Pollution is the presence of harmful substances in the air, water and soil that cause damage to human health and ecosystems. It hinders sustainable economic growth and development, exacerbates poverty and inequality in urban and rural areas and contributes to climate change.
People have a responsibility to prevent pollution. They need to take measures to reduce their environmental footprint, including reducing consumption and production and ensuring that products are made sustainably. They also need to adopt a greener lifestyle and improve waste management.
The most visible type of pollution is air pollution, which kills about 7 million people a year globally and disproportionately affects children. It is caused by a variety of human activities, from burning coal, oil and gas in vehicles and cooking on cookstoves to using pesticides and endocrine disrupting chemicals in the home. Air pollutants also come from natural sources, such as smoke from wildfires, ash and gases released by volcanoes, and dust and sand from desertification.
Other types of pollution include water pollution, which can be caused by industrial effluents, the addition of inorganic substances or organic ones and agricultural runoff; and soil pollution, which results from the accumulation of solid and liquid waste materials, mainly organic but sometimes chemical or radioactive, on the land. The pollution from these pollutants can be classified as point source, when the contaminant is highly concentrated in one specific area, or nonpoint source, when it is spread out over an entire area.