The Art of Engineering

Mercury in compact fluorescent tubes (CFLs) is a health hazard and therefore we should not use CFLs....at least that is the false message being spread by many people.

Yes, there is mercury in CFLs (typically less than 5mg), and yes, they need to be recycled correctly to ensure that the mercury (and electronic components) stay out of landfills. The thing is, the benefits of using CFLs and the associated reduction in mercury emissions far outweigh any issues associated with the mercury in a CFL.

So why do CFLs contain mercury? All fluorescent lamps contain mercury (compact fluorescents as well as conventional straight tubes). The mercury is excited by an electrical current which causes the mercury to emit ultraviolet light. The ultraviolet light stimulates phosphor in the tube which produces visible light. Interestingly enough normal fluorescent tubes have escaped the mercury stigma even though they can contain more mercury that a CFL.

What does coal have to do with it? The burning of coal to produce energy is one of the largest sources of mercury from human activity (in South Africa 80% of our energy comes from coal). This mercury enters the atmosphere and eventually lands in our water systems. Mercury entering into aquatic systems can be transformed by microbial action into methylmecury which bioaccumulates in the food chain.

Incandescent bulbs release more mercury into the environment than CFLs. When you take mercury emissions from coal into accout it turns out that a normal incandescent bulb results in more mercury being released into the environment than a CFL, even when a CFL is disposed into a landfill rather than properly recycled. The US EPA estimates that 1.8mg of mercury enters the environment from a dumped CFL while the use of an incandescent bulb results in 5.8mg (for 8000 hours of use). See the Energy Star's mercury fact sheet for their assumptions.


What about CFL breakages in the home? Breakages need to be dealt with carefully, but do not pose a serious hazard. Ventilate and have any people or pets leave the room. Follow the recommended clean–up guidelines in the EPA mercury fact sheet. There is an old and false story about expensive clean–up procedures which came about due to a misunderstanding – snopes.com has the full history of that story, which makes for interesting reading.

What do we need to do? Switch to CFL or LED bulbs wherever and as soon as possible. This reduces both energy consumption and mercury emissions which is good for our well–being. Consider LEDs where suitable – they contain no mercury and have a longer life span than CFLs (although they only available in certain light formats, provide a different type of light, and you need to compare their efficiency to CFLs). Correctly dispose of your CFLs (and LEDs) for recycling, as this keeps the mercury out of the landfills and allows it to be reused in new lights.

Please share this, blog about it, write newspaper articles, tweet (and retweet) it, stumble it, tell your friends, and explain it to anyone who does not know that using CFLs will actually reduce your exposure to mercury. CFLs help us to reduce energy consumption and keep our environment clean – let the world know.

More resources:
[1] "Global Atmospheric Mercury Assessment: Sources, Emissions and Transport," UNEP 
[2] UNEP mercury programme

Image courtesy of Energy Star.

When was the last time that you enjoyed the wonder of a night time sky? I have fond memories of family holidays to Jeffery's Bay, and one of the things that stands out clearly in my mind is the beauty of the night sky from the beach near the house we stayed in. The richness and depth of the starry night seemed to suck you into itself.

When I look up from my home now all that I can see is a few of the brightest constellations while the rest is hidden by the haze of city lights. We have lost our night sky and we do not even know what the implications of that are (here are some). I was reminded of this by a photo essay on light pollution. The last line of the essay is particularly poignant: For all the benefits of artificial light, "we shouldn't pretend that nothing is lost."

On 28 March at 20h30 the WWF is asking us to turn out the lights for one hour as a vote for Earth and a vote against climate change. This global action will be presented to leaders at the Global Climate Change Conference in Copenhagen.

This is not a vote against climate change, this is an action to win back some of what we have lost. This is an opportunity to start reclaiming our night sky. This is the chance to turn off not only your lights, but your TV, computer, cellphone and any other distraction and to spend an hour with the people you love – connecting and enjoying your humanity. This is a vote for a happier, cleaner and healthier world.

Sign up on the South African or International Earth Hour websites.



Image courtesty of Steve Jurvetson, licensed under a Creative Commons license.

We have allowed ourselves to be framed as consumers. We hear it constantly – we are not referred to as people, or producers, or savers, we are referred to as consumers. The more I hear the term, the more it bothers me, and the more I feel that referring to ourselves in that way takes away a part of our humanity. It leaves me with this image of gluttonous people at a table unable to stop eating and waiters who are all too happy to keep bringing food as they picture the giant tip at the end of the evening. We are fed an information diet from news to advertising which keeps telling us that we are consumers and we need to consume. It is degrading and we need to reframe how we see ourselves.

Paul Graham referred to an interesting statement in a recent essay, "You make what you measure." And what is it that we measure? GDP – gross domestic product – a measure of a country's consumption. One of the goals of our incumbent economic system is to keep growing GDP, which is to keep producing more and more, which in turn means to continuously grow consumption. So we measure consumption and we create consumers.

We don't measure happiness, we don't measure how much water is available, we don't measure how much we waste, we measure consumption. Imagine how much would change if our leading indicator was the measure of people's happiness. If you want to know, look at the city of Bogota.

To support our current economic system we seek out ways to create more consumption. Disposable paper cups, nappies, razor blades, and more. Even our "durables" have become disposable – replacement is so cheap...and it is encouraged.

We are left with a world spiralling out of control. We put pressure on our environment to produce more and more so that we can consume more and more. And in the mean time we are not getting happier or healthier.

To stop this we have to fight to regain our humanity. We can no longer accept being referred to as consumers – we are people: mothers, fathers, brothers, sisters, children. We are more than consumers: we are creators, artists, workers, partners – we are human.

We need to stop measuring ourselves as consumers, and start measuring ourselves as humans.

Some alternatives to GDP are Gross National Happiness and the Genuine Progress Indicator. The Happy Planet Index (a NEF initiative) measures the efficiency with which nations convert ecological resources into long and happy lives for their citizens – their manifesto is a stimulating read.