Pollution is something introduced into the environment that is dirty, unclean or has a harmful effect. Toxic waste dumped into the water is an example of pollution.Some of the main causes of pollution include industrial emissions, poor disposal of wastes, mining, deforestation, use of fossil fuels and agricultural activities. Pollution can affect the air, the land and water bodies throughout the world.The burning of fossil fuels, in both energy plants and vehicles, releases massive amounts of carbon dioxide into the atmosphere, causing climate change. Long-term exposures also can lead to significant climatic changes that can have far reaching negative impacts on food, water and ecosystems.The groups most affected by air pollution are people of color, elderly residents, children with uncontrolled asthma, and people living in poverty. Vulnerable populations may experience more health effects because these populations already have higher rates of heart and lung conditions.