About one in five of us know the misery of summer, the inescapable itchy, burning eyes, the sneezing bouts, runny or blocked up nose, the headaches that come with clogged sinuses, the urge to grab a cold, damp flannel to flap over one's face and find a darkened bedroom in which to slump until the autumn comes. They could make a horror movie far more tormenting than The Birds or Jaws: The Pollen.
Yes, it is hay fever season again for those of us in the temperate zones of the northern hemisphere with their trees wafting pollen, grasses and flowers swaying in the breeze shedding their fertilizing loads. For some reason sniffing in the gene-carrying particles from the male parts of many of these different plants seems to trigger allergic rhinitis, an over-protective immune and inflammatory response by our bodies to this largely innocuous airborne particulate.
Personally, I never suffered from allergies as a child; I grew up at the coast and had only one friend who suffered awful hay fever as a child, it seemed an oddity. However, during my first-year university exams, having spent most of that first year in a city surrounded by arable land, I suddenly developed what would soon become the tell-tale itchy, painfully prickly, itchy eyes and the sneezed and the bunged up nose of mid-Spring. What changed? Was it the city pollution, reaching adulthood, exam stress, exposure to some new trigger, changing pollen levels (fields of rapeseed which most of us had never even seen growing up on the 1960s and 1970s) or something else?
More to the point, it seems I was not alone. Lots of people develop allergies later in life. "Late-onset" hay fever, asthma, eczema, the unholy trinity of inflammatory response. I later still developed asthma when I moved to Cambridge. None of it is any fun especially if you like to be outdoors enjoying the sun and unfortunately nobody seems to have an explanation.
Various hypotheses have been proposed but none has reached the standing of a theory and none of these explanations has been experimentally demonstrated to explain the problem. Rising levels of vehicle pollution from petrol and diesel engines alike, but perhaps diesel nano-particulates in particular? Changes in agricultural practices, whether agrochemicals, changes in mass crops? Maybe it is "organic" farming methods that are to blame even though they purportedly don't use agrochemicals. It might even be the over-hygienic, centrally heated and double-glazed homes we now inhabit. Our lives also have a surfeit of polymeric packaging materials that are seemingly sterile and wipe clean. It might be a lack of exposure to the dirt and fur of farm animals and pets. Nobody knows. Yet.
Researchers are trying to find out, of course, but the industrial incentive is to treat symptoms rather than look for causes and cures. Back in pre-industrial times when there were scant effective treatments for anything, allergies were lost in the milieu of infectious disease before we even understood what infections were. Hay fever existed; it was more commonly referred to as a summer cold or by 1828 as summer catarrh. It was, however, derided as an affectation and those who sought to treat it were seen as quacks. It certainly was not considered to be a proper illness and the fact that nobody died of sneezing left it on the shelf for many years despite the aforementioned misery to suffers, even if there is no fever and indeed no hay.
Allergy UK reckons the inexorable rise in numbers of sufferers could see more than 30 million sufferers in the UK alone by the year 2030. It seems that while no one is born allergic, we might have an innate tendency to overreact to an allergen at some point in our lives and it just takes exposure to that allergen at the wrong time in our lives to make us "allergic". Unfortunately, it seems that once you develop that allergy, you are stuck with it and you may find that you develop allergies to other substances, whether animal (e.g. cat dander and horse hair), vegetable (e.g. pollen and fungal spores) or mineral (nickel and other base metals). The initial allergy may begin as hay fever, but then asthma and eczema arise through repeated exposure to the trigger or additional triggers. There is no escape for many people.
The daily pollen count as usually reported by summertime TV weather reports along with the sunburn time is rising year on year, the migration of populations from rural to urban life paradoxically also seems to coincide with the rise in the incidence of allergic rhinitis. There is endless advice on copying with hay fever or attempting to reduce one's symptoms, most of it wholly unhelpful: stay indoors (not so great for bird watchers), wear sunglasses, dab petroleum jelly on your nostrils, take this or that medication nasal sprays, eye drops, tablets, eat local honey (yuk!), try herbal remedies, take up yoga and/or meditation, wear a face mask, get allergy injections, move to the mountains…or the Moon. I have personally tried at least some of this "helpful" advice to no avail. And aside from building me a hermetically sealed plastic bubble with filtered air or offering me a waxy gel to paste around my nostrils, I am afraid that materials science may well not offer the answer either…
David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".