Pollution is the introduction of contaminants into the natural environment that causes harm to plants, animals and human beings. Pollution can take the form of chemical substances or energy, such as noise, heat, or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is the largest environmental cause of disease and premature death. Pollution causes more than 9 million premature deaths (16% of all deaths worldwide). Major forms of pollution include air pollution, light pollution, noise pollution, plastic pollution, soil contamination, radioactive contamination, thermal pollution, and water pollution. The following are a few types of pollution:
Air pollution is the presence of undesirable substances in the air that are harmful to human health and the environment. It is the contamination of the air by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere. Vehicle emissions, fuel oils and natural gas to heat homes, by-products of manufacturing and power generation, particularly coal-fueled power plants, and fumes from chemical products are the primary sources of human-made air pollution. Pollutants include particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide.
Air pollution has various health effects. Short-term exposure to air pollutants is closely related to COPD (Chronic Obstructive Pulmonary Disease), cough, shortness of breath, wheezing, asthma, respiratory disease, and high rates of hospitalization (a measurement of morbidity).The long-term effects associated with air pollution are chronic asthma, pulmonary insufficiency, cardiovascular diseases, and cardiovascular mortality.
Water pollution occurs when harmful substances—often chemicals or microorganisms—contaminate a stream, river, lake, ocean, aquifer, or other body of water, degrading water quality and rendering it toxic to humans or the environment. Water pollution reduces the ability of the body of water to provide the ecosystem services that it would otherwise provide. Water pollution traditionally is attributed to four sources: sewage, industry, agriculture, and urban runoff. The main water pollutants include bacteria, viruses, parasites, fertilisers, pesticides, pharmaceutical products, nitrates, phosphates, plastics, faecal waste and even radioactive substances.
Water pollutants may cause disease or act as poisons. Bacteria and parasites in poorly treated sewage may enter drinking water supplies and cause digestive problems such as cholera and diarrhoea. Hazardous chemicals, pesticides, and herbicides from industries, farms, homes and golf courses can cause acute toxicity and immediate death, or chronic toxicity that can lead to neurological problems or cancers.
Light pollution refers to the excessive and unwanted use of poorly implemented artificial light by urban and other heavily-populated areas. This light is from artificial sources, mainly electricity from houses, offices, streetlamps, billboards or car headlights. It disrupts the natural patterns of wildlife, contributes to the increase in carbon dioxide (CO2) in the atmosphere, disrupts human sleep and the activities of nocturnal animals, and obscures the stars in the night sky.
There are three other kinds of light pollution: glare, clutter, and light trespass. Glare is excessive brightness that can cause visual discomfort (when driving). Clutter is bright, confusing, and excessive groups of light sources (Times Square in New York City). Light trespass is when light extends into an area where it is not wanted or needed (like a streetlight illuminating a nearby bedroom window).
Noise pollution, also known as environmental noise, refers to the unwanted or excessive sound that can impact human health, wildlife, and environmental quality. The World Health Organization (WHO) defines noise above 65 decibels (dB) as noise pollution. To be precise, noise becomes harmful when it exceeds 75 decibels (dB) and is painful above 120 dB.
The sources of noise include loud music, transportation, lawn care maintenance, construction, electrical generators, wind turbines, explosions, and people. Poor urban planning may give rise to noise disintegration or pollution, side-by-side industrial and residential buildings can result in noise pollution in the residential areas. This type of pollution can contribute to cardiovascular effects in humans and an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfering with reproduction and navigation, and contributing to permanent hearing loss.
Soil pollution or soil contamination refers to the toxic chemicals (pollutants or contaminants) in the soil in high concentrations that poses a risk to human health and the ecosystem. Soil pollution consists of pollutants and contaminants. The major pollutants are biological agents and human activities. Soil pollution is mainly caused by deforestation, soil erosion, mining activities, industrialization, construction activities, sewage treatment, and overcrowded landfills.
Soil pollution affects plants, animals and humans alike. While anyone is susceptible to soil pollution, soil pollution effects may vary based on age, general health status and other factors, such as the type of pollutant or contaminant inhaled or ingested. Soil pollution may cause a variety of health problems, starting with headaches, nausea, fatigue, skin rash, eye irritation and potentially resulting in more serious conditions like neuromuscular blockage, kidney and liver damage and various forms of cancer.