Tar sands in Canada's Alberta Province are emitting more hazardous air pollutants than official reports suggest, according to new research from the University of Toronto Scarborough.
Writing in the journal Proceedings of the National Academy of Science, Frank Wania, a professor of environmental chemistry, and his PhD candidate Abha Parajulee report that carcinogenic pollutants known as polycyclic aromatic hydrocarbons (PAHs) are being underreported.
"When dealing with chemicals that have such great potential to harm people and animals, it is absolutely vital that we truly understand how, and how much they are being released into the environment," said Parajulee, the lead author of the paper.
In addition to cancer, PAHs have been linked to higher instances of asthma and lower IQs in children born to women exposed to the pollutants.
PAHs are produced by the extraction process used to collect the petroleum present in the tar sands.
Prior studies on levels of PAHs released into the environment from tar sands extraction suggest that the PAHs are being emitted at reasonable levels. But Parajulee and Wania contend that other indirect pathways are responsible for emitting PAHs and are not being assessed.
One example the researchers noted is that polluted water from tailing ponds, which are created by the oil-extraction process, do not typically get taken into account, event though they may actually introduce more PAHs in the environment than direct emissions.
"Tailing ponds are not the end of the journey for the pollutants they contain. PAHs are highly volatile, meaning they escape into the air much more than many people think," Parajulee said.
Parajulee's model also factors in PAHs released during the transport and storage of other waste material from operations in the tar sand fields.
"We need to take a holistic approach that includes both modeling and monitoring," Wania said. "This is the single most powerful way to inform public policy and private management strategies for the region."