Our sense of smell is eroding, and Covid-19 is not to be blamed this time!
2 min read . Updated: 26 Feb 2023, 05:01 PM IST
Premium- Olfactory senses will exist only in biology books and historical narratives as severe air pollution has now started affecting people's ability to smell
Losing sense of smell was a symptom that was considered synonymous with Covid-19. For over three years loss of smell was the first red flag for a person to get checked for Covid-19. However, a recent report on BBC, shows that not Covid-19, but air pollution is the latest evil to affect people's sense of smell and this is here to stay!
Olfactory senses will exist only in biology books and historical narratives as severe air pollution has now started affecting people's ability to smell. Air pollution has been gradually affecting the sense of smell, eroding it away over years.
Air Pollution eroding sense of smell
Exposure to PM2.5 – the collective name for small airborne pollution particles, largely from the combustion of fuels in vehicles, power stations and our homes – has previously been linked with "olfactory dysfunction".
However, this olfactory dysfunction has crept its way out of industrial set-up and has crept into everyday lives of people.
A researcher, Murugappan Ramanathan Jr, a rhinologist at the Johns Hopkins School of Medicine, Baltimore, has said, "Our data show there's a 1.6 to 1.7-fold increased [risk of] developing anosmia with sustained particulate pollution,"
In a survey, the researcher found that the increasing number of patients for ‘anosmia’ were higher in neighbourhoods that reported ‘significantly’ higher levels of PM2.5.
PM2.5 is not the only devil
One recent study in Brescia, northern Italy, for example, found the noses of teenagers and young adults became less sensitive to smells the more nitrogen dioxide – another pollutant produced when fossil fuels are burned, in particular from vehicle engines – they were exposed to.
Another year-long study in São Paulo, Brazil, also indicated that people living in areas with higher particulate pollution had an impaired sense of smell.
How air pollution affects sense of smell?
Ramanathan has pointed out two potential routes.
One is that some of the pollution particles are passing through the olfactory bulb and getting directly into the brain, causing inflammation, according to BBC report. "Olfactory nerves are in the brain but they have little holes at the base of skull where little fibres go into the nose, [looking] almost like little pieces of angel hair pasta," says Ramanathan. "They are exposed."
The other potential mechanism, says Ramanathan, is by hitting the olfactory bulb on an almost daily basis, that causes inflammation and damage to the nerves directly, slowly wearing them away.