[Give An Essay On Water Pollution
Luther Lazaro
Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain, a wastewater treatment plant or an oil spill. Non-point sources are more diffuse. An example is agricultural runoff.[4] Pollution is the result of the cumulative effect over time. Pollution may take many forms. One would is toxic substances such as oil, metals, plastics, pesticides, persistent organic pollutants, and industrial waste products. Another is stressful conditions such as changes of pH, hypoxia or anoxia, increased temperatures, excessive turbidity, or changes of salinity). The introduction of pathogenic organisms is another. Contaminants may include organic and inorganic substances. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.
Control of water pollution requires appropriate infrastructure and management plans as well as legislation. Technology solutions can include improving sanitation, sewage treatment, industrial wastewater treatment, agricultural wastewater treatment, erosion control, sediment control and control of urban runoff (including stormwater management).
Pathogens can produce waterborne diseases in either human or animal hosts.[11] Some microorganisms sometimes found in contaminated surface waters that have caused human health problems include Burkholderia pseudomallei, Cryptosporidium parvum, Giardia lamblia, Salmonella, norovirus and other viruses, and parasitic worms including the Schistosoma type.[12]
The source of high levels of pathogens in water bodies can be from human feces (due to open defecation), sewage, blackwater, or manure that has found its way into the water body. The cause for this can be lack of sanitation procedures or poorly functioning on-site sanitation systems (septic tanks, pit latrines), sewage treatment plants without disinfection steps, sanitary sewer overflows and combined sewer overflows (CSOs)[13] during storm events and intensive agriculture (poorly managed livestock operations).
The environmental effect of pharmaceuticals and personal care products (PPCPs) is being investigated since at least the 1990s. PPCPs include substances used by individuals for personal health or cosmetic reasons and the products used by agribusiness to boost growth or health of livestock. More than twenty million tons of PPCPs are produced every year.[22] The European Union has declared pharmaceutical residues with the potential of contamination of water and soil to be "priority substances".[3]
PPCPs have been detected in water bodies throughout the world. More research is needed to evaluate the risks of toxicity, persistence, and bioaccumulation, but the current state of research shows that personal care products impact the environment and other species, such as coral reefs[23][24][25] and fish.[26][27] PPCPs encompass environmental persistent pharmaceutical pollutants (EPPPs) and are one type of persistent organic pollutants. They are not removed in conventional sewage treatment plants but require a fourth treatment stage which not many plants have.[22]
Microplastics persist in the environment at high levels, particularly in aquatic and marine ecosystems, where they cause water pollution.[32] 35% of all ocean microplastics come from textiles/clothing, primarily due to the erosion of polyester, acrylic, or nylon-based clothing, often during the washing process.[33]
Stormwater, untreated sewage and wind are the primary conduits for microplastics from land to sea. Synthetic fabrics, tyres, and city dust are the most common sources of microplastics. These three sources account for more than 80% of all microplastic contamination.[34][35]
Surface water pollution includes pollution of rivers, lakes and oceans. A subset of surface water pollution is marine pollution which affects the oceans. Nutrient pollution refers to contamination by excessive inputs of nutrients.
Globally, about 4.5 billion people do not have safely managed sanitation as of 2017, according to an estimate by the Joint Monitoring Programme for Water Supply and Sanitation.[36] Lack of access to sanitation is concerning and often leads to water pollution, e.g. via the practice of open defecation: during rain events or floods, the human feces are moved from the ground where they were deposited into surface waters. Simple pit latrines may also get flooded during rain events.
As of 2022, Europe and Central Asia account for around 16% of global microplastics discharge into the seas,[34][37] and although management of plastic waste and its recycling is improving globally, the absolute amount of plastic pollution continues to increase unabated due to the large amount of plastic that is being produced and disposed of.[38] Even if sea plastic pollution were to stop entirely, microplastic contamination of the surface ocean would be projected to continue to increase.[38]
In many areas of the world, groundwater pollution poses a hazard to the wellbeing of people and ecosystems. One-quarter of the world's population depends on groundwater for drinking, yet concentrated recharging is known to carry short-lived contaminants into carbonate aquifers and jeopardize the purity of those waters.[50]
Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain.
The U.S. Clean Water Act (CWA) defines point source for regulatory enforcement purposes (see United States regulation of point source water pollution).[51] The CWA definition of point source was amended in 1987 to include municipal storm sewer systems, as well as industrial storm water, such as from construction sites.[52]
Sewage typically consists of 99.9% water and 0.1% solids.[53] Sewage contributes many classes of nutrients that lead to eutrophication. It is a major source of phosphate for example.[54] Sewage is often contaminated with diverse compounds found in personal hygiene, cosmetics, pharmaceutical drugs (see also drug pollution), and their metabolites[55][31] Water pollution due to environmental persistent pharmaceutical pollutants can have wide-ranging consequences. When sewers overflow during storm events this can lead to water pollution from untreated sewage. Such events are called sanitary sewer overflows or combined sewer overflows.
Industrial processes that use water also produce wastewater. This is called industrial wastewater. Using the US as an example, the main industrial consumers of water (using over 60% of the total consumption) are power plants, petroleum refineries, iron and steel mills, pulp and paper mills, and food processing industries.[2] Some industries discharge chemical wastes, including solvents and heavy metals (which are toxic) and other harmful pollutants.
Agriculture is a major contributor to water pollution from nonpoint sources. The use of fertilizers as well as surface runoff from farm fields, pastures and feedlots leads to nutrient pollution.[63] In addition to plant-focused agriculture, fish-farming is also a source of pollution. Additionally, agricultural runoff often contains high levels of pesticides.[2]
Air deposition is a process whereby air pollutants from industrial or natural sources settle into water bodies. The deposition may lead to polluted water near the source, or at distances up to a few thousand miles away. The most frequently observed water pollutants resulting from industrial air deposition are sulfur compounds, nitrogen compounds, mercury compounds, other heavy metals, and some pesticides and industrial by-products. Natural sources of air deposition include forest fires and microbial activity.[64]
Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.[65] Some governments have made efforts since the 1970s to reduce the release of sulfur dioxide and nitrogen oxide into the atmosphere. The main source of sulfur and nitrogen compounds that result in acid rain are anthropogenic, but nitrogen oxides can also be produced naturally by lightning strikes and sulphur dioxide is produced by volcanic eruptions.[66] Acid rain can have harmful effects on plants, aquatic ecosystems and infrastructure.[67][68]
Carbon dioxide concentrations in the atmosphere have increased since the 1850s due anthropogenic influences (emissions of greenhouse gases).[69] This leads to ocean acidification and is another form of water pollution from atmospheric contributions.[70]
Water pollution may be analyzed through several broad categories of methods: physical, chemical and biological. Some methods may be conducted in situ, without sampling, such as temperature. Others involve collection of samples, followed by specialized analytical tests in the laboratory. Standardized, validated analytical test methods, for water and wastewater samples have been published.[71]
The use of a biomonitor or bioindicator is described as biological monitoring. This refers to the measurement of specific properties of an organism to obtain information on the surrounding physical and chemical environment.[73] Biological testing involves the use of plant, animal or microbial indicators to monitor the health of an aquatic ecosystem. They are any biological species or group of species whose function, population, or status can reveal what degree of ecosystem or environmental integrity is present.[74] One example of a group of bio-indicators are the copepods and other small water crustaceans that are present in many water bodies. Such organisms can be monitored for changes (biochemical, physiological, or behavioral) that may indicate a problem within their ecosystem.
A study published in 2017 stated that "polluted water spread gastrointestinal diseases and parasitic infections and killed 1.8 million people" (these are also referred to as waterborne diseases).[77] Persistent exposure to pollutants through water are environmental health hazards, which can increase the likelihood for one to develop cancer or other diseases.[78]
795a8134c1