Children’s Lead Risk from Housing
Children’s Lead Risk from Housing
What is lead?
Lead is a toxic heavy metal that occurs naturally in the environment. However, the highest levels of lead present in the environment are a result of human activities. Historically, lead has been used in house paint, plumbing, and as a gasoline additive. While lead levels have declined over the past five decades in the United States, it still persists in older housing.
Why is this indicator included in CalEnviroScreen?
- Lead house paint is the most significant source of lead exposure in children.
- Children are most sensitive to the effects of lead exposure, which has no known safe level.
- Lead exposure in childhood can adversely affect brain development, and can result in blood, kidney, and endocrine toxicity.
- Studies have found that elevated blood lead levels are associated with cognitive impairments.
- Historically-used lead persists in paint, old plumbing, and contaminated soil.
- Elevated blood lead levels are associated with older housing and higher poverty levels.
- Other CalEnviroScreen indicators account for other sources of potential lead exposures such as the indicators for drinking water contaminants and toxic releases from facilities, and the hazardous waste indicators.
What measure is used to evaluate children’s lead exposure from housing in CalEnviroScreen 4.0?
We used the following methodology to calculate scores for the risk of elevated lead exposure from housing for census tracts across California:
- Digital Map Products maintains residential parcel data on the year residential housing units were built (SmartParcels). This data was used to calculate the number of housing units in several age categories.
- Percentage of homes per census tract with likelihood of lead-based paint hazards was calculated using a weighted average by age, with older homes considered more likely to have lead-based paint hazards. Weights were based on reported percentage of homes with lead-based paint hazards extracted from a study of West Coast homes.
- The United States Department of Housing and Urban Development (HUD) Comprehensive Housing Affordability Strategy maintains data on household information by percent HUD-adjusted median family income. This data was used to estimate the number of households both with an income less than 80% of the county median and with at least one child under the age of 6. The most recent results available at the time of analysis were the 5-year estimates for 2013-2017.
- For each census tract, these two percent calculations were combined as a weighted sum and assigned a percentile based on the statewide distribution of values.
A complete description of the Children’s Lead Risk from Housing indicator is contained in the CalEnviroScreen 4.0 report.
Where can I find more information about lead and lead pollution levels?
- California Department of Public Health: Information and Resources for Keeping Your Family Lead-Safe
- Tracking California – Childhood Lead Poisoning