Population-based morality data suggests remediation is only modestly effective in two Superfund counties

Abstract

TPS 641: Policies, interventions, communication, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: The health effects of living in proximity to both active copper and molybdenum mining as well as remediation sites were evaluated for residents of two contiguous counties in the US state of Montana. The open pit copper and molybdenum mine has been open since 1984; it operates with crushers and concentrator facilities where tons of raw ore are processed. Simultaneously, the Superfund remediation efforts were established in 1983 at the site of a closed mine and smelter. Methods: Employing county level death certificate data obtained from the US Centers for Disease Control WONDER site, sex and age- adjusted standardized mortality ratios (SMRs) for targeted causes of death were calculated using observed versus expected mortality for both counties, and compared to the expected mortality from the remaining Montana counties. Results: Cancers, cerebro- and cardiovascular diseases (CCVD), and organ failure were elevated for the two counties during the study period, 2000–2016, with SMRs of 1.19 (95% CI 1.10, 1.29); 1.36 (95% CI 1.29, 1.43); and 1.24 (95% CI 1.10, 1.38). Neurological conditions were not elevated for the two counties. Time trend analyses performed using Cox regression models indicate that deaths from cancers (HR = 0.97; p = 0.0004), CCVDs (HR = 0.95; p B 0.0001), and neurological conditions (HR = 0.97; p = 0.01) decreased over the study period. Conclusions: Our approach of using publicly available death certificate data over time, along with an understanding of the potential risks associated with specific metal exposures, can be utilized to monitor population health impacts during continued mining and remediation efforts. The time trends indicate there is a small downward trajectory in the mortality rates for cancer, cerebro-cardiovascular, and neurological conditions. These findings suggests there is a continuing need for monitoring mortality, in order to keep the public aware of ongoing risks.