Thursday, August 14, 2008

Are you eating arsenic with your picnic?

The article below from an Australian sociologist shows some restraint but omits entirely to note the central truth of toxicology: That the harm lies in the dose. The amount of arsenic ingested under the circumstances concerned would be extremely small. For context, note that arsenic was up until not long ago widely used in medicines, so its toxicity results only from a fairly HIGH dose.

The article also makes no mention of why CCA treatment is done. Could it be a scheme by evil businessmen? No: "Wood, such as radiata pine, is treated with CCA to prolong its life. CCA is used for the `control and prevention of damage to timber and timber structures by insects, wood rot, wood fungus and general timber decay. CCA is generally used on wood intended for outdoor uses, such as telegraph poles, decking and fencing, in landscaping, and in building structures'. It is also commonly used in playgrounds, children's cubby houses, public picnic tables, garden edgings, handrails, boat bulkheads, dock pilings and vineyard stakes. CCA-treated timber can often be identified when it is new by its green tinge but this fades with time"

So it would be costly to cease such treatment and would require a lot more trees to be felled in order to replace the timber more frequently

They're panicking in Indiana, US. When TV news show 13 Investigates tested the surface of picnic tables there recently, it found high levels of arsenic. Now, thousands of picnic tables are being removed from parks or painted with an oil-based stain. The picnic tables are made of timber treated with copper chrome arsenate (CCA), used in most of Australia's park picnic tables. Should we also be panicking?

Scientists have demonstrated that arsenic leaks out of CCA-treated timber, even 20 years after it has been treated. It is also known that exposure to arsenic can cause cancer. According to the World Health Organisation [A UN body and a prolific fountain of nonsense], arsenic is a known carcinogen and is acutely toxic. It can cause lung, bladder and skin cancer, as well as reproductive and neurological problems.

But is there enough arsenic in Australian picnic tables to cause such dire consequences? We don't really know because no one has done wipe tests. Without such data, and given the high levels of arsenic found by such studies overseas, can we be complacent about the risks involved? Some nations have taken a precautionary approach. CCA-treated timber has been banned altogether in Switzerland, Vietnam and Indonesia and severely restricted in Japan and Europe. In 2005 the Australian Pesticides and Veterinary Medicines Authority cancelled the use of CCA for treating timber destined for garden furniture, picnic tables, exterior seating, children's play equipment, patio and domestic decking and handrails.

But should we be worried about the picnic tables (and play equipment) already out there in our parks and on our beaches? Should our councils be allowing parents and children to eat food off treated timber picnic tables that could be coated in arsenic? People can be exposed to arsenic through touching CCA-treated timber because surface arsenic sticks to human skin. It then can be transferred to the mouth, for example by subsequent handling of food. It also can be transferred to the mouth by eating food placed directly on CCA-treated surfaces.

Yet how many people think twice about eating off council picnic tables? Surely that is what they are there for? The APVMA claims it has no power to control how people use the structures made from CCA-treated timber. It is local councils that control the ongoing use of existing picnic tables. Local councils may be comforted by the fact that picnic tables have been around for many years and no one has yet set out to prove that they got cancer from them.

But who would dream that their lung or bladder or skin cancer might have been caused by eating off picnic tables in their youth? Especially given that Australian authorities didn't admit to the potential problem until recently. The lack of past lawsuits will not provide comfort to the wider community. Perhaps only tests showing picnic tables are arsenic-free will do that. Otherwise there might be good reason to follow Indiana park authorities and do something about all those picnic tables.


New pill to offer respite from the common cold

A PILL to cure the common cold has been developed by scientists. The holy grail of cold research, it could be used to clear up sniffles in healthy people and prevent life-threatening infections in asthma and cystic fibrosis sufferers. Trials on hundreds of British volunteers started yesterday. If successful, the cold-busting pill could be on the market in five years. Effective against the bugs that cause half of colds in adults and almost all colds in children, it could net its Australian creators billions of dollars a year.

The drug, which is known as BTA798, latches on to cold-causing human rhinoviruses (HRV), preventing them breaking into the body's cells and causing infection. In a double-pronged attack, it also stops any infection that has taken hold from spreading. In lab tests, the drug killed large quantities of cold virus within a couple of hours. The first limited human trials finished last year and showed BTA798, which is being developed by the Victoria-based Biota Holdings, to be safe.

Peter Cook, the company's chief executive officer, hailed the results as a significant milestone in the development of what could be a world-first anti-viral treatment for HRV in high-risk patients. Larger-scale trials are now under way to determine whether it can actually prevent people from catching a cold. Two hundred healthy people will be given the drug or a dummy pill before being exposed to human rhinovirus. Three different doses of the drug will be used, in order to determine which, if any, can keep the infection at bay.


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