Information and Research Needs

Historically, a primary role for the PHS has been to conduct applied research, which has guided public policy and contributed to social progress. Coordination between agencies and the setting of priorities are essential steps toward minimizing in a cost-effective manner the waterborne hazards experienced by the public. Priority areas for investigation include the following concerns:

• The EPA is required by the SDWA to publish maximum contaminant level goals (MCLG’s) and promulgate MCL’s for contaminants in drinking water that may cause adverse effects to human health and that are known or anticipated to occur in public water systems. As part of this process, the EPA reviews available data to quantify the human risks from specific contaminants. The data to complete the risk assessment come from toxicity studies of laboratory animals or from epidemiologic studies. To ensure that the best available scientific data are used when characterizing risks for specific drinking water contaminants, it is important to establish a procedure for sharing toxicologic and epidemiologic data generated across Federal organizations. In addition, it is important to coordinate research efforts and to prevent unnecessary duplication of efforts and to utilize effectively the limited resources available.
  
• At present, extensive monitoring of water quality occurs in natural systems and in the waterworks of utilities. The 1991 Inventory of Environmental Exposure-Related Data Systems in the Federal Government listed no less than 25 data systems related to water quality; none have as a goal the recording of human exposures to contaminants in drinking water. Likewise, several registries (reportable diseases, adverse reproductive outcomes, cancer) measure adverse health outcomes that may be associated with contaminants in water. Yet, only in focused studies is the water exposure of individuals characterized for seeking associations between water quality and health outcomes. In the absence of such studies, data gaps usually are filled by using default values. Collecting environmental data and health outcome data should be done in concert to permit the evaluation of associations between water constituents and chronic or rare disease outcomes. Where such coordination is not possible, additional information should be acquired to characterize human exposure to waterborne contaminants.
  
• The development of laboratory and field techniques for identifying drinking water contaminants and monitoring their effects upon human health remains crucial for the Federal Government. As new threats are discovered, methods for measuring chemical and biological disease-causing agents in water are essential for estimating adverse health outcomes associated with water contamination and for preventing future exposures. Methodologies for identifying chemical contaminants in drinking water and their metabolites in human samples are often crucial for documenting past exposures and for determining the extent of an exposure within a population.   HHS scientists have made significant contributions to the development of laboratory techniques for identifying such contaminants as Escherichia coli O157:H7, rotavirus, benzene, heavy metals and metabolites of atrazine, metalachlor, alachlor, and chlorpyrifos in samples from humans. However, the need for methodologies for detecting water pollutants is likely to increase, given public concern about drinking water quality and new evaluations regarding the association between specific chemical exposures and chronic diseases and adverse reproductive outcomes.
  
• 13.8 million households obtain their drinking water from single or multihouse water systems that are not regulated under the SDWA. These wells and small systems are not routinely inspected or tested. A recent survey of more than 5,000 household wells in the Midwest found that 12 percent contained Escherichia coli and 10 percent had nitrate concentrations of greater than 20 mg/L, indicating that problems with these unregulated systems are common. The extent of the health problems that are a result of poor construction, maintenance, or source protection is unknown. Modest amounts of research could quantify the hazards associated with various unsanitary conditions and provide insight into preventive measures. There is a need for guidelines regarding the monitoring, maintenance, and evaluation of all systems that are not regulated (e.g., wells, multihouse systems, and home-treatment units).
  
• Some of the most frequently overlooked elements of a safe community water system relate to the knowledge, skills, and abilities of the water system operators. While considerable engineering, process, and management training now is conducted by the water industry, the PHS should play a role in developing minimum educational standards for operators of water systems that are based on the public health consequences of actions related to potable water treatment and delivery. These educational efforts should be expanded to include the public where appropriate.
  
• HRSA estimates that several million people in the United States, primarily rural and migrant workers, lack running water. The IHS estimates that 20,400 American Indian and Alaska Native homes lack piped potable water. The extent of this problem and its associated health consequences, both urban and rural, should be investigated and monitored.