Assessing risks and preventing disease from environmental chemicals

Risk analysis for environmental health triage

The Homeland Security Act mandates the development of a national, risk-based system to support planning for, response to, and recovery from emergency situations involving large-scale toxic exposures. To prepare for and manage consequences effectively, planners and responders need not only to identify zones of potentially elevated individual risk but also to predict expected casualties. Emergency response support systems now define "consequences" by mapping areas in which toxic chemical concentrations do or may exceed Acute Exposure Guideline Levels (AEGLs) or similar guidelines. However, because AEGLs do not estimate expected risks, current unqualified claims that such maps support consequence management are misleading. Intentionally protective, AEGLs incorporate various safety/uncertainty factors depending on the scope and quality of chemical-specific toxicity data. Some of these factors are irrelevant, and others need to be modified, whenever resource constraints or exposure-scenario complexities require responders to make critical trade-off (triage) decisions in order to minimize expected casualties. AEGL-exceedance zones cannot consistently be aggregated, compared, or used to calculate expected casualties and so may seriously misguide emergency response triage decisions. Methods and tools well established and readily available to support environmental health protection are not yet developed for chemically-related environmental health triage. Effective triage decisions involving chemical risks require a new assessment approach that focuses on best estimates of likely casualties, rather than on upper plausible bounds of individual risk. If risk-based consequence management is to become a reality, federal agencies tasked with supporting emergency response must actively coordinate to foster new methods that can support effective environmental health triage.

The sentinel role of poisons centers in the protection of children's environmental health

Growing concern exists about the threats posed by environmental pollutants and physical agents on children's health. A number offactors, including globalization, increased industrialization, and trade of chemicals and poverty have an impact on the quality of the environment and on children's health. Acute toxic exposures lead to poisoning, and chronic low-level exposures may cause functional and organ damage during periods of special vulnerability. The need to protect children's environmental health is urgent, in view of the magnitude of the problem and the fact that "children are not little adults." The effects suffered during special developmental periods-"windows of vulnerability"-can be permanent and irreversible. The main global environmental problems affecting children's health are lack of access to safe drinking water and sanitation and exposure to indoor air pollution. Furthermore, environmentally related accidents, injuries, and poisonings have a major impact on children and adolescent's morbidity and mortality. A number of examples that illustrate the complexity of assessing and dealing with children's environmental health issues are presented. A Task Force on the Protection of Children's Environmental Health that aims to prevent disease and disability in children associated with chemical and physical threats was set up in 1999 by the World Health Organization. The priorities for action include the consideration of accidents, injuries, and poisonings (accidental, intentional, and occupational), and children in the workplace (e.g., scavenging children, children in cottage industries). Poisons Centers and related toxicology centers are in a strategic position to play a "sentinel" role in the protection of children's environmental health. They record acute and chronic toxic exposures in children in a harmonized manner, using controlled vocabularies and definitions. This will allow collecting a large, highly valuable database on the main toxicological problems affecting children, including those of environmental origin. The analysis of observations entered in such a database will help assess the burden of disease and collect the evidence for planning prevention and promoting regulatory measures. Centers are called to play a proactive role in raising awareness about children's environmental health and contribute to research, information dissemination, training, and other activities required for the protection of children's health and development.