1.
Air pollution
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Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earths atmosphere. It may cause diseases, allergies or death in humans, it may cause harm to other living organisms such as animals and food crops. Human activity and natural processes can both generate air pollution, indoor air pollution and poor urban air quality are listed as two of the worlds worst toxic pollution problems in the 2008 Blacksmith Institute Worlds Worst Polluted Places report. According to the 2014 WHO report, air pollution in 2012 caused the deaths of around 7 million people worldwide, an air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made, pollutants are classified as primary or secondary. Primary pollutants are usually produced from a process, such as ash from a volcanic eruption, other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories. Secondary pollutants are not emitted directly, rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant, some pollutants may be both primary and secondary, they are both emitted directly and formed from other primary pollutants. Substances emitted into the atmosphere by human activity include, Carbon dioxide - Debate continues over whether carbon dioxide should be classified as an atmospheric pollutant, because of its role as a greenhouse gas it has been described as the leading pollutant and the worst climate pollution. Against this it is argued that carbon dioxide is a component of the atmosphere, essential for plant life. This question of terminology has practical effects, for example as determining whether the U. S. Clean Air Act is deemed to regulate CO2 emissions, CO2 increase in earths atmosphere has been accelerating. Sulfur oxides - particularly sulfur dioxide, a compound with the formula SO2. SO2 is produced by volcanoes and in industrial processes. Coal and petroleum often contain sulfur compounds, and their combustion generates sulfur dioxide, further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one of the causes for concern over the impact of the use of these fuels as power sources. Nitrogen oxides - Nitrogen oxides, particularly nitrogen dioxide, are expelled from high temperature combustion and they can be seen as a brown haze dome above or a plume downwind of cities. Nitrogen dioxide is a compound with the formula NO2
2.
Pollution
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Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution, Air pollution has always accompanied civilizations. Pollution started from prehistoric times when man created the first fires, metal forging appears to be a key turning point in the creation of significant air pollution levels outside the home. The burning of coal and wood, and the presence of horses in concentrated areas made the cities the cesspools of pollution. The Industrial Revolution brought an infusion of untreated chemicals and wastes into local streams that served as the water supply, king Edward I of England banned the burning of sea-coal by proclamation in London in 1272, after its smoke became a problem. But the fuel was so common in England that this earliest of names for it was acquired because it could be carted away from some shores by the wheelbarrow and it was the industrial revolution that gave birth to environmental pollution as we know it today. London also recorded one of the extreme cases of water quality problems with the Great Stink on the Thames of 1858. Pollution issues escalated as population growth far exceeded view ability of neighborhoods to handle their waste problem, reformers began to demand sewer systems, and clean water. In 1870, the conditions in Berlin were among the worst in Europe. There were no toilets in the streets or squares. Visitors, especially women, often became desperate when nature called, in the public buildings the sanitary facilities were unbelievably primitive. As a metropolis, Berlin did not emerge from a state of barbarism into civilization until after 1870. Chicago and Cincinnati were the first two American cities to enact laws ensuring cleaner air in 1881, as historian Martin Melosi notes, The generation that first saw automobiles replacing the horses saw cars as miracles of cleanliness. By the 1940s, however, automobile-caused smog was an issue in Los Angeles. Other cities followed around the country early in the 20th century. Extreme smog events were experienced by the cities of Los Angeles and Donora, Pennsylvania in the late 1940s, Air pollution would continue to be a problem in England, especially later during the industrial revolution, and extending into the recent past with the Great Smog of 1952. Awareness of atmospheric pollution spread widely after World War II, with fears triggered by reports of fallout from atomic warfare. Then a non-nuclear event, The Great Smog of 1952 in London and this prompted some of the first major modern environmental legislation, The Clean Air Act of 1956
3.
Acid rain
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Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions. It can have effects on plants, aquatic animals and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, some governments have made efforts since the 1970s to reduce the release of sulfur dioxide and nitrogen oxide into the atmosphere with positive results. Nitrogen oxides can also be produced naturally by lightning strikes, Acid rain is a popular term referring to the deposition of a mixture from wet and dry acidic components. Distilled water, once carbon dioxide is removed, has a neutral pH of 7, liquids with a pH less than 7 are acidic, and those with a pH greater than 7 are alkaline. Clean or unpolluted rain has an acidic pH, but usually no lower than 5, a common example is nitric acid produced by electric discharge in the atmosphere such as lightning. Acid deposition as an issue would include additional acids other than H2CO3. The corrosive effect of polluted, acidic city air on limestone and marble was noted in the 17th century by John Evelyn, since the Industrial Revolution, emissions of sulfur dioxide and nitrogen oxides into the atmosphere have increased. In 1852, Robert Angus Smith was the first to show the relationship between rain and atmospheric pollution in Manchester, England. Though acidic rain was discovered in 1853, it was not until the late 1960s that scientists began widely observing and studying the phenomenon, the term acid rain was coined in 1872 by Robert Angus Smith. Canadian Harold Harvey was among the first to research a dead lake, occasional pH readings in rain and fog water of well below 2.4 have been reported in industrialized areas. Industrial acid rain is a problem in China and Russia. These areas all burn sulfur-containing coal to heat and electricity. The problem of acid rain has not only increased with population and industrial growth, the use of tall smokestacks to reduce local pollution has contributed to the spread of acid rain by releasing gases into regional atmospheric circulation. Often deposition occurs a considerable distance downwind of the emissions, with mountainous regions tending to receive the greatest deposition, an example of this effect is the low pH of rain which falls in Scandinavia. The earliest report about acid rain in the United States was from the evidence from Hubbard Brook Valley. In 1972, a group of scientists including Gene Likens discovered the rain that was deposited at White Mountains of New Hampshire was acidic, the pH of the sample was measured to be 4.03 at Hubbard Brook. The Hubbard Brook Ecosystem Study followed up with a series of research that analyzed the effects of acid rain
4.
Indoor air quality
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Indoor air quality is a term which refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. IAQ can be affected by gases, particulates, microbial contaminants, source control, filtration and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality in most buildings. Residential units can further improve air quality by routine cleaning of carpets. Determination of IAQ involves the collection of air samples, monitoring human exposure to pollutants, collection of samples on building surfaces, IAQ is part of indoor environmental quality, which includes IAQ as well as other physical and psychological aspects of life indoors. Indoor air pollution in developing nations is a health hazard. A major source of air pollution in developing countries is the burning of biomass for heating and cooking. The resulting exposure to high levels of particulate matter resulted in between 1.5 million and 2 million deaths in 2000, second-hand smoke is tobacco smoke which affects other people other than the active smoker. The only certain method to improve air quality as regards second-hand smoke is the implementation of comprehensive smoke-free laws. Radon is an invisible, radioactive gas that results from the radioactive decay of radium. Radon is probably the most pervasive serious hazard for air in the United States and Europe. There are relatively simple test kits for do-it-yourself radon gas testing, radon gas enters buildings as a soil gas and is a heavy gas and thus will tend to accumulate at the lowest level. Radon may also be introduced into a building through drinking water particularly from bathroom showers, the half life for radon is 3.8 days, indicating that once the source is removed, the hazard will be greatly reduced within a few weeks. Radon mitigation methods include sealing concrete slab floors, basement foundations, water drainage systems and they are usually cost effective and can greatly reduce or even eliminate the contamination and the associated health risks. Mold is always associated with moisture, and its growth can be inhibited by keeping humidity levels below 50%, in areas where cellulosic materials become moist and fail to dry within 48 hours, mold mildew can propagate and release allergenic spores into the air. In many cases, if materials have failed to dry out several days after the suspected water event, through a mold investigation, which may include destructive inspection, one should be able to determine the presence or absence of mold. In a situation there is visible mold and the indoor air quality may have been compromised. There are some varieties of mold that contain toxic compounds, however, exposure to hazardous levels of mycotoxin via inhalation is not possible in most cases, as toxins are produced by the fungal body and are not at significant levels in the released spores. The primary hazard of mold growth, as it relates to air quality
5.
Global dimming
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Global dimming is the gradual reduction in the amount of global direct irradiance at the Earths surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has estimated to be of the order of a 4% reduction over the three decades from 1960–1990. However, after discounting an anomaly caused by the eruption of Mount Pinatubo in 1991, global dimming is thought to have been caused by an increase in particulates such as sulfate aerosols in the atmosphere due to human action. It has interfered with the cycle by reducing evaporation and may have reduced rainfall in some areas. Global dimming also creates an effect that may have partially counteracted the effect of greenhouse gases on global warming. It is thought that global dimming is probably due to the presence of aerosol particles in the atmosphere caused by human action. Aerosols and other particulates absorb solar energy and reflect back into space. The pollutants can also become nuclei for cloud droplets, water droplets in clouds coalesce around the particles. Increased pollution causes more particulates and thereby creates clouds consisting of a number of smaller droplets. The smaller droplets make clouds more reflective, so that more incoming sunlight is reflected back into space and this same effect also reflects radiation from below, trapping it in the lower atmosphere. In models, these smaller droplets also decrease rainfall, clouds intercept both heat from the sun and heat radiated from the Earth. Their effects are complex and vary in time, location, in the late-1960s, Mikhail Ivanovich Budyko worked with simple two-dimensional energy-balance climate models to investigate the reflectivity of ice. He found that the ice-albedo feedback created a feedback loop in the Earths climate system. The more snow and ice, the solar radiation is reflected back into space and hence the colder Earth grows. Other studies found that pollution or an eruption could provoke the onset of an ice age. His findings appeared to contradict global warming — the global temperature had been rising since the 70s. Less light reaching the earth seemed to mean that it should cool, ohmura published his findings Secular variation of global radiation in Europe in 1989. Dimming has also observed in sites all over the former Soviet Union
6.
Global warming
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Global warming and climate change are terms for the observed century-scale rise in the average temperature of the Earths climate system and its related effects. Multiple lines of evidence show that the climate system is warming. The largest human influence has been emission of gases such as carbon dioxide, methane. These findings have been recognized by the science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing. Future climate change and associated impacts will differ from region to region around the globe, anticipated effects include warming global temperature, rising sea levels, changing precipitation, and expansion of deserts in the subtropics. Warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the retreat of glaciers, permafrost. Effects significant to humans include the threat to security from decreasing crop yields. Possible societal responses to global warming include mitigation by emissions reduction, adaptation to its effects, building systems resilient to its effects, most countries are parties to the United Nations Framework Convention on Climate Change, whose ultimate objective is to prevent dangerous anthropogenic climate change. Public reactions to global warming and concern about its effects are also increasing, a global 2015 Pew Research Center report showed a median of 54% consider it a very serious problem. There are significant regional differences, with Americans and Chinese among the least concerned, the global average surface temperature shows a warming of 0.85 °C in the period 1880 to 2012, based on multiple independently produced datasets. Earths average surface temperature rose by 0. 74±0.18 °C over the period 1906–2005, the rate of warming almost doubled for the last half of that period. The rest has melted ice and warmed the continents and atmosphere, the average temperature of the lower troposphere has increased between 0.12 and 0.135 °C per decade since 1979, according to satellite temperature measurements. The warming that is evident in the temperature record is consistent with a wide range of observations. The probability that these changes could have occurred by chance is virtually zero, temperature changes vary over the globe. Since 1979, land temperatures have increased about twice as fast as ocean temperatures, ocean temperatures increase more slowly than land temperatures because of the larger effective heat capacity of the oceans and because the ocean loses more heat by evaporation. Since the beginning of industrialisation the temperature difference between the hemispheres has increased due to melting of sea ice and snow in the North. Average arctic temperatures have been increasing at almost twice the rate of the rest of the world in the past 100 years, the thermal inertia of the oceans and slow responses of other indirect effects mean that climate can take centuries or longer to adjust to changes in forcing. Some of this warming will be driven by past natural forcings which are still seeking equilibrium in the climate system
7.
Water pollution
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Water pollution is the contamination of water bodies. This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds, Water pollution affects the entire biosphere – plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and population, Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels. It has been suggested that pollution is the leading worldwide cause of deaths and diseases. An estimated 580 people in India die of water related illness every day. About 90 percent of the water in the cities of China is polluted, as of 2007, half a billion Chinese had no access to safe drinking water. In addition to the problems of water pollution in developing countries. The head of Chinas national development agency said in 2007 that one quarter the length of Chinas seven main rivers were so poisoned the water harmed the skin. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause changes in water quality. Although interrelated, surface water and groundwater have often studied and managed as separate resources. Surface water seeps through the soil and becomes groundwater, conversely, groundwater can also feed surface water sources. Sources of surface water pollution are generally grouped into two based on their origin. Point source water pollution refers to contaminants that enter a waterway from a single, identifiable source, 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 defines point source for regulatory enforcement purposes, 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. Nonpoint source pollution refers to contamination that does not originate from a single discrete source. NPS pollution is often the cumulative effect of small amounts of contaminants gathered from a large area, a common example is the leaching out of nitrogen compounds from fertilized agricultural lands. Nutrient runoff in storm water from sheet flow over a field or a forest are also cited as examples of NPS pollution. Contaminated storm water washed off of parking lots, roads and highways, however, because this runoff is typically channeled into storm drain systems and discharged through pipes to local surface waters, it becomes a point source
8.
Environmental monitoring
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Environmental monitoring describes the processes and activities that need to take place to characterise and monitor the quality of the environment. All monitoring strategies and programmes have reasons and justifications which are designed to establish the current status of an environment or to establish trends in environmental parameters. In all cases the results of monitoring will be reviewed, analysed statistically, the design of a monitoring programme must therefore have regard to the final use of the data before monitoring starts. Air quality monitoring is performed using specialized equipment and analytical methods used to establish air pollutant concentrations, air monitors are operated by citizens, regulatory agencies, and researchers to investigate air quality and the effects of air pollution. Air dispersion models that combine topographic, emissions and meteorological data to predict air pollutant concentrations are often helpful in interpreting air monitoring data. If an air monitor produces concentrations of chemical compounds, a unique chemical fingerprint of a particular air pollution source may emerge from analysis of the data. Soil monitoring is the process of collection of soil and testing in laboratory by analytical methods, in laboratory, soil can be tested for pH, Chlorides, Sulphates, Phosphates and other metals. Water quality monitoring is of use without a clear and unambiguous definition of the reasons for the monitoring. Almost all monitoring is in some part invasive of the environment under study and extensive and this may be a critical consideration in wilderness areas or when monitoring very rare organisms or those that are averse to human presence. Unless individual monitoring projects fit into a strategic framework, the results are unlikely to be published. The list can be expanded or reduced based on developing knowledge, freshwater environments have been extensively studied for many years and there is a robust understanding of the interactions between chemistry and the environment across much of the world. However, as new materials are developed and new pressures come to bear, in the last 20 years acid rain, synthetic hormone analogues, halogenated hydrocarbons, greenhouse gases and many others have required changes to monitoring strategies. In ecological monitoring, the strategy and effort is directed at the plants. However, in more generalised environmental monitoring, many act as robust indicators of the quality of the environment that they are experiencing or have experienced in the recent past. The steep decline in fish populations was one of the early indications of the problem that later became known as acid rain. In recent years much more attention has been given to a holistic approach in which the ecosystem health is assessed and used as the monitoring tool itself. It is this approach that underpins the monitoring protocols of the Water Framework Directive in the European Union, the ‘measurement’ of dose often means the measurement of a dose equivalent quantity as a proxy for a dose quantity that cannot be measured directly. Also, sampling may be involved as a step to measurement of the content of radionuclides in environmental media.8
9.
Groundwater pollution
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Groundwater pollution occurs when pollutants are released to the ground and make their way down into groundwater. The pollutant creates a contaminant plume within an aquifer, movement of water and dispersion within the aquifer spreads the pollutant over a wider area. The movement of the plume, called a front, may be analyzed through a hydrological transport model or groundwater model. Analysis of groundwater pollution may focus on soil characteristics and site geology, hydrogeology, hydrology, pollution can also occur from naturally occurring contaminants, such as arsenic or fluoride. Using polluted groundwater causes hazards to health through poisoning or the spread of disease. Different mechanisms have influence on the transport of pollutants, e. g. diffusion, adsorption, precipitation, decay, the interaction of groundwater contamination with surface waters is analyzed by use of hydrology transport models. Contaminants found in cover a broad range of physical, inorganic chemical, organic chemical, bacteriological. Principally, many of the pollutants that play a role in surface water pollution may also be found in polluted groundwater. Arsenic and fluoride have been recognized by the World Health Organization as the most serious inorganic contaminants in drinking-water on a worldwide basis, the metalloid arsenic can occur naturally in groundwater, as seen most frequently in Asia, including in China, India and Bangladesh. In the Ganges Plain of northern India and Bangladesh severe contamination of groundwater by naturally occurring arsenic affects 25% of water wells in the shallower of two regional aquifers, arsenic in groundwater can also be present where there are mining operations or mine waste dumps that will leach arsenic. Natural fluoride in groundwater is of growing concern as deeper groundwater is being used, fluoride can especially be released from acidic volcanic rocks and dispersed volcanic ash when water hardness is low. Pathogens contained in feces can lead to groundwater pollution when they are given the opportunity to reach the groundwater, groundwater that is contaminated with pathogens can lead to fatal fecal-oral transmission of diseases. Nitrate is the most common contaminant in the world’s groundwater. In some low-income countries nitrate levels in groundwater are extremely high and it is also stable under high oxygen conditions. Nitrate levels above 10 mg/L in groundwater can cause blue baby syndrome, Drinking water quality standards in the European Union stipulate less than 50 mg/L for nitrate in drinking water. However, the linkages between nitrates in drinking water and blue baby syndrome have been disputed in other studies, the syndrome outbreaks might be due to other factors than elevated nitrate concentrations in drinking water. Elevated nitrate levels in groundwater can be caused by on-site sanitation and it can therefore have an urban or agricultural origin. Volatile organic compounds are a dangerous contaminant of groundwater and they are generally introduced to the environment through careless industrial practices
10.
Marine debris
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Marine debris, also known as marine litter, is human-created waste that has deliberately or accidentally been released in a lake, sea, ocean or waterway. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, deliberate disposal of wastes at sea is called ocean dumping. Naturally occurring debris, such as driftwood, are also present, with the increasing use of plastic, human influence has become an issue as many types of plastics do not biodegrade. Waterborne plastic poses a threat to fish, seabirds, marine reptiles. Dumping, container spillages, litter washed into storm drains and waterways, more recent studies have found that more than half of plastic debris found on Korean shores is ocean-based. Six pack rings, in particular, are considered emblematic of the problem, the US military used ocean dumping for unused weapons and bombs, including ordinary bombs, UXO, landmines and chemical weapons from at least 1919 until 1970. Millions of pounds of ordnance were disposed of in the Gulf of Mexico and off the coasts of at least 16 states, eighty percent of marine debris is plastic. Plastics accumulate because they typically do not biodegrade as many other substances do and they photodegrade on exposure to sunlight, although they do so only under dry conditions, as water inhibits photolysis. Fishing nets left or lost in the ocean by fishermen – ghost nets – can entangle fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs and other creatures. These nets restrict movement, causing starvation, laceration and infection,8.8 million metric tons of plastic waste are dumped in the worlds oceans each year. Asia was the source of mismanaged plastic waste, with China alone accounting for 2.4 million metric tons. Plastic waste has reached all the worlds oceans and this plastic pollution harms an estimated 100,000 sea turtles and marine mammals and 1,000,000 sea creatures each year. Microplastics on the other hand harm smaller marine life, pelagic plastic pieces in the center of our ocean’s gyres for example outnumber live marine plankton, and are passed up the food chain to reach all marine life. A1994 study of the seabed using trawl nets in the North-Western Mediterranean around the coasts of Spain, France, plastic debris accounted for 77%, of which 93% was plastic bags. Nurdles, also known as mermaids tears, are plastic pellets, typically under five millimetres in diameter and they are a raw material in plastics manufacturing, and enter the natural environment when spilled. Research performed by MBARI found items including plastic bags below 2000m depth off the west coast of North America, an estimated 10,000 containers at sea each year are lost by container ships, usually during storms. One spillage occurred in the Pacific Ocean in 1992, when thousands of rubber ducks, the toys have since been found all over the world, providing a better understanding of ocean currents. Similar incidents have happened before, such as when Hansa Carrier dropped 21 containers, in 2007, MSC Napoli beached in the English Channel, dropping hundreds of containers, most of which washed up on the Jurassic Coast, a World Heritage Site
11.
Ocean acidification
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Ocean acidification is the ongoing decrease in the pH of the Earths oceans, caused by the uptake of carbon dioxide from the atmosphere. Seawater is slightly basic, and the process in question is a shift towards pH-neutral conditions rather than a transition to acidic conditions, Ocean alkalinity is not changed by the process, or may increase over long time periods due to carbonate dissolution. An estimated 30–40% of the carbon dioxide from human activity released into the atmosphere dissolves into oceans, rivers, to achieve chemical equilibrium, some of it reacts with the water to form carbonic acid. Some of these extra carbonic acid molecules react with a molecule to give a bicarbonate ion. Between 1751 and 1996 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14, representing an increase of almost 35% in H+ ion concentration in the worlds oceans. By increasing the presence of hydrogen ions, each molecule of carbonic acid that forms in the oceans ultimately results in the conversion of two carbonate ions into bicarbonate ions. Ongoing acidification of the oceans threatens food chains connected with the oceans, while ongoing ocean acidification is anthropogenic in origin, it has occurred previously in Earths history. The most notable example is the Paleocene-Eocene Thermal Maximum, which occurred approximately 56 million years ago, for reasons that are currently uncertain, massive amounts of carbon entered the ocean and atmosphere, and led to the dissolution of carbonate sediments in all ocean basins. Ocean acidification has been called the twin of global warming. The carbon cycle describes the fluxes of carbon dioxide between the oceans, terrestrial biosphere, lithosphere, and the atmosphere, human activities such as the combustion of fossil fuels and land use changes have led to a new flux of CO2 into the atmosphere. About 45% has remained in the atmosphere, most of the rest has been taken up by the oceans, the carbon cycle involves both organic compounds such as cellulose and inorganic carbon compounds such as carbon dioxide and the carbonates. The inorganic compounds are relevant when discussing ocean acidification for it includes many forms of dissolved CO2 present in the Earths oceans. When CO2 dissolves, it reacts with water to form a balance of ionic and non-ionic chemical species, dissolved carbon dioxide, carbonic acid. The ratio of these depends on factors such as seawater temperature. These different forms of dissolved inorganic carbon are transferred from a surface to its interior by the oceans solubility pump. The resistance of an area of ocean to absorbing atmospheric CO2 is known as the Revelle factor. Since the industrial revolution began, it is estimated that surface ocean pH has dropped by more than 0.1 units on the logarithmic scale of pH. It is expected to drop by a further 0.3 to 0.5 pH units by 2100 as the oceans absorb more anthropogenic CO2, the impacts being most severe for coral reefs and the Southern Ocean
12.
Oil spill
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An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. The term is applied to marine oil spills, where oil is released into the ocean or coastal waters. Cleanup and recovery from an oil spill is difficult and depends upon factors, including the type of oil spilled, the temperature of the water. Spills may take weeks, months or even years to clean up, oil spills can have disastrous consequences for society, economically, environmentally, and socially. The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons, but volume is a limited barometer of damage or impact. Oil spills at sea are generally much more damaging than those on land and these can kill seabirds, mammals, shellfish and other organisms they coat. Oil spills on land are more readily containable if an earth dam can be rapidly bulldozed around the spill site before most of the oil escapes. An oil spill represents an immediate fire hazard, the Kuwaiti oil fires produced air pollution that caused respiratory distress. The Deepwater Horizon explosion killed eleven oil rig workers, the fire resulting from the Lac-Mégantic derailment killed 47 and destroyed half of the towns centre. Spilled oil can contaminate drinking water supplies. For example, in 2013 two different oil spills contaminated water supplies for 300,000 in Miri, Malaysia,80,000 people in Coca, in 2000, springs were contaminated by an oil spill in Clark County, Kentucky. Contamination can have an impact on tourism and marine resource extraction industries. For example, the Deepwater Horizon oil spill impacted beach tourism and fishing along the Gulf Coast, in general, sрilled oil can affect animals and plants in twо ways, dirесt from the oil and from the respоnsе or cleаnup process. There is no relationship between the amount of oil in the aquatic environment and the likely impact on biodiversity. A smaller spill at the wrong time/wrong season and in an environment may prove much more harmful than a larger spill at another time of the year in another or even the same environment. Animals who rely on scent to find their babies or mothers cannot due to the scent of the oil. This causes a baby to be rejected and abandoned, leaving the babies to starve, oil can impair a birds ability to fly, preventing it from foraging or escaping from predators. As they preen, birds may ingest the oil coating their feathers, irritating the digestive tract, altering liver function, together with their diminished foraging capacity, this can rapidly result in dehydration and metabolic imbalance
