Canada’s environment continues to face challenges with respect to air and water quality and greenhouse gas emissions, according to the third annual report of environmental indicators from Statistics Canada.

Exposure to some components of smog increasing over the long term

The air quality indicators track measures of Canadians’ exposure to ground-level ozone and fine particulate matter during the warm season (April 1 to September 30). These pollutants are key components of smog and can lead to adverse health effects even at low concentrations in the air.

The report shows that the ozone exposure indicator increased by an average of 0.8% a year between 1990 and 2005. This is equivalent to an overall increase of about 12% between 1990 and 2005.

Regionally, the ozone exposure indicator increased in southern Ontario and in southern Quebec over the period. The indicator level was unchanged in other regions.

The exposure indicator for fine particulate matter did not show any significant increase or decrease between 2000 and 2005, the only period for which consistent data are available.

Transportation, electricity generation, wood burning and the use of chemical products such as paint and solvents can increase levels of ozone and fine particulate matter in the air.

Greenhouse gas emissions up sharply since 1990, despite decline in intensity

In 2005, Canada’s greenhouse gas emissions were estimated at 747 million tonnes of carbon dioxide equivalent, up 25% from 1990. These emissions were 33% above the target set by the Kyoto Protocol.

Greenhouse gas emissions increased significantly between 1990 and 2005, despite the fact that 17.8% less greenhouse gas was emitted per unit of economic activity in 2005 compared with 1990. Increases in overall economic activity resulted in increases in both energy use and greenhouse gas emissions.

Contrary to the general trend since 1990, greenhouse gas emissions were nearly stable between 2003 and 2005. This change was due primarily to a reduction in emissions from electricity production (reduced coal-fired generation and increased hydro and nuclear generation), reduced demand for home heating fuels due to warm winters and a reduced rate of increase in fossil fuel production.

Freshwater quality: Phosphorous a concern for aquatic life

This indicator assesses surface freshwater quality with respect to the protection of fish, aquatic invertebrates and plants. It does not assess the quality of water for human consumption and use. The indicator is based on information gathered from 2003 to 2005.

Water monitoring results throughout southern Canada show that guidelines for protecting aquatic life were not met, at least occasionally, at many sites.

Tests at 359 river and lake monitoring sites in southern Canada found that freshwater quality was rated as “good” or “excellent” at 44% of the sites, “fair” at 33%, and “marginal” or “poor” at 23%.

The report found that phosphorus was a major concern for surface freshwater quality in Canada. Phosphorus levels in southern Canada did not meet the water quality guidelines for aquatic life over half the time at 127 of 344 monitoring sites.

Most phosphorus in water comes from sewage, agricultural runoff and industrial wastewater.

An oversupply of phosphorous in water can result in excessive growth of aquatic plants such as algae and reduce the amount of dissolved oxygen available for fish and other aquatic animals. Some algal blooms can be toxic, threatening livestock and human health.

Challenges for the Growing Canadian Economy

The indicator results are partly due to the growing Canadian population and economy. Between 1990 and 2005, Canada’s population increased by 17%, to 32.3 million. This increase, coupled with economic growth, led to greater resource use and waste production, increased greenhouse gas emissions and, in certain cases, more air and water pollution.

21 Oct 2007