Our health and our environment

As a Brisbane GP a large part of my life has been spent helping people with common health issues such as chest infections and minor injuries, a growing list of chronic diseases, the occasional emergency, and those very serious conditions that don’t simply interfere with life but can take it away altogether.

Away from the clinic, I have always been interested in our wonderful natural surroundings and wildlife and, increasingly in the many threats they face from environmental degradation.

Recently, I have become much more aware that many of the problems I see as a doctor and the ones I am concerned about as a citizen are closely linked. Here are just four examples, showing that sound public policy, as well as a doctors' skills, will be needed if we are to prevent more environmentally-caused health issues in coming decades.

Respiratory conditions

I see many patients with respiratory diseases, such as asthma, bronchitis, and - increasingly - a progressive inflammatory condition of the lungs called chronic obstructive pulmonary disease (COPD). This disease is predicted to be the world’s third biggest cause of death and the fifth leading cause of disability by 2020. It used to be thought that cigarette smoke was responsible for almost all COPD in developed countries, but it’s now recognised that pollutants, including the fine particles from vehicle exhaust, make an important contribution.

Brisbane’s air quality is generally very good, but at three of the five Brisbane monitoring sites the national standard for fine particles was exceeded last year. Traffic volumes for Brisbane are forecast to be 46 per cent higher than 2005 levels by 2020. It will be very hard to control vehicle pollution without tougher emissions standards, greater uptake of electric and hybrid vehicles, more freight moved by rail, improved public transport, and more flexible work arrangements to reduce unnecessary commuting.

Seafood

Many of my patients consciously include fish as part of a balanced diet. We love our seafood and recognise the benefits of the low fat levels and plentiful Omega 3 fatty acids that many seafoods contain. But now there’s not only a collapse in global fish stocks, there are also serious threats to the stability of the world’s marine ecosystems, as recently reviewed by the University of Queensland’s own Ove Hoegh-Guldberg (Science, June 18). These include increases in surface temperatures, higher levels of acidity, reduced complexity of marine habitats, loss of native and the spread of sometimes harmful exotic species.

There are also concerns about the accumulation in crustaceans, fish and marine mammals of various organic chemicals and heavy metals such as cadmium, chrome and mercury.

Unfortunately, some of these effects can be compounded by changes in salinity levels, water temperature, and the amount of oxygen in the water, but we have only the sketchiest understanding of these processes. What we do know is that we can only expect seafood to remain safe for human consumption if we ensure the marine environment is healthy.

Heatwaves

We love our sub-tropical climate and it does allow us to enjoy an active outdoor lifestyle year-round. South-east Queensland temperatures are not the most extreme in the country, but we all know the discomfort of a prolonged hot spell. While many can retreat to air conditioning others, particularly the elderly, the unwell and the poor, can succumb to extreme temperatures.

Last year, Victoria’s State Coroner attributed an extra 374 deaths to the January heatwave. Hospital admissions for heart attacks, for example, have been shown to increase by more than a third if the average temperature is above 27C for three days in a row.

The Bureau of Meteorology reports that in the last half century eight of the top 12 years for the number of “very hot days” have occurred since 2000. More heat-related deaths are almost inevitable in coming decades and the failure of governments to put a price on carbon will extend and worsen this effect of climate change on human health.

Dengue fever

I am a GP the Brisbane suburb of Alderley. It was in 1905 that another Alderley GP, Thomas Bancroft, first demonstrated that this disease is spread by the Aedes aegypti mosquito, a story beautifully described by QUT’s John Aaskov. A century later, Dengue is making a comeback, and we have seen outbreaks in Townsville, Cairns, and elsewhere along the Queensland coast.

With climate change, Brisbane’s climate may become more tropical, and we will need to work hard on a range of prevention and treatment options if we are to remain free of this debilitating condition - and potentially, other tropical diseases.

These links between human health and environmental degradation are complex, long-term, and we still have much to learn about them. And, of course they are not the only issues we face. What we should understand, though, is that your GP is powerless to stop these trends. What will make a difference is an informed public, a properly supported research community, and far-sighted, serious, and honest political leadership committed to keeping our world liveable.