What is Pollution?
[[File:Contamination Studies 1, Keffi, Nigeria.jpg|thumb|Pollution tests in [[Nigeria]]]] '''Pollution''' is when harmful substances are added to the environment and then change it in a bad way. There are six kinds of pollution of the [[environment]]: * [[water pollution]] * [[air pollution]] * [[light pollution]] * [[noise]] pollution * [[soil]] pollution * [[thermal pollution]]. As pollution grows, ways to combat it have been in demand. [[Solar energy]] and [[wind energy]] give people clean opportunities to power their homes. But these may also have [[:en:Environmental_issues|environmental issues]] depending on the situation. When people use these [https://www.inspirecleanenergy.com/blog/clean-energy-101/types-of-alternative-energy alternative forms of energy], they put less [[carbon dioxide]] into the environment.<ref>{{Cite web|url=https://www3.epa.gov/climatechange/ghgemissions/|title=United States Environmental Protection Agency|first=|last=|date=October 6, 2016|website=Greenhouse Gas Emissions|publisher=|accessdate=June 15, 2016}}</ref> == Water pollution == [[File:Water pollution.jpg|thumb|Waste from a [[sewer]] pipe is an example of water pollution]] [[Water pollution]] is the presence of harmful materials in water, such as [[sewage]], dissolved [[metal]], waste from [[farm]]s, [[factories]] and [[petroleum|crude oil]] [[oil spill|spilled]] from oil tankers. The three main substances that pollute water are [[nitrate]]s from [[fertiliser|fertilizer]]s, sewage, and [[detergent]]s. Activities such as bathing and washing clothes near lakes, ponds or rivers add [[nutrient]]s like nitrate and [[phosphate]] into the water bodies.This leads to excessive growth of [[algae]] on the surface of water. It blocks the penetration of sunlight and air, thus reducing oxygen. It causes harm to organisms living in water and can also harm people's health. In extreme cases, it may cause diseases like [[cancer]].<ref>[https://www.nytimes.com/2013/03/03/world/asia/spill-in-china-lays-bare-environmental-concerns.html Spi