Two senators gathered in Washington, DC on Wednesday to encourage the Obama administration to block TransCanada's (TSE:TRP) propsoed Keystone XL pipeline.
Senator Sheldon Whitehouse, a Democrat from Rhode Island, and California Senator Barbara Boxer said the pipeline would not only increase air pollution but also endanger human health.
Last month the State Department came out with a report that said the pipeline would not greatly increase carbon emissions – Obama has cited air pollution as his biggest concern regarding the pipeline.
The White House is expected to issue a final decision before the summer.
Speaking at the press conference, Boxer spoke about "dramatic new information that will shine a spotlight on the health impacts of tar sands oil" and called Alberta's oil sands "one of the filthiest kinds of oil on our planet."
"The health impacts of tar sands oil are being ignored."
Boxer said that while the State Department report covered the environmental impacts of the pipeline, it did not consider risks to human health.
A University of Toronto study published earlier this month suggested that the oil sands' impact on human health and the environment may have been underestimated due to flawed environmental assessment procedures.