Pollution in Canada refers to the introduction of contaminants into the natural environment, including air, water, and soil systems. It is recognized in scientific literature and government policy as a significant environmental and public health issue, and associated with industrial activity, transportation emissions, agricultural runoff, resource extraction (notably mining, oil and gas development), and urban development.
Air pollution primarily associated with greenhouse gas emissions, particulate matter, nitrogen oxides, and ground-level ozone, largely produced by transportation, industry, and energy production. While air quality has improved in many regions due to regulatory measures, certain urban and industrial areas continue to experience elevated pollution levels, with documented associations to respiratory and cardiovascular health effects.
Water pollution historically been linked to industrial waste, agricultural runoff, inadequate wastewater treatment in some regions, and contamination of freshwater ecosystems. Although Canada has extensive freshwater resources and regulatory frameworks intended to protect water quality, localized issues persist, including nutrient loading, toxic waste, and advisories affecting drinking water in some Indigenous and rural communities.
Soil contamination occurs in areas affected by industrial activity, waste disposal, mining, and the use of agricultural chemicals. Remediation efforts are ongoing at contaminated sites across the country, particularly in former industrial zones and resource extraction regions.
Pollution contributes to broader policy debates on economic development, resource extraction, and environmental protection, with public concern linked to its health impacts, environmental degradation, and effects on biodiversity. Environmental policy in Canada also increasingly incorporates climate change mitigation and sustainable development goals, while regulation is addressed through a combination of federal legislation, such as the Canadian Environmental Protection Act, provincial environmental regulations, and municipal bylaws.
Air pollution
Air pollution in Canada is caused by industrial and vehicle emissions, agriculture, construction, wood burning, and energy production. Ongoing monitoring of Canada's Air Pollutant Emissions Inventory shows that 14 of the 17 of the air pollutants monitored are decreasing compared to historical levels. Data of 2019 shows that Canada is expected to meet or exceed its emission reduction commitments for 2020, as per the amended Gothenburg Protocol.
Oil sands pollution
While overall pollution levels have dropped, it was found that oil sand pollution has increased by 20% since 2009. mirror Tar sands facilities were found to be among the top four highest polluters of volatile organic compounds (VOCs)- a major air contaminant. VOCs and other air contaminants are set to increase in the future as a result of continued output from the oil sands. Oil sand pollution is not only set to increase VOCs, but also, acid rain. Acid rain is rain that has been contaminated by airborne chemicals, making it acidic. Two major causes of acid rain are sulphur dioxide and nitrogen oxide. Acid rain can cause damage to soil, water, wildlife, plants and buildings. Additionally, the airborne particles that cause acid rain can also contribute to smog. In recent years progress has been made in reducing acid rain, however, Alberta's oil sands may soon set back this progress.
Pollution from oil wells In southeastern Saskatchewan, air pollution from oil production has breached provincial air quality standards hundreds of times since 2014.
Canada/United States transboundary pollution In recent years, the Canada-United States Air Quality Agreement, signed on 13 March 1992, has improved air quality by reducing sulfur dioxide and nitrogen oxide emissions in both countries. The agreement was meant to address the issue of transnational air pollution between the two countries. The agreement was expanded in 2000 to also include goals of reducing emissions of volatile organic compounds and levels of ground-level ozone. Ground-level ozone is caused by reactions between nitrogen oxides and VOCs in the presence of sunlight. Ozone is a contributor to smog and is known to cause numerous respiratory diseases. The 2012 Canada-United States Air Quality Agreement Progress Report found that "Canada's total emissions of sulfur dioxide have decreased by 57% from 1990 levels while the U.S. has reduced total sulfur dioxide emissions from covered sources by 67% from their 1990 emission levels. Between 2000 and 2010, Canada reduced total emissions of nitrogen oxides by 40% in the transboundary ozone region while U.S. total nitrogen oxide emissions decreased by 42% in the region".
While transnational pollution between the United States and Canada has decreased many Canadians still say they contend with polluted air as a result of drifting pollution from the U.S. Approximately 70% of the air pollution in Canada comes from the United States. In 2006 the government of Ontario announced that "5,000 premature deaths caused by smog in the province every year can be attributed to air pollution that crosses the Canada-U.S. border." Additionally, the then (2006) mayor of Halifax, Peter Kelley, also proclaimed "over 50 per cent of air pollutants over New Brunswick and Nova Scotia are from the U.S. For us, we're trying to deal with what's coming our way, but also what we generate here as well." In an attempt to combat the pollution a petition was created. In 2006 the petition was filed by thirteen Canadian municipalities to the U.S. Environmental Protection Agency calling for a reduction in coal-fired plants.
Climate Change Accountability Act The Climate Change Accountability Act called for greenhouse gas emissions to be 25% below 1990 levels by 2021, and 80% below 1990 levels by 2050. Although the bill was passed by the House of Commons, the bill was defeated by the Senate. Environment Minister Jim Prentice stated in early 2010 that the new goal for greenhouse gas emissions would be 17% below 2005 levels by 2020, the equivalent of a 3% increase from 1990.
Water pollution
While most of Canada's surface and ground water is generally clean there is some local and regional water pollution that can be caused by "industrial and municipal discharge, runoff, spills, and deposition of airborne pollutants". Contaminated water can result in a myriad of serious consequences for human health.
Oil sands pollution As previously stated, Alberta's oil sands are set to cause growing levels of acid rain consequentially leading to an increase in water contamination in the area. Acid rain will cause Canada's lakes and rivers to become further acidified. This is a problem as it decreases levels of surface water calcium. This lower concentration of calcium is already having particularly adverse effects on plant life, as can be seen with the Daphnia species-an important food source for aquatic species and marine life.
A recent study at the University of Alberta found levels of metals like arsenic, lead and mercury to be considerably higher than national guidelines in water downstream from Albertan oil sites. This pollution could potentially result in harmful health implications for fish and other wildlife. The study further discerned that their findings were "contrary to claims made by industry and government" who purported that "pollutants are from natural sources and not from the expanding production of oil from tar sands."
Other than contributing to acid rain and high levels of metals in water, sites of oil production can also cause significant damage by human error and runoff. A prominent example is the 2007 case involving the Athabasca River. Due to human error, energy magnate Suncor spilled 9.8 million liters of oil sands waste water into the river causing adverse effects for people and wildlife in the area. The Athabasca River can also be used as an example of oil sands runoff. It was found that the Athabasca's waters, which are downstream from the oil sands, had higher concentrations of pollutants as a result of runoff. High concentrations of pollutants can have serious consequences for wildlife and humans. Recently, it was reported that there were significant increases in fish deformities as well as an increase in cancer rates in a Native community downstream from the Athabasca.
Great Lakes pollution Pollution of the Great Lakes, the world's biggest bodies of fresh water, continue to be a significant problem for both Canada and the United States. According to Derek Stack, executive director of Great Lakes United, "High pollution levels in the Great Lakes basin continue to take an apparent toll on the air and water quality of the ecosystem." In 2002, it was reported that the Great Lakes basin was home to 45% of all toxic air pollution in Canada, in turn affecting the Great Lakes' water. An even more recent report suggests that the Alberta oil sands' impact could reach as far as the Great Lakes. The report warns that "[oil] refineries will be using the Great Lakes 'as a cheap supply' source for their copious water needs and the area’s air 'as a pollution dump'."
Sulphur dioxide emissions have also contributed to the acidity in Canada's Lakes. The thousands of lakes in Canada (including the Great Lakes) have an average pH of 5, which is harmfully acidic for aquatic life in these lakes.
In September 2012, the United States and Canada signed an amended version of the Great Lakes Water Quality Agreement. The overarching purpose of the Agreement is to "restore and maintain the chemical, physical and biological integrity of the waters". Significant amendments made to the Agreement include "address[ing] aquatic invasive species, habitat degradation and the effects of climate change, and support continued work on existing threats to people's health and the environment in the Great Lakes Basin such as harmful algae, toxic chemicals, and discharges from other vessels". However, some people contend that the changes made to the Agreement while good in principle, lack the "hard number goals, and actions to reach them."
Arctic waters pollution Under the 1970 Arctic Waters Pollution Prevention Act, the Canadian government established a document to prevent pollution of Canadian Arctic waters. However, in recent years Arctic waters have become increasingly polluted. It was recently found that due to pollution some waters have levels of lead that are higher than the Canadian guidelines.
Coastal communities that emit waste also contribute to arctic pollution. Arctic coastal communities do not presently have the infrastructure necessary to properly deal with their waste, this could lead to greater pollution in the future as these communities continue to grow in size. Other than coastal communities, waste and litter from the rest of the world continues to be a significant issue in the Arctic, with waste levels doubling in the past ten years. The most significant types of litter found are plastic items and plastic bags.
Pollution from sewage