Ammonia: A Hazardous Air Pollutant? Understanding Its Impact

Ammonia is a colourless, pungent-smelling gas that is widely recognised as an air pollutant. It is a compound of nitrogen and hydrogen, and a byproduct of agriculture and industry. Ammonia is hazardous to human health and the environment, and is listed as a hazardous air pollutant in the US Code. This article explores the question: is ammonia a hazardous air pollutant?

Ammonia is a hazardous air pollutant

Ammonia (NH3) is a compound of nitrogen and hydrogen. In the atmosphere, it reacts with other pollutants, such as sulfuric and nitric acids, to form fine particles of ammonium salts, known as PM2.5. These particles are small enough to enter the human lungs and bloodstream through inhalation, causing serious health issues such as asthma, lung cancer, cardiovascular problems, birth defects, and even premature death. The presence of ammonia in the air also contributes to the formation of harmful particulate matter, which can have adverse effects on both human health and the environment.

Ammonia pollution is a global issue, and only a handful of countries have implemented measures to reduce their emissions. The European Union, for example, has had policies in place since 1999 to address ammonia pollution, including the Gothenburg Protocol and the Directive on Integrated Pollution Prevention and Control. The National Emission Ceilings Directive was also enacted in 2001 to further curb NH3 emissions. The Gothenburg Protocol was revised in 2012 to set stricter ceiling limits on ammonia emissions for all EU-27 countries.

Ammonia pollution has severe consequences for ecosystems, particularly aquatic ones. It is toxic to aquatic life, leading to increased fish mortality and decreased biodiversity. Ammonia also contributes to the processes of soil acidification and eutrophication of water bodies, altering the natural chemistry of the soil and water. Sensitive plant groups, such as lichen and moss, are especially vulnerable to ammonia pollution, and habitats like bogs, peatlands, grasslands, and forests are significantly impacted.

In summary, ammonia is a hazardous air pollutant that poses risks to both human health and the environment. Its ability to form fine particulate matter and its toxic effects on ecosystems underscore the importance of implementing effective emission reduction strategies. While some regions have taken steps to mitigate ammonia pollution, further global efforts are necessary to address this pressing environmental challenge.

Ammonia is a colourless, pungent gas

Ammonia is a hazardous air pollutant, and is irritating to the eyes, nose, throat, and skin in low quantities. In high quantities, it is poisonous to humans and aquatic life. It combines in the atmosphere with sulphates and nitrates to form secondary fine particulate matter (PM2.5), which is known to have harmful effects on human health and the environment. PM2.5 can cause asthma, lung cancer, cardiovascular issues, birth defects, and premature death in humans.

Ammonia is also a precursor to ammonium salts, which are a harmful form of fine particulate matter. It combines with other compounds in the atmosphere, such as nitric and sulphate acids, to form these salts. Ammonia is a persistent pollutant, and despite efforts to reduce emissions of other compounds, such as sulfur dioxide and nitrogen oxides, ammonia pollution continues to reduce air quality, particularly in densely populated urban areas.

Ammonia is measured by its presence in the atmosphere, and samples are collected through methods such as filter packs, fabric denuders, satellite imaging, and rainwater analysis.

Ammonia is an essential nitrogen-containing nutrient, and 90% of commercially produced ammonia is used in fertiliser. It is also used in household cleaning products, where it is effective at removing vegetable oil and animal fat stains.

Sources of ammonia pollution

Ammonia (NH3) is a chemical compound of nitrogen and hydrogen. It is a byproduct of agriculture and industry. As a hazardous air pollutant, it poses risks to human health and the environment. The sources of ammonia pollution can be classified as either anthropogenic or natural.

Anthropogenic Sources

The largest source of ammonia emissions is agriculture, including animal husbandry, intensive farming practices, and NH3-based fertilizer applications. In 2010, the agricultural sector was responsible for 89% of UK NH3 emissions. High-density livestock farming, particularly dairy and beef production, can result in significant ammonia emissions. Poultry farming, biomass burning, and fertiliser manufacturing also contribute to ammonia pollution.

Other non-agricultural anthropogenic sources include catalytic converters in petrol cars, landfill sites, sewage works, composting of organic materials, combustion, and industrial waste.

Natural Sources

Natural sources of ammonia pollution include the burning coal mines of Jharia, caustic Lake Natron, and the guano of seabird colonies. Seabird colonies can emit significant amounts of NH3, particularly in remote and otherwise "clean" areas.

Impact on Aquatic Ecosystems

Ammonia seeps into aquatic ecosystems through wastewater, fertilizers, and industrial waste. It is directly toxic to aquatic life, leading to increased fish deaths and decreased biodiversity. In freshwater ecosystems, elevated ammonia levels can cause eutrophication, an overabundance of nutrients that leads to increased algal growth and decreased oxygen levels in the water.

Impact on Terrestrial Ecosystems

Ammonia pollution affects terrestrial ecosystems, particularly sensitive plant groups such as lichen and moss. It increases soil acidity, degrades habitat conditions, and decreases biodiversity.

Ammonia's effects on human health

Ammonia (NH3) is a hazardous air pollutant that poses serious risks to human health. It is a colourless gas with a pungent odour, often noticeable at concentrations above 50 parts per million (ppm). While ammonia has various natural and anthropogenic sources, agricultural practices, particularly livestock waste management and fertilizer production, are the most significant contributors to ammonia emissions.

The effects of ammonia on human health depend on the level of exposure. At high concentrations, ammonia is poisonous and can be fatal. Inhaling lower amounts can irritate the eyes, nose, and throat, and skin. Long-term exposure to ammonia can lead to serious health issues, with sensitive groups such as the elderly, children, or those with pre-existing respiratory conditions being especially vulnerable.

Ammonia combines with other pollutants in the atmosphere, such as nitric and sulphate acids, to form harmful fine particulate matter known as PM2.5. These tiny particles, measuring 2.5 micrometres or less, can infiltrate the lungs and enter the bloodstream through inhalation. The health risks associated with PM2.5 exposure include asthma, lung cancer, cardiovascular problems, birth defects, and even premature death.

In addition to the direct health impacts, ammonia also contributes to environmental degradation, which has indirect consequences for human health and well-being. Ammonia pollution leads to soil acidification, reducing the viability of sensitive plant groups like lichen and moss, and altering the habitats of various species. It also plays a role in the eutrophication of water bodies, decreasing biodiversity and causing harm to aquatic life, including increased fish deaths.

Recognizing the dangers posed by ammonia, some countries and regions have implemented policies to curb emissions. The European Union, for instance, has had the Gothenburg Protocol and the Directive on Integrated Pollution Prevention and Control in place since 1999. The United Kingdom has also announced plans to cut emissions by 16% by 2030. However, the persistent presence of ammonia pollution, particularly in densely populated urban areas, continues to be a challenge for air quality management globally.

Reducing ammonia emissions

Ammonia is a colourless gas with a pungent odour that is noticeable at concentrations above 50 ppm. It is a hazardous air pollutant, contributing to the formation of harmful PM2.5. Ammonia is emitted from both natural and man-made sources, with the majority of emissions coming from livestock waste management and fertilizer production.

Livestock Management

Ammonia emissions from livestock operations can be reduced by improving waste management practices. Keeping floors in livestock areas clean and dry is essential. Concrete floors contaminated with slurry provide an emitting surface, so frequent scraping and washing of these areas are necessary. Additionally, proper design of cubicle passages, feed passages, and loafing areas to facilitate quick drainage and scraping can minimize the amount of slurry exposed to the air.

Slurry Management

Ammonia emissions from slurry can be significantly reduced by minimizing its contact with air. This can be achieved by covering slurry stores with flexible sheeting systems or roofs, floating covers, or natural materials like straw or bark. Reducing the exposed surface area of slurry by storing it in deeper pits or lagoons can also help suppress ammonia production.

Fertilizer Use

Fertilizer production and use are significant contributors to ammonia emissions. Acidifying slurry to a neutral pH level of 6 before application can reduce ammonia outgassing by at least 50%. Switching from urea-based fertilizers to ammonium nitrate or injecting liquid urea into the soil can also lower emissions. Immediate incorporation of manure into the soil after application can prevent up to 90% of ammonia losses.

Dietary Adjustments

In dairy farming, reducing crude protein levels in cow diets to 15% through nutritionally balanced maize silage-based diets can decrease ammonia emissions without negatively impacting milk output or fertility.

Storage Practices

Solid manure should be stored as dry as possible, and in covered, well-ventilated areas with minimal surface area exposure. This helps to reduce the volatilization of ammonia.

By implementing these measures, significant reductions in ammonia emissions can be achieved, leading to improved air quality and a decrease in the harmful environmental and health impacts associated with this pollutant.

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