Childhood Lead Poisoning

Lead Poisoning

These displays present information on the estimated number and percent of children with a confirmed blood lead test ≥5 μg/dL. Under Maine law, lead poisoning is defined as a blood lead level of 5 μg/dL or higher. Estimated numbers and percents are calculated from total number of children with confirmed blood lead test ≥5 μg/dL plus 38% of children with unconfirmed tests 5-<10 μg/dL. The conversion factor of 38% is based on the historically observed percent of unconfirmed test results of 5-<10 μg/dL that have a confirmatory venous test result ≥5 μg/dL.

Blood Lead Testing

These displays present the number and percent of children tested for blood lead. As of 2019, Maine law requires blood lead tests for all children at 1 and 2 years of age. “1-year-olds tested” and “2-year-olds tested” looks at how many children were tested in a given calendar year. “Tested at 1 and 2” is not a combination of “1-year-olds-tested” and “2-year-olds tested" but rather an estimate of how many children born in a given year were tested twice before age three per State guidelines.

County Comparisons

Use these maps to compare measures between different groups. For example, compare numbers of poisoned children by age groups. Or compare percent pre-1950 housing status (rent vs. own). Latest single year or 5-year aggregate is shown.

Childhood Lead Poisoning in High-risk Areas

Lead Poisoning, Testing, and Risk-factor Town Data

Lead Poisoning, Testing, and Risk-factor Tables

Create a custom table of data about children with a confirmed blood lead test ≥5 μg/dL, children tested for blood lead, or lead poisoning risk factors. Some measures may be accessible here that are not found in other displays (for example, Poisoning by MaineCare status).

Measure Definitions

Lead Poisoning

• Under Maine law, lead poisoning is defined as having a confirmatory blood lead level at or above 5 micrograms per deciliter (μg/dL).
• Number: Refers to the estimated number of children with a blood lead level ≥5 μg/dL with no prior history of a confirmed blood lead test ≥5 μg/dL. Estimated numbers are calculated from the total number of children with a confirmed blood lead test ≥5 μg/dL plus 38% of children with an unconfirmed test 5-<10 μg/dL. The conversion factor of 38% is based on the historically observed percent of unconfirmed test results 5-<10 μg/dL that have a confirmatory test result ≥5 μg/dL.
  • Confirmed Number: Refers to the number of children with a confirmed blood lead level ≥5 μg/dL with no prior history of a confirmed blood lead test ≥5 μg/dL. A venous blood test ≥5 μg/dL or two capillary blood tests ≥5 μg/dL drawn within 12 weeks of each other are considered confirmed.
  • Unconfirmed Number: Refers to the number of children with an unconfirmed capillary blood lead test 5-<10 μg/dL. A capillary test is unconfirmed when there is a single capillary test ≥5 μg/dl or two capillary tests ≥5 μg/dL drawn more than 12 weeks apart with no prior history of a confirmed blood lead test ≥5 μg/dL.
  • Separate Confirmed and Unconfirmed values are available only in the Tables tab.
• Percent: Refers to the estimated number of children with lead poisoning (Number, as defined above), divided by the number of children tested for lead poisoning who have no prior history of a confirmed blood lead test ≥5 ug/dL. Five-year values are the sum of the estimated number of children with lead poisoning divided by the sum of children tested.

Lead Testing (Calendar Year)

• This measure is sometimes referred to as lead screening.
• Number: the total number of children tested for blood lead who have no prior history of a confirmed blood lead test ≥5 μg/dL. Five-year values are the sum of 5 individual years.
• Percent: the number of children tested for blood lead, divided by the number of children in the population. Five-year values are the sum of children tested annually divided by the sum of annual populations.

Lead Testing (Birth Year)

• This measure is sometimes referred to as "birth cohort" analysis.
• Number: the total number of children born in a specific year and tested by a specific age (e.g., 36 months, or 3 years old). This can also represent having multiple tests at particular ages (e.g., testing at both 1 and 2 years of age before turning 3 years old).
• Percent: the number of children born in a specific year and tested for blood lead, divided by the number of children born in the same year.
• In the Testing tab, the year used to calculate percent "Tested at 1 and 2" is the year in which a child turned age three. For example, 2022 values represent children born in 2019 who turned three in 2022. Displaying these data by the last calendar year involved helps synchronize comparisons across measures (e.g., comparing the percent of children who were tested at ages 1 and 2 with the percent of one year old children tested in 2022). By contrast, in the Tables tab, the year represents birth year for "Testing (Birth Year)." For example, data for the age group "1 and 2" representing children born in 2019 and turning three in 2022 are shown as 2019 data.

Risk Factors

• Poverty measures are computed both for all families ("Poverty - All"), and for those with children under the age of 5 ("Poverty - with Children"). The denominator for "Poverty - All" is the total number of families in a jurisdiction (county or other). The denominator for "Poverty - with Children" is the total number of families with children under age 5 in a jurisdiction (county or other).
• Pre-1950 Housing measures show the number or percent of occupied housing units built before 1950, for all housing units, owned housing units, and rental housing units.

Limitations

Lead Tests

• In June 2019, Maine established universal testing, requiring all 1- and 2-year-olds to be tested for lead. Lead testing prior to 2019 may not be comparable due to the change in requirements for testing.
• The percentage of children age 0-<36 months screened for lead poisoning is calculated using a population denominator that includes children age 0-9 months even though children are not usually tested for lead poisoning before 9 months. Measures for this age group may appear low when compared to other age groups considered at risk of lead poisoning (e.g., one-year olds, tested between 12-<24 months).
• Analysis is based on a child’s residence at the time of the test which may be different from where the child was exposed to lead.
• Due to differences in the analysis of data and measures, lead testing and poisoning data presented by Maine Tracking Network should not be compared to analysis by other entities (e.g., US CDC’s National Center for Environmental Health Childhood Lead Poisoning Prevention Branch).

Additional Details

• Data are suppressed for small populations when counts are less than 6.
• Data may also be secondarily suppressed to protect against indirect identification.
• Lead Testing (Birth Year) uses the number of children born in a specified year for the denominator. Lead Testing (Calendar Year) denominators use U.S. Census population estimates for the time period, with the exception of town-level testing, which uses birth data to estimate populations age <3.
• Only data on Maine residents <6 years of age tested for lead exposure are included in the analysis.