INTRODUCTION
Alice Springs has a permanent population of about 27,000, and is situated in the Northern Territory of Australia. It is almost at the geographical centre of the continent. The town is an important centre for the tourism, pastoral, mining and defence industries. There are 500,000 tourists annually.
CENTRAL AUSTRALIAN ABORIGINES
The aborigines have lived in Australia for 40,000 years. There are several language groups within a 500 kilometre radius of Alice Springs. These include Arrernte, Walpiri and Pitjantjatjara, among others.
Peter Latz was a Senior Botanist with the Department of Parks and Wildlife of the Northern Territory. A non-aboriginal, he was born and raised in the aboriginal community of Hermannsburg, 120 kilometres west of Alice Springs. In his wonderful book “Bushfires and Bushtucker – Aboriginal Plant Use in Central Australia” (IAD press, 1995), he writes:
“Desert aborigines have a rich and complex social and religious life and a supreme confidence brought about by an intimate knowledge of the environment in which they live.”
More than $40 million has been invested in Central Australian businesses by aboriginal interests since the 1980s. These include commercial properties, pastoral properties, tourism, mining, media and transport. In 1989 it was estimated that one third of the total economy in Central Australia was derived from the aboriginal community.
THE CENTRAL AUSTRALIAN DESERT
Central Australia is an arid zone with an average annual rainfall of 250 mm (10 inches). Summer temperatures frequently exceed 40 degrees Celsius, and winter nights are cold with frosts.
The land is ancient, containing the oldest known rocks in the world. An inland sea in the past, Central Australia lies about 650 metres above sea level, with the massive Macdonnell Ranges running east and west from Alice Springs, and reaching heights of about 350 metres above the plain. One of the oldest rivers in the world, the mighty Finke River, runs north-south through the area. Dry for most of its length, apart from numbers of amazing permanent water-holes, the Finke River is in continuous flow only a few times per century.
This is not a barren, sandy desert, but an area with varied and often beautiful flora. There are distinct plant communities, which in simple terms can be classified as: 1) spinifex hills, plains and dunes 2) grassy foothills (native grasses and acacia) 3) watercourse woodlands, mainly Eucalyptus camaldulensis (river red gum trees) 4) mulga (Acacia) plains 5) salt bush (chenopod) plains 6) salt lakes.
I recommend that interested readers purchase a book called “The Centre – The Natural History of Australia’s Desert Regions” by Penny Van Oosterzee (Reed:1993). It is a beautiful soft-back book which is a winner of the University of NSW Press Science Book Prize. The text is outstanding and the photographs breath-taking. Inquiries can be made to William Heinemann Australia, Level 9 North Tower, Railway Street, Chatswood, NSW 2067.
The book by Peter Latz, referred to earlier, is superb, and is recommended as a detailed informative analysis of the flora in the context of the aboriginal plant use.
An excellent booklet while in the field is “Wildflowers and Plants of Central Australia” by Anne Urban (Southbank:1990). Inquiries can be made to Southbank Communications Group, Salmon and Lorimer Streets, Port Melbourne, Victoria 3207. It’s the book to take when you are exploring the central Australian bush.
ALLERGY IN THE CENTRAL ARID ZONE
Allergy, particularly hay fever and asthma, is a major cause of chronic illness in Alice Springs. What is the evidence for this statement?
Anecdotal or hearsay evidence. This is not scientific data. But speak to the locals. Everyone knows someone who gets severe hay fever from October to April (the hot and occasionally wet months). Pharmacists can run out of allergy medication at that time of the year. The local doctors are swamped with hay fever, sinus or asthma sufferers. Sports teams can be affected by illness due to allergies.
Medical evidence. When I worked at the regular allergy clinics in Alice Springs Hospital, they were packed. Two-thirds of the people attending suffered from hay fever and/or asthma. Most had positive allergy tests (skin tests) to pollens, and the common pollen allergy was to couch grass (Bermuda grass).
Research evidence. Support from the Joint Defence Facility, Pine Gap, allowed the completion of a research project on pollen allergy in the area. (Reference: Weiner JM et al. Allergy and asthma: their relation to pollen exposure in Alice Springs, Central Australia – Tucson re-visited? Allergy and Asthma Proceedings 1996; 17:115). Pollen counts were measured in Alice Springs during an 18-month period and very high pollen levels were noted from September to March. Sensitisation (allergy proved by skin testing) to couch grass (Bermuda grass) was common in the non-aboriginal population who had allergies. The Parks and Wildlife Commission confirms that the introduced couch grass is a major grass pollinator in the area and it grows extensively as a destructive weed.
Apart from couch grass pollen, there are other potential sources of allergy in the area. Buffel grass (not buffalo grass) was introduced in the 1960s to stop soil erosion around Alice Springs airport. It has spread widely throughout the Alice Springs region and it is a heavy pollinator. Little is known about its allergy properties.
Again, not much is known about the most native grasses and trees with respect to their allergy potential, with some exceptions. White cypress pine (Callitris spp) is known to cause allergy in New South Wales through the work of Dr Diana Bass, a Sydney allergist. This pretty tree grows along the higher ridges of the Macdonnell ranges. The she-oak or Australian Pine (Casuarina spp) occurs as a desert variety in parts of the arid zone. It is a beautiful tree, with a dark trunk and rather weeping branches, often growing in clumps of tens to hundreds. It is a known cause of allergies (even in Florida!), but there are not many in the immediate Alice Springs area.
Moulds are present in large amounts as evidenced from observations with the pollen research. Little is known about mould allergy in the area, but a large minority of patients with hay fever or asthma show allergy to mould on skin testing. Most houses have air conditioners or coolers which can contain mould in their filters.
People with hay fever and sinus problems from Tennant Creek (about 600 kilometres north of Alice Springs) are known whose only allergy has been to cockroach dust. This is a common and important allergy in the warm, humid and tropical areas.
Much of the time (not all the time), the weather is dry with low humidity. This is not the type of climate that promotes the house dust mite. Indeed Dr Euan Tovey from Sydney has shown that there are very few mites in the area. Nevertheless, there is a small minority (about 5%) of hay fever sufferers who admit to perennial (year-round) allergies, and tests show allergy to dust mite only. Aggressive anti-mite treatment (either reducing the mite or administering desensitising injections) helps most of these patients. This outcome is anecdotal and not based on a scientific study. It should be remembered that most of the population in Alice Springs has a doona, usually feather and down, because of the cold nights in winter. These may harbour mites, and further studies are needed.
What about other types of allergic diseases in Alice Springs? The whole range is represented, including food and insect allergy, and major allergy (anaphylaxis), just as in coastal Australia.
Allergy and asthma sufferers in Alice Springs should speak to their doctor about a blood test for inhalant allergy. The local doctors are very good and extremely experienced in the treatment of allergy and asthma. In many cases, allergy treatment can be helpful.
