The sticky business of pollen counting

EN - Melbourne has a history of pollen counting going back to the 1930s. Miss Marjorie Sherwood first counted pollen at the Baker Medical Research Institute at the Alfred Hospital. Professor Bruce Knox counted pollen in the 1970s, and I took over in 1997 - the School of Botany saw it as a very useful engagement activity.

EN - The Melbourne Pollen Count was a subscriber service, but newspapers can’t afford to pay for much now. So Edwin - a molecular biologist with an aptitude for programming - developed the app and website that we now use to interact with people interested in that information. Jeremy’s interest is in thunderstorms, in how grass pollen gets from its site of production to Melbourne, and I’m interested in the biology of the pollen.

EN - For pollen to be a major allergen, it must be a dominant feature of the landscape. Grazing pastures are obviously a feature of Western Victoria. These grasses are wind-pollinated plants - their flowers are not attractive, they have no nectar rewards, but they are supremely well adapted to produce and distribute large amounts of pollen.

EN - The word pollen derives from the Italian word for flour - polenta - it’s a dry powder. Grass pollen is too large to get into the small, intricate parts of the lungs, and instead gets trapped in the nose and the upper respiratory passageways causing hayfever.

JS - But when there’s enough moisture in the air, which you often get in thunderstorm conditions, the pollen grains can rupture into smaller particles.

EN - These attach to diesel particles and are carried deeper into the lungs, causing asthma. We are looking at the relationship between high grass pollen days, thunderstorms, and numbers of admissions to emergency departments of people with uncontrolled asthma. I think we can say that thunderstorm asthma is a regular seasonal occurrence in Melbourne, under the right sorts of conditions.

EN - In places like Spain, Greece and the Mediterranean region, it’s olive pollen which is the major problem. Olives are a weed, and birds carry the seeds out after the farm stops farming. Across much of the USA, the prevalent pollen allergen is ragweed, a type of daisy. Ragweed arrived in Australia quite recently, it grows voraciously and certainly has the capacity to expand across the country.

EN – With climate change, as we move into warmer winters and drier summers, we’ll have more frequent burns of forests, causing a shift away from forested land to grassed, savannah type land.

JS - There’s also research suggesting that that in higher CO2 conditions, the pollen produced tends to be more allergenic.

ERL - Hayfever and asthma sufferers are looking for information and they also want to share what they’ve learnt. The Melbourne Pollen Count website and App allows people to help each other with their symptoms, and we’ve had over 26,000 responses since we created the app in 2012.

ERL - The Melbourne Pollen Count App demonstrates the power of citizen science. One of the great things about the website is the feedback from users. We can see where people have more hay fever symptoms, and correlate those symptoms with our pollen count data. The idea is that eventually all of this data will feed back into our research and help us refine our forecasts.

ERL - The Pollen Count is now being rolled out to other cities - Canberra, Sydney and Brisbane. There’s the potential to build up a truly national pollen count network.

EN - Europe has 600 pollen count sites - we don’t want to keep running off the smell of an oily rag.

JS - We’re now talking with people in Sydney about satellites and remote censoring. You can see how much grass is there, track plant growth and see when it starts to dry off.

ERL - This is a great example of where multi-disciplinary research is a necessity - and there’s so much more that can be done.

- As told to Shelby Oliver

Banner image: David Midgely, Laden with Pollen, via Flickr