Short-term elemental mercury exposures at three Arizona schools: public health lessons learned

Acute exposure of schoolchildren to elemental mercury continues to produce public health crises that drain available health and environmental resources. In this retrospective study, we report three incidents of limited exposure to elemental mercury in Arizona schoolchildren. Health workers screened 347 students, family, and staff by history and physical exam for exposure level and symptomatology. Urine and blood mercury testing further evaluated at-risk individuals. Environmental contamination was also assessed. Despite up to 28% of patients reporting symptoms, no individual was found to have elevated serum or urinary mercury levels requiring treatment. Elevated airborne mercury levels were demonstrated in the classrooms, dormitories, buses, and student homes and appropriate clean-up measures were instituted. Previous studies of multiple exposures to elemental mercury either focus on significant patient morbidity or lack biological data. In contrast, this study reports biological and environmental data demonstrating no clinical toxicity following acute exposure in a large sample. Confirmatory studies are necessary to develop cost-effective guidelines for the appropriate management of these public health crises.