US research has found that chemicals in everyday household products are now a key contributor to city air pollution, rivalling some vehicle emissions.
The study, led from Colorado University, focussed on so-called volatile organic compounds (VOCs).
This appears a somewhat surprising result because by weight, we use far more fuel than we do these other chemical products.
‘Reduce your use’
About 95% of raw oil goes into the production of fuels, whereas roughly only 5% is refined for use in chemicals that are included in the likes of deodorants, pesticides, and adhesives.
But Dr Jessica Gilman said it should not be seen as that remarkable because vehicle fuels are burned (to yield mostly carbon dioxide and water), whereas many of the household products are simply wafted into the air by design.
“It would be difficult to remove them because the alternative is to use straight water, which as you know doesn’t work for all stains.”
One of Dr Gilman’s colleagues, Dr Brian McDonald, did however suggest that reduced use would be helpful.
“Use as little of the product as you can to get the job done,” he said.
The researchers cite as an example the current estimates from the US Environmental Protection Agency.
The EPA considers that about 75% of petroleum-based VOC emissions come from vehicle fuels, and roughly 25% from chemical products.
The Colorado reassessment puts the split closer to 50-50.
“The use of these products emits VOCs in a magnitude that’s comparable to what comes out of the tailpipe of your car. One of the main reasons for this is that in the US, as well as in Europe, air quality regulations have been really successful at controlling emissions from motor vehicles,” said Dr McDonald, who is affiliated to the Cooperative Institute for Research in Environmental Sciences (CIRES) in Colorado and is the lead author on the study.
“In some ways, this is a good news story that, as we control some of the bigger sources in the past, the other sources are emerging in relative importance, such as these consumer products.”
Experts say the results of this research are broadly applicable to other industrialised nations, including those in Europe.
Anthony Frew, a professor of respiratory medicine at Brighton & Sussex Medical School in the UK, commented: “This research is a useful reminder that discussions of air pollution need to consider all sources of pollutants and that measures targeting cars only address part of the problem.
Vehicles emit pollutants beyond just VOCs, of course. These include nitrogen oxides (NOx). Indeed, it is the reaction between the NOx and the VOCs that produces some of the particles of most health concern.