Carbon Monoxide Pollution: Causes And Concerns

Carbon monoxide (CO) is a colourless, odourless, and poisonous gas that is formed by the incomplete combustion of carbon-containing fuels, such as coal, wood, oil, natural gas, gasoline, and propane. It is a common air pollutant, particularly in urban areas, due to vehicle and industrial emissions. Indoor sources of CO include gas stoves, malfunctioning or improperly vented gas appliances, space heaters, fireplaces, tobacco smoke, and car emissions. High levels of CO can cause serious health issues, including dizziness, confusion, unconsciousness, and even death.

Incomplete combustion of fuels

During combustion, the atoms in the fuel react with oxygen in the air to form oxides. In the case of incomplete combustion, there is not enough oxygen for all the carbon to be converted into carbon dioxide, resulting in the formation of carbon monoxide. This is particularly dangerous as carbon monoxide is a toxic and odourless gas that can cause serious health issues and even death.

The incomplete combustion of carbon-containing fuels such as natural gas, gasoline, and wood is a significant source of carbon monoxide emissions. This includes emissions from motor vehicles, power plants, wildfires, and incinerators. Additionally, indoor sources of carbon monoxide, such as gas stoves, malfunctioning or improperly vented gas appliances, and tobacco smoke, can also contribute to air pollution and pose health risks to those exposed.

To address the issue of carbon monoxide air pollution from incomplete combustion, it is crucial to ensure proper ventilation and maintenance of combustion sources. This includes regularly cleaning and servicing burners, boilers, and other fuel-burning appliances. In the case of indoor sources, such as gas stoves and heaters, it is essential to have adequate ventilation to prevent the buildup of carbon monoxide.

Furthermore, monitoring and minimising carbon monoxide emissions during combustion processes is essential. While complete elimination of carbon monoxide from incomplete combustion may not be possible, regulatory bodies such as the EPA have implemented standards and regulations to control and reduce carbon monoxide pollution, particularly in outdoor air. These efforts are crucial in mitigating the health risks and environmental impacts associated with carbon monoxide exposure.

Industrial emissions

One of the primary industrial sources of CO emissions is the processing of metals and chemical manufacturing. Industries that utilise high-temperature combustion processes, such as power generating facilities, contribute to ambient air pollution, including CO emissions. The combustion of natural gas, coal, and coke in industrial plants releases CO into the atmosphere.

In addition, transportation-related emissions, including motor vehicles, aviation, and shipping, are also significant contributors to CO pollution. The incomplete combustion of fossil fuels in vehicle engines, particularly in areas with heavy traffic congestion, leads to high levels of CO in the air. This is particularly prevalent in urban areas, where the majority of outdoor CO emissions occur.

Furthermore, industrial activities can also indirectly contribute to CO pollution through the release of other pollutants. For example, nitrogen dioxide (NO2) emissions from industrial processes can lead to the formation of ground-level ozone (O3), which is a major component of smog and is closely linked to respiratory issues such as asthma.

It is important to note that industrial emissions of CO are not limited to a specific geographic area. Pollution emitted on one continent can travel across oceans and impact air quality on other continents. Regulatory bodies, such as the National Pollutant Inventory (NPI) in Australia, play a crucial role in tracking and monitoring industrial emissions to help minimise their harmful effects on the environment and human health.

Vehicle emissions

Carbon monoxide (CO) is a colourless, odourless, and deadly gas that is formed by the incomplete combustion of carbon-containing fuels such as natural gas, gasoline, and wood. It is emitted by a wide range of combustion sources, including motor vehicles, which are the largest source of air pollution in Washington State.

Gasoline-powered vehicles also emit methane (CH4) and nitrous oxide (N2O) from the tailpipe, and all vehicles can emit hydrofluorocarbon (HFC) from leaking air conditioners. While electric vehicles (EVs) emit far fewer tailpipe emissions, they are not entirely without environmental impact, as they can still release small amounts of greenhouse gases due to HFC leakage from air conditioners.

It is important to note that vehicles with internal combustion engines do not need to "warm up" in cold weather, as restarting them does not use more fuel or cause more wear and tear than letting them idle. Idling gets zero miles per gallon, so turning off the engine when possible can help reduce carbon monoxide emissions. Driving habits, such as observing speed limits and accelerating gradually, can also influence the amount of pollution emitted by a vehicle.

To reduce carbon monoxide emissions from vehicles, it is recommended to maintain proper tyre inflation, keep the vehicle in good repair, and choose the most fuel-efficient vehicle that meets your needs. These actions not only reduce pollution but can also lead to cost savings.

Residential wood burning

Carbon monoxide (CO) is an odourless, colourless, and toxic gas produced in large amounts by burning wood with insufficient air. It is harmful to human health, as it reduces the blood's ability to supply oxygen to body tissues, causing stress on the heart and reduced exercise capacity. Prolonged exposure to carbon monoxide can lead to dizziness, confusion, severe headaches, unconsciousness, and even death. Those most vulnerable to its effects are unborn children and individuals with anaemia, heart, circulatory, or lung disease.

Residential wood-burning appliances, such as wood stoves and fireplaces, are often used continuously, worsening outdoor air quality. Inadequate ventilation or improper usage of these appliances can result in the release of wood smoke and its pollutants into indoor spaces, posing similar health risks. Additionally, the smoke from wood burning contains over 100 hazardous chemicals, including toxic and carcinogenic compounds like benzene, formaldehyde, and benzo-a-pyrene.

To mitigate the negative impacts of residential wood burning, it is advisable to avoid burning wood, especially during high pollution days. Instead, alternative heating sources, such as solar panels, electric, or geothermal heat pumps, are recommended. If wood-burning is unavoidable, it is crucial to use newer, certified wood-burning devices that produce less smoke, minimise air pollution, and are more energy-efficient. Proper installation, maintenance, and operation of wood-burning appliances are also essential to reduce the release of harmful pollutants into the air.

Overall, residential wood burning significantly contributes to air pollution, particularly through the production of carbon monoxide and other toxic pollutants. To protect public health and improve air quality, it is important to transition to cleaner heating alternatives and ensure the proper use and maintenance of wood-burning appliances.

Forest fires

Wildfires produce a complex mixture of air pollutants, including particulate matter, toxic air contaminants, and carbon monoxide. The smoke released during a wildfire contains fine particles that can easily penetrate homes and buildings, increasing indoor particle concentrations. These fine particles, known as PM2.5, are of significant health concern as they can travel deep into the lungs and potentially enter the bloodstream. Individuals with cardiovascular or respiratory diseases, older adults, children, pregnant women, outdoor workers, and those of lower socioeconomic status are at greater risk of adverse health effects from exposure to wildfire smoke.

The combustion of fossil fuels and wildfires both contribute to climate change, but wildfires are part of the natural carbon cycle. Wildfires release carbon dioxide (CO2) emissions and other greenhouse gases (GHG) that contribute to global warming. While the burned areas regenerate and remove CO2 from the air, human-induced climate change disrupts this balance by increasing the frequency and intensity of wildfires, leading to a feedback loop.

Additionally, wildfires emit volatile organic compounds, such as black carbon, and gases that form ozone. These emissions have complex effects on warming and cooling. While some aerosols can block sunlight and cool the atmosphere, others, like black carbon, have a warming effect. The impact of wildfires on climate change is challenging to determine due to the terrestrial carbon cycle, but scientists estimate that wildfires emit approximately 8 billion tons of CO2 per year.

To mitigate the effects of wildfires, organizations like the California Air Resources Board (CARB) work with land managers and air districts to increase the use of prescribed fires as a forest management tool. By supporting controlled burning under specific meteorological conditions, they aim to minimize the impact of wildfires on air quality while also improving forest health and reducing the risk of severe wildfires.

Frequently asked questions