Run For One Planet Blog

By Chris Tilley

I was asked a question in the comments of the CFL bulb article. Yes there is mercury in CFL bulbs and they should be recycled properly. The amount of mercury in a bulb is fairly minimal between 1.4 and 4 mg.(source) The image shows a 1 g droplet of mercury so 1 mg would be one thousandths that amount. If you should happen to break a bulb there are clean up procedures in the above source. Other items in you house also contain mercury, watch batteries being the most common contain 25mg which is why we should disposes of them properly as well.(source)

The next question is the mercury emission from the burning of coal. The EPA states that the US emits 104 Tonnes of mercury per year mostly from coal fired power plants. This mercury is a large source of the mercury found in fish.(source) The US averages .012mg of mercury per KWh. So over the lifespan of a CFL bulb the electricity emits an average of 1.2 mg and an incandescent bulb that takes more electricity emits 5.8 mg. So even is we garbage every bulb and released all of the 4mg of mercury we would still release less mercury that the electricity to power an incandescent. Recycling the bulb results in the capture and reuse of the mercury.(source)

Going back to the original article replacing one incandescent with a CFL and recycling that CFL and the end of it life would save .876 mg of mercury emissions per year. Replacing 30 bulbs and recycling them would save 26.28 mg of mercury emissions per year.