Cancer cluster investigation in a school district

Because of concern about a possible cancer cluster among employees of an elementary school, an industrial hygiene survey and health investigation were completed. An indoor-air quality survey was conducted by a certified industrial hygienist (CIH). A separate health survey concerning cancer occurrence was conducted by the authors among current (1995) and former (back to 1990) employees. Cancer data from the state health department registry were used to supplement self-reports. The number of observed cancers were compared to those expected based on statewide and county data. A marginally significant increased risk was found for breast cancer among female employees who had worked for the school. No other excess in cancers was found. This excess of breast cancer was unlikely to have been related to an occupational exposure. Based on the study supported by the school district, which prefers to remain anonymous, this paper discusses the conduct of cancer cluster investigations in schools and recommends that screening and education for breast cancer be conducted in schools.