Kitimat SO2 Alert Pilot Project

In response to concerns by the public and recommendations from the Environmental Appeal Board, the Ministry of Environment and Climate Change Strategy has initiated a pilot project in Kitimat to alert the public of periods of elevated sulphur dioxide (SO2) levels.

What is SO2?

Sulphur dioxide (SO2) is a colourless gas with a strong odour at higher concentrations. It is produced during the combustion of sulphur-containing fuels and industrial operations involving sulphur-containing materials. The largest sources of SO2 in B.C. include the upstream oil and gas sector, metal smelting facilities, the pulp and paper sector and marine vessels.

How does it affect my health?

Short-term exposures to elevated SO2 levels can cause the air passages in the lungs to constrict or tighten, leading to breathing difficulties and tightening in the chest. Those most sensitive to the effects of SO2 include persons with asthma, children and the elderly. Symptoms may worsen during vigorous exercise or hard physical labour. See HealthLinkBC for summary health recommendations and Heath Canada’s Human Health Risk Assessment for Sulphur Dioxide for more detailed information.

What is the SO2 alert system and how can I sign up to receive alerts?  

The Ministry has started a pilot project in Kitimat, in response to local concerns about increasing SO2­ emissions and recommendations from the Environmental Appeal Board regarding the Rio Tinto Alcan permit amendment. Alerts are posted here, when SO2 concentrations become elevated at any of three community monitoring sites. Alternatively, members of the public can receive these alerts directly by e-mail or text message through services provided by the Bulkely Valley Lakes District Airshed Management Society at: Each alert message includes information on 1-hour SO2 concentrations over the past hour and associated health guidance, focussing on advice for those most sensitive to SO2 exposure.

How was the alert system developed?

The health guidance was developed in consultation with the BC Centre for Disease Control, the Ministry of Health and Northern Health Authority. Different sets of health advice were established for moderate (36-70 ppb), high (71-185 ppb) and very high (>185 ppb) levels of SO2. The health advice was based on guidance established by Health Canada for the Air Quality Health Index and by the Island Health Authority in its Health Risk Guide developed for the James Bay Sulphur Dioxide Monitoring Program.

Where can I find additional information on the alert system?

For additional information, please see: