Risk perception and water fluoridation support and opposition in Australia

A considerable body of evidence confirms that water fluoridation effectively reduces the community incidence of dental caries with minimal side effects. However, proposals to introduce this widely endorsed public-health measure are often perceived as controversial, and public opinion frequently plays a role in the outcome. Despite this, the public's perception of risk associated with water fluoridation has not been well researched and remains poorly understood. Our objectives were to determine whether risk perceptions reflecting various "outrage" factors are associated with water fluoridation support and opposition.

We conducted a cross-sectional questionnaire survey of a national sample of 517 Australian adults (response rate = 34.7 percent) aged 18-92 years.

Approximately 70.5 percent of respondents supported water fluoridation, with 15.1 percent opposed and 14.3 percent neutral. Sixteen of the 20 assessed outrage factors were significantly associated with water fluoridation stance in the predicted direction, with greater outrage being related to increased water fluoridation opposition. An overall outrage index computed from the 16 significant outrage factors accounted for a statistically significant 58 percent of the variance in water fluoridation stance beyond the effects of age, gender, socioeconomic status, and age and presence of children.

Outrage factors are important aspects of the public's perception of risk in relation to water fluoridation. Given that water fluoridation appears to be a low-risk, high-outrage controversy, efforts to mitigate the level of public outrage, rather than continuing to deny possible hazards, may offer a worthwhile strategy in gaining public acceptance for the extension of water fluoridation.