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Various definitions of pollution exist, which may or may not recognize certain types, such as noise pollution or greenhouse gases.The United States Environmental Protection Administration defines pollution as "Any substances in water, soil, or air that degrade the natural quality of the environment, offend the senses of sight, taste, or smell, or cause a health hazard.
A pollutant or novel entity [1] is a substance or energy introduced into the environment that has undesired effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts).
Air pollution can occur naturally or be caused by human activities. [3] Air pollution causes around 7 or 8 million deaths each year. [4] [5] It is a significant risk factor for a number of pollution-related diseases, including heart disease, stroke, chronic obstructive pulmonary disease (COPD), asthma and lung cancer.
A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses." [1]: 6 Water is typically referred to as polluted when it is impaired by anthropogenic contaminants.
Sources of water pollution are either point sources or non-point sources. [155] 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. [156] Pollution is the result of the cumulative effect over time.
Levels of air pollution rose during the Industrial Revolution, sparking the first modern environmental laws to be passed in the mid-19th century. The environmental movement (sometimes referred to as the ecology movement) is a social movement that aims to protect the natural world from harmful environmental practices in order to create ...
Environmental pollution and ecological degradation has resulted in economic losses for China. In 2005, economic losses (mainly from air pollution) were calculated at 7.7% of China's GDP. This grew to 10.3% by 2002 and the economic loss from water pollution (6.1%) began to exceed that caused by air pollution. [18]
Environmental degradation is the deterioration of the environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable.