Le mercure dans les ampoules à basse consommation

3. Do mercury emissions due to light bulb use and disposal pose a risk to the environment?

• 3.1 How much mercury is released by different light bulbs during use and disposal?
• 3.2 How much mercury is released into the environment from other sources?
• 3.3 Do mercury releases from light bulbs pose a risk to the environment?

3.1 How much mercury is released by different light bulbs during use and disposal?

Several types of light bulbs contain mercury. These include compact fluorescent lamps, straight fluorescent tubes, as well as other lamps such as high-pressure sodium lamps. However, at present there is not sufficient information on how many lamps of each type are sold, how long they last and how they are disposed of, so it is not possible to fully assess the risk that their use poses to the environment.

In 2007, approximately 4% of the total electricity consumption in the EU-27 was used to provide power to light bulbs (excluding spot lights) and three quarters of this electricity is used in homes. In 2007, the best-selling lamps in Europe were frosted incandescent bulbs. Compact fluorescent lamps sold half as much as these, closely followed by clear incandescent lamps.

Power generation based on coal implies emissions of mercury to air. [According to the DG Joint Research Centre, the generation of 1 kWh emits 0.016 mg of mercury to air, assuming that 31 % of the electricity used in the EU comes from coal.] Therefore, using any type of light bulb contributes indirectly to mercury emissions, even if the lamp itself does not contain mercury. To assess the contribution of each type of lamp to the total amount of mercury released, it is necessary to add the mercury emissions associated with energy production for their use to the amount of mercury that reaches the environment when the lamp breaks.

Of the lamps investigated, incandescent lamps result in the highest emissions of mercury to the environment per unit of light produced, and halogen lamps the least per unit of light produced.

Compact fluorescent lamps lie somewhere in between. This calculation is based on the assumption that only 20% of the lamps would be recycled at the end of their useful life. In this case, three quarters of the overall mercury release by CFLs would occur at the end of the lamps’ lifetime when the CFL is not disposed of appropriately, i.e. thrown with unsorted household waste and not recycled. Overall, for the light bulbs sold in 2007 over 5000 kg of mercury would be released to the environment in the EU as a result of light bulb usage and disposal. More...

3.2 How much mercury is released into the environment from other sources?

Worldwide, an estimated 3400 to 5300 tonnes of mercury are released into the environment each year. 1400 to 2300 tonnes are due to natural events (e.g. volcanic activity, weathering of rocks) but the remaining 2000 to 3000 tons of emissions are the result of human activity.

Mercury is released into the soil, water and atmosphere, but most of the human emissions are to the soil, mainly due to mining.

An important use of mercury is in dental amalgams used for tooth fillings. Some of this mercury finds its way into the environment through wastewater discharges from dental practices and through the leaching of mercury from the teeth of deceased people. More...

3.3 Do mercury releases from light bulbs pose a risk to the environment?

The mercury emissions due to the use and disposal of household lamps (incandescent, halogen & CFLs combined) are approximately 20 times lower than those from dental practices and represent a tiny proportion of the overall mercury released from all human activities so they are considered very unlikely to pose any risk to the environment. However, sites that collect and dispose of light bulbs could be a local risk if they do not deal with potential mercury releases appropriately. More...