Ramanathan, for whom traffic pollution and waste incinerators top the local pollution concerns in Baltimore, says "air quality matters". "I think we need tight regulations and control," he says. Many people may not even realize the pollution they are exposed to, so they rely on politicians regulating it to protect the populations in the surrounding areas.
"This is one of many pollution-related conditions," he added. "But this is kind of a special one, right? If you have COPD "chronic obstructive pulmonary disease" you could probably still enjoy your glass of wine. But not with this one."
Loss of smell has been linked to increased likelihood of depression and anxiety in various studies, and is known to play a role in obesity, weight loss, malnutrition and cases of food poisoning. The reasons are perhaps obvious – our noses play a key role in our experience of the world around us, affect our ability to taste food and help us avoid meals that have gone off.
A poor sense of smell may mean that sufferers are likely to seek out stronger tasting food, which is very often salty and fatty. By contrast, a total loss of smell can put people off food and lose enjoyment from it, ultimately becoming underweight – a particular problem among the elderly.
Ramanathan has seen many patients who "can't taste food, can't smell their wine, the things that gave them pleasure in life". He recalls one patient who was a professional sommelier, for whom developing anosmia was both personally and professionally devastating.
Smell and taste are also linked to memory. "People don't remember what that pastry looked like that they ate in France, but they remember what the shop smelled like", he says. Re-experiencing a particular smell can transport our memories straight back to that moment in pastry shop. This raises the question – albeit yet to be properly studied – whether the inverse could also true, and no longer being able to smell could impair our ability to create new memories in the same way.
Anosmia could also be an indicator of other, wider health issues. Numerous studies, typically of smokers – for whom smell impairment persists even 15 years after quitting – have shown that olfactory dysfunction is significantly associated with increased mortality among older adults. One particular study even hypothesized that anosmia could be used as a predictor for greater likelihood to die – from any cause – among older adults over a five-year-period. In a study of 3,005 US adults aged 57 to 85, those with anosmia were found to be four times more likely to die than their peers five years later. The researchers concluded that deteriorating sense of smell could be a "bellwether" for the accumulation of toxins from the environment or slowed regeneration of cells.
Ekström says tackling air pollution is not simple. World events can also cause unexpected shifts in behavior – Ekström mentions anecdotally that winter wood burning has been on the rise in Stockholm as worried residents wean themselves off Russian gas. But even the every-day, low-level air pollution we are exposed to “should be taken more seriously", she says. And what's more, “olfactory impairment should definitely be taken more seriously”, too.
So, should we care that air pollution – to which we are all exposed – is impairing our sense of smell and causing anosmia?
Clearly, the answer lies somewhere between "yes" and "hell yes".