Danish Study Discovers How Candles are #1 Indoor Air Pollutant

Danish Study Discovers How Candles are #1 Indoor Air Pollutant

Several years ago Danish scientists conducted a study on indoor air pollution.¹ They wanted to measure how bad the air quality was in city apartments near busy streets. Mind you, Denmark is relatively sparsely populated, and Copenhagen, the biggest city of this Scandinavian country, has a population of just over a million people. How polluted could the air really be, compared to New York (8.8ml) or Shanghai (25ml).  

The Danish scientists put air measuring systems, called particle counters, in 56 Copenhagen homes of non-smokers and began measuring the air quality. They asked residents to make note of their daily activities so the scientists could connect pollution to certain activities.  

To their consternation the scientists discovered that not the busy streets or the outdoor air was to blame for poor indoor air quality. By far the biggest source of indoor air pollution were everyday candles. This is especially the case for so called ultra-fine particles (UFP)², the worst kind of air pollution. While our bodies can stop larger particles from entering our airways, they have no way of stopping nanoparticles from entering lung tissue and to enter the blood stream. These nano particles are therefore considered to be the most dangerous particle pollutants. An article in Experimental and Molecular Medicine found substantial evidence that UFP pollution increase the risk of lung diseases and heart attacks, atherosclerosis, chronic cough, nerve and brain damage, digestive problems, diabetes, and an increased risk of many cancers. A 2007 review article in Indoor Air found that exposure to high levels of indoor UFPs during childhood can cause lung damage and inflammation that risks developing lifelong asthma.⁴

The scientists learned that burning a candle for two hours day contributes to almost two-thirds of the total UFP indoor air pollution. 28 of the 56 homes lit one or more during the two-day experiment. Burning for an average of 2 hours, they contributed to 58 percent of the total indoor UFP pollution in these homes. Cooking was the other major contributor, with 30% of nano particle pollution. In other words, candles and cooking represented more than 80% of the worst kind of indoor air pollution while the nearby roads only contributed 3%. The scientists realized that indoor air quality in the Danish homes they studied was almost the same as in Beijing but in Beijing 70% of all UFP pollution came from outdoor sources while in Denmark it’s the other way around.

These study findings are not limited to Denmark. Household conditions in most of Europe and the United States are very comparable and what applies to a Danish home, applies to all of us. This raises the question why nothing is done about the obvious danger to our health? The reason is that ULF particle pollution is not regulated. No regulatory standards exist to control UFP emissions so there were never any rules developed to specifically address this issue.

What can we do about it?

Candles are a wonderful and almost indispensable accessory to our homes. They create a romantic and cozy ambiance, especially the popular fragranced candles. But almost all candles are made from petroleum-based wax. Its cheap and it burns consistent. But since they are made from oil, they emit toxins. The Danish study discovered how much they really pollute our indoor environment. Of course there are substitutes, but most of these have a hidden price tag as well. Beeswax candles are a popular alternative, but it is well known that the beeswax used for cosmetics and candles has contributed to pushing the world’s bee population to the edge of extinction. Our candles should not help further destroy these precious bee colonies⁵. Soy-based candles are made from soy, that is still wrecking havoc to the rainforest of the Amazon⁶ and the destruction of coral reefs and sea life⁷. Needless to say, palm oil candles are the worst. Palm oil is almost single handedly responsible for the horrifying deforestation of the rain forests of Malaysia and Indonesia, thereby putting the Orangutan and the white Rhino (among many other animals) on the endangered species list.

But there are other options. Esas developed candles with wax that is made from olive and coconut wax.  All these ingredients grow naturally in the wild. These candles burn just as clean as the other non-petroleum-based candles but don’t destroy bee colonies or the rain forests. Esas believes that we can live healthy without nature paying the price.   

¹ https://sciencenordic.com/chemistry-denmark-environment/our-homes-are-filled-with-soot-nanoparticles-from-candle-flames/1390377

² https://pubs.acs.org/doi/abs/10.1021/es402429h

³ These nanoparticles refer to particles smaller than 0.1 micron in diameter.
⁴ https://www.iqair.com/us/newsroom/ultrafine-particles

⁵ https://www.shoplikeyougiveadamn.com/en-us/blogs/why-should-you-avoid-honey-beeswax-/bl-292

⁶ https://unearthed.greenpeace.org/2021/05/19/food-giants-soya-amazon-deforestation-brazil/