Tiny particles pose threat: scientists

Tiny particles in consumer products sold in New Zealand and around the world pose health and environmental risks and need to be tracked, scientists say.

Amid growing worldwide concern about the potential effects of nanoparticles, Kiwi scientists, academics and officials want the Government to introduce a labelling system identifying nanomaterials used in products on supermarket shelves and to maintain a public database of nanoproducts.

Nanoparticles are about 1000 times smaller than the width of a human hair and are used in more than 800 consumer products, including cosmetics, sunblock, clothing, food, washing machines and refrigerators.

A report on the opportunities and drawbacks of nanotechnology has just been published by the Ministry of Research, Science and Technology. It lists more than 70 actions the Government should take.

Report editor and University of Canterbury physicist Simon Brown told The Press that apart from nanotechnology's obvious advantages in the computer and electronics world, there were known and unknown hazards.

There was a strong sense the Government had yet to face up to nanotechnology.

"My impression is they're keen to work on the issues, but their departments don't see it as a priority.

"Fundamentally, it's been well-established that some nanoparticles cause negative health impacts. We know that certain nanoparticles cause cancer, damage to genes, and can accumulate in your brain if they get into your body.

"How should we regulate new products when there is a lack of clarity about the risks? And how do we balance the benefits and risks?"

Silver nanoparticles used in disposable nappies were an example of the possible risks.

"Do they accumulate in sewage ponds, which may stop them breaking down the sludge because they are antibacterial, or if it is then used as fertiliser, is it possible those nanoparticles will accumulate in those plants that grow?"

Another example of unintended consequences had been found in Australia, where sunblock containing nanoparticles used by roofing workers had been shown to cause unpredicted chemical reactions when it fell on to a roof, prematurely corroding the iron.

"It is this potential for the unexpected that makes this difficult to deal with. There's not just the potential for health and environmental risk, but a business risk too.

"Labelling gives people a choice and instils a bit of discipline on the system, but it's not a solution in itself. The worst thing we can do, which is what we're doing at the moment, is sit around and do nothing," Brown said.

- © Fairfax NZ News