A review of events that expose children to elemental mercury in the United States.

Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. We reviewed federal, state, and regional programs with data on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. Primary exposure locations were at home, at school, and at others such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. Primary prevention should include health education and policy initiatives.

A review of events that expose children to elemental mercury in the United States: [review] / Uma revisão dos eventos que expõem as crianças ao elemento mercúrio nos Estados Unidos: [revisão]

Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. We reviewed federal, state, and regional programs with data on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. Primary exposure locations were at home, at school, and at others such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. Primary prevention should include health education and policy initiatives.

Uma preocupação pela exposição de crianças ao elemento mercúrio estimulou a Agência para Substâncias Tóxicas e Registro de Doenças e os Centros para Controle e Prevenção de Doenças a rever as fontes de exposição a este elemento por crianças, descrever a locação e proporção de crianças afetadas e fazer recomendações de como prevenir essas exposições. Nesta análise, foi excluída a exposição a mercúrio em instalações de queima de carvão, amálgamas dentários, consumo de peixes, incineradores de lixo hospitalar ou vacinas contendo timerosal. Analisamos programas regionais, estaduais e federais com dados sobre liberação de mercúrio, juntamente com relatórios de crianças expostas ao elemento nos Estados Unidos. Selecionamos todos os eventos relacionados ao mercúrio que documentaram exposição (ou potencial exposição) de crianças. As principais localidades de exposição foram em casa, na escola e outras como indústrias não adequadas ou instalações médicas. A exposição a pequenos derramamentos de termômetros quebrados foram o cenário mais comum; todavia, relatos de tais exposições estão diminuindo. A informação analisada sugere que a maior parte dos comunicados não conduz a danos demonstráveis se o período de exposição for curto e o mercúrio for devidamente limpo. A prevenção primária deve incluir educação em saúde e iniciativas de políticas.

A review of events that expose children to elemental mercury in the United States.

OBJECTIVE: Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. DATA SOURCES: We reviewed federal, state, and regional programs with information on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. We then explored event characteristics (i.e., the exposure source, location). DATA SYNTHESIS: Primary exposure locations were at home, at school, and at other locations such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. DISCUSSION AND CONCLUSIONS: Childhood exposures to elemental mercury often result from inappropriate handling or cleanup of spilled mercury. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. RECOMMENDATIONS: Primary prevention should include health education and policy initiatives. For larger spills, better coordination among existing surveillance systems would assist in understanding the risk factors and in developing effective prevention efforts.

Biomonitoring for environmental exposures to arsenic.

Arsenic (As) is a widely occurring environmental contaminant. To assess human exposures to As, public health officials and researchers often conduct biomonitoring. Samples of urine, hair, nails, or blood are collected from potentially exposed people and are analyzed for As compounds and their metabolites. When analyzing for As exposure, it is useful to distinguish between As species, since they differ in their origin and toxicity. Urine is the most frequently used biological medium for biomonitoring. Measuring the urinary concentration of As is useful in assessing recent exposure to As, and high-quality reference ranges are available for urinary As concentrations in the U.S. population. Biomonitoring for As in hair and nails has been used in many studies and is particularly useful in evaluating chronic exposures to As. Interpreting the health implications of As concentrations in biological samples is limited by the small number of studies that provide information on the correlation and dose-response relationship between biomonitoring test results and adverse health effects. This study discusses the advantages and limitations of biomonitoring for As in biological samples and provides illustrative case studies.

Biomarkers of exposure in community settings.

Biomonitoring is a valuable tool for assessing human exposures to chemical contaminants in the environment. Biomonitoring tests can be divided into biomarkers of exposure, effect, and susceptibility. In studies of community exposure to an environmental contaminant, biomarkers of exposure are most often used. The ideal biomarker should be sensitive, specific, biologically relevant, practical, inexpensive, and available. Seldom does a biomarker meet all of these criteria--most biomarkers represent a compromise of these criteria. In designing a community exposure study, consideration should also be given to the selection of the test population, the practicality of collecting biological samples, temporal or seasonal variations in exposure, the availability of background comparison ranges, and interpretation of the test results. Biomonitoring tests provide unequivocal evidence of exposure, but they do not typically identify the source of exposure. Furthermore, rarely do the test results predict a health outcome. For many chemicals, testing must be conducted soon after exposure has occurred. In spite of these limitations, the use of biomonitoring is finding wider application in many scientific disciplines. Recent advances in analytical techniques are expanding the utility of biomarker testing in public health investigations.

Human exposure to uranium in groundwater.

High concentrations of uranium (mean=620 microg/L) were detected in water samples collected from private wells in a residential community. Based on isotopic analyses, the source of the uranium contamination appeared to be from naturally occurring geological deposits. In homes where well water concentrations of uranium exceeded the drinking water standard, the residents were advised to use an alternate water source for potable purposes. Several months after the residents had stopped drinking the water, urine samples were collected and tested for uranium. Elevated concentrations of uranium (mean=0.40 microg/g creatinine) were detected in urine samples, and 85 percent of the urine uranium concentrations exceeded the 95th percentile concentration of a national reference population. Urine uranium concentrations were positively correlated with water uranium concentrations, but not with the participants' ages or how long they had been drinking the water. Six months later, a second urine sample was collected and tested for uranium. Urine uranium concentrations decreased in most (63 percent) of the people. In those people with the highest initial urine uranium concentrations, the urine levels decreased an average of 78 percent. However, urine uranium concentrations remained elevated (mean=0.27 microg/g), and 87 percent of the urine uranium concentrations exceeded the 95th percentile concentration of the reference population. The results of this investigation demonstrated that after long-term ingestion of uranium in drinking water, elevated concentrations of uranium in urine could be detected up to 10 months after exposure had stopped.

An international perspective on hazardous waste practices.

In developing countries, public health attention is focused on urgent health problems such as infectious diseases, malnutrition, and infant mortality. As a country develops and gains economic resources, more attention is directed to health concerns related to hazardous chemical wastes. Even if a country has little industry of its own that generates hazardous wastes, the importation of hazardous wastes for recycling or disposal can present health hazards. It is difficult to compare the quantities of hazardous wastes produced in different countries because of differences in how hazardous wastes are defined. In most countries, landfilling is the most common means of hazardous waste disposal, although substantial quantities of hazardous wastes are incinerated in some countries. Hazardous wastes that escape into the environment most often impact the public through air and water contamination. An effective strategy for managing hazardous wastes should encourage waste minimization, recycling, and reuse over disposal. Developing countries are especially in need of low-cost technologies for managing hazardous wastes.