Could masks be making us sick? That’s the suggestion in a Japanese study, published this week in Nature’s Scientific Report’s journal, which looked at bacterial and fungal growth on face masks worn during the pandemic. The results may put you off your tea.
The study looked at the masks of 109 people and shows that bacteria grows in bigger colonies on the inside of the mask compared with the outside. The opposite was true for fungus. Wearing the same mask for a long period of time ‘significantly’ increased the amount of fungus growing on a mask but had no effect on the amount of bacteria.
Every mask bar one – 99 per cent of the masks examined – contained bacterial colonies on the inside and 94 per cent on the outside. The type of mask worn – cloth or disposable – made no difference to the spread of bacteria. On the other hand, fungus was found on the outside of 95 per cent of masks and on the inside of 79 per cent. An interesting finding was that bacterial counts were lower on the insides of masks worn by women. It suggested this may be because they wear makeup and take better care of their skin.
What you eat can be a factor too. The Japanese are fond of a dish called Natto – which is fermented soybeans. Perhaps unsurprisingly, the study participants who consumed the dish regularly had a nearly three times higher count of B. subtilis bacteria on their masks, the same bug used to brew the beans.
Although many of us have now ditched masks there’s a stubborn minority holding out. They perhaps have a false sense of security, given the most convincing transmission benefit of masks occurred when a large percentage of the population wore them – protecting others from transmission rather than themselves.