Exposure assessment of a mercury spill in a Nevada school—2004

Background. Although mercury is toxic, few studies have measured exposure in children who handled elemental mercury briefly. In 2004, a student spilled approximately 60 milliliters of mercury at a Nevada school. Within 12 hours, all students were removed from the source of exposure. We conducted an exposure assessment at the school. Methods. We administered questionnaires and obtained urine samples from students. Using two-sample t-tests, we compared urine mercury levels from students who self-reported exposure to mercury levels of other students. Results. Two-hundred students participated, including 55/62 (89%) who were decontaminated. The students' geometric mean urine mercury level was 0.36 μg/L (95% confidence interval 0.32–0.40 μg/L). The student who brought the mercury to school was the only one to have an elevated urine mercury level (11.4 μg/L). Conclusion. Despite environmental contamination, mercury exposure may have been minimized because of rapid identification of the elemental mercury spill a...