"A coalition of environmental groups wants air-quality officials to determine if the refining of heavy Canadian crude has an effect on local health and safety."
"A coalition of environmental groups says it has discovered that large-scale shipments of low-quality heavy crude oil from Canada's tar sands are being delivered by rail for processing by Southern California refineries.
The groups on Tuesday called for an investigation by air-quality officials to evaluate the effects on health, air quality, safety and the climate of processing the heavy Canadian crude, which requires intensive processing to remove higher levels of sulfur to meet U.S. standards.
The Natural Resources Defense Council and Communities for a Better Environment say they worry that refineries now processing the semi-solid form of oil have increased their noxious emissions and raised risks of accidental spills and accidents. The process of refining tar sands oil is more corrosive on refinery equipment and produces more greenhouse gases than liquid crude, environmentalists said."