Water pollution happens when chemicals or dangerous foreign substances are introduced to water, including chemicals, sewage, pesticides and fertilizers from agricultural runoff, or metals like lead or mercury.According to the Environmental Protection Agency (EPA), 44% of assessed stream miles, 64% of lakes and 30% of bay and estuarine areas are not clean enough for fishing and swimming.
Adequate sanitation helps to keep sewage and other contaminants from entering the water supply.
According to National Oceanic and Atmospheric Administration (NOAA), 80% of pollution in marine environment comes from the land through sources like runoff.
The nutrient works like fertilizer and makes algae grow at excessive rates, according to NOAA. The plants die and their decomposition leads to less oxygen in the water. The air we breathe has a very exact chemical composition; 99% of it is made up of nitrogen, oxygen, water vapor and inert gases.
Air pollution occurs when things that aren't normally there are added to the air.
According to the EPA, the greenhouse effect is when gases absorb the infrared radiation that is released from the Earth, preventing the heat from escaping.
This is a natural process that keeps our atmosphere warm.Land can become polluted by household garbage and by industrial waste. A little over half of the waste — 136 million tons— was gathered in landfills. Organic material was the largest component of the garbage generated, the EPA said.In 2014, Americans produced about 258 million tons of solid waste, according to the U. Paper and paperboard accounted for more than 26%; food was 15% and yard trimmings were 13%.Industries generate hazardous waste from mining, petroleum refining, pesticide manufacturing and other chemical production.Households generate hazardous waste as well, including paints and solvents, motor oil, fluorescent lights, aerosol cans and ammunition.According to the EPA, low levels of dissolved oxygen in the water are also considered a pollutant.Dissolved is caused by the decomposition of organic materials, such as sewage introduced into the water. The artificial warming of water is called thermal pollution.Plastics comprised about 13% of the solid waste, while rubber, leather and textiles made up 9.5% and metals 9%.Wood contributed to 6.2% of the garbage; glass was 4.4% and other miscellaneous materials made up about 3%.Water pollution isn't just a problem for the United States.According to United Nations, 783 million people do not have access to clean water and around 2.5 billion do not have access to adequate sanitation.