Radiograph of condor 318 with lead fragments in the digestive tract, with a pullout photo of the actual lead fragment removed from the bird. This bird died from lead poisoning in 2012. NPS. Lead Poisoning is the Biggest Threat to California Condors. Numerous scientific studies have reached a consensus: lead poisoning is the biggest threat facing the successful recovery of the California condor. Semi-annual test results show that the majority of free-flying condors at Pinnacles National Park have blood lead levels that exceed 10 ug/dL (micrograms per deciliter), which is the same threshold used by the Center for Disease Control as an initial warning sign that a human child is at risk. Some condors have been measured with blood lead levels higher than 800 ug/dL, a value that would potentially kill a human. By the time condors at Pinnacles reach breeding age of 7 years old, almost all of them have received emergency, life-saving chelation treatment at least once. Numerous condors in the flock have now required multiple chelation cycles.