Do nanoparticles pose big risk?

PROVIDENCE, R.I. — Those stain-resistant khakis you just picked up at the mall, the tennis ball that holds its bounce longer and sunscreen that's clear instead of white have something in common — nanotechnology.

Scientists manipulating matter at the molecular level have improved on hundreds of everyday products in recent years and are promising dramatic breakthroughs in medicine and other industries as billions of dollars a year are pumped into the nascent sector.

But relatively little is known about the potential health and environmental effects of the tiny particles — just atoms wide and small enough to easily penetrate cells in lungs, brains and other organs.

While governments and businesses have begun pumping millions of dollars into researching such effects, scientists and others say nowhere near enough is being spent to determine whether nanomaterials pose a danger to human health.

Michael Crichton's bestselling book "Prey" paints a doomsday scenario in which a swarm of tiny nanomachines escapes the lab and threatens to overwhelm humanity. Scientists believe the potential threat from nanomaterials is more everyday than a sci-fi thriller but no less serious.

Studies have shown that some of the most promising carbon nanoparticles — including long, hollow nanotubes and sphere-shaped buckyballs — can be toxic to animal cells. There are fears that exposure can cause breathing problems, as occurs with some other ultrafine particles, that nanoparticles could be inhaled through the nose, wreaking unknown havoc on brain cells, or that nanotubes placed on the skin could damage DNA.

The National Institute for Occupational Safety and Health is developing guidelines for working with nanomaterials, saying the tiny particles may raise health concerns and the risk to those who work with them is unknown.

Also unknown is the risk to consumers and the environment.

"No one knows, and that's the problem," said Pat Roy Mooney, executive director of the ETC Group, an Ottawa-based nonprofit that studies the impact of technology on people and the environment. "People are rubbing them on our skin as sunscreens and as cosmetics."

Mooney's group is calling for products, such as sunscreen, that are directly absorbed into the body to be taken off the shelf until there is more study.

"Frankly, I don't think that skin creams or stain resistant pants or food additives are a good reason to sacrifice someone's health," he said.