About the Data
About Childhood Lead Data
Lead poisoning is caused by swallowing or breathing lead. Lead can stay in your body for a long time. Young children absorb lead more easily than adults. The harm done by lead may never go away. Even low levels of lead can harm the health of a child. There is no safe level of lead exposure. Lead in the body can hurt the brain, kidneys, and nervous system, slow down growth and development, make it hard to learn, damage hearing and speech, and cause behavior problems. However, lead poisoning is preventable. Most children who have lead poisoning do not look or act sick. A simple screening test is the only way to identify a child with elevated blood lead levels. For this reason, state law requires that all children must be screened for lead poisoning each year through the age of three (children in high risk communities must be screened again at age four). All children must show proof of screening at least once in order to enter daycare, pre-kindergarten programs, and kindergarten. The U.S. Centers for Disease Control and Prevention (CDC) used a reference value of 5 micrograms per deciliter (µg/dL) to identify children with blood lead levels higher than most children’s levels from 2012-2021. Public Health officials use this reference value to identify children who have been exposed to lead and who require case management. In October 2021, CDC lowered this reference value to 3.5 µg/dL.
Lead paint continues to be the most important source of elevated blood lead levels in children. The older a house or apartment, the more likely it is to contain lead paint. Homes built before 1978 may have lead paint on the inside and outside of the building. Deteriorating paint (chipping, flaking, and peeling) and paint disturbed during home remodeling often results in the release of tiny paint chips and lead dust that children get onto their hands and into their mouth. Children can also breathe in lead dust. Lead dust also comes from opening and closing old windows. The key to preventing lead poisoning is to stop children from coming into contact with lead and managing the care of those who have been poisoned by lead. In order to do that:
- Homes must be inspected for lead hazards
- Lead in a child’s environment must be removed or properly contained
- All public and health care professionals have to be educated about lead poisoning and how to prevent it
- Children who are at risk of lead poisoning need to be tested and, if necessary, treated
- Home renovation and repairs must be done following lead safe work practices
Lead from sources other than housing may also present a hazard to children. Other sources of lead include:
This data set was created for the MDPH Population Health Information Tool to help identify disparities in childhood lead poisoning and community health needs for public health prevention and intervention.
How prevalence is calculated:
Data on childhood blood lead poisoning is presented by calendar year. Data by calendar year provides blood lead screening percentages and blood lead level prevalence based on the year in which the child was tested for children between the ages of 9 and 47 months. If a child had multiple tests within the same calendar year, only the highest confirmed test is included for that year. A confirmed test result is one venous test or two capillary tests (within 12 weeks of each other) during a given year. For determining prevalence, children can be counted only once per year, but can appear in multiple years. Prevalence is the number of tests in a given blood lead level category out of all the children screened in that year within specific age ranges, per 1,000 children.
The data is stratified by year of screening, county of residence, and community of residence. The data is available by individual year as well as by an aggregate of 5 year groupings. The 5 year groupings are provided as an alternative to avoid suppression frequently found in individual years. Data is suppressed when the number of children screened or case count is between 1-5 and population or total screened is less than 1,200. These small numbers are suppressed to protect privacy.
In order to assess statistical significance, 95% confidence intervals are presented for percentages and prevalence. Non-overlapping confidence intervals are statistically significant. The data does not include complete race/ethnicity information.
Confirmed versus unconfirmed test results:
Confirmed blood lead levels include both venous and confirmed capillary test results. Unconfirmed blood lead levels include single capillary test results only. Estimated confirmed blood lead levels ≥5 µg/dL include both confirmed results and a proportion of unconfirmed results estimated to be truly elevated based on known capillary test reliability. This measure is used because a single capillary test does not provide adequate precision or reliability to be considered confirmatory of an elevated blood lead level. Until confirmatory testing of preliminary capillary tests 5-<10 µg/dL is uniformly adopted per the 2017 regulation requirements, a calculation is used to estimate the true number of children with blood lead levels ≥5 µg/dL.