Thursday 12 March 2009

One Light Bulb, Two Plastic Bags

Here’s another reason (SCMP letter below) why plastic bags are indispensable. People who mistakenly believe they are being environmentally-friendly when opting to use energy-saving light bulbs are advised to “double-bag” on all used light bulbs when throwing them away, hopefully for recycling. How delightfully ironic!

January 3, 2009 Saturday

Energy saving bulbs do not live up to name

Regarding Michael R. K. Mudd's letter ("We must opt for energy- saving light bulbs", December 27), the record must be set straight as to their "environmentally friendly" credentials.

Energy efficient they may be but this does not make them good for the environment or for humans to be in contact with.

Energy efficient compact fluorescent lamps contain poisonous substances including mercury. Contact with mercury is harmful to health and, even where contact is not direct, should these bulbs be thrown into a normal waste bin the mercury could find its way back into the food chain.

Government guidelines in England and America recommend that these light bulbs be disposed of in double thickness plastic bags and specially recycled. Should a bulb break, government advice is to leave the room for 15 minutes, clear it up with rubber gloves and put the pieces in a sealed glass jar before taking them to specially designated local authority tips.

A fundamental problem with these compact fluorescent light bulbs is that, being a gas discharge lamp, they cannot generate the full spectrum of light of a traditional light bulb. Even extra coatings of phosphate to these compact light bulbs show limited improvements. Additional coatings also reduce their efficiency.

Further, these compact light bulbs only save energy if run for long periods of time. Tests have shown that if only kept on for short periods they at best use the same amount of energy and at worst can actually use more than the traditional bulb. As they age, the efficiency of the compact bulbs is reduced whereas traditional light bulbs have a constant efficiency level throughout their lifespan. The compact light bulbs use between 3.5 and 11 times more resources to manufacture than the traditional bulb.

Tests have shown that some people, under a compact light bulb, can experience a number of skin irritations and tiredness.

Energy efficient light bulbs may reduce energy used when switched on and help governments meet their carbon dioxide emission targets. However, they are not environmentally friendly when their full costs are assessed, nor are they healthy.

Robert Hanson, PhD researcher, Bartlett school of the built environment, University of London

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