According to a report released in January by the California Department of Public Health, more than 6,000 California workers have elevated levels of lead in their blood. Health problems from lead exposure include heart disease, reproductive problems, cognitive difficulties and kidney failure.

From 2012 to 2014, 38,440 workers had their blood tested for lead, and 6,051 workers were identified with an elevated level of 5 or more micrograms of lead per deciliter (about 3.3 ounces) of blood. Workers with the highest blood lead levels — 40 micrograms or more per deciliter — mostly worked at shooting ranges or in ammunition manufacturing, gun repair, and firearm instruction, although some worked in other metal industries, painting and construction.

Read more about the study in Barbara Feder Ostrov’s coverage.