Environmental pollution

What is Environmental Pollution?

Environmental pollution may be defined as unwanted material in the environment due to human activities. The agents which cause environmental pollution are called pollutants. It can be described as a chemical, biological, or physical substance unintentionally released into the environment which is directly or indirectly harmful to humans and other living organisms.

Types of Environmental Pollutants

Pollutants are classified based on varied criteria:

• Form of persistence after release into the environment
• Those that remain in the environment in the condition in which they were added are Primary pollutants: plastic DDT
• Secondary pollutants are formed as a result of interactions between primary pollutants. The exchange of hydrocarbons and nitrogen oxides, for example, produces peroxyacetyl nitrate (PAN)

Nature of existence

• Naturally occurring substances that become pollutants when their concentration exceeds a certain threshold are quantitative pollutants—for example, Nitrogen oxide and Carbon dioxide
• Qualitative Pollutants are artificial and do not exist in nature. Herbicides, Fungicides, DDT, and similar pesticides are examples
• Disposal nature
• Waste products that microbial action degrades are biodegradable pollutants—for instance, sewage
• Pollutants that do not decompose due to microbial action are non-biodegradable—glass, Plastics, Heavy metal salts, DDT, Toxic compounds, etc

Origin

• Nature
• Anthropogenic

Types of Environmental Pollution

Environmental pollution may be of the following types:

• Air pollution
• Noise pollution
• Water pollution
• Soil pollution
• Thermal Pollution
• Radiation pollution

Air Pollution

Air pollution is a type of environmental pollution that can be described as the composition of any gaseous, liquid, or solid substance in the atmosphere.

It includes noise and radioactive radiation with concentrations harmful to humans, other living organisms, property, and plants. In addition, it also interferes with normal environmental processes. Air pollutants are of two types: 

• Suspended particulate matter.
• Gaseous pollutants like NOx, CO2, etc.

Water Pollution

• Adding certain substances to water, such as inorganic, heat, biological, organic, and radiological substances that degrade the water’s consistency and render it unfit for human consumption leads to water pollution  
• One of the most severe environmental issues is water pollution. Effects of water pollution can be seen all around us—human activities such as agricultural, industrial, and domestic activities that all contribute to water pollution. For example, agricultural runoff containing unnecessary pesticides and fertilisers, industrial effluents containing hazardous chemicals, and sewage water retaining animal and human waste pollute our water

• Soil erosion, mineral leaching from rocks, and organic matter degradation are all-natural causes of water contamination. In addition, point and nonpoint sources can pollute oceans, rivers, estuaries, lakes, and groundwater sources

• Point source pollution occurs when pollutants are discharged from a particular location, such as a drainpipe containing industrial effluents discharged directly into a water body

• Nonpoint sources include waste discharged from diffuse sources or over a broader area, such as drainage from farm fields, pasture lands, building sites, abandoned mines and dumps, and roads and streets

Sources

Types of Sources

Point Sources

It is directly attributable to one influence. Here pollutants travel now from source to water. Point sources are easy to regulate.

Diffuse or Nonpoint Source

It comes from a variety of ill-defined and hazy sources. They are difficult to monitor since they differ spatially and temporally. The following are the primary sources of water pollution:

• Community wastewater: Discharges from commercial, residential, and industrial facilities linked to the public sewerage system are included. In sewage, food residues, animal and human excreta, detergents, cleaning agents, and other wastes are all present
• Industrial Wastes:  Industries emit inorganic and organic contaminants that can be particularly harmful to living things
• Agricultural sources: Fertilisers are rich in phosphorus, nitrogen, and potassium, essential plant nutrients. Excess fertilisers can leach into groundwater or mix with surface water in reservoirs, rivers, and ponds due to drainage and runoff
• Fungicides, insecticides, herbicides, rodenticides, nematicides, and soil fumigants are examples of pesticides. Metallic salts, organophosphates, chlorinated hydrocarbons, carbonates, acetic acid derivatives, thiocarbonates, and other chemicals are contained. Many pesticides are non-biodegradable, and their residues will last for years
• During the rainy season, animal excreta such as urine, dung, wastes from piggeries, poultry farms, slaughterhouses, and so on enter the water through runoff and surface leaching.
• Thermal Pollution: Thermal and nuclear power stations are the primary sources. Water is used as a coolant in the power plants, and the hot waters are returned to the source. Fish and other marine creatures die when the temperature increases abruptly
• Underground water pollution: Many people rely on groundwater for residential, drinking, agricultural, and commercial worldwide. Groundwater is widely recognised as a clean and healthy source of water. However, water pollution of groundwater is caused by human activities such as farmyard dumping, manures, excessive waste disposal, agricultural chemicals, and industrial effluents. In many parts of India, groundwater pollution is a product of seepage from municipal wastes and industrial waste effluents, drainage channels, and agricultural runoff
• Marine Pollution: Oceans are the most significant drain for all toxins, both natural and man-made. Pollutants are discharged into the sea by rivers. Coastal cities’ sewage and trash are also pumped into the sea. Grease, navigational discharges of tar, sewage, detergents, underwater oil mining, hazardous wastes, and oil spills are other causes of ocean contamination

Soil Pollution

In the list of environmental pollution, soil pollution is defined as the introduction of substances into the soil that harms the soil’s chemical, biological and physical properties and its productivity.

Sources of Soil Pollution

• Plastic bags: Low-density polyethylene (LDPE) plastic bags are almost indestructible, posing substantial environmental risks. Plastic, being non-biodegradable, remains in the soil and keeps on releasing its toxins
• Industrial sources: chemical residues fly ash, metallic and nuclear wastes. Many dyes, synthetic chemicals, acids, and other harmful substances find their way into the soil
• Agricultural sources: The soil is polluted by agricultural chemicals, particularly

Fertilisers and pesticides. Excessive use of chemical fertilisers decreases the population of soil-borne species and the crumb structure of the soil, as well as its fertility and salt content.

• Radioactive wastes: Nuclear power plants and mining release radioactive elements into the water, entering the soil
• Other pollutants: Many air contaminants and water pollutants end up in the soil, and certain harmful chemicals are released into the ground during the weathering of some rocks

Noise Pollution

Noise is described as “any unwanted sound by the recipient.” It is simply sound without value. It is an unpleasant noise created by people or machines that can be annoying, distracting, intrusive, and physically painful. This type of environmental pollution is caused by home appliances, traffic on roads, transportation, etc. 

Sources of Noise Pollution

• Engines, radio, electric fans, television, air conditioners, various home appliances, air coolers, and family disputes are all indoor noise sources. In addition, because of the higher concentration of factories, residents, and activities such as noise pollution, transportation is more prevalent in cities
• Outdoor sources of noise pollution include indiscriminate use of loudspeakers, industrial activities, automobiles, rail traffic, aeroplanes, and activities such as those at the marketplace, religious, social, and cultural functions, sports, and political rallies. In rural areas, farm machines and pump sets are the primary sources of noise pollution. In addition, during festivals, marriage, and many other occasions, firecrackers contribute to noise pollution

Thermal Pollution

The fall or rise in temperature of a natural aquatic environment caused by anthropogenic influence is thermal pollution.

Major Sources:

• Power plants: By dumping hot water from factories and power plants
• Deforestation of the shoreline: Removing trees and vegetation that shade streams, permitting sunlight to raise the temperature of these waters
• Water as a cooling agent: Release cold water, which lowers the temperature

Radiation Pollution

• Radiation is an energy form that passes through space. Radioactive pollution is defined as the increase in the natural radiation levels caused by human activities. It is estimated that about 20% of the radiation we are exposed to is due to human activities
• Radiation from the decay of radioactive nuclides is one of the most important causes of radiation emissions
• Radiations can be categorised into two groups
• Non-ionising radiations: There are short-wave radiations, such as ultraviolet rays, emitted by the sun. They have a low penetrating ability and affect the cells and molecules they absorb
• Ionising radiations: X-rays, gamma rays, and atomic radiations are examples of ionising radiations (radiations by radioactive elements). These have a high penetration power and cause macromolecules to break apart

Types of radiation particles

• A sheet of paper and human skin can also block alpha particles
• Beta particles can pass through the skin but are stopped by glass and metal
• Gamma rays can quickly penetrate human skin, killing cells along the way, and can only be prevented by a thick, solid, massive piece of concrete

Natural

Cosmic rays from space and terrestrial radiations from radionuclides found in the earth’s crust, such as uranium-238, radium-224, potassium-40, thorium-232, carbon-14, etc.

Man-made

These include nuclear power plants (nuclear reactor accident at Chernobyl in 1986), nuclear weapons (atomic explosions in Nagasaki and Hiroshima), atomic material transportation, nuclear waste disposal, uranium mining, and radiation therapy.

Conclusion

To sum up, environmental pollution is described as “the contamination of the earth/atmosphere system’s physical and biological components to such a degree that normal environmental processes are negatively impacted.”