Making choices about the kind of light bulbs we should be using, on the simple basis of energy consumption, and hence carbon emissions, may be a little short-sighted. Thus, the old fashioned incandescent bulbs are no longer commonly on sale, though there is something of a black market in them, due to the poorer quality of light given out by their alternatives – low-power CFLs (compact fluorescent light bulbs) and LEDs (light emitting diodes).
Despite the wide, and almost exclusive, adoption of CFLs and LEDs in place of the original design, a life-cycle analysis http://pubs.acs.org/doi/abs/10.1021/es302886m has shown that there may be an environmental legacy, beyond carbon emissions, or their reduction, in the form of toxic metals, especially copper, lead, mercury and zinc, with smaller amounts of arsenic and antimony, which needs to be given greater consideration.
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