Nitrogen is an essential part of life on Earth. It’s a major component of plants and animals, and it’s in the atmosphere. But there are many ways nitrogen can be bad for people and the environment. When nitrogen enters the environment, it gets changed into various forms including nitrate and ammonia. Nitrogen pollution can come from many sources, such as fertilizer runoff, wastewater treatment plants, and factories that make car parts.
What Is Nitrogen Pollution?
Nitrogen pollution is when too much nitrogen gets into the soil, water, or air. Nitrogen gas makes up about 78 percent of the Earth’s atmosphere, and plants and animals need it to live, but too much of a good thing can be bad. The most common form of nitrogen pollution comes from fertilizers used in agriculture. They contain nitrogen compounds that can get into the soil and water.
Nitrogen can cause many harmful effects on both the environment and human health. In natural waters such as rivers, lakes, and seas, it causes algal blooms that block sunlight from reaching underwater grasses. This destroys habitat for fish and other wildlife. Nitrogen also increases bacteria levels in water bodies, which can be harmful to people swimming in these waters or eating fish caught there.
Nitrogen Pollution Sources
The primary source of nitrogen pollution is fossil fuel combustion, which releases oxides of nitrogen into the atmosphere. Fossil fuels are burned to produce energy in power plants, automobile engines, and industrial facilities. Emissions from these activities account for nearly 80 percent of all anthropogenic emissions of nitrogen oxides (NOX) in the United States.
In addition to NOX emissions, fossil fuel combustion results in emissions of carbon dioxide (CO2), a greenhouse gas that contributes to global climate change. This can have a secondary impact on the environment by contributing to warmer temperatures that increase the frequency and intensity of rainstorms. These storms can cause increases in nitrogen pollution in lakes, rivers, bays, and estuaries as a result of runoff from land.
Although natural processes, such as lightning and bacteria, produce small amounts of NO and NO2, most are created by burning fossil fuels. This can take place anywhere there are automobiles, factories, or power plants.
When we burn fossil fuels like coal or oil, their chemical bonds break down releasing energy. Energy can be released as light energy (fire), heat (the energy you feel), and mechanical energy (energy used to do work). When fossil fuels are burned to produce electricity or power a car, much of their energy is released as heat to make mechanical energy. The more efficiently this process produces energy, the less waste heat is released into the atmosphere.
Oxides of Nitrogen Pollution
Oxides of nitrogen (NOx) are gases that are produced whenever fuels are burned at high temperatures. They are also produced by natural sources, such as volcanoes, lightning, and bacteria.
Man-made sources of NOx include motor vehicles and power plants. Nitric oxide (NO) is a minor component of the Earth’s atmosphere, but it plays a significant role in atmospheric chemistry. Many NOx compounds act as powerful oxidizing agents in the atmosphere. Oxidation of nitrogen causes the production of ozone and other secondary pollutants, such as peroxyacetyl nitrate (PAN), nitrous acid (HONO), and nitric acid (HNO3). The oxidation products can be transported over large distances by winds before they return to Earth with rain.
Oxides of nitrogen pollution can lead to the formation of ground-level ozone, which is a serious air pollutant created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Exposure to elevated levels of ground-level ozone can cause serious health problems, particularly for children, older
Nitrogen Pollution Causes
Nitrogen pollution is caused by human activities, primarily the overuse of nitrogen-containing fertilizers and the burning of fossil fuels. Airborne nitrogen sources include vehicle exhaust, power plants, industrial facilities, farm operations, and livestock wastes. Here are some causes of nitrogen pollution.
- Agriculture: When farmers use synthetic fertilizers to grow crops, some of the nitrogen in these fertilizers leeches into groundwater or runs off into surface water, causing eutrophication and other harmful effects.
- Mining: Explosives used in mining operations release nitrogen oxides into the air that contribute to smog formation and acid rain.
- Combustion of fossil fuels: The combustion of fossil fuels releases nitrous oxides into the atmosphere that contribute to acid rain and ground-level ozone formation.
- Industrial processes: Industries such as steel manufacturing use fossil fuels with high nitrogen content, releasing nitrous oxides into the atmosphere during combustion as well as through industrial processes such as welding, cutting, soldering, and brazing.
- Forest fires: Forest fires release large amounts of nitrogen into the atmosphere as well as ash that can contaminate water sources with toxic metals such as mercury and lead.
What Causes Nitrogen Pollution in Water?
Nitrogen pollution is a problem that occurs when there is too much nitrogen in a body of water, such as a river, lake, or ocean. It can cause damage to plants, animals, and the ecosystem in general.
When it rains, fertilizer applied to crops washes into streams, lakes, and oceans. Since this fertilizer contains nitrogen, it can cause nitrogen pollution in water.
Too much nitrogen in water can cause a process called eutrophication. This occurs when algae grow rapidly in the water due to excess nutrients like nitrogen and phosphorus. The algae eventually die and decompose, often using up most of the dissolved oxygen in its surrounding environment. Without enough oxygen, fish and other marine life may die off.
Nitrogen Pollution from Agriculture
Agriculture is one of the most significant sources of nitrogen pollution. The amount of nitrogen applied to fields varies from place to place, as well as from year to year depending on weather conditions and crop demands. In addition, farmers often apply more nitrogen than plants can immediately use, which increases the chances that excess nitrogen will be lost to surface waters or groundwater.
In India as well as the United States, agriculture accounts for about half of all nitrogen runoff. Of this, about three-quarters comes from the application of synthetic nitrogen fertilizer to farmland. About a quarter comes from animal waste — primarily cow manure, which is stored in lagoons on concentrated dairy farms and then spread on fields to fertilize crops.
Nitrogen runoff is a major source of nitrates in waterways, especially rivers and lakes. When these nitrates reach drinking water supplies, they can cause illnesses as mild as stomach flu or as severe as cancer and death. This is because nitrates promote algal blooms that can deplete oxygen levels in lakes and coastal waters, killing fish and other aquatic life; they also are linked to human health problems when ingested through drinking water or fish meat.
Effects of Nitrogen Pollution
Nitrogen pollution is one of the biggest threats to biodiversity. Our atmosphere is made up of 78 percent nitrogen, but it is the most unreactive gas in the world. So how does it become a threat to life?
When natural forces like lightning, bacteria, and volcanoes release nitrogen, it stays in the atmosphere. Nitrogen-fixing bacteria, which can be found in root nodules and on the leaves of plants, convert it into a form that other lifeforms can use; this makes up just 2 percent of all naturally occurring nitrogen. The rest is unavailable to most forms of life on Earth.
Human activities have led to an increase in reactive nitrogen or nitrogen that is available for lifeforms to use. Unlike natural sources of reactive nitrogen, human activities do not rely on natural cycles to return unused nitrogen back into the biosphere – instead, we lock it up in concrete and fossil fuels when we produce products like plastics and petrol.