for higher lead levels. Blood lead testing of Medicaid-enrolled children increased to 41.9% from 19.2% in 1988–1991. Only 43.0% of children with elevated blood lead levels had previously been tested. CONCLUSIONS. Childrens blood lead levels continue to decline in the United States, even in historically high-risk groups for lead poisoning. To maintain progress made and eliminate remaining disparities, efforts must continue to test children at high risk for lead poisoning, and identify and control sources of lead. Coordinated prevention strategies at national, state, and local levels will help achieve the goal of elimination of elevated blood lead levels.

Global approach to reducing lead exposure and poisoning

Lead poisoning is an important environmental disease that can have life-long adverse health effects. Most susceptible are children, and most commonly exposed are those who are poor and live in developing countries. Studies of childrens blood-lead levels (BLLs) are showing cognitive impairment at increasingly lower BLLs. Lead is dangerous at all levels in children. The sources of lead exposure vary among and within countries depending on past and current uses. Sources of lead may be from historic contamination, recycling old lead products, or from manufacturing new products. In all countries that have banned leaded gasoline, average population BLLs have declined rapidly. In many developing countries where leaded gasoline is no longer used, many children and workers are exposed to fugitive emissions and mining wastes. Unexpected lead threats, such as improper disposal of electronics and childrens toys contaminated with lead, continue to emerge. The only medical treatment available is chelation, which can save lives of persons with very high BLLs. However, chelating drugs are not always available in developing countries and have limited value in reducing the sequelae of chronic low dose lead exposure. Therefore, the best approach is to prevent exposure to lead. Because a key strategy for preventing lead poisoning is to identify and control or eliminate lead sources, this article highlights several major sources of lead poisoning worldwide. In addition, we recommend three primary prevention strategies for lead poisoning: identify sources, eliminate or control sources, and monitor environmental exposures and hazards.

A global approach to childhood lead poisoning prevention

Childhood lead poisoning is an important, preventable environmental disease affecting millions of children around the world. The effects of lead are well known and range from delayed and adversely affected neurodevelopment to severe health outcomes including seizures, coma, and death. This article reviews the childhood effects of lead poisoning, the approach being taken to the problem in the United States, and the obstacles faced by developing nations in dealing with lead exposure. The United States has attacked the childhood lead poisoning problem by attempting to eliminate sources of exposure, including gasoline, solder in water pipes and cans, and industrial emissions. These actions have resulted in a dramatic reduction in the number of children with elevated blood lead levels in the United States over the last two decades. However, many developing countries are just beginning to address the problem. Successful efforts will need to incorporate epidemiologic methods, source identification, enforced regulations, and a long-term government commitment to eliminating lead as a threat to the next generation of children.

Risk factors associated with clinic visits during the 1999 forest fires near the Hoopa Valley Indian Reservation, California, USA.

Forest fires burned near the Hoopa Valley Indian Reservation in northern California from late August until early November in 1999. The fires generated particulate matter reaching hazardous levels. We assessed the relationship between patients seeking care for six health conditions and PM10 exposure levels during the 1999 fires and during the corresponding period in 1998 when there were no fires. Multivariate logistic regression analysis indicated that daily PM10 levels in 1999 were significant predictors for patients seeking care for asthma, coronary artery disease and headache after controlling for potential risk factors. Stratified multivariate logistic regression models indicated that daily PM10 levels in 1999 were significant predictors for patients seeking care for circulatory illness among residents of nearby communities and new patients, and for respiratory illness among residents of Hoopa and those of nearby communities.

Screening for Lead Poisoning: A Geospatial Approach to Determine Testing of Children in At-Risk Neighborhoods

OBJECTIVE To develop a spatial strategy to assess neighborhood risk for lead exposure and neighborhood-level blood lead testing of young children living in the city of Atlanta, Georgia. STUDY DESIGN This ecologic study used existing blood lead results of children aged <or=36 months tested and living in one of Atlantas 236 neighborhoods in 2005. Geographic information systems used Census, land parcel, and neighborhood spatial data to create a neighborhood priority testing index on the basis of proxies for poverty (Special Supplemental Nutrition Program for Women, Infants and Children [WIC] enrollment) and lead in house paint (year housing built). RESULTS In 2005, only 11.9% of Atlantas 18,627 children aged <or=36 months living in the city had blood lead tests, despite a high prevalence of risk factors: 75,286 (89.6%) residential properties were built before 1978, and 44% of children were enrolled in WIC. Linear regression analysis indicated testing was significantly associated with WIC status (P < .001) but not with old housing. CONCLUSIONS This neighborhood spatial approach provided smaller geographic areas to assign risk and assess testing in a city that has a high prevalence of risk factors for lead exposure. Testing may be improved by collaboration between pediatricians and public health practitioners.

Reduction of Elevated Blood Lead Levels in Children in North Carolina and Vermont, 1996–1999

Background Few studies have examined factors related to the time required for children’s blood lead levels (BLLs) ≥ 10 μg/dL to decline to < 10 μg/dL. Objectives We used routinely collected surveillance data to determine the length of time and risk factors associated with reducing elevated BLLs in children below the level of concern of 10 μg/dL. Methods From the North Carolina and Vermont state surveillance databases, we identified a retrospective cohort of 996 children < 6 years of age whose first two blood lead tests produced levels ≥ 10 μg/dL during 1996–1999. Data were stratified into five categories of qualifying BLLs and analyzed using Cox regression. Survival curves were used to describe the time until BLLs declined below the level of concern. We compared three different analytic methods to account for children lost to follow-up. Results On average, it required slightly more than 1 year (382 days) for a child’s BLL to decline to < 10 μg/dL, with the highest BLLs taking even longer. The BLLs of black children [hazard ratio (HR) = 0.84; 95% confidence interval (CI), 0.71–0.99], males (HRmale = 0.83; 95% CI, 0.71–0.98), and children from rural areas (HRrural = 0.83; 95% CI, 0.70–0.97) took longer to fall below 10 μg/dL than those of other children, after controlling for qualifying BLL and other covariates. Sensitivity analysis demonstrated that including censored children estimated a longer time for BLL reduction than when using linear interpolation or when excluding censored children. Conclusion Children with high confirmatory BLLs, black children, males, and children from rural areas may need additional attention during case management to expedite their BLL reduction time to < 10 μg/dL. Analytic methods that do not account for loss to follow-up may underestimate the time it takes for BLLs to fall below the recommended target level.

Training Public Health Advisors.

Federal public health advisors provide guidance and assistance to health departments to improve public health program work. The Centers for Disease Control and Prevention (CDC) prepares them with specialized training in administering public health programs. This article describes the evolving training and is based on internal CDC documents and interviews. The first federal public health advisors worked in health departments to assist with controlling syphilis after World War II. Over time, more CDC prevention programs hired them. To meet emerging needs, 3 major changes occurred: the Public Health Prevention Service, a fellowship program, in 1999; the Public Health Associate Program in 2007; and integration of those programs. Key components of the updated training are competency-based training, field experience, supervision, recruitment and retention, and stakeholder support. The enduring strength of the training has been the experience in a public health agency developing practical skills for program implementation and management.

Healthier homes for a healthier nation.

The relationship between housing conditions and health was recognized among public health practitioners in the United States and Europe in the early 1800s.2 Growing awareness of the connection between a specific housing condition and a specific health condition or injury resulted in the development of policies and practices to protect the health and safety of people in their homes. The initial focus was to control communicable diseases and to prevent injuries. For example, requiring housing to have proper sewage connections and regular waste removal controlled several infectious diseases, and adoption of electrical codes helped to reduce the number of deaths due to fires. Over time, studies have provided evidence that a home’s physical features can also prevent poisoning and various chronic diseases. These features can support mental and emotional health and independence during a wide range of developmental stages. Such physical features include structural aspects and safety devices in the home (ie, how the home is designed, constructed, and maintained, its physical characteristics, and the presence or absence of safety devices), quality of indoor air, water quality, and chemicals used and stored in the home, as well as the house’s immediate surroundings. Although the evidence supporting the link between housing and health has been increasing, the evidence demonstrating effective interventions to protect health against specific hazards has lagged. In addition, where intervention studies have been reported, public health practitioners may be uncertain about which interventions are likely to be most effective in protecting health. This supplement presents findings from panels of subject matter experts who systematically reviewed ev-