Air quality in New Brunswick 

Air quality is constantly changing. It is affected by a wide variety of factors, including the weather, long range movements of air from other parts of the world, natural events, industry cycles and other human activities. Pure air contains about 79% nitrogen, 20.9% oxygen, 0.04% carbon dioxide and trace amounts of other gases and components. Air pollution is the general term used to describe unwanted, potentially harmful substances that can also occur in our air. 

Air pollution comes in many different forms and from many different sources. Nature has a hand in it: smoke from forest fires, windblown dust and pollen, electrical storms, salt spray from the ocean and even the eruption of a far-off volcano can affect the quality of air in New Brunswick. Many pollutants are present naturally in the environment. Human activities can also increase the concentration of pollutants in the atmosphere. For example, by spreading sand on winter roads or crushing rock in a gravel pit, we increase the amount of dust in the air. 

Not surprisingly, pollution from human sources tends to concern us more on a day-to-day basis than natural sources. For example, when people burn tires or garbage, or use a wood stove improperly, a whole range of harmful gases are released into the atmosphere. The largest source of this type of air pollution is the burning of fuel: for transportation, to heat our buildings, to make electricity and to operate industries.

Borders mean nothing when it comes to air pollution. In fact, much of New Brunswick’s air pollution comes from sources beyond our borders. That is why the federal government has a significant role to play in monitoring long-range pollutants and in establishing agreements with other jurisdictions. 

Air masses can cross the heavily populated and industrialized areas of central Canada and the United States before they reach us, picking up pollutants on the way. Southern New Brunswick gets more pollution from long-range transport than the northern parts of the province, which tends to be influenced by cleaner air masses.

What distance air pollutants will travel depends on what they are, where and how they are emitted and atmospheric conditions. Pollutants that stay in the lower levels of the atmosphere are often deposited near their source, while others are transported many hundreds of kilometers before their effects are noticed. In New Brunswick, the long-range transport effect is significant for ground-level ozone, acid deposition and fine particulates.

Local geographic and weather conditions have a strong influence on air quality. The funnel shape of the Bay of Fundy, for example, can channel polluted air from the southwest into the southeastern part of the province and those cold Atlantic waters help to cool air close to the surface, which can prevent pollution from rising and mixing.

Pollutants tend to gather in low-lying areas or valleys and New Brunswick’s rolling terrain has lots of pockets where temperature inversions are more frequent, and winds are light. Inversions occur when temperature increases with height instead of decreasing, creating an invisible barrier that prevents pollutants from scattering as they would normally.

Other local New Brunswick effects include fog and wind patterns around the Bay of Fundy. When fog blankets our communities, it reduces visibility and its moisture may react with pollutants, aggravating their effects on humans and the environment.

Air pollution can cause a wide range of environmental and health issues. It is particularly problematic for children, the elderly and people with respiratory or heart problems. It can also affect:

• crop production
• drinking water
• fish and wildlife
• forests
• the quality of bodies of water
• visibility (haze)

Some air contaminants can affect buildings and other infrastructure. Air pollutants may also cause nuisance issues that affect our comfort and well-being, such as excessive dust and odours. Some of the more common air pollutants include:

• Fine Particulate Matter (PM_2.5)
• Ground Level Ozone (O₃)
• Sulfur Dioxide (SO₂)
• Nitrogen Dioxide (NO₂)
• Hydrogen Sulphide (H₂S)
• Volatile Organic Compounds (VOC)
• Carbon Monoxide (CO)

Particulate matter refers to tiny solid or liquid particles that are suspended in the air. These include dust, ash, soot, smoke and other microscopic pollutants. Most of these particles are smaller than grains of pollen, which means they can easily travel long distances through the air. Because of their size and widespread presence, particulate matter is a major contributor to air pollution.

Particulate matter comes from both human and natural sources. Common human sources include:

• agricultural operations
• burning of fuels such as wood, gasoline, oil and coal (e.g., in homes, vehicles and industry)
• construction and demolition activities
• road dust from vehicles

Natural sources include:

• ocean salt spray
• volcanic activity
• windblown pollen, dust and sand

In addition, some particles form in the atmosphere when gases like sulfur dioxide and nitrogen oxides react with each other. These chemical reactions contribute to the formation of smog, especially over urban areas.

Fine particulate matter—small enough to be invisible to the naked eye—can pose serious health risks. These particles can enter deep into the lungs, reducing oxygen intake and putting extra strain on the respiratory system. Individuals with asthma, bronchitis or other lung conditions are especially at risk when particle concentrations are high.

Particulate matter can also have environmental and aesthetic effects. For example:

• depending on their chemical makeup, particles may damage vegetation, corrode metals and degrade other materials
• it can cause buildings to become stained with soot, particularly in older industrial zones
• it reduces visibility by contributing to haze and smog

Total Suspended Particulate

All sizes of particles are represented in Total Suspended Particulate. It includes natural particles, such as pollen and spores, as well as particles from vehicles or smokestacks. The levels may be higher in rural areas during the spring allergy season, when many plants and grasses release their pollen. In urban areas, it may reflect traffic volume, construction or other dust-generating activities.

Total Suspended Particulate was a standard pollution measurement for many years but is becoming less important as monitoring efforts shift toward smaller particle sizes, which are of greater concern for human health. 

Coarse or respirable particulate (PM₁₀)

Coarse or respirable particles describe particles that are 10 microns or less in diameter. A micron is only one-millionth of a metre, so these particles are invisible to the naked eye. They can be made up of smaller pollen, spores and dust from roads, quarries and tire wear, with smaller contributions from sea salt and vehicle exhaust.

Fine particulate (PM_2.5)

Fine particulates are 2.5 microns in diameter or less. The most common source is organic fuel combustion (wood, oil, natural gas, coal, etc.), including vehicle exhaust, home heating and industrial emissions. Other typical sources of particulate matter such as road dust contribute relatively little. Many studies over the past decade have confirmed that these smallest particles are the most important with respect to human health. Fine particulates are closely linked to human respiratory and cardiovascular disease.

Ozone is an invisible and odorless gas. It is often found at relatively high concentrations during hot, hazy summer weather. In such conditions, ground-level ozone may build up day by day into a white or yellowish haze called smog. Fine particles in the air give smog its color.

Unlike most other air pollutants, ozone is not directly emitted but is formed as a result of a chemical reaction in the atmosphere. It forms when certain other pollutants in the atmosphere react together in the presence of strong sunlight. Electrical storms also produce some ozone.

Most of our ozone pollution is carried here (through long-range transport) by air masses originating in heavily populated regions in the northeastern United States and central Canada.

Ground-level ozone can irritate the lungs and make breathing difficult. It can also:

• attack metals and painted surfaces
• cause damage to forests and other vegetation
• cause damage to sensitive crops such as potatoes and tomatoes
• weaken rubber tires  

Sulfur dioxide is a colourless gas. It has a sharp odour, like that of a struck match. At higher concentrations, many people can notice an acid taste in the air.

Sulfur dioxide is released as a by-product when fuels containing sulfur—such as oil and coal—are burned. The main sources include:

• fossil-fuel powered electricity generation
• industrial heating systems
• metal smelters
• oil refineries
• pulp and paper mills

Sulfur dioxide can have harmful effects on both the environment and human health. At high concentrations, it can: 

• damage trees and agricultural crops
• corrode metals and other materials
• irritate the eyes and throat

People with respiratory conditions or chronic heart and lung diseases are especially sensitive to sulfur dioxide, though even healthy individuals may experience discomfort when exposed.

In the atmosphere, sulfur dioxide reacts with water vapour in clouds to form sulfuric acid. This acid contributes significantly to acid deposition, commonly known as acid rain, which can harm ecosystems, degrade infrastructure and acidify lakes and soils.

Nitrogen oxides are a group of gases produced when nitrogen and oxygen combine, typically when fuels are burned at high temperatures and pressures. Nitrogen oxides - which include nitrogen dioxide (NO₂), nitric oxide (NO), nitrous oxide (N₂O) and other nitrogen-oxygen compounds - are collectively referred to as NO_X.

In New Brunswick, a major source of nitrogen oxides is the combustion of fossil fuels, particularly from motor vehicles and power-generating stations. Other sources include:

• any other process involving combustion
• kraft and paper mills
• oil refining and gas production
• waste incineration
• wood burning 

Exposure to nitrogen oxides can irritate the lungs and reduce resistance to respiratory infections. It can also harm vegetation, including important food crops.

Nitrogen oxides damage materials by corroding metals, fading fabrics and degrading rubber. Environmentally, it plays a major role in:

• the creation of ground-level ozone and smog when combined with volatile organic compounds (VOCs) in sunlight
• the formation of acid deposition (like sulfur dioxide)

Hydrogen sulfide is a colourless gas that is heavier than air. It is a reduced sulfur gas, with a characteristic smell of rotten eggs.

Hydrogen sulfide is found naturally beneath the earth's surface as an impurity within natural gas. It is also a product of natural decomposition processes, such as those occurring in marshes and swamps. Industrially, hydrogen sulfide originates from various sources, including: 

• fish processing plants
• kraft pulp mills
• livestock feedlots
• oil refineries
• wastewater treatment facilities 

The presence of hydrogen sulfide is noticeable even at very low concentrations (below one part per billion) due to its distinct odor. As concentrations increase, it can cause irritation to the eyes and mucous membranes, exacerbate existing respiratory issues and lead to symptoms like nausea, fatigue and headaches. The severity of these health effects is directly related to the concentration level and the duration of exposure.

Additionally, hydrogen sulfide exhibits corrosive properties towards certain metals and can dissolve in water to form an acid. When combusted, it transforms into sulfur dioxide, a significant contributor to acid rain. 

Volatile organic compounds are a group of carbon-containing substances. Some of these compounds take the form of gases; those that are liquids - such as gasoline - will readily evaporate, hence the term volatile. Thousands of different VOCs exist in the air, many of which occur naturally.

The production and burning of fossil fuels is a major source of VOCs. They are also emitted from a variety of industrial processes and from the evaporation of liquid solvents and fuels such as gasoline, paint thinner, rubbing alcohol and barbecue starter or lighter fluid. Oil-based paint and lacquers also emit these compounds.

Volatile organic compounds, reacting with other substances such as nitrogen oxides in the presence of heat and strong sunshine, contribute to the formation of ground-level ozone and smog. Some VOCs, like benzene, are also harmful or poisonous on their own.

Carbon monoxide is a colourless, odourless and flavourless gas.

Carbon monoxide is produced by the incomplete burning of carbon-containing materials such as coal, oil, gasoline, wood or natural gas. Motor vehicles can be a major source of carbon monoxide. Higher levels are found on city streets with heavy traffic and in confined spaces like parking garages. Forest fires, industrial activity and home heating systems also contribute significantly. 

New Brunswick’s few cities and small population mean that carbon monoxide is not normally a problem outdoors. Monitored levels seldom approach any of the existing air quality standards. Recent improvements in the efficiency of car engines and other fuel-burning devices typically result in more complete fuel combustion and less carbon monoxide production. 

Carbon monoxide primarily affects the body’s cardiovascular and nervous systems. Symptoms may include dizziness, headaches and fatigue. Very high exposure has been linked with impaired vision, reduced work capacity, decreased learning ability, lowered manual dexterity and poor performance of complex tasks.

It also interferes with the blood’s ability to carry oxygen to vital organs and tissues. As a result, it can affect any living thing that needs oxygen to survive. Vulnerable birds and other wildlife can become ill or die from exposure at levels that may be safe for humans. Even relatively low concentrations may affect children and other susceptible individuals, such as people with heart disease. Most healthy adults will only be affected at higher concentrations.