Highlights

Lead exposure in children can cause permanent neurological damage (1). Behavioral disorders are associated with lead exposure even at detectable blood levels at or below 5 µg/dL (1–4). The most common highly concentrated source of lead for children in the United States is lead paint. When paint containing lead deteriorates into flakes, chips, or fine dust, it is easily inhaled or ingested by small children.

In 2011, a total of 34 states, the District of Columbia, and New York City submitted BLL data to CDC; however by 2013, only 27 states, the District of Columbia, and New York City submitted data (a 17% reduction in contributors). By 2014, the number of states reporting childhood blood lead data increased to 30 states, the District of Columbia, and New York City. Although the decrease in state and local health departments submitting data to CDC makes it difficult to assess the trend over time, it is still possible to evaluate new cases of children with confirmed BLLs ≥10 µg/dL and cases in children with BLLs 5–9 µg/dL from the jurisdictions that continue to submit data to CDC.

In 2014, during the warmest weather months (August–October), 36% of new cases were identified, more than any other consecutive 3-month period (Table 1). In warm weather, windows possibly painted with lead-based paint are opened and closed, creating lead dust in the air and on the ground (13). Repainting and renovation activities also are more common in warmer months. Increased presence and activity of children in and around the home might lead to children having more contact with contaminated dust, surfaces, and soil (14). This contact can lead to higher BLLs in the late summer and early fall.

The East North Central region reported the greatest number of new cases in 2014 with 3,157 children aged <5 years with newly confirmed BLLs ≥10 µg/dL reported to CDC, followed by the Mid-Atlantic region, with 2,865 children (Table 2). These two regions (comprising nine state and local health departments that reported data) accounted for 68% of the new cases in the United States and for approximately 49% of the children aged <5 years tested and reported to CDC for 2014 (data not shown). The other seven geographic areas (comprising 23 jurisdictions that reported data to CDC for 2014) accounted for the remaining 32% of new cases and for 51% of the children aged <5 years tested and reported to CDC for 2014.

The number of children aged <5 years with a first-ever confirmed BLL ≥10 µg/dL reported to CDC, continued to decrease from 2009 to 2013, but increased in 2014 when federal funding was restored (Table 3). Although not all jurisdictions reported data to CDC, the denominator is the entire child population aged <1 year and aged 1–4 years from the U.S. Census across all years. Children aged 1–4 years continue to have a higher rate of confirmed BLLs ≥10 µg/dL than children <1 year across all years (50.7% vs 19.9% respectively), possibly because of increased hand-to-mouth activity and mobility for younger children. The prevalence of children aged <5 years with a BLL 5–9 µg/dL also declined until 2014 (Table 4). The rate of decline for children with BLLs 5–9 µg/dL (Table 4) is sharper than the rate for children with newly confirmed BLLs ≥10 µg/dL (Table 3) over time (67% and 45% versus 49% and 36%).

The numbers of newly confirmed children with BLLs ≥70 µg/dL remains inconsistent over the past 6 years. Changes in the number of states reporting data to CDC over these 6 years make it difficult to show any trend or clear pattern. One Healthy People 2010 environmental health objective was eliminating BLLs ≥10 µg/dL (15). These children have BLL’s at least seven times above the Healthy People 2010 goal.

Prevalence data indicate that 76,680 children aged <5 years had BLLs 5–9 µg/dL in 2014 (Table 5). A blood lead test is collected through either a capillary or venous sample. In a small number of tests, the sample type was unknown, and for analysis purposes, was combined with capillary samples. A single capillary test is not a confirmatory test, but in 2014, of the 76,680 children aged <5 years tested and reported to CDC with BLLs 5–9 µg/dL, 41% had a confirmed BLL 5–9 µg/dL by venous sample type. The change in the reference value in 2012, and the loss of federal funding to state and local health departments from CDC, made it difficult for most states to extend follow up testing for capillary tests 5–9 µg/dL. Although venous blood lead samples have been the gold standard, one study has shown that capillary blood draws are suitable alternatives to venous blood draws when screening children aged <6 years to determine lead exposure and provide reasonable estimates at the population level (16).

During 2009–2011, a majority of the children aged <5 years with BLLs ≥5 µg/dL had BLLs 5–9 µg/dL (Figure 2). The percentage of children with confirmed BLLs ≥10 µg/dL increased from 7.6% to 13.4% during the same period. CDC, along with state and local health departments, continues efforts to reduce BLLs ≥5 µg/dL and confirmed BLL ≥10 µg/dL through screening and primary prevention (17).

Effective surveillance requires state and local health departments to track a substantial number of children and their blood lead test results over time. More detailed annual summaries describing the number of children tested for lead by state, county, and BLL are published periodically by CDC; a summary of childhood lead exposure in 2014, the most recent year for which data is available, is provided at https://www.cdc.gov/nceh/lead.