Washington State Department of Health, Vox Media, & PolicyMap
| Categories | Environment, Climate & Weather |
|---|---|
| Detail | Lead Exposure Risk Index |
| Download Available | yes |
| Geographies | Census Tract |
| Last Updated on PolicyMap | May 2026 |
| PolicyMap Exclusive | yes |
| Public Edition or Subscriber-only | Public Edition |
| Source | Washington State Department of Health, Vox Media, PolicyMap |
| Years Available | 2020-2024 |
Description:
Lead-based paint was banned in 1978, but exposure risk persists. The Washington State Department of Health (WSDOH) developed an index combining age of housing and poverty as the primary risk factors. Vox Media worked with WSDOH to apply the index nationally; PolicyMap applied the Vox Media methodology to the current American Community Survey (ACS) 5-year estimates.
Age of Housing
The share of at-risk homes in a census tract is estimated by multiplying homes in each construction-year band by a weight representing the likelihood of significantly deteriorated lead-based paint, then dividing the total weighted count by all housing units. Weights come from the American Healthy Homes Survey II (2018-2019):
| Construction Year | Weight |
|---|---|
| After 1978 | 0.000 |
| 1960-1979 | 0.075 |
| 1940-1959 | 0.309 |
| Before 1940 | 0.619 |
Because ACS reports housing age in decade bands, the 1960-1979 band serves as the proxy for the WSDOH-defined 1960-1977 category, meaning homes built in 1978-1979 are included at the 0.075 weight. This produces a slight overestimate of risk where those homes are concentrated. These weights replace those from Jacobs et al. (1998-2000) used in V1; the largest change is for 1940-1959 homes, reduced from 0.43 to 0.309.
Poverty
Poverty risk is measured as the proportion of the population with incomes at or below 125% of the federal poverty level. Following the Vox Media methodology, this uses population rather than households, which produces slightly different values than WSDOH. Children in poverty in pre-1950 housing face the greatest lead exposure risk, as older homes are more likely to have deteriorating lead paint.
Combined Index
Housing age and poverty are weighted equally in the final index. V1 weighted the two variables using risk-difference estimates from CDC blood lead testing data, but WSDOH determined those differences were not stable over time and adopted equal weighting for V2.
PolicyMap suppresses data for census tracts where more than 50% of the population lives in group quarters.