When is a little dioxin too much dioxin?
Dioxin is a persistent organic pollutant (POP) that accumulates in the food chain and is highly toxic to living systems. The Stockholm Convention on Persistent Organic Pollutants commits signatories to ‘reduce or where feasible, eliminate the production and environmental release’ of dioxin.
So we know that dioxin is not a good thing to be releasing into the environment. And we also know that particular human activities, such as the smelting process that produces certain metals and chlorine bleaching of wood pulp in the paper industry produce dioxin. The question is when is it ‘feasible’ to eliminate the production and environmental release of dioxin?
“Feasible”, that is an interesting word. It is a wriggle word. A word that allows us to avoid doing what we all know we should be doing. Is it ‘feasible’ to avoid the production and environmental release of dioxin? Consider the two examples above. Smelting produces dioxin. If we could produce certain metals without producing dioxin surely that would be a good thing. I don’t know much about the smelting process, but I do know we need metal. The modern world would grid to a halt without metal. So if we can’t produce certain metals without producing some dioxin perhaps we will have to live with environmental releases of dioxin related to the smelting process. Perhaps some dioxin production is a necessary evil.
But dioxin produced in the paper industry through the bleaching of wood pulp is a completely different matter (I know little bit more about bleaching wood pulp). Dioxin is produced in the bleaching process because chlorine in some form is used. Chlorine bleaching produces ‘very bright’ paper and other processes that don’t use chlorine produce ‘less bright’ paper (there are other differences, but the reason chlorine is used is for its bleaching role in the process). Now the ‘feasibility’ of eliminating dioxin release in the case of paper pulp seems to me like a no-brainer. It is feasible to produce paper without producing dioxin, end of story. I might not be able to get by without metal, but I certainly can get by without bright paper.
So it amazes me that pulp mills that use some form or chlorine bleaching process are still being planned and built. Surely the health of present and future generations of humans (let alone other species) is more important than having access to bright paper! Therefore, given what we know about dioxin, we should stop planning and building pulp mills that use chlorine of some sort to bleach paper pulp. This really does seem obvious to me, but not to everyone. Today a pulp mill that will use a chlorine bleaching process (Elemental Chlorine Free) has approval to be built and operated in the Tamar Estuary in northern Tasmania, Australia. As soon as the forestry company, Gunns, obtains funding building will commence.
Now for the record, the Australian Government has set maximum limits for the monthly average effluent concentration of dioxin (and furans) from the mill at 3.4 pg TEQ/L (TEQ is a standard measure of toxic equivalence). And I am the first to admit that 3.4 picograms (10-12 grams) is not much, but why should we be allowing the release of any dioxin into the environment just to have bright paper? I simply don’t get it. I for one am very happy to live without bright paper! Maybe I am missing something, but bright paper is not a necessity, is it a luxury. And I don’t want to increase the dioxin load of the planet just so I can have the luxury of bright paper. It just does not seem fair to future generations!
The Tasmanian community is deeply divided over the proposed pulp mill. Some believe that it will be the economic saviour of the state, while others think it will be an environmental disaster. In response to the proposed pulp mill a range of Australian academics have undertaken a detailed analysis of the environmental impact of the proposed Tamar Valley pulp mill (including an analysis of the ethics of sustainable development). This analysis is presented in a soon to be released book entitled: Pulp Friction in Tasmania: a review of the environmental impact assessment of Gunn’s proposed mill. The book is edited by Fred Gale and is available to order by emailing info@pencilpinepress.com. Details of the book are available at http://www.pencilpinepress.com/ (cut and paste this address into your internet browser).
3.4 picograms (10-12 grams) is still ten million dioxin molecules(TEQ), (in fact hundreds of millions of dioxin congenor molecules) in every litre of effluent. These all have the potential to bioaccumulate as they pass up the food chain. Putting discharge limits on biaccumulative chemicals is stupid. You have to turn off the tap- chlorine free pulp- to solve the dioxin problem
That is a good point, Gordon, thanks.
I often find myself, perhaps quite understandably, thinking on the scale of mid sized objects like, trees, and animals and humans. After all, our cognitive systems evolved to help us interact with such mid sized objects. But, as the case of 'germ theory' in the history of medicine demonstrates, something like bacteria, invisible to the human eye, can and must be taken into account in the management of human health. Just because it is small and we cannot see it does not mean that we can ignore it.
The lesson we have learnt in human health management is yet to be learnt in environmental management. And as you correctly point out, just because it is only a 'small amount' of dioxin does not mean that it is doing no damage. The challenge for humanity is to understand nature not only on the human scale, but also on the very large scale and, equally importantly, on the very small scale.
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