Communicating drinking water health risk: an information system that may help the process.

This paper introduces resource that may help expedite the communication of drinking water health risk. Drinking Water Solutions, a computer information system, was developed and evaluated to meet an applied educational need--a lack of local expertise on drinking water information. The objective was to deliver information to owners of individual water supply systems concerning potential drinking water contaminants and their effects on human health. The system includes information on 20 regulated contaminants and a report option to allow for dissemination of pertinent data.Although a sample of water may appear clear and free of harmful substances, the history of a water source may prompt us to question our observations. In fact, recent media reports have created a cloud of uncertainty around our drinking water supplies. Individuals using private water systems seem particularly vulnerable, since the integrity of their drinking water is the individual's responsibility. This paper introduces a resource that may help expedite the communication of drinking water health risk.Information needsIn Pennsylvania, drinking water quality has become a health risk issue. Mancl et al. (1) concluded after two water quality surveys that many water systems fail to meet drinking water standards. There have been more than 500 incidents of toxic contamination in the past 10 years and approximately 300,000 residents were required to boil drinking water due to giardia cyst and other biological contamination (2). The Bureau of Census (3) data show almost 900,000 Pennsylvania households depend on individual water supplies. Since these water systems are privately owned, they are not regulated by local, state and federal authorities (4). Makuch and Ward (5) reported Pennsylvania has slightly more than 2.6 million residents who depend on drinking water not routinely monitored for contaminants.In determining the information needs of private water system owners, Mancl et al. (1) suggested four major water quality areas for Pennsylvania. They include bacterial contamination; contamination from mineral extraction activities; corrosion; and nitrates.A closer look at drinking water sources, however, suggests bacterial contamination, mining activities, corrosion and nitrates are only part of the contamination problem. The variety of contaminants has grown in complexity and volume. By 1994 the United States Environmental Protection Agency (USEPA) will be regulating more than 80 drinking water contaminants in public water systems. Thousands of new chemical compounds are developed every year, often finding their way into our drinking water (6). Mandatory testing for these contaminants would put an enormous economic burden on both private and public water systems. Francis et al. (7) also saw a potential health risk involved with both organic and inorganic agents ingested at very low concentrations over long periods of time.A high incidence of contaminated drinking water within Pennsylvania has led many communities to seek help. In many instances, extension agents are considered the primary source of water quality information in rural areas. Hence, Drinking Water Solutions (DWS) was developed for Pennsylvania extension agents to provide information about alternatives to reduce or control drinking water contamination.Need for systemThe impetus for developing DWS was the"National Assessment for Water Quality Training Needs for Cooperative Extension Staff" conducted by the USDA-Extension Service (8). DWS, a computer information system, was developed and evaluated to meet an applied educational need--a lack of local expertise on drinking water information. The objective was to deliver information to owners of individual water supply systems concerning potential drinking water contaminants and their effects on human health.DWS was developed to provide owners of individual water systems the same level of protection as a person relying on a public water system. The system includes a health component that provides consumers with data and information about the possible ingestion of contaminants which are typically monitored in public water supplies. A consumer may obtain water testing, treatment, health and environmental fate information on 20 regulated contaminants and a report option to allow for dissemination of pertinent data. Future versions will include parameters added to the USEPA list of regulated contaminants.Use of systemUse of DWS requires agents to have effective risk communication skills. Risk communication is not a simple matter of crafting better messages. Risk communication requires a specialized expertise, deliberate planning and constant review (Committee on Risk Perceptions and Communication, National Research Council, 1989). It requires the user to have a foundation in communicating risk, because the data doe not explicitly transfer the magnitude of a risk. Ultimately, risk is determined by the individual consuming the water. The messages developed for DWS are oriented to help extension agents assess an individual exposure to known contaminants. The agent becomes the intermediary who helps a client rationally approach their risk management problem: agents are educators, the client is the decision maker. The messages only provide data salient to individual drinking water quality.Format of systemThrough the use of text and graphic information, an information system was developed that enables extension agents to make immediate responses to drinking water inquiries. The program was designed for a person familiar with the Macintosh computing system. Five topic areas (testing information, treatment options, expert references, health data and environmental fate data) inform agents about 20 drinking water contaminants that are known to occur in Pennsylvania. Successful communication of drinking water health risk is particularly important, since risk communication can increase the likelihood that people take appropriate action to reduce health hazards as well as decrease excessive and needless actions when risks are low.System descriptionDWS, a Macintosh application, was developed and designed with Hypercard 1.2.5 software. Testing, Treatment and Environmental fate have screens similar in appearance to Health Data: these elements all contribute to the overall assessment of a particular contaminant.The Health Data topic will be used in this paper to describe the general features of DWS. Figure 1 is a display of atrazine's introductory screen within the "Health Data" topic. Along the bottom of the text screen, "Health Data" has three buttons, each leading to a different category of information. The categories of information include "Risk Estimate," "Occurrence/Exposure," and "Pharmacokinetics."Risk estimate: "Risk Estimate" information is displayed along a horizontal histogram. Contaminant concentrations increase from left to right along the histogram. USEPA has defined several health advisory levels, which are indicated by arrows. Buttons appear at the top of the screen that give guidance about what action may be appropriate at different ranges of concentrations. If an agent had a client with 20 ppb atrazine in their water supply, DWS suggests they continue to test their water supply for atrazine.Concentration and exposure: "Occurrence and Exposure" displays data on reported contaminant incidents and known sources of exposure. For instance, atrazine has been reported to occur in Pennsylvania. Exposure is thought to occur through groundwater sources as a result of herbicide applications.Pharmacokinetics: "Pharmacokinetics" is the study of the adsorption, distribution, metabolism and elimination of chemicals in humans and animals. This information is probably most beneficial to people exposed to acutely toxic levels or to moderate amounts of a substance over a period of years. For instance, if an individual is exposed to atrazine, how will the human body respond to this foreign substance?Summary and conclusionsDWS development implies a free flow of information. Sources are cited to acknowledge the limits of DWS scope and maturity relative to other sources of drinking water information. The intent is to develop options to manage risk related to a drinking water problem, especially those that involve a potential health risk. Censoring or limiting the access of this information would only lead to loss of credibility and trust between scientist and the private drinking water system owner.During an evaluation, extension agents found DWS useful as a delivery system for drinking water information (Kubek, 1991 ). Agents found DWS would be useful as a quick reference device and an educational tool for all agents and clientele.References1. Mancl, K., W. Sharpe and J. Makuch (1989), Educating the Rural Public about Safe Drinking Water. Water Resources Bulletin 25(1):155-158.2. Robillard, P.D. (1989), Changing Priorities in Water Quality Management, paper presented at Pennsylvania in the Year 2000: The News Conference. The Pennsylvania State University, University Park, PA.3. U.S. Bureau of Census (1982), U.S. Census of Population and Housing, 1980.4. Sharpe, W.E., D.W. Mooney and R.S. Adams (1985), An Analysis of Groundwater Data Obtained from Private Individual Water Systems in Pennsylvania, Northeastern Environmental Science, 4(3/4), 155-159.5. Makuch, J and J. Ward (1987), Groundwater and Agriculture in Pennsylvania (Circular 341). The Pennsylvania State University, Cooperative Extension, University Park, PA.6. Manawing, J.F. (1985), Public Drinking Water and Chemicals. In: Rice, R.G. (ed.), Safe Drinking Water: The Impact of Chemicals on a Limited Source, Lewis Publishers, Inc., Chelsea, MI, pp. 21-32.7. Francis, J.D., B.L. Brower, W.F. Graham, O.W. Larsen III and H.M. Vigorita (1983), National Statistical Assessment of Rural Water Conditions, ASI No. 9208-118, The Office of Drinking Water, U.S. Environmental Protection Agency; Washington, D.C.8. Casey, M.A., F. Bergsrud and R. Krueger (1989) Clean Water: Everybody's Concern, Special Project No. 89-EWOI-9001, University of Minnesota, Division of Agricultural Education, Department of Vocational and Technical Education, St. Paul, MN.Perry Kubek, M.Ed, Dept. of Agricultural and Biological Engineering. 6 Agricultural Engineering Bldg., Pennsylvania State University, University Park, PA 16802.