Media Releases

Research shows that reported oil sands emissions greatly underestimated

February 3, 2014

TORONTO, ON – A new com­pre­hen­sive mod­el­ing assess­ment of con­t­a­m­i­na­tion in the Athabas­ca Oil Sands Region indi­cates that offi­cial­ly report­ed emis­sions of cer­tain haz­ardous air pol­lu­tants have been great­ly under­es­ti­mat­ed.

The results of the assess­ment, which was car­ried out by Uni­ver­si­ty of Toron­to Scar­bor­ough Envi­ron­men­tal Chem­istry pro­fes­sor Frank Wania and his PhD can­di­date Abha Para­julee, will be pub­lished in the Pro­ceed­ings of the Nation­al Acad­e­my of Sci­ence Mon­day, Feb­ru­ary 3 2014. The study con­sti­tutes the most com­pre­hen­sive such mod­el that has been done for the Oil Sands Region.

The team used a mod­el to assess the plau­si­bil­i­ty of report­ed emis­sions of a group of atmos­pher­ic pol­lu­tants known as poly­cyclic aro­mat­ic hydro­car­bons (PAHs). Many PAHs are high­ly car­cino­genic.

“When deal­ing with chem­i­cals that have the poten­tial to harm peo­ple and ani­mals, it is vital that we have a good under­stand­ing of how, and how much they are enter­ing the envi­ron­ment,” said Para­julee, the lead author of the paper.

PAHs are released dur­ing the process of extract­ing petro­le­um from the oil sands. Envi­ron­men­tal Impact Assess­ments have so far only con­sid­ered the PAHs that are released direct­ly into the atmos­phere. The risk asso­ci­at­ed with those direct releas­es was judged to fall with­in accept­able reg­u­la­to­ry lim­its.

The mod­el used by Para­julee and Wania takes into account oth­er indi­rect path­ways for the release of PAHs that hadn’t been assessed before or were deemed neg­li­gi­ble. For instance, they found that evap­o­ra­tion from tail­ings ponds – lakes of pol­lut­ed water also cre­at­ed through oil sands pro­cess­ing – may actu­al­ly intro­duce more PAHs into the atmos­phere than direct emis­sions.

“Tail­ings ponds are not the end of the jour­ney for many of the pol­lu­tants they con­tain. Some PAHs are volatile, mean­ing they escape into the air much more than many peo­ple think,” says Para­julee. (pic­tured seat­ed at right with Wania).

The high­er lev­els of PAHs the UTSC sci­en­tists’ mod­el pre­dicts when account­ing for emis­sions from tail­ings ponds are con­sis­tent with what has actu­al­ly been mea­sured in sam­ples tak­en from areas near and in the Athabas­ca Oil Sands Region.

The authors also found, how­ev­er, that tail­ings ponds emis­sions are like­ly not sig­nif­i­cant con­trib­u­tors of rel­a­tive­ly involatile PAHs to the Oil Sands Region atmos­phere. Instead, oth­er emis­sions sources not tak­en into account by the envi­ron­men­tal impact assess­ment, such as blow­ing dust, are prob­a­bly more impor­tant for these chem­i­cals.

The pair of researchers mod­eled only three PAHs, which they believe are rep­re­sen­ta­tive of oth­ers. Still, they say, their mod­el indi­cates bet­ter mon­i­tor­ing data and emis­sions infor­ma­tion are need­ed to improve our under­stand­ing of the envi­ron­men­tal impact of the oil sands even fur­ther.

“Our study implies that PAH con­cen­tra­tions in air, water, and food, that are esti­mat­ed as part of envi­ron­men­tal impact assess­ments of oil sands min­ing oper­a­tions are very like­ly too low,” says Wania. “There­fore the poten­tial risks to humans and wildlife may also have been under­es­ti­mat­ed.”



Abha Para­julee
PhD Can­di­date
UTSC Depart­ment of Envi­ron­men­tal Sci­ence
Tel: 416–287-7506

Media con­tact:

Don Camp­bell
Media Rela­tions Offi­cer
Uni­ver­si­ty of Toron­to Scar­bor­ough
Tel: 416–208-2938