The town of Sydney, located on the north coast of Nova Scotia, is Canada's most contaminated community. The local tidal estuary, called the tar ponds, was used as a receptacle for industrial waste from a century of coke production and steel making and is estimated to contain more than 700,000 metric tons of polycyclic aromatic hydrocarbons, 50,000 metric tons of polychlorinated biphenyls, and many other residuals including arsenic, naphthalene, and toluene. Many residents have expressed consternation over the potential for exposure and subsequent health effects from the ponds. Recent epidemiological studies estimate a 30 to 40 percent increased incidence in several types of cancer within the community. This paper examines the claims and responses made by a variety of interested parties about the chemical contamination in Sydney. It also considers how those claims, in addition to a number of other mediating factors, may have influenced the local community in the mobilization of a response to the contamination.