The implications of an epidemiological mistake: A community's response to a perceived excess cancer risk

Objectives. The response of community residents to a perceived cancer excess may include changes in attitude, health-related behavior, and property values. In 1986, a cancer agency conducted a study of cancer incidence (1979 to 1983) in two suburbs of Edmonton, Alberta, and reported elevations on the order of 25% over expected for most sites. Reanalysis of these data several months later revealed an error. Correction brought the rates into line with Alberta as a whole and with other communities surrounding Edmonton. Methods. We used public opinion trends and property value trends (during the period of concern) to study the two communities affected by the allegation of increased cancer risk. Results. A survey of residents found significant differences at the time in health-related behavior and beliefs suggesting increased perception of personal, family, and community risk and modest changes in behavior. Real estate values in one community temporarily lost an average of $4000, or about 5% of total value, compared with a similar, adjacent housing market. Conclusions. The perception of an elevated cancer risk, in the absence of a true risk, may have a substantial negative effect on the affected community, both psychologically and economically.