Editorial

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The development of coal seam gas extraction in Australia has been likened to a latter-day gold rush, which is as much a comment about the speed with which derricks have begun to appear across the country as it is about the profits that have been turned by the energy companies involved. The rush - which is centred mostly in rural NSW and Queensland - has also been fuelled by the supposed environmental benefits of burning gas rather than coal to generate electricity. That has not been conclusively established, but so well established is coal seam gas' reputation as clean and green that government and industry have had little trouble down-playing concerns about the safety of the drilling process - known as fracking.

However, the appearance of drilling rigs close to regional towns, and the likelihood that they could soon encroach on the suburbs of south-western Sydney, has changed this dynamic. In response to growing community and political concerns, the NSW government announced this week that drilling would not be permitted within two kilometres of residential areas and that similar exclusion zones would apply to wine-producing and horse-breeding areas. It follows a similar move by the Queensland government.

Mr O'Farrell's announcement is unlikely to lead to environmental activists packing up and moving on, however. In fact, it's possible the ban may cause them to redouble their efforts to have coal seam gas mining excluded from entire areas such as the horse-breeding and wine-growing districts of the Hunter Valley. Their concerns rest on the long-term impacts of coal-seam gas extraction, particularly with regard to aquifers and water systems. According to the National Water Commission, fracking (the injection of fluid under high pressure into rock strata to liberate gas) can lead to a ''dramatic de-pressurisation of coal systems''. This has the ''potential to induce connection and cross-contamination between aquifers, with impacts on groundwater quality'' and water availability generally.

Supporters of coal seam gas extraction have always minimised such risks. The absence of information about the long-term environmental impacts of fracking does not support their insouciance, however. Opening up areas like the Hunter Valley and Gunnedah Basin to wholesale fracking will deliver a dividend to energy companies and governments, but that dividend will be short lived. In doing so, however, we may compromise the long-term viability of these reliable and productive farm regions, of which Australia has few. The case for exploitation looks even more threadbare when one considers Australia has plentiful supplies of natural gas on the North-West shelf.

Healthy diet clarity

Those who value their health know there is a veritable truckload of information and advice on what constitutes a sound diet and what does not. The job of sifting through this information is frequently complicated by the publication of new evidence that overturns or debunks apparently well-established views. The net effect of this disagreement on what foods should be included in dietary guidelines (and in what proportion) is to completely bamboozle and confuse consumers.

The National Health and Medical Research Council's new Australian dietary guidelines will provide some clarification. The guidelines are a development of the NHMRC's 2003 benchmarks, and are based on a review of 55,000 pieces of scientific research and the modelling of 100 dietary patterns. Much of the advice, reassuringly, is little changed from 2003. People are still encouraged to eat plenty of vegetables and fruit, wholegrain foods and legumes, lean meats and fish and reduced-fat dairy products. There are, though, important changes of emphasis, particularly regarding fat. While advising that low-fat diets are not suitable for children under the age of two, the guidelines stress the need to reduce foods high in saturated fats. For those partial to high-fat foods, the guidelines recommend their substitution with foods containing predominantly polyunsaturated and mono-unsaturated fats such as (olive) oils and avocado.

The advice regarding the consumption of sugar, salt and alcohol remains more or less unchanged: limit your intake. And in order ''to achieve and maintain a healthy weight, be physically active''. With more Australians than ever battling weight problems, the importance of these updated guidelines cannot be overstated.