Dioxins and furans can be produced when almost anything is burned under the right conditions. Two major sources are municipal waste and hospital incinerators, though emissions from these sources have been reduced in recent years because so many of these incinerators have shut down in recent years in many cases due to opposition from local grassroots community based organizations. Bleaching wood pulp with chlorine to make paper white has been another major source. Dioxin is found in the waste water released from these plants, although the amounts have declined because many plants have converted to processes that use less chlorine.PCBs were used as insulators in electrical equipment, but their production was banned in 1977. Today, they remain in use mostly in electrical transformers and capacitors, especially in large office or apartment buildings.PCBs are commonly found in river sediment nears plants where PCBs were generated or used.