Gas And Air Pollution: A Toxic Mix

Air pollution is the presence of dangerous substances in the atmosphere in concentrations high enough and for long enough durations to cause harm. Gases that cause air pollution include nitrogen oxide, volatile organic compounds, carbon dioxide, sulphur oxide, methane, and more. These gases are produced by human activities such as industry and transportation, as well as natural factors. The combustion of fuels, such as gasoline and diesel, contributes significantly to air pollution. Gas stoves, for example, release methane and other pollutants, exposing people to respiratory disease-triggering pollutants.

Gas stoves and respiratory issues

The use of gas stoves has been linked to respiratory issues, particularly in children. Burning methane, the primary component of gas, creates heat, enabling nitrogen and oxygen to form nitrogen dioxide (NO2). Nitrogen dioxide is a lung irritant and has been linked to asthma. Research from the US has found that 12.7% of childhood asthma cases can be attributed to gas stove emissions. Children living in households that use gas stoves for cooking are 42% more likely to have asthma. Long-term exposure to NO2 from gas stoves has also been linked to an increased risk of developing asthma and other respiratory illnesses.

In addition to nitrogen dioxide, gas stoves can emit other harmful pollutants, including carbon monoxide, nitrous oxides, formaldehyde, benzene, hexane, and toluene. Carbon monoxide is particularly dangerous as it depletes oxygen in the air and in the blood, leading to potential health repercussions such as headaches, dizziness, unconsciousness, and even death in extreme cases.

The health risks associated with gas stove emissions have sparked debates and initiatives to reduce their use. Some states in the US, such as New York, have imposed restrictions on the use of natural gas in new buildings. Incentives, such as rebates and refunds, are also being offered to encourage the transition to electric stoves, which do not rely on methane gas and can use renewable energy sources.

While transitioning away from gas stoves can be challenging due to factors like cost and clutter, there are alternatives available, such as induction hobs, and steps that individuals can take to mitigate the risks associated with gas stove use. These include improving indoor air quality by opening windows while cooking, using exhaust fans, and investing in air purifiers.

Nitrogen oxide from heavy traffic

Nitrogen oxide (NOx) is a major contributor to air pollution, particularly in urban areas with heavy traffic. NOx is produced from the reaction of nitrogen and oxygen during combustion at high temperatures, which occurs in vehicle engines. As such, vehicles are the primary source of NOx emissions, with heavy-duty diesel-fuelled vehicles being the biggest culprits.

The presence of dangerous substances, such as NOx, in the atmosphere in high enough concentrations and for long enough durations can cause harm to human health and the environment. NOx emissions from traffic have been linked to adverse effects on respiratory and cardiovascular systems, as well as birth outcomes. Studies have shown that living in close proximity to roads with heavy traffic can increase the risk of experiencing these adverse health effects.

The concentration of NOx pollutants is significantly higher near roadsides, especially within 100 metres, and on working days when there are more vehicles on the road. In metropolitan areas, maximum permissible values of NOx are consistently breached, and actual NOx emission levels may be up to four times higher than predicted by some models. This is due to the numerous factors that affect vehicle emissions, such as individual driving behaviour, vehicle type, age, and fuel type.

Regulatory thresholds, such as those outlined in the Clean Air Act in the USA, aim to limit NOx emissions. However, in many places, NOx levels remain far above these standards, leading to the implementation of driving bans and speed limits in some areas. While efforts are being made to reduce NOx emissions, it remains a significant challenge to manage and control this type of air pollution effectively.

Sulphur dioxide from burning coal/oil

Air pollution is caused by the presence of dangerous substances in the atmosphere in high enough concentrations and for long enough durations to cause harm. Gases, chemicals, dust, suspended particles, and other pollutants can be released by natural or human factors, but only those generated by human activities may be subject to reduction and control.

Sulphur dioxide (SO2) is a pollutant gas that is produced by the combustion of coal or oil. Coal-fired power plants are the largest human-caused source of sulphur dioxide, which contributes to the production of acid rain and causes significant health problems. When coal is burned, the sulphur it contains naturally combines with oxygen to form sulphur oxides, including sulphur dioxide and sulphur trioxide (SO3). Sulphur dioxide is not considered a major greenhouse gas and does not receive as much attention as other gases. However, it is still a significant pollutant and health hazard.

The burning of coal and oil releases sulphur dioxide into the atmosphere, where it reacts with other molecules to form sulphate particles. These particles can be very small, less than one-tenth the width of a human hair, and contribute to haze, smog, and acid rain. They can cause respiratory complications and exacerbate conditions such as asthma. Sulphur dioxide emissions from coal burning are particularly high in India and China, impacting the health and economy of these countries.

While sulphur is an undesired contaminant in fuels, it is often not completely removed during the refining process. This means that even low-sulphur fuels can still contain a significant amount of sulphur, which is then released into the atmosphere during combustion. Efforts to improve desulfurisation techniques and reduce sulphur dioxide emissions are ongoing, with proposed standards and rules aiming to significantly reduce emissions from power plants and other sources.

Additionally, while the COVID-19 pandemic led to a substantial decrease in air pollution in some areas, air pollution remains a major concern globally, and society continues to tackle this issue.

Methane from landfills and agriculture

Gases are one of the major contributors to air pollution. While some gases are emitted due to natural factors, gases generated by human activities, such as industry and transportation, are the main contributors to air pollution. One of the major gases contributing to air pollution is methane (CH4). Methane is released from landfills, natural gas and petroleum industries, and agriculture.

Landfills are one of the largest sources of methane emissions. As organic waste such as food scraps, wood, and paper decompose, they release methane into the atmosphere. The Environmental Integrity Project reported that more than 1,100 municipal landfills emitted at least 3.7 million metric tons of methane in 2021, with the largest polluter being the Sampson County Landfill in Roseboro, North Carolina, which released over 32,000 metric tons of methane. Texas and California have the highest methane emissions from landfills, with Texas reporting about 130,000 more metric tons of methane emissions than California in 2021.

The Environmental Protection Agency (EPA) has struggled to accurately track and quantify methane emissions from landfills, with some arguing that their methods for estimating emissions are outdated and result in significant under-reporting. However, the EPA has proposed revisions to its methodology and reached an agreement with the Environmental Integrity Project to review and revise its methods for reporting landfill methane emissions.

Food waste in landfills is a significant contributor to methane emissions. The EPA's report, "Quantifying Methane Emissions from Landfilled Food Waste," found that while total emissions from municipal solid waste landfills are decreasing, methane emissions from landfilled food waste are increasing. The report also provides a calculator for users to estimate the methane emissions reductions per ton of food waste diverted from landfills.

Agriculture is another major source of methane emissions. Grazing animals, fertilizer use, manure, and the burning of agricultural residues contribute to methane emissions in this sector. Methane is released from the digestive systems of grazing animals, making it a significant source of methane pollution in agriculture.

Methane is a potent greenhouse gas that contributes to global warming and climate change. It has a much higher warming potential than carbon dioxide, with a molecule of methane being at least 84 times more potent over two decades, despite having a shorter lifetime in the atmosphere. Reducing methane emissions could curb climate change, as it does not linger in the atmosphere as long as carbon dioxide.

Gasoline and health risks

Gasoline and its vapours are toxic and can seriously damage a person's health. Limited exposure to gasoline is unlikely to cause significant health issues. However, chronic exposure to gasoline and its vapours can be deadly.

One of the greatest risks of gasoline exposure is the harm it can do to your lungs when you inhale its fumes. Direct inhalation can cause carbon monoxide poisoning, which is why it is advised not to run a vehicle in an enclosed area, such as a garage. Long-term exposure to gasoline in the open can also damage your lungs. In addition, carbon monoxide is both invisible and odourless, so you may inhale large quantities without even knowing it. This can cause permanent brain damage and death.

The American Cancer Society has stated that chronic or severe exposure to fuel products made from gasoline, such as diesel and benzenes, can also cause severe health complications, including certain types of cancer. In 2012, the International Agency for Research on Cancer (IARC), a division of the World Health Organization (WHO), classified diesel as carcinogenic to humans. More recent studies have reinforced the IARC’s findings.

Gasoline in both liquid and gas forms can adversely affect your health. Swallowing gasoline can damage the inside of your body and cause permanent damage to major organs. If a person swallows a large amount of gasoline, it can even cause death.

Children are more likely to experience serious side effects from gasoline because they absorb more gasoline vapours due to a greater surface area in their lungs, and because they are shorter than adults, vapour concentrations are higher closer to the ground.

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