Connecticut Childhood Lead Poisoning Surveillance Report

Prevalence 2020

Prevalence, the number of existing cases of disease in a population, reflects the burden of disease in a population.  Understanding prevalence and the burden of disease can help decision makers determine where efforts and investments should be targeted. 
Prevalence of childhood lead poisoning is defined as the proportion of children under 6 years of age with a confirmed lead test whose blood lead level was ≥5 μg/dL in a specific calendar year. The previous reference value in place since 1991 was 10 μg/dL. A growing body of research identified that blood lead levels below 10 μg/dL can harm children in terms of their IQ, cognitive functions, and academic achievement. In May 2012, the CDC recommended a new “reference value” of 5 μg/dL, for lead poisoning among young children. The State of Connecticut adopted the new reference value in May 2013. As such, Connecticut local health departments (LHDs) are required to initiate public health case management actions for children with a confirmed blood level of ≥5 μg/dL. In October 2021, the CDC further reduced the recommended “reference value” to 3.5 μg/dL. This report defines 5 μg/dL and greater as an elevated blood lead level.

Response Policies for Actionable Blood Lead Levels

Per state laws, CGS Secs. 19a-110(d) and 19a-111, local health departments (LHDs) are responsible for responding to reported venous blood lead levels of 10 μg/dL or more. With the adoption of the reference value of 5 μg/dL, all LHDs were required, by July 2013, to implement new response policies related to education/outreach and case management at lower blood lead values. When a child’s venous blood lead level is ≥ 5 μg/dL or a capillary ≥10 μg/dL, the LHD must provide the parent or guardian with information describing the dangers of lead poisoning, precautions to reduce the risk of lead poisoning, information about potential eligibility for services under the Birth-to-Three Program, and laws and regulations pertaining to lead abatement.

Distribution of Elevated Lead Levels
In 2020, a total of 1,024 children under 6 years of age were identified with blood lead levels ≥5 μg/dL, indicating exposure to lead hazards. Among these children, the majority, 740 (72%) had a level between 5-9 μg/dL.

The prevalence rate (existing cases) did not significantly decrease from 2019 however it did statistically significantly decline from 2018 with a 23% reduction in the number of cases.

Number of Cases by Blood Lead Level Category
In 2020, of the 61,317 children with a confirmed lead test 60,293 (98.3%) of the children had lead levels that were less than 5 µg/dL.
Prevalence Number
≥5 µg/dL = 1,024 
  • This is a 14% decrease in number of existing cases from 2019, and a 23% decrease from 2018.
≥15 µg/dL = 120
  • This is a 14% decrease in number of existing cases from 2019, and a 27% decrease from 2018.
≥20 µg/dL = 58
  • This is a 18% decrease in number of existing cases from 2019, and a 21% decrease from 2018.

Percent of Cases by Blood Lead Level Category
  • ≥5 µg/dL = 1.67% prevalence 
  • ≥15 µg/dL = 0.20% prevalence 
  • ≥20 µg/dL = 0.09% prevalence 

Although the prevalence rates remained relatively similar to 2019, there has been a more significant reduction when compared to 2018 and prior years.  This may be due to potential increased exposures during COVID-19 quarantine measures.

Number of Cases  by Town

Town Data Table by Blood Lead Level


Below are links to CT maps that display the number and percent of elevated levels within each town.  Each map also has a "Get the data" link in the bottom left hand corner which provides all the data for that elevated lead level category by town and year as shown in the map below for 2020. For information on the cities with the highest prevalence, go to "Top 5 Cities" 
All data is based on confirmed screens.  Statistics for towns with less than 50 children tested were suppressed if there was any child with an elevated blood lead level. Suppressed values were expressed as "null" in linked data tables and towns greyed out on maps.  For more information, see About the Data.

For information on the cities with the highest prevalence, go to "Top 5 Cities"