Skip to content

Tealight Candles present health hazard due to small (nano) particles released during burning

Small-Ion and Nano-Aerosol Production During Candle Burning: Size Distribution and Concentration Profile with Time

Matthew D. Wright, A. Peter Fews, Paul A. Keitch, and Denis L. Henshaw
H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, United Kingdom

Burning of paraffin wax produces small-ions and aerosols in the diameter range 0.4 nanometers (nm) to 1.1 micrometers (μm).* The study investigated the particle characteristics formed by burning paraffin tea-light candles.  The study summarized here investigated the particle characteristics formed by burning paraffin tea-light candles.  There were peaks observed in the number concentration of particles in the diameters 10–30 nm and 100–300 nm. These are consistent with “normal” and “sooting” burn modes. They also saw a smaller mode in the size range 2.5–9 nm and interpreted it as a "soot-precursor." When they placed a fan behind the burning candle they saw a “modified small-ion” signal of particles at sizes 1.1–2.0 nm. This small size was "...not observed without the fan present or when a lamp chimney was used. During burning, aerosol concentration was elevated and small-ion counts were low. However after extinction of the flame, this trend was reversed and the number of small-ions increased to levels higher than those observed prior to burning, remaining so for several hours."

The researchers observed that "...although not the major source of indoor air pollution in most environments, a vastly increased inhaled dose of nano-aerosols from combustion could be received by anyone present in a typical domestic room containing a burning candle. Further work is required to characterize the charge state of the smallest particles produced in candle flames and to determine the extent of such increased deposition of combustion particles in the lung." However, regardless of the "charge state" [ion characteristics] of the particles, it is highly likely that particles in the nano-particle size ranges measured coming off the candle will be deposited in the human lung. This could have very serious health implications and should suggest both further research as well as caution on the part of those who frequently are exposed to burning tealight candles.

* 1 micrometer (μm) = 1,000 nanometers (nm). A nanometer is one billionth of a meter or 26 millionths of an inch. A human hair is about 5 x 10-5 meters or 50,000 nanometers in diameter.

Reference: Matthew D. Wright, A. Peter Fews, Paul A. Keitch, and Denis L. Henshaw, 2007. "Small-Ion and Nano-Aerosol Production During Candle Burning: Size Distribution and Concentration Profile with Time." Aerosol Science and Technology, 41:475–484, 2007.

Solar energy conversion — The handy reference guide to solar energy

Do you want to know the potential for solar energy to solve our energy needs as well as eliminate greenhouse gas emissions? Bill McDonough closed his keynote lecture at GreenBuild 2006 in Denver with a comment about our (Earth’s) own nuclear power plant, 93 million miles away. Yes, of course it’s the sun.

A downloadable primer, well-written and illustrated, places the potential of the sun in perspective relative to our energy use and needs. It gives details not only of the potential applications of solar energy but also of the limitations. It places solar energy and its use on Earth in great perspective. Here are some excerpts from the article:

"The San Francisco 1906 earthquake of magnitude 7.8 released an estimated 1017 joules of energy, the amount the Sun delivers to Earth in one second."

"Earth's ultimate recoverable resources of oil, estimated at 3 trillion barrels, contains 1.7 x 1022 joules of energy, which the Sun supplies to Earth in 1.5 days."

"The amount of energy humans use annually, about 4.6 x 1020 joules, is delivered to the Earth by the Sun in one hour."

"The enormous power that the Sun continuously delivers to Earth 1.2 x 105 terawatts dwarfs every other energy source, renewable or nonrenewable. It dramatically exceeds the rate at which human civilization produces and uses energy, currently about 13 TW. "

The article nicely describes the potential for photovoltaics to satisfy our energy needs without greenhouse gas emissions. It discusses the various processes now being developed to increase the efficiency and lower the cost of photovoltaic energy, now far more costly than fossil fuels [ed: by human economic standards]. It also discusses the conversion of solar energy by plants and the potential use of the resulting “biofuels.”

For the scientifically inclined, the article is a thorough discussion of the fundamental physical processes involved. No resource we know of does such a nice job of putting solar energy in perspective. You can download the article for free from www.physicstoday.org.

 

Reference: Crabtree, G., and N.S. Lewis, 2007, Solar energy conversion. Physics Today, March 2007, 37-42. The article is available for free download here

Climate Change: Kofi Annan’s Comments in Nairobi

By Kofi Annan, Former Secretary General of the United Nations

NAIROBI,

I thank the government and people of for hosting this international conference. You have warmly welcomed thousands of people into your midst, and created excellent conditions for the crucially important work on our agenda. Thank you for yet another strong show of support for the United Nations.

All of us in this hall are devoted to the betterment of the human condition. All of us want to see a day when everyone, not just a fortunate few, can live in dignity and look to the future with hope. All of us want to create a world of harmony among human beings, and between them and the natural environment on which life depends.

That vision, which has always faced long odds, is now being placed in deeper jeopardy by climate change. Even the gains registered in recent years risk being undone.

Climate change is not just an environmental issue, as too many people still believe. It is an all-encompassing threat.

It is a threat to health, since a warmer world is one in which infectious diseases such as malaria and yellow fever will spread further and faster.

It could imperil the world’s food supply, as rising temperatures and prolonged drought render fertile areas unfit for grazing or crops.

It could endanger the very ground on which nearly half the world’s population live - coastal cities such as Lagos or Cape Town, which face inundation from sea levels rising as a result of melting icecaps and glaciers.

All this and more lies ahead. Billion-dollar weather-related calamities. The destruction of vital ecosystems such as forests and coral reefs. Water supplies disappearing or tainted by saltwater intrusion.

Climate change is also a threat to peace and security. Changing patterns of rainfall, for example, can heighten competition for resources, setting in motion potentially destabilizing tensions and migrations, especially in fragile States or volatile regions. There is evidence that some of this is already occurring; more could well be in the offing.

This is not science fiction. These are plausible scenarios, based on clear and rigorous scientific modelling. A few diehard sceptics continue to deny global warming is taking place and try to sow doubt. They should be seen for what they are: out of step, out of arguments and out of time.

In fact, the scientific consensus is becoming not only more complete, but also more alarming. Many scientists long known for their caution are now saying that global warming trends are perilously close to a point of no return.

A similar shift may also be taking place among economists. Earlier this month, a study by the former chief economist of the World Bank, Sir Nicholas Stern of the , called climate change "the greatest and widest-ranging market failure ever seen." He warned that climate change could shrink the global economy by 20 percent, and cause economic and social disruption on a par with the two World Wars and the Great Depression.

The good news is that there is much we can do in response. We have started using fossil fuels more cleanly and efficiently. Renewable energy is increasingly available at competitive prices. With more research and development - current levels are woefully, dangerously low - we could be much farther along.

Spurred by the Kyoto Protocol, international carbon finance flows to developing countries could reach $100 billion per year. Markets for low-carbon energy products are expected to grow dramatically.

But we need more "green" approaches to meet surging energy demand. And we need to put the right incentives in place to complement the constraint-based efforts that have prevailed to date.

The climate challenge offers real opportunities to advance development and place our societies on a more sustainable path. Low emissions need not mean low growth, or stifling a country’s development aspirations.

So let there be no more denial. Let no one say we cannot afford to act. It is increasingly clear that it will cost far less to cut emissions now than to deal with the consequences later.

And let there be no more talk of waiting until we know more. We know already that an economy based on high emissions is an uncontrolled experiment on the global climate.

But even as we seek to cut emissions, we must at the same time do far more to adapt to global warming and its effects. The impact of climate change will fall disproportionately on the world’s poorest countries, many of them here in Africa . Poor people already live on the front lines of pollution, disaster and the degradation of resources and land. Their livelihoods and sustenance depend directly on agriculture, forestry and fisheries.

Think, for example, of the women and girls forced to forage for fuel and water in the absence of basic energy services. Or of the innumerable African communities that have suffered climate-related disasters in recent years. The floods of , the droughts in the Sahel and here in , are fresh in our memories. For them, adaptation is a matter of sheer survival. We must make it a higher priority to integrate the risks posed by climate change into strategies and programs aimed at achieving the Millennium Development Goals.

The message is clear. Global climate change must take its place alongside those threats - conflict, poverty, the proliferation of deadly weapons - that have traditionally monopolized first-order political attention. And the United Nations offers the tools the world needs to respond.

Regional and national initiatives have their value. But the UN Framework Convention is the forum in which a truly global response is being formulated.

The Kyoto Protocol is now fully operational, and its Clean Development Mechanism has become a multibillion-dollar source of funding for sustainable development.

This mechanism is an outstanding example of a UN-led partnership linking government action to the private sector in the developing world.

I am pleased to announce that six UN agencies have launched, at this conference, the "Nairobi Framework," a plan to support developing countries, especially in Africa , to participate in the Clean Development Mechanism. I encourage donor countries to help make these efforts a success.

I am also pleased to note that today, UNDP and UNEP are embarking on an initiative to help developing countries, again including in Africa, to factor climate change into national development plans - so-called "climate proofing" in areas such as infrastructure.

UN agencies will continue to bring their expertise to bear. But the primary responsibility for action rests with individual atates - and for now, that means those that have been largely responsible for the accumulation of carbon dioxide in the atmosphere. They must do much more to bring their emissions down.

While the Kyoto Protocol is a crucial step forward, that step is far too small. And as we consider how to go further still, there remains a frightening lack of leadership.

In developing countries, meanwhile, emissions cannot continue to grow uncontrolled. Many of them have taken impressive action on climate change. Rapidly growing economies, like , have been increasingly successful in decoupling economic growth from energy use, thereby reducing the emission intensities of their economies. But more needs to be done.

Business, too, can do its part. Changes in corporate behavior, and in the way private investment is directed, will prove at least as significant in winning the climate battle as direct government action.

And individuals too have roles to play. A single energy-efficient light bulb placed in a kitchen socket may not seem like much; but multiplied by millions, the savings are impressive.

Voting power could be similarly compelling, if people were to make action on climate change more of an election issue than it is today and individuals, through their purchasing choices, can put pressure on corporations to go green.

There is still time for all our societies to change course. Instead of being economically defensive, let us start being more politically courageous.

The Nairobi Conference must send a clear, credible signal that the world’s political leaders take climate change seriously.

The question is not whether climate change is happening or not, but whether, in the face of this emergency, we ourselves can change fast enough.

Let’s pick the biggest, lowest hanging fruit!

Roughly 70% of all workers in the United States travel to work in single occupancy motor vehicles. It seems to me that this is one of the lowest hanging pieces of fruit on the tree of opportunity. Perhaps the only lower one is the wastefulness of energy use in buildings.

For example, while California has been a model for stabilizing total energy consumption for the past 30 years in spite of its population growth, there is still only something on the order of 12% market penetration of compact fluorescent lamps in the residential market. The reason frequently given when I raise this point is ‘color rendition.’ This may have been the case at some point in the past, but a wide range of color rendition is available in CFLs now. Go to a good lighting specialty store where they display the range of CFLs available and you will be able to see this. When an investment of $2.50 to $5.00 results in a lamp lifetime saving of $40 to $50, it is hard to explain. Potential electrical energy saving — huge!

Now for the really big one — passive solar. Why do we restrict the minimum size and amount of opening area of windows and yet let people put windows on any side of a building regardless of compass orientation? Passive solar is the invisible low-hanging fruit. Use overhangs and properly oriented and sized windows and you can save half the heating costs for a house in most North American climates, far more in sunnier, warmer locations like nearly the entire west coast and southwest. Get a clue! Heating is nearly half of residential energy use, therefore, nearly 1/3 of building energy use and nearly 15% of all U.S. energy use.

Let’s pick the biggest, lowest hanging fruit first — no new technology is required.

Anybody out there know how to do this?

Bill Clinton on greening buildings at Greenbuild 2007

At the U.S. Green Building Council's annual conference, Greenbuild 2007, Bill Clinton presented the keynote address focusing on green buildings and climate change.

What I heard was an unequivocal statement that addressing climate change through changed business practices including but not limiting to reducing carbon emissions attributable to buildings would be good for the economy and was an untaped opportunity with abundant profits available. The conference was attended by almost 23,000 people, up from 14,000 last year and 9,000 the year before. It has become clear that this is not just a movement, it is a tsunami.

President Clinton said: "This is the biggest economic opportunity that our country has had to mobilize and democratize economic opportunity since World War II," he said.

You can see the CNET coverage of Clinton's speech at:  http://www.news.com/8301-10784_3-9813101-7.html?tag=nefd.only

Here is a selective summary of some of the highlights of Clinton's talk:

* Challenge / opportunity that is going to create jobs and businesses to create a sustainable planet to leave to our children and grandchildren.
* World is plagued by persistent economic inequality except in the countries that are going to meet their Kyoto targets.
* In Denmark, they grew their economy 50% without an increase in their GHG emissions. Wages are raising and inequality is falling.
* In Europe wages are rising without increasing inequality because of energy transformation.
* The UK is meeting their Kyoto targets.
* 75% of GHG come from urban areas. About 70% of those come from buildings. In NY , where the Clinton Foundation is headquartered,  it’s 80%.
* Clinton Foundation is in partnership with 40 cities to retrofit buildings; using energy services companies to save energy and money, and to use the savings to pay off the cost of the retrofits.
* The value of a couple of blocks of downtown Chicago is $5B. This capital is enough to finance the retrofits of a large fraction of downtown Chicago to take advantage of the opportunities provided by the inefficiency of the existing stock, the cost of energy, and the coming cost of carbon.
* Announced a program with the worlds biggest building – McCormack Place Convention Center.
* GE Real Estate -- $71B worth of real estate in their portfolio throughout the world. Now committed to retrofitting their holdings in partnership with the Clinton Foundation.
* Prove through economies of scale that this can be done, others will follow your lead.
* 20% of population goes to school in America. Greening schools is another opportunity awaiting. Operational savings more than pay for the cost of retrofit in green schools.
* We have to keep score. Several years down the line, when people ask us what we did, we have to keep score so we can tell them what we did. We need to measure the baselines of performance and track our improvements over time.
* Staggering economic opportunity – greening for the benefit of the American dream, as well as to save the climate.