Annual testing of children under 6 provides information on the number of children tested each year for lead levels in the blood. The data are used to better understand and interpret blood lead level (BLL) surveillance, compare testing and BLLs within and across counties, and monitor progress towards eliminating BLLs greater than the current BLRV of 3.5 mcg/dL.
Iowa requires all children to be tested at least once before the age of 6 because children may have elevated BLLs and not have any specific symptoms. Elevated blood lead levels in young children have been associated with adverse health effects ranging from learning impairment and behavioral problems to death.
The measures presented here focus on blood lead testing of children under six based on the year tested. Evaluating blood lead testing results contributes to the overall understanding of the impact and burden of lead poisoning in Iowa. These measures can also be helpful for healthcare providers and local public health agencies for program assessment and improvement.
Iowa requires all children to be tested at least once before the age of six. Evaluating blood lead testing results on an annual basis contributes to the overall understanding of the impact and burden of lead poisoning in Iowa, and can also be helpful for healthcare providers and local public health agencies for program assessment and improvement.
Measure Description
The Children Tested is the number of children under age six tested for blood lead level (BLL) during the year.
The Children with Confirmed Elevated BLL is the number of children under age six tested for blood lead level (BLL) during the year and had a confirmed result greater than or equal to 10 mcg/dL.
The Percent of Children with Confirmed Elevated BLL is the percent of children tested that had Confirmed Elevated BLL result.
Iowa requires all children to be tested for lead poisoning at least once before the age of six. In a single year, only a portion of children will be tested. The annual testing data can be helpful for healthcare providers and local public health agencies for program assessment and improvement; however, the Birth Cohort Children Under 6 is a better indicator of compliance with the testing requirement.
Measure Description
The Children Tested is the number of children under age six tested for blood lead level (BLL) during the year.
The Percent of Population Tested is the percent Children Tested among the age group specific population.
Counties are not homogeneous with respect to the distribution of lead hazards or risk factors for lead exposure. Evaluating data at a city level can help identify areas with a higher risk of lead exposure. The ten largest cities, based on the 2010 census population, in Iowa are featured.
Measure Description
The Children Tested is the number of children under age six tested for blood lead level (BLL) during the year.
The Children with Confirmed Elevated BLL is the number of children under age six tested for blood lead level (BLL) during the year and had a confirmed result greater than or equal to 10 mcg/dL.
The Percent of Children with Confirmed Elevated BLL is the percent of children tested that had Confirmed Elevated BLL result.
About the Annual Testing Data for Children Under 6
List items for About the Annual Testing Data for Children Under 6
The number and percent of children tested for blood lead prior to either 3 or 6 years of age in Iowa, by test year - the year that the blood test was performed.
Among children who were tested, the number and percent of children with elevated blood lead levels in the state of Iowa.
The geographic distribution of testing rates and elevated blood lead levels.
To inform the public about testing coverage for blood lead levels in children and elevated blood lead levels.
For program planning and evaluation by state and local partners
Results are representative of children living in Iowa because blood lead testing is universal, all children are required to have at least 1 test before kindergarten. Statewide, about 85% of children are tested for blood lead by the time they reach 3 years of age, and only about 25% of children under 6 years of age are tested each year.
Data cannot tell us exactly how or where a child was exposed to lead.
Data on blood lead testing and elevated blood lead levels are provided by Iowa HHS which implements the Childhood Lead Poisoning Prevention Program (CLPPP), and are extracted from the Healthy Homes and Lead Poisoning Surveillance System (HHLPSS)
The Iowa Public Health Tracking portal displays lead testing data from the year 2000 through the most recent year of data available.
On October 28, 2021, CDC updated the blood lead reference value (BLRV) from 5.0 μg/dL to 3.5 μg/dL. A BLRV is intended to identify children with higher levels of lead in their blood compared with levels in most children. The value is based on the 97.5th percentile of the blood lead distribution in U.S. children ages 1–5 years.
The National Tracking Network defines a “confirmed” elevated blood lead level as one "venous" test result greater than or equal to 10 mcg/dL, or two "capillary" test results greater than or equal to 10 mcg/dL within 12 weeks of each other.
Capillary blood specimens are drawn from a finger stick, and the blood is collected either in capillary tubes or on filter paper. These specimens are considered "screening" tests because they are prone to falsely high results because of surface contamination when children's hands are not properly washed (prior to drawing the blood). Capillary tests, however, tend to be more acceptable to parents and may be performed in a wider range of settings (i.e., outside of clinical settings).
Venous specimens are considered "diagnostic" tests because they are drawn directly from a vein, but they may be less acceptable to some parents because of a child's discomfort. These tests also require greater expertise in drawing the blood.
If a child has multiple confirmed tests, only the highest confirmed test result is displayed. This applies to an individual test year or a birth year. However, children can appear in multiple test years using the annual method.
Blood lead testing is universal but not randomly sampled in Iowa, so the data collected by HHLPSS may not be representative of all Iowa children. Iowa HHS Childhood Blood Lead Screening Guidelines direct physicians to order blood lead tests for certain populations at higher risk for lead exposure.
More detailed documentation of the lead poisoning data can be found in the following documents:
