Cancer risk to First Nations' people from exposure to polycyclic aromatic hydrocarbons near in-situ bitumen extraction in Cold Lake, Alberta.

BACKGROUND: The Alberta oil sands are an important economic resource in Canada, but there is growing concern over the environmental and health effects as a result of contaminant releases and exposures. Recent studies have shown a temporal and spatial trend of increased polycyclic aromatic hydrocarbon (PAH) concentrations in sediments and snowpack near the Athabasca oil sands operations (i.e., open pit mines), but thus far similar studies have not been done for the Cold Lake region where steam assisted gravity drainage (in situ) extraction is performed. METHODS: Many PAHs are known mutagenic carcinogens, and this study measured soil and atmospheric concentrations of PAHs in the Cold Lake region to assess the excess lifetime cancer risk posed to the First Nations' inhabitants of the region. Using both deterministic and probabilistic risk assessment methods, excess lifetime cancer risks were calculated for exposures from inhalation or inadvertent soil ingestion. RESULTS: The mean excess cancer risk for First Nations' people through ingestion who engage in traditional wilderness activities in the Cold Lake region was 0.02 new cases per 100,000 with an upper 95% risk level of 0.07 cases per 100,000. Exposure to PAHs via inhalation revealed a maximum excess lifetime cancer risk of less than 0.1 cases per 100,000. CONCLUSIONS: Excess lifetime risk values below 1 case per 100,000 is generally considered negligible, thus our analyses did not demonstrate any significant increases in cancer risks associated with PAH exposures for First Nations people inhabiting the Cold Lake region.

Is there widespread metal contamination from in-situ bitumen extraction at Cold Lake, Alberta heavy oil field?

The extraction of oil sands by in-situ methods in Alberta has expanded dramatically in the past two decades and will soon overtake surface mining as the dominant bitumen production process in the province. While concerns regarding regional metal emissions from oil sand mining and bitumen upgrading have arisen, there is a lack of information on emissions from the in-situ industry alone. Here we show using lake sediment records and regionally-distributed soil samples that in the absence of bitumen upgrading and surface mining, there has been no significant metal (As, Cd, Cu, Hg, Ni, Pb, V) enrichment from the Cold Lake in-situ oil field. Sediment records demonstrate post-industrial Cd, Hg and Pb enrichment beginning in the early Twentieth Century, which has leveled off or declined since the onset of commercial in-situ bitumen production at Cold Lake in 1985.

Rural doctors' attitudes to and knowledge of medicinal cannabis.

The use of cannabis for medical purposes remains controversial. Since support from general practitioners would be needed for the successful operation of a legalised prescription regime, New South Wales Northern Rivers general practitioners were surveyed on their attitudes to and knowledge of medicinal cannabis. A representative random sample of general practitioners, stratified by age and gender, was derived and interviewed. Results indicated generally high levels of knowledge of cannabis's medical uses. The mean number of patients seen in 2004 with medicinal cannabis-treatable conditions was 66.8, with chronic pain patients accounting for 36.7. Overwhelming majorities of respondents reported they would prescribe medicinal cannabis if it were legal, professionally supported and backed by research and that they would approve of clinical trials and a legalised regulatory scheme under such conditions. These results suggest the need to conduct a Statewide general practitioners' survey to confirm or refute the present findings.