A U.S. federal agency has announced it will be starting a study into the potential impact of spills of diluted bitumen (dilbit) produced in Alberta's oil sands on the environment and public health. The research will examine whether dilbit spills are more toxic and more dangerous than those of traditional oil, which is lighter in comparison.

The question of the consequences of dilbit leaks has been particularly pressing in light of a series of planned projects for carrying Canadian fuels to the United States through pipelines, such as Keystone XL, and after several dilbit spills reported over the past few years in Arkansas, Michigan and other states, Inside Climate News reported. Isolated leaks have been examined and there is evidence that they could cause serious damage, such as polluting aquifers and waterways, but the new research will aim to draw broader conclusions on the effect of dilbit spills.

According to Cynthia Quarterman, administrator of the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA), the study will be conducted by the National Academy of Sciences. The PHMSA has been working on fulfilling mandates under the 2011 pipeline safety act and as part of this year's budget a further study into dilbit spills in comparison to other types of crude oil was required, Quarterman said. The news of the study was announced at a Congressional hearing, at the Subcommittee on Railroads, Pipelines and Hazardous Materials.