UVic research shows sulphur dioxide levels pose health risks

Sulphur dioxide levels in James Bay certainly won’t “leave people dead in the street,” but could prove high enough to exacerbate pre-existing conditions like asthma or bronchitis, said Michael Pennock, population health epidemiologist with Vancouver Island Health Authority.

New air-quality research, conducted by the University of Victoria, found that SO2 levels exceed World Health Organization standards on about 15 per cent of days during cruise-ship season. The results have implications for more than just James Bay.

“Some of the plumes will be blown over to the Songhees areas at an altitude where some of the upper units in some of the condos are experiencing some exposures,” Pennock said.

Over the summer, two UVic researchers measured levels of various pollutants using new equipment purchased by the Ministry of Environment.

Called a Mobile Air Monitoring Laboratory, the unit detects SO2, nitric oxide, nitrogen dioxide and other particles.

“It’s like a big cube van and up on top there’s a couple of antennas that stick out of it,” said researcher Eleanor Setton.

All summer, the van took continuous readings while parked by the community garden and day care.

“It’s the first time that we’ve measured sulphur dioxide in that specific area,” Setton said. “It did show some short term, one-hour peaks.”

These peaks are suspected to coincide with the coming and going of cruise ships, but more analysis is required, said Pennock.

“(SO2) levels go up and down, and they’re high enough at their peak that we need to take a good look at what the potential health implications are.”

If VIHA determines levels are problematic, it would work with stakeholders, such as the Greater Victoria Harbour Authority, to find ways to mitigate them. Limiting the number of cruise ships coming into port would not be an option, Pennock said. “It could be that in two or three years, this problem will take care of itself.”

For the James Bay Neighbourhood Association, action is long overdue.

“The objective in my mind is to lower SO2 levels to within WHO standards on an ongoing basis,” said board member Marg Gardiner, who has been working to promote awareness and research and into air quality for years.

rholmen@saanichnews.com

By the Numbers

Acceptable levels of sulphur dioxide differ depending on who you ask.

• Canada: max 150 micrograms of SO2 per cubic metre.

• Capital Regional District: 125 mcg/m3.

• World Health Organization: max 20 mcg/m3.