Environmental Issues of Compact Fluorescents
from Wikipedia and other sources
-
Since CFLs use about 1/4 of the energy of incandescent bulbs they are a key part of efforts to fight climate change (global warming). By requiring less energy to produce an equivalent amount of light, they reduce the amount of fossil fuel usage and consequently the amount of carbon dioxide generated.
However, compact fluorescent lights contain trace amounts of mercury. The amount is not large enough to pose a hazard to users, but it does become a concern at landfills and trash incinerators where the mercury from many bulbs can potentially escape and contribute to air and water pollution. It is commonly accepted that the positive effects of compact fluorescent bulbs outweigh the controversy over mercury usage.
Some manufacturers, such as Phillips, make very low mercury content CFLs. Safe disposal of compact fluorescents requires storing the bulbs unbroken until they can be processed. Consumers should seek advice from local authorities. Usually, one can either:
-- Bring back used CFLs to where they were purchased, so the store can recycle them correctly; or
-- Bring used CFLs to a local recycling facility.
The first step of processing involves crushing the bulbs in a machine that uses negative pressure ventilation and a mercury-absorbing filter or cold trap to contain and treat the contaminated gases. Many municipalities are purchasing such machines. The crushed glass and metal is stored in drums, ready for shipping to recycling factories.
Note that coal power plants are the single largest source of mercury emissions into the environment. According to the United States Environmental Protection Agency (EPA), when coal power is used the mercury released from powering an incandescent bulb for five years exceeds the sum of the mercury released by powering a comparably bright compact fluorescent bulb for the same period and the mercury contained in the lamp.