"Related to blood-lead levels, these medical referrals often come from health departments, medical providers or hospitals," Allen stated in an email. Workers Became Lead-Poisoned at Exide in a Matter of Months Our investigation found that in California, communication about workers with high levels of lead in their blood was nearly nonexistent between Cal/OSHA and CDPH, the two agencies responsible for keeping workers safe from lead hazards. Between 1994 and 2014, CDPH tracked over 2,300 cases of workers with blood-lead levels at or above 25 micrograms per deciliter at Exide's Vernon plant; yet CDPH referred the Vernon plant for an inspection to Cal/OSHA just once, in 1996. Along the way, there were health experts who saw warning signs.