Lead Data

Testing of Childhood Blood Lead Levels in Allegheny County

In 2021, the Allegheny County Health Department began collecting data for the new reference limit for elevated blood lead level of 3.5 μg/dL. This captured an additional 0.77% of the venous confirmed tests to be identified as elevated.

The number of children under 6 tested for blood lead levels with a venous confirmation in 2021 compared to 2020 is very similar. However, the percent of elevated lead levels at the 5 μg/dL reference level increased slightly from 1.67% to 1.91%, but is still lower compared to 2015–2018.

Weekly data from 2021 indicate steady blood lead level testing throughout the year, with more testing at the beginning of the year compared to the end.

In 2021, the greatest number of children under 6 were tested in the month of March and the least were tested in September.

The City of Pittsburgh consistently has a higher rate of confirmed elevated blood lead levels among children tested compared to the rest of the county. In 2021, the increase in percent of elevated blood lead levels (>= 5 μg/dL) in Allegheny County can be attributed to an increase in the City of Pittsburgh. Exposure to lead through lead-based paint in older homes is a significant risk for elevated blood lead and may help to explain the different rates of EBLL between the City and the remainder of the County. Lead paint was banned for consumer use in 1978; houses built prior to this are at an increased likelihood of containing lead-based paint. The older the home the higher the likelihood of containing lead-based paint. In the city of Pittsburgh an estimated 59.6% of housing units were built before 1950 compared to 39.1% of all county housing units. A higher percentage of homes built prior to the banning of lead paint likely contributes to an increased risk of exposure for children living in this area.

See "Housing Built Before 1980" and "Housing Built Before 1950" in the Maps and Testing Data section below.

Allegheny County’s universal testing policy requires a child’s first test to be completed between 9–12 months of age. According to Pennsylvania’s age range requirements for screening visits, 412 days is the maximum age to complete the 1 year screening visit. The percent of Allegheny County children who received testing for lead by the age of 412 days has increased since 2014. Of all Allegheny County children tested in 2021, 36.5% were under the age of 1.

Testing Story Map

View the above Story Map on the ARCGIS website

Testing Data

• Aggregated Percent of Children Tested with Elevated Blood Lead Levels by Census Tract, 2017 – 2021(PDF, 200KB)
• Aggregated Percent of Children Tested with Elevated Blood Lead Levels by Municipality and Neighborhood, 2017 – 2021(PDF, 162KB)
• Aggregated Percent of Children Tested with Elevated Blood Lead Levels by School District, 2017 – 2021(PDF, 108KB)

Additional Data

• Allegheny County Priority Lead Risk Factor and Elevated Blood Lead Level Areas by Census Tract (Map)(PDF, 972KB)
• Housing Built Before 1950(PDF, 4MB)
• Housing Built Before 1980(PDF, 4MB)

• December 2017 Lead Task Force Final Report and Recommendations(PDF, 3MB)
• September 2018 Inaugural Allegheny County Lead Report(PDF, 2MB)
• December 2022 Allegheny County Lead Report(PDF, 2MB)

≥3.5 µg/dL – The Health Department currently treats confirmed blood lead level tests with 3.5 µg/dL or more of lead as elevated. This measurement is based off of the Centers for Disease Control and Prevention’s definition established in 2012.

Elevated capillary without follow up – Capillary tests are preliminary tests that can identify if a child does not have an elevated blood lead level. However, if a capillary test returns an elevated level, then it must be confirmed by a venous blood test. The Health Department is encouraging pediatricians to have children with elevated capillary tests confirmed in a timely manner.

Percent confirmed elevated (children with a confirmed elevated test / all children tested) – The percent of elevated blood lead levels that the Health Department follows is the number of individual children with confirmed elevated tests (only blood venous tests count as confirmed tests) divided by the number of individual children tested. For county–wide stratified data (5 – 9.9 µg/dL, 10 + µg/dL), a child’s highest confirmed value is used. Measurements are not affected by multiple elevated blood tests for a single child in a single period.

Elevated capillary lead level without follow up – Capillary tests are preliminary tests that can identify if a child does not have an elevated blood lead level. However, if a capillary test returns an elevated level, then it must be confirmed by a venous blood test. The Health Department encourages pediatric health care provider to obtain a venous blood lead test for children with elevated capillary tests.

Children (study population)– Lead surveillance is focused on children under age six years in alignment with state and national surveillance standards. Lead is particularly toxic to the developing brain and the hand-to-mouth habits of young children put them at increased risk of ingestion from contaminated sources.

Data accuracy is dependent upon laboratory reporting – The accuracy of blood test results for lead reported to the Health Department is dependent on the laboratory conducting the tests and reporting the results. Different laboratories use different instruments to test blood samples.

Potential biases in those who are getting tested – Mandatory lead testing for children will be implemented in Allegheny County on January 1, 2018. Children voluntarily tested for lead before that date may have received a blood test for a specific reason. This means that community data before 2018 may not be fully representative of the total population.

Technical Resources

• Health Note(PDF, 420KB)
• PA NEDSS, ACHD & You(PDF, 253KB)
• ACHD Lead Data Technical Changes Timeline(PDF, 109KB)