Investigation and Control of a Mercury Outbreak of a Rural Community in Puerto Rico

BACKGROUND: Exposure to small amounts of mercury can cause serious health problems, especially in children and pregnant women. Mercury is a silver liquid metal that is still found in old thermometers, barometers, thermostats, electrical switches, and science labs. Inhalation of mercury vapor can produce harmful effects on the nervous, digestive and immune systems, lungs and kidneys, and may be fatal. On December, 2012, residents from a rural community in Ciales, Puerto Rico, including children, adolescents and adults, were exposed to elemental mercury discovered next to mailboxes. Unfamiliar with the harmful effects of mercury, residents kept an amount of mercury at home for at least a year, allowing children and adults to play with the toxic metal. Children/ adolescent decided to share mercury drops with classmates at school. Fortunately, the health education teacher identified the substance and reported the action to social worker and referred students to a hospital emergency room. The Office of Public Health Preparedness and Response of Puerto Rico Department of Health conducted an epidemiological investigation to assess the level exposure and provide education to the community. This presentation outlines the outcomes of the epidemiological investigation. 

METHODS: A questionnaire was designed to gather exposure history and symptoms through face-to-face interviews. Urine samples were obtained for mercury exposure levels for 42 out of 47 (89.4%) individuals. Conducted education on health effects for toxic metals to teachers and residents, with the support of United States Environmental Protection Agency officers. 

RESULTS: Analysis results were within the normal ranges (<20 µg/L) established by the Agency for Toxic Substances and Disease Registry. After assessing the environmental conditions of homes, United States Environmental Protection Agency officers completely restored the contaminated areas. 

CONCLUSIONS: Although there were no laboratory confirmed cases, the investigation provided a good opportunity to approach the community about the guidance and recommendations for preventing future hazardous environmental exposure.