By Eleni Mann
With its longer nights and warmer days, for many people, summer is a welcome sight. The grass is green, the sun is shining, and the sound of the ice cream van is music to our ears. However, every year summer brings with her a sordid villain, guaranteed to disrupt daily life and ruin our attempts of soaking up the sun’s rays.
After the year we’ve had stuck inside, you’d be forgiven for ranting about hay fever ruining your ‘Hot Girl Summer’. As I’m writing this article, eyes itching and uncontrollably sneezing, I too have joined the social media chorus of “Why is hay fever so bad this year?”. It clearly isn’t me alone that has noticed how hard the suffering seems to have hit us this year, so the question is – why?
The best place to start is to establish what hay fever actually is. Hay fever, also called seasonal allergic rhinitis, is the body’s reaction to inhaling pollen, which is released from most flowers, trees, and grasses at the end of spring and the start of summer. As temperatures rise, plants release their pollen into the air aiming to pollinate and reproduce, but instead, it often finds its way up our noses, resulting in sneezing, tiredness, and other irritating symptoms. It is estimated that one in four people in the UK suffer from hay fever, although that figure is likely much higher, especially this year, with surveys by Allergy UK and Kleenex showing a “significant increase” in hay fever cases, with 37% of respondents having developed symptoms for the first time in the last five years.
Many leading experts have varying hypotheses for why hay fever cases are on the rise; however, climate change is arguably the main cause of this increase.
Data analysis undertaken across 34 European research sites has shown we are now able to forecast the severity of the forthcoming grass pollen season by studying past weather conditions. Specifically, pre-seasonal air temperature and precipitation were identified as the key parameters driving grass seasonal pollen, with warmer weathers and late-spring rain encouraging pollen release. Recent studies have shown that the North Atlantic Oscillation (NAO) index is also an important influence of pollen circulation. (The NAO is a large-scale atmospheric pressure system that controls climate patterns across Europe and North America, and some studies suggest anthropogenic climate change has caused variations in the balance of positive and negative oscillations since late the 1980s.)
As well as this, the aforementioned study by Kurganskiy and fellow scientists simulated long-term changes in the severity of the grass pollen season, enabling us to model how pollen levels may increase as a result of climatic change, such as because of increasing CO2 levels.
Other experts, such as Amena Warner, head of clinical services at Allergy UK, corroborate these findings. Warner explains that research has shown plants produce more pollen as a response to high atmospheric carbon dioxide (CO2) levels, and therefore as CO2 levels increase due to human activity, hay fever symptoms are expected to get worse when pollution levels are high. This also will contribute to the long-term trend of rising pollen levels in the UK.
However, there are other reasons that we all might be feeling hay fever more brutally than usual, as a direct result of the lockdown. The ‘hygiene hypothesis’, as explained by immunologist Professor Daniel Altmann, suggests that, as a result of all the excess cleaning and disinfecting, our immune systems have adapted to be more reliant on external protections, leaving our immune response ‘inappropriately programmed’ and therefore making us more likely to suffer from allergy and asthma.
Sudden exposure to pollen after months inside may also contribute to our misery; we have all been encouraged to meet up outside, and by combining our lack of pollen immunity with increased outside pollen exposure, hay fever symptoms may appear more severe. Delays in NHS allergy treatment also compile the increase in more severe hay fever symptoms people are experiencing.
Or, some have argued, we may just be overreacting. Are symptoms really more extreme, or are we just more aware of our symptoms after months of no exposure? There seems to be increasing evidence to the contrary, and both increasing pollen counts and reduced exposure seem to be a lethal combination for hay fever sufferers this year, but there is still the possibility that we’re just noticing symptoms more.
Regardless, none of this detracts from the fact that hay fever is horrible. However, unfortunately for us hay fever sufferers, the science isn’t showing hay fever lessening her vendetta against our immune systems in the near future, so stock up on your antihistamines – hay fever is going to be with us for the long haul.
Illustration: Victoria Cheng