Energy saving lamps contain mercury, a substance which is extremely harmful for humans, animals and the ecosystem in general. It is especially toxic to the brain, the nervous system, the liver and the kidneys. Fetuses, babies and infants are the most vulnerable, as mercury exposure negatively influences the development of the brain (eg. lower IQ) and nervous system. Mercury can also damage the cardiovascular, immune and reproductive systems and possibly lead to tremors, emotional instability, memory loss, insomnia, neuromuscular changes, headaches, cancer and Alzheimer’s (1).
It is often said that energy saving lamps contain only a very small amount of mercury, which therefore can’t be harmful. Though one has to ask the question: small in comparison to what? The safe intake of mercury for a human body is a only a few micrograms (2). CFL’s contain three to five thousand micrograms.
Exposure to the mercury in CFL’s normally only occurs when the lamp breaks, which can happen very easily. Measurements show that the levels of mercury in the air after lamp breakage can well exceed the existing safety limits (3). After the breakage, a large number of fairly complicated measures need to be taken to limit the health risks. However, very few people are aware of the needed precautionary measures. Moreover, a study by the state of Maine (United States) shows that even when all precautionary measures are taken, the mercury concentrations in the room where the lamp broke can stay very high (4). This is because the mercury can get absorbed into all sorts of textiles (carpet, curtains, etc.), which can then give off mercury vapour for a long time after the breakage.
For children playing on the carpet this can lead to very high exposures. More generally, it can be said that: “Babies and other small children are more vulnerable to airborne mercury exposures, because their small body sizes and more rapid respiration rates give them a larger dose of mercury than an adult gets from inhaling air with the same mercury concentration. Mercury vapor is heavier than air, and mercury concentrations in indoor air tend to be higher near the floor. Infants and toddlers who crawl, sit, walk, play and breathe on or close to the floor are thus likely to be most heavily exposed to the mercury vapor from a broken CFL.” (4, p. 7)
Lamps that are thrown in the garbage can break in the garbage can in the house or in the dump truck, from where the mercury vapour can escape and are thus transferred all over the town or city (2). Once the lamps end up on the landfill, the mercury can evaporate further, seep into the ground and contaminate water. The amount of mercury in one lamp is enough to contaminate 23.000 liters (6,000 gallons) of water (5). Even when the lamps don’t break, the mercury in them constitutes a time bomb for future generations (2).
Environmental organisations, the lamp industry and government agencies often claim that energy saving lamps will ultimately reduce the amount of mercury in the environment. It is said that the production of electricity in coal-fired power plants is an important source of mercury emissions. Because CFLs use less electricity than incandescent lights, CFLs will ultimately reduce the amount of mercury in the environment, or so the argument goes. However, several experts question the validity of this argument. John Gilkeson, head of the Minnesota Pollution Control Agency in the United States says that less use of electricity is not directly linked to fewer mercury emissions. Using less electricity does not necessarily mean that less coal is burned. Since coal is cheap, power companies tend to keep their coal-fired plants running day and night; when demand for electricity ebbs, they cut back on more expensive natural gas, not coal (6).
Professor Ron Hui, chairman of the electronic engineering department at the City University of Hong Kong also remarks: “Talking about the amount of mercury emitted from power stations is a false argument. With power stations, the contamination is in that area, but now we are talking about bringing that contamination into every home and every street. We may have less mercury in the whole production process than with incandescent light bulbs but the difference with CFLs is that the mercury will be in our homes, in our streets” (5) and in our water supplies.
(2) ‘Understanding fluorescent light bulbs’, cnn.com, 27/07/2008
(3) Li, Y. and L. Jin (2011). Environmental Release of Mercury from Broken Compact Fluorescent Lamps, Environmental Engineering Science. 28 (10).
(5) ‘Shining a light on hazards of fluorescent bulbs’, MSNBC News, 20/03/2008
(6) Are we screwing in the wrong bulbs?’, Lake Oswego Review, 30/10/2009