Inside every one of us, as we go about our daily lives, is a personal burden of toxic contamination - volatile chemicals, heavy metals and other substances which are the legacy of 150 years of development. The health consequences for individuals are unknown and maybe unknowable, but scientists are certainly concerned this cocktail of pollutants may be playing its part in the contemporary pandemic of cancers and chronic disease.
We know that these substances - in particular persistent organic pollutants (POPs) - have spread from the equator to the poles, and are to be found even in societies and wildlife far from urban centres, where they exist all around us, in our soil, groundwater and air. While impossible to estimate accurately, there are probably around 10 million contaminated sites worldwide: a third of them in Asia, 100,000 of them in Australia.
The issue is what Australia can and should do about this problem, both as it affects our own backyard and also as it affects our neighbours, many of whom are only now just starting to pass through the most contaminating phase of their development.
The answer is to turn a problem into an opportunity by making our next phase of development the cleanest in history and, in the process, providing solutions for others. Australia is already well down this track. Our researchers in publicly funded institutions and industry are coming up with some of the smartest solutions to this apparently intractable problem yet seen.
Until recently, if serious contamination was found, there were usually only three answers: fence it off, seal it in (if possible), or dig it up and move it somewhere else. None of them very satisfactory or permanent.
Now there is a fresh approach, in which Australia has played a significant global pioneering role: risk-based land management. This involves finding out exactly what pollutants are down there, how dangerous they are and whether they can get into our water, food supply and our bodies by various pathways. Where pollutants are tightly bound into soil matrices and are not present in a form that enables its transfer from land into water, crops or human, the sites may be declared safe. Such an approach is now being recognised worldwide.
Previously if arsenic was found, everyone assumed it was highly toxic. But arsenic can exist in several different forms where the toxicity varies considerably. Then it depends whether the arsenic is mobile - able to get into our bodies by some means - or is tightly bound to clay or some other substance, in which case it is far safer. The new approach calls for a close assessment of the contaminants and the nature of the site, and then for a specially-tailored approach to make them safe, at a much lower cost than conventional methods.
Heavy metals, for example, can be removed by using certain plants and trees to absorb them through their roots. Or we can use electrical energy to attract them to an electrode and so remove them. Or we can create “designer” clays to lock them up so they pose no threat. Similarly with organic chemicals like pesticides and fuel residues, which can be broken down using the soil’s naturally-occurring bacteria, with specially-bred bacteria, with plants, fungi, oxidants, filtration and mechanical processes.
Techniques like these helped make Sydney’s Homebush safe enough for the 2000 Olympics. And similar methods can turn low-value urban “waste-land” into multi-billion dollar development sites safe for residential, recreational or office use - a huge return on the nation’s most valuable real estate.
The export opportunities are greater still. Every country in the world is plagued with contamination from the past, some natural but mostly man-made. Asia alone has an estimated three million sites in need of treatment - and more appear every week as development using old technologies accelerates.
Australia’s opportunity is to help make these sites safe. It is also to instill a philosophy of “zero waste” where we use or make safe every single thing that comes out of our production systems. This is the core of a major new export industry.
Just as health care, education and mining services have become billion-dollar export sectors, the knowledge of how to clean up our living environment and keep it clean, is a priceless advantage in a world of headlong economic development. Australia today is ahead of the game. We are alert to the problem, we have some outstanding technologies, we have industries which are highly alert to the need for clean production and we have a regulatory system which is devising some of the world’s best rules to combat contamination. It’s a potent package for a cleaner future.