Page 19 - PR Mag Sep18

POLLEN COUNTING

is not something to be

Sneezed at

AUTHORS: Ed Newbigin, Associate Professor of Botany, University of Melbourne & Janet Davies
Senior Research Fellow, Lung and Allergy Research Centre, The University of Queensland

Ah, spring, the sun shines again, the birds sing and - ach-hoo! Airborne peaks in November. And it’s no coincidence this is also the peak time for
grass pollens trigger bouts of hay fever and episodes of asthma in sales of the oral antihistamines.
people with pollen allergies. Knowledge Network
But there is a way we could mitigate the impact of the season - pollen Pollen counting can tell us how much grass pollen is in the air on a
counts. These work in the same way as summer UV alerts, by telling us particular day. By combining this information with the weather forecast,
when there’s enough of something around to cause health harms. we can predict grass pollen levels for the next few days.
And this helps manage the impact of UV or pollen by giving us Knowing the grass pollen forecast can help people allergic to grass
time to prepare, by wearing UV protection, for instance, or taking pollen plan ahead. But before you can forecast pollen levels for a
antihistamines. But while this sounds like a good idea, most places in particular place, you need to have a few seasons’ worth of counts under
Australia don’t have a pollen count, so those of us with allergies are left your belt so you know how weather patterns affect pollen levels locally.
to our own devices. Unfortunately, Australia has very few pollen counting stations and most
Pollen and Health operate only sporadically. The lonely exception is Melbourne’s pollen
Let’s talk first about how pollen affects health. Hay fever is the most count, which has been running consistently for over 20 years.
obvious example. This makes a stark contrast with Europe, where a network of more than 600
According to the 2007–08 National Health Survey, hay fever affects one pollen counting stations operates throughout the northern allergy season.
in six Australians, severely impairing their quality of life by making sleep That’s from early spring, when the trees flower, through to early autumn
difficult and causing them to under-perform at work or school. when weeds, such as dock and mugwort, flower.
Hay fever is strongly associated with asthma; more than 80% of allergic The network operates efficiently across several countries and languages.
asthmatics also have hay fever. Asthma costs the Australian community And a similarly large network of stations operates across North America.
over $700 million annually and this impact has made it one of the Australia’s lack of a pollen count network is surprising and means we often
country’s national health priorities. guess at things we really should know. For instance, we suspect Australia’s
Asthma and hay fever are caused by our immune systems responding allergy season will be relatively simple to track compared to Europe’s, as we
inappropriately to substances in the environment that are not harmful. mainly have to contend with grass pollen.
These are known as triggers. But subtropical grasses that flower in summer are abundant in northern
Hay fever triggers cause the lining of the eyes, nose and throat to parts of Australia adding to the burden of hay fever. Right now, we don’t
become inflamed, producing the typical symptoms of sneezing, itchy have a way of quantifying their role in the hay fever and asthma experienced
eyes and a runny nose. Asthma triggers cause the lining of the small by the population.
airways of the lung to swell, making it harder to breath. Knowledge and the Power to Help
Free Like the Wind Melbourne’s pollen data has been vital for understanding how grass pollen
Pollen from certain wind-pollinated plants is the main asthma and hay in the air influences hospital admissions for asthma. It seems ridiculous that
fever trigger in the outdoor environment. The plants in question use we don’t know this for all Australian cities.
wind to transport their pollen between plants, rather than relying on Not only do we need a network to monitor pollen, we need to be able to
insects and birds. link it with weather forecasts for it to become a predictive tool.
Because they don’t need to attract animals, the flowers of wind- On November 25, 2010, Melbourne’s ambulance service was overwhelmed
pollinated plants are rather dull in comparison to the bright, showy with a massive number of calls from people with acute respiratory problems
flowers of animal-pollinated plants. because of thunderstorm asthma.
But what they lack in colour, wind-pollinated plants more than make up Thunderstorm asthma occurs when there’s a thunderstorm during a
for with prodigious pollen production. A single plant can release untold high pollen count period. Prediction of pollen-induced epidemics of
millions of pollen grains into the air. thunderstorm asthma could help hospital emergency departments
While Australia’s native plants are generally not wind-pollinated, prepare for such events.
many introduced plants are. These include trees from the northern This is only one of the many ways a national pollen count network could
hemisphere commonly found in gardens and along suburban roads, help improve public health throughout Australia. We just need to join the
such as birch, elm, and ash. rest of the developed world and start gathering data that can inform us
But the worst plants by far for pollen allergies are grasses. Perennial about what to do.
ryegrass is a valuable pasture grass planted across vast areas of southern
Australia. By sheer weight of numbers perennial ryegrass pollen is
Australia’s number one outdoor allergy trigger.
Flowering of perennial ryegrass across much of southern Australia

September 2018 www.pineriversqld.com.au 19