Indicator Type: Environmental Condition
Hydrogen sulphide (H2S) is a gas with a "rotten egg" smell. Industrial emissions are the chief source. This indicator shows trends in annual average concentrations of hydrogen sulphide.
More about hydrogen sulphide
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Trend: Mixed Trends
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What does the indicator show?
Annual hydrogen sulphide concentrations have decreased at urban stations in Alberta from 1990 to 2007 by 3 to 89%. The only statistically significant decreasing trend was found at Sherwood Park (89%) from 1998 to 2003. Note that data for the Fort McMurray station only span 1990 to 1997. Annual hydrogen sulphide concentrations have increased in the oilsands area north of Fort McMurray (by 71 to 135%) since monitoring began in 1999. A statistically significant increasing trend was found at Mildred Lake, where average annual hydrogen sulphide concentrations have increased 135% since 1999. In 2007, the highest annual average hydrogen sulphide concentrations were found at Mildred Lake (1.3 ppb), Mannix (1.2 ppb) and Lower Camp (1.0 ppb).
Currently, there are two air quality objectives for hydrogen sulphide in Alberta. The one-hour average objective is based on odour perception. It is 10 parts per billion (ppb). The 24-hour average objective is based on health effects. It is 3 parts per billion. Analyses of peak concentrations and exceedances of these objectives are also available.
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Why is this indicator important?
Exposure to hydrogen sulphide at low concentrations can irritate the eyes, nose and throat or cause headaches, dizziness, and nausea. Exposure at higher concentrations can result in sleepiness, blurred vision or death from respiratory failure. Hydrogen sulphide can be highly toxic, in the short term, to aquatic life, birds, and animals (Australian National Pollutant Industry). Hydrogen sulphide also presents an odour problem.
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What actions are being taken?
In 1998, the Board of the Clean Air Strategic Alliance (CASA) approved a recommendation from the CASA Air Toxics Project Team that "a research program be developed and funded to address the knowledge gaps related to the health effects database for hydrogen sulphide". In response to a proposal submitted in 1999 by the Alberta Lung Association, Alberta Environment approved funding for the search of background information on hydrogen sulphide. The results of that search are available in the Health Effects of Hydrogen Sulphide: Knowledge Gaps report.
Hydrogen sulphide emissions are regulated by Alberta Environment and the Alberta Energy and Utilities Board. These emissions are dependent on the industrial process and are therefore managed on a by-industry basis. If the potential for hydrogen sulphide emissions is present, industrial approvals, issued by Alberta Environment, will require on-site monitoring and adherence to air quality guidelines. Alberta Environment has issued Environmental Protection Orders to address unacceptable levels of H2S emissions at oil sands sites near Fort McMurray. Environmental Protection Orders are issued under the authority of Alberta’s Environmental Protection and Enhancement Act.
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Links to additional information
More information on H2S monitoring: http://www.casadata.org/pollutants/hydrogen_sulphide.asp
Health Effects of Hydrogen Sulphide: Knowledge Gaps (report): http://www3.gov.ab.ca/env/protenf/publications/H2S_Report.pdf
Air Quality in the Oil Sands: http://environment.alberta.ca/2584.html
Hydrogen Sulphide Emissions and Safety (as it pertains to the Agriculture Industry): http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex8269
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Feedback
E-mail the SOE Coordinator: SOE.Coordinator@gov.ab.ca or complete this short on-line questionnaire to provide your feedback: http://www.zoomerang.com/
survey.zgi?p=WEB224DW6P3E2K.
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