Low Energy Light Bulbs     "Low Energy Light Bulbs - Savers or Wasters?" A special feature by Dave Mulligan

The possibility of being required by the EU to use CFLs in place of filament bulbs has prompted me to dig into this a bit more. Here's what I've found:

Potential for Pollution In 1994 the UK produced about 286 million tungsten lamps, 61 million fluorescent tubes, and 6 million other lamps. We also imported about 80 million fluorescent tubes. This information is from www.wasteonline.org.uk. Allowing for some growth since 1994 this could equate to about 400 million units per year. This seems about right since the total EU usage is estimated at 4 billion units per year (10 times my UK estimate). We could be about to replace these with 400 million CFLs. At 10 mg mercury per bulb this equates to 4 tonnes of mercury. This is rather a lot of mercury to sweep under the carpet. Apparently (www.wasteonline.org.uk) one fluorescent tube can pollute 30000 litres of water beyond UK safe drinking requirements. The wasteonline figures indicate 50 mg mercury per tube, which is 3 to 5 times higher than the CFL estimates. So one CFL might pollute 6000 - 10000 litres of water. Let's estimate 8000 litres. Note: It should be said that mercury is unreactive, not water soluble, and is the densest element. Just pouring mercury into water will not cause instant contamination. It will sink to the bottom rather than being suspended. On the other hand the mercury in CFLs can be highly dispersed - an ideal physical form for chemical reaction. Fish and other organisms can then ingest it from the sediment layer. 8000 litres per tube is the pollution potential. There is no conceivable reason for thinking that it is good to get mercury into our environment. 400 million CFLs could pollute 3.2 billion tonnes of water. The UK stock of CFLs could pollute Lake Windermere - England's largest lake - ten times over. I await the headlines Back

Methyl Mercury (AKA Methylmercury) A correspondent has introduced me to Methyl Mercury. Speaking chemically for a moment this is a methyl group attached to a mercury atom and is a cation which can readily associate with anions such as chloride and hydroxide and therefore dissolve in water. This gives it a huge poisoning advantage over metallic mercury, as metallic mercury is almost completely insoluble and is chemically nearly inert. Indeed it is possible for metallic mercury to pass through the body without causing harm (don't try this at home! It is only possible - NOT CERTAIN!). (See 1st paragraph of U.S. Geological Survey - Mercury in the Environment). I don't understand (or fully believe) all the mechanisms which are suggested for its formation (incineration, landfill, bacterial, volcanic, forest fires, coal power stations, groundwater chemistry, etc.) and I'm not going to get into that. But there is little doubt that it exists in the environment and is much more dangerous than the metallic mercury which is its source. So - disposing of CFLs to landfill, quite apart from being illegal because of their hazardous waste status and eletronics content, is even more dangerous than I had realised. Should you wish to be disturbed further try the following links: Wikipedia Methyl Mercury U.S. Geological Survey - Mercury in the Environment

Some better news Fluorescent tubes are classified as Hazardous Waste in England and Wales, and as Special Waste by the Scottish Environmental Protection Agency (SEPA). Incineration is out of the question because of the considerable dangers of mercury vapour. Tubes should be recycled or taken to landfill sites which can cater for mercury bearing wastes. Few do.  There is a UK specialist recycler - Mercury Recycling Ltd. - with whom I have no connection and had never heard of until I visited the wasteonline site. According to www.wasteonline.org.uk (written, I think, in 2004) Mercury Recycling Ltd. were planning for a capacity of 20 million tubes per year, to be set against about 80 million tubes a year currently going to (the wrong type of?) landfill, and a hugely escalating disposal rate if we do indeed switch to CFLs. I don't know any more about Mercury Recycling Ltd. than I can read on their web site, but a starting point is infinitely better than a void! Back