Charting Uncertainty in Science-Policy Discourses: The Construction of the Chlorinated Drinking-Water Issue and Cancer

Drinking-water guidelines remain an ongoing issue within Canada, as elsewhere. Given recent epidemiological evidence concerning chlorinated disinfection byproducts in drinking water and cancer outcomes, some branches within Health Canada have been undertaking an extensive review of the issue. This paper examines what impact contested scientific authorities, as filtered through a regulatory agency, may have on the policymaking process in the setting of Canadian drinking-water guidelines. Using an agenda-setting framework, we rely on a textual analysis of a Health Canada expert panel report and a position paper written to accompany the panel report; Canadian print media translations of scientific evidence; and in-depth interviews with scientists (from the academy, industry, and government) and other interested stakeholders [for example, chlorine and water industry, and environmental nongovernmental organizations]. Through this analysis we reconstruct a discourse which suggests government-science in policy, rather than policymakers, is primarily and presently driving the issue. The issue itself appears to remain a debate which is largely over the strength of the scientific evidence from regulatory and public-health scientists (for example, in Health Canada), and their colleague research scientists (for example, leading researchers in the field). Although we argue that it is primarily cancer that drives the science-policy agenda, with respect to chlorinated drinking water, it is possible that reproductive effects are likely to be central to the debate for controlling chlorine use in the future.