Tests in Alberta industrial heartland reveal air quality concerns
Researchers find brief, dramatic spikes in levels of benzene, a known carcinogen for which there is no safe level.
Progress at fuel producer after environmental conviction
Found guilty in 2013 of knowingly releasing the carcinogen benzene into the air.
Apple bans potentially hazardous materials from iPhone, iPad assembly
Benzene can cause leukaemia if not handled properly; n-hexane has been linked to nerve damage.