One-Third of California’s High-Risk Kids Not Tested for Lead Poisoning
September 19, 2017

One-Third of California’s High-Risk Kids Not Tested for Lead Poisoning : Methodology

Assessing the degree to which the state has met its mandate to test children at risk for lead exposure is complicated by the fact that in response to EWG’s Public Records Act requests, the Department of Public Health only released detailed testing summaries for 2012 and 2013. The DPH also provided the crude numbers of lead tests done from 2014 to 2016, but these numbers include duplicate tests and tests for adults.

State law mandates that all children enrolled in Medi-Cal and other public assistance programs – such as the Women, Infants and Children Program, and CalFresh – receive tests at 12 and 24 months. But the DPH said it did not know the number of children tested who received Medi-Cal or other public assistance, a key measure of the department’s performance and the state’s compliance with federal regulations. Instead, the department said an estimated 88 percent of children tested are enrolled in Medi-Cal.

How many 1- and 2-year-olds receive Medi-Cal benefits?

Based on U.S. Census data and other publicly available population databases, we estimated the number of California children who received publicly funded health insurance in 2013 at the county and state levels. For populous counties, we used the American Community Survey 1-Year Estimates to calculate the number of 1- and 2-year-olds enrolled in public health insurance programs. The data said 1,406,409 children under 6 years old were enrolled, and one-third of that number yielded an estimate of 468,803 1- and 2-year-olds.[1]County-level enrollment numbers were not given for 18 rural counties.

This estimated number is significantly smaller than the DPH’s estimate of 570,000 1- and 2-year-olds whose family income in 2012 was less than 250 percent of the federal poverty level, the qualifying benchmark for many public assistance programs. This suggests that about 100,000 1- and 2-year-olds who qualify for public assistance are not enrolled and receiving it. These children are clearly still at risk for lead exposure, but are hard to identify and test.

How many 1- and 2-year-olds on public assistance were screened for lead exposure in 2013?

According to the DPH, the total number of children tested statewide in 2013 who were less than 3 years old was 350,784 – 61 percent of all children under 6 who were tested. This could include a small number tested before the standard 12-month well child visit. We assumed that this age breakdown would be similar among counties, and created county-level estimates of the number of 1- and 2-year-olds tested.

The department couldn’t identify how many of the children tested were on Medi-Cal or other public assistance, but said 88 percent would be a reasonable estimate. This is based on the DPH’s observation that 88 percent of children with highly elevated blood lead levels – greater than 14.5 to 19 micrograms per deciliter – in 2013 and 2015 were enrolled in Medi-Cal, which at that point at had merged with most other government-funded public health insurance programs for children.[2]We multiplied the estimated number of 1- and 2-year-olds tested in each county by 88 percent to derive the estimated number of publicly enrolled children who were tested for lead exposure statewide – 308,690 – as well as county-level estimates.

Identifying counties with poorer screening rates

We compared DPH data on the number of children tested per county with our estimates of the number of 1- and 2-year-olds enrolled in Medi-Cal. This yielded our statewide estimate of 34 percent of Medi-Cal kids who were not tested, as well as county-level estimates.

The American Community Survey did not provide estimates for the number of children receiving public health care in 18 rural counties. These children make up less than 2 percent of all Medi-Cal children statewide as well about 2 percent of the children who missed out on lead screening statewide.

[1] U.S. Census. American Fact Finder. Public Health Insurance by Sex and Age. 2012. American Community Survey. Available at

[2] California Lead Poisoning Prevention Program, communication with EWG in response to Public Records Requests. May to August 2017.