WIC Participation and Blood Lead Levels among Children 1–5 Years: 2007–2014
Authors: Yutaka Aoki, and Debra J. Brody
Childhood lead exposure can result in lower IQ, reduced attention span and increased behavioral problems, as well as physical health problems. Many of the effects of lead poisoning are irreversible.
Lead is most commonly measured in our bodies through blood testing, and levels reported as “blood lead levels” (BLL). In 2012 the Centers for Disease Control and Prevention (CDC) set the reference BLL for children aged 1-5 at 5 micrograms of lead per deciliter of blood (5 μg/dL). CDC recommends initiation of public health actions when children exceed this reference level. However it is not a health-based standard. Rather, the 5 μg/dL level is based on the highest 2.5% of children when tested for lead in their blood. No level of lead exposure is considered safe.
CDC estimates that approximately half a million U.S. children have BLLs above 5 μg/dL. However, some researchers estimate the number of children with elevated BLLs to be closer to 1.2 million.
Children who live in older, poorly maintained houses, which may contain lead paint or drinking water service lines, are at higher risk for elevated BLL. Since families of lower socioeconomic status are more likely to live in such housing, children enrolled in certain public assistance programs are required to be screened for lead exposure. Initially, the Centers for Medicare and Medicaid Services (CMS) only required screening of children receiving Medicaid. However, this excluded a portion of the population with incomes deemed too high to be eligible for Medicaid, but not too high to qualify for the Special Supplemental Nutrition Program for Women, Infants and Children (WIC). In 2012 CMS began targeting participants in WIC. Prior to this study, there were very few reports on the BLLs of children participating in WIC but not in Medicaid.
This study investigates whether children enrolled in WIC but not in Medicaid have higher BLLs than children in neither program.
The study examines data from the annual National Health and Nutrition Examination Survey (NHANES). The dataset included 3,180 U.S. children 1-5 years of age. Blood samples from each NHANES participant were analyzed for blood lead. Results were separated into samples with under 5 micrograms of lead per deciliter of blood (<5 µg/dL) and 5 or greater micrograms of lead per deciliter of blood (≥5 µg/dL), where the latter was considered high. Results were then adjusted for age, race/Hispanic origin, WIC status and/or Medicaid status, WIC eligibility and urbanization.
The prevalence of elevated BLL for the entire dataset was 1.9%. For children enrolled in WIC, Medicaid, and both WIC and Medicaid, prevalence was higher than in children enrolled in neither program. Additionally, children who were not enrolled but were income-eligible for WIC had a greater prevalence of elevated BLL than children who were not eligible. Age and race/Hispanic origin did not significantly affect the association between WIC/Medicaid status and elevated BLL.
The results suggest that children enrolled in WIC, Medicaid, or both programs are more likely to have elevated BLL than children in neither program. This includes children 1-2 years of age, which is the age range targeted by CMS for required blood lead screening tests. Therefore, targeting children enrolled in WIC for blood lead tests would indeed identify additional children with elevated BLL.
In addition, children who were eligible to receive WIC and/or Medicaid but were not enrolled in either program were more likely to have a high BLL than children who were not eligible. However, low-income children who do not receive WIC or Medicaid are not required to undergo blood lead screenings.
While screening for lead-exposed children is important for intervention and possible treatment, the U.S. needs to focus more funding and effort toward environmental hazard elimination so that children stop being harmed by lead. Efforts to reduce lead exposure should prioritize low-income communities. Efforts should include elimination of lead paint hazards from low-income housing, schools and child care facilities, enforcement of U.S. Environmental Protection Agency (EPA) rules for renovations and repairs when working with lead-based paint, safe replacement of lead service lines that deliver drinking water to between 6-10 million homes in the U.S., and effective and enforced regulations to keep lead out of children’s food and products.
Paint, dust, and soil exposure
Policymakers should continue to strengthen federal standards for many sources of lead exposure. Much of children’s exposure to lead from lead paint is from the dust and flakes from poorly maintained or disturbed lead paint. The EPA has proposed to lower the acceptable standard of lead in dust on floors and windowsills to 10 µg/ft2 and 100 µg/ft2 respectively. This is a good step in the right direction. However, even these proposed new standards may not be sufficient to keep children’s BLL below 5 μg/dL. Additionally, EPA needs to strengthen its standards for lead in paint and soil.
Drinking water exposure
The largest potential source of lead in drinking water comes from lead service lines (LSLs). Although the use of lead pipes was banned in 1986, an estimated 6-10 million LSLs still exist in the U.S., and replacing them will likely cost communities $16-80 billion. The EPA’s Water Infrastructure Finance and Innovation Act (WIFIA) provides subsidies for water infrastructure projects, including the removal of LSLs. Adequate funding for this and for the Drinking Water State Revolving Fund program are essential.
EPA should require regular testing for lead in water in all child care facilities and schools and should also lower its recommended action levels for lead in municipal water systems (15 ppb) and in schools and child care facilities (20 ppb).
Ambient air exposure
In 2008, EPA updated its 1978-era National Ambient Air Quality Standards for lead from 1.5 µg/m3 to 0.15 µg/m3. The Clean Air Act (CAA) requires the EPA to review its standards for lead and other pollutants at five-year intervals based on an extensive science assessment, risk/exposure assessment, and policy assessment. It is crucial that the EPA continue to enforce the CAA and consider the latest scientific evidence when reviewing lead air pollutant standards.
A report released by the Environmental Defense Fund (EDF), Lead in Food: A Hidden Health Threat, states that their analysis of 11 years of the U.S. Food and Drug Administration (FDA) data found lead in 20% of baby food samples and up to 89% of fruit juice samples. FDA needs to lower its current guidance limits to manufacturers, and to make them actual enforceable regulations.
Additionally, FDA’s established maximum daily intake level for lead in foods is 6 µg/day, which was determined in 1993, based on CDC’s then (higher) BLL reference level of 10 µg/dL. Because CDC lowered the BLL reference level to 5 µg/dL in 2012, it is past time for FDA to lower the maximum daily intake level for lead in foods, accordingly. Even at the too-high level it is currently set at, approximately 1 million children exceed the exposure. This reconfirms the need for stronger, enforceable food and juice lead tolerances.
Exposure from consumer products
Children may be exposed to lead through products like toys and jewelry. As regulated by the Consumer Products Safety Commission (CPSC), children’s products may not contain more than 100 ppm of lead. However, many American toy companies have been violating these regulations for years, and overseas manufacturers often do not adhere to the same safety standards as the U.S.
Recent testing found that 81% of dollar store products contain one or more hazardous chemicals, including lead. Dollar stores are less likely than mainstream retail stores like Walmart or Target to identify and remove products with harmful chemicals. Since people in low-income communities are more likely to shop at dollar stores, they are disproportionately affected by the lack of safer chemical policies at these stores.
The CPSC must remain strict in regulating manufacturers and retailers of children’s products and recalling all products that do not meet federal regulations. The Commission should also adopt stricter policies on chemicals in children’s products, require more rigorous testing and inspection of factories, and publicly release the names of factories/manufacturers whose products are recalled from the market. Retailers of children’s products, especially dollar stores, need to ensure that their products use safe chemicals and disclose and eliminate chemicals of concern.
Better screening of, and support services for children should be enacted and enforced to screen all children who are eligible for (whether or not they are enrolled in) government assistance programs so that more children with elevated lead exposure can be identified for interventions and treatment.
Additionally, low income families suffer disproportionately from environmental health hazards, while also facing more barriers to proper healthcare. Policymakers should improve access to quality treatment and wraparound services for children with elevated BLL, who may need specialized care or education programs.
- Clean Air Act, 42 USCS §7409 (1977)
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