The production of plastics has a number of adverse effects on the environment. The production process releases harmful chemicals into the air and water, and the production of certain types of plastics can release dioxins, which are highly toxic. Plastics also contribute to pollution when they are disposed of improperly. When they are burned, they release toxic chemicals into the air, and when they are thrown away, they often end up in landfills, where they can take hundreds of years to decompose.