COMMUNITY EXPOSURE TO SODIUM-HYDROXIDE IN A PUBLIC WATER-SUPPLY

In 1993, a Texas community was exposed to highly alkaline water (pH 12 .0) through a municipal water supply, A follow-up investigation was co nducted to determine what adverse health effects were experienced by t he community as a result of this exposure. Review of medical records o f 248 patients seen at the city's only hospital indicated that 54 perc ent of the patients experienced skin problems that included burning, r edness, irritation, and rashes; Approximately 24 percent were diagnose d with burns, the majority of which (88 percent) were first-degree bur ns. One quarter of the patients had documented gastrointestinal proble ms such as nausea, vomiting, diarrhea, and abdominal pain, A follow-up mail survey sent five months after the incident did not uncover any s erious health sequelae. This incident underscores the importance of we ll-trained and vigilant water treatment operators in the maintenance o f safe municipal water supplies. As a result of the incident, Texas st andards for the design of chemical feed facilities were changed to req uire the use of chemical day tanks or equivalent equipment between bul k storage tanks and the treatment process. This regulatory change will help prevent chemical overfeed incidents, thereby ensuring a higher l evel of public health protection.