Defog sprays used to stop glasses steaming up when wearing a face mask could be exposing people to cancer-causing chemicals, study warns
- Duke University-led researchers analysed nine popular anti-fogging products
- They found all contain 'fluorotelomer alcohols' and 'fluorotelomer ethoxylates'
- These both types of so-called per- and polyfluorinated alkyl substances (PFAS)
- Little is known about the health impacts of the particular PFAS the team found
- However, some PFAS are linked to cancer, immune issues and thyroid disease
- And there is fear the identified chemicals may break down into harmful variants
The anti-fogging sprays and cloths that have become popular to help stop glasses from steaming up when wearing a face mask may be exposing users to carcinogens.
That is the warning from Duke University-led experts, who found these treatments may contain cancer-causing per- and polyfluorinated alkyl substances (PFAS).
The team subjected four anti-fogging sprays and five anti-fogging cloths — all of which have received top ratings on Amazon — to high-resolution mass spectrometry.
Specifically, the chemical analysis found that all nine products contained so-called fluorotelomer alcohols (FTOHs) and fluorotelomer ethoxylates (FTEOs).
These are two types of PFAS that have, until now, largely flown under the radar — meaning that scientists are not certain what health impacts they may carry.
However, research has suggested that, once inhaled or absorbed via the skin, FTOHs could well break down in the body into other, long-lived and toxic forms of PFAS.
Such may include perfluorooctanoic acid (PFOA), which — along with perfluorooctanesulfonic acid (PFOS) — has been linked to disorders like cancer.
The anti-fogging sprays (pictured) and cloths that have become popular to help stop glasses from steaming up when wearing a face mask may be exposing users to carcinogens
PFAS HEALTH RISKS
While little is currently known about the FTOHs and FTEOs used in anti-fogging products, other types of PFAS are known to carry health risks.
Some of these chemicals — notably perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) — have been linked to cancer, impaired immune function and thyroid disease, among other health disorders.
Experts believe that breastfeeding mothers and young children may be at particular risk from PFAS, which can affect both developmental and reproductive and health.
The study was carried out by environmental scientist Nicholas Herkert of Duke University in North Carolina and his colleagues.
'Our tests show the sprays contain up to 20.7 milligrams of PFAS per millilitre of solution, which is a pretty high concentration,' Dr Herkert said.
'If we were to assume that FTOHs and FTEOs have similar toxicity to PFOA and PFOS, then one spray from these bottles would expose you to PFAS at levels that are several orders of magnitude higher than you’d receive from drinking a litre of water that contains PFAS at the current EPA health advisory limit for safe consumption, which is 70 nanograms per litre.'
The idea for the study came after environmental chemist Heather Stapleton — also of Duke University — reviewed the ingredient list on a bottle of anti-fogging spray that the researcher had bought for her 9-year-old daughter to use.
'Ironically, it was advertised as safe and nontoxic. It said to spray it on your glasses and use your fingers to rub it around,' Professor Stapleton said, noting that the eight other products the team tested did not even list their ingredients.
'It's disturbing to think that products people have been using on a daily basis to help keep themselves safe during the pandemic may be exposing them to a different risk.'
Dr Herkert also noted that the FTEOs used in all four of the popular spray mixtures they analysed exhibited, in their laboratory tests, significant toxicity that altered cells and converted them to fat.
'FTOHs and FTEOs could be metabolic disrupters, but the only way to tell is through in vivo testing on whole organisms,' he explained.
'We only did in vitro (lab dish) testing.'
More studies will be needed to flesh out these initial findings, the team said, with the next logical step being to analyse a larger selection of anti-fogging products and to assess the impact of the chemicals used on living organisms.
'It's disturbing to think that products people have been using on a daily basis to help keep themselves safe during the pandemic may be exposing them to a different risk,' said paper author and environmental chemist Heather Stapleton of Duke University
'Because of COVID, more people than ever — including many medical professionals and other first-responders — are using these sprays and cloths to keep their glasses from fogging up when they wear masks or face shields,' Professor Stapleton added.
'They deserve to know what’s in the products they’re using,' she concluded.
The full findings of the study were published in the journal Environmental Science & Technology Letters.
ARE PEOPLE WHO WEAR GLASSES MORE INTELLIGENT?
Glasses wearers really are more intelligent than those with perfect vision.
According to the largest genetic study of cognitive function ever conducted, there are significant links between intelligence and glasses.
Researchers from the University of Edinburgh found that the most intelligent among us are 30 per cent more likely to need glasses.
The largest genetic study of cognitive function ever conducted has uncovered a link between intelligence and poor eyesight. According to the University of Edinburgh study, the most intelligent among us are 30 per cent more likely to need glasses
The extensive study also linked higher cognitive ability to genes known to play a crucial role in good cardiovascular health.
The genetic data of 44,480 people was examined in the study, which was published in the journal Nature Communications.
Those who participated took part in a variety of thinking tests, and the results were tallied into a general cognitive ability score.
Unfortunately, the study’s design means that researchers were unable to say why there is such a direct correlation between a person’s intelligence, poor eyesight, and cardiovascular health.