Grass and tree pollens are a major cause of allergy in Australia. About 30% of the population is allergic to these tiny packets of concentrated protein which are so light that they are carried by the wind. These pollens cause seasonal hay fever and seasonal asthma. Which season? Usually spring and early summer, but in some cases, the allergy can start in late winter or extend through summer.
The pasture grasses and weeds are the worst offenders. These include perennial rye grass (Lolium perenne), couch or Bermuda grass (Cynodon dactylon), plantain (Plantago species) and paspalum (Bahia species), as well as many others. The main allergenic trees are cypress and pine. There is increasing recognition of the importance of other exotic plants such as silver birch, olive, privet and pellitory in certain parts of Australia. Flowers may irritate or cause asthma because of their strong scent, but are rarely, if ever, the cause of pollen allergy. Native shrubs and trees are not a common cause of pollen allergy. The wattle tree (Acacia) and ti-tree (Melaleuca) can lead to problems, but the pollens are not wind-blown very far, and you have to get close to the trees to get symptoms. The worst areas are is south-eastern Australia, and Melbourne is one of the worst affected cities in the country. Why? Because Melbourne has millions of hectares of grassland to the north, and spring in Victoria is characterised by hot, gusty northerly winds. These carry the pollen over Melbourne. Then things get really interesting. Melbourne can get very polluted, as it is a large city (three million people) with a huge number of cars. And there is a lot of industry, particularly to the west. This type of pollution has been shown to increase allergies.
Also, the frequent cool changes during spring bring rain-storms, and the moisture actually ruptures the pollens, causing the release of huge amounts of allergy material. This can lead to epidemics of asthma in Melbourne (thunderstorm asthma), and admissions to hospital for asthma can increase 30-fold! What about other cities. Canberra is very bad, due to its geography, and the large amount of exotic (non-native) plants in the city. Other southern cities (Adelaide, Perth) and Tasmania are bad, including all points in-between. The further north, the less the pollen problem, but each city has its own peculiar seasonal allergy.
Alice Springs in Central Australia is, in my opinion, the WORST place in Australia for pollen allergy (please read the information sheet on allergy in Alice Springs).
Avoidance of the pollens is almost impossible. Apart from drug treatment, allergy injections often help (see the information sheet on allergy injections). There is also an oral vaccine available (no needles!) which is excellent. Our clinic uses the oral vaccine almost exclusively. Pollens are OFTEN a major cause of asthma attacks in Australia.
