Scientists herald nanotechnology as the first major scientific revolution of the 21st century, which could open a world of wonders for humanity, researchers at a bioethics think tank at the University of Toronto said on Thursday.

Its applications include everything from nanorobots, or nanobots - tiny machines that could travel throughout the body destroying viruses or cancer cells - to data storage systems the size of a sugar cube, which could hold virtually everything ever published.

But those opposed to the technology argue that there could be severe environmental damage, including the release of nanomaterials that could create illnesses not seen before.

Some critics outline a scenario where trillions of self-reproducing nanobots take on a life of their own and reduce our planet to a massive "grey goo" - a theme popularized in Michael Crichton's recent novel "Prey".

"The scary scenarios are the ones that will undermine public confidence and support of nanotechnology," said Dr. Abdallah Daar, director of the Joint Centre for Bioethics at the University of Toronto, who is also co-author of the study published in the British journal "Nanotechnology".

"We see a widening gap between the science and the ethics. The backlash is already gathering momentum and we've seen calls for a moratorium," said Dr. Peter Singer, who is also director of the bioethics center and a co-author of the study.

A Winnipeg-based organization called ETC Group has proposed a moratorium on commercial production of nanomaterials. It wants a global process to evaluate the socioeconomic, health and environmental implications of the technology.

ETC estimates nanotechnology will create an economic "revolution" worth a trillion US dollars by 2015 in virtually all sectors of the economy, but poses a fundamental question: "Who will control nanotechnology?"

"We're moving toward a showdown of the type we saw in genetically modified crops," Singer told Reuters. "That would be very unfortunate because the potential benefits of the technology might be prematurely and inappropriately rejected."

Daar and Singer's study calls for a closing of the gap between the science and the ethics. It argues that if the ethics debate does not speed up, the science and research are going to get slowed down.

"What we're saying is that we don't want a moratorium," Daar said. "We need to discuss realistic applications, not scaremongering."

Applications of nanotechnology include removal of greenhouse gases cheaply and efficiently by rearranging the molecules into harmless or even beneficial substances.

Molecules could also be manipulated into creating materials like steel, but would be 100 times stronger and much lighter, or a protective spacesuit that fits better than slacks and a sweat shirt.

The study suggests there should be an appropriate level of funding for research into the ethical issues of nanotechnology and that scientists and activists should interact more.

In addition, developing countries should also be involved in this debate lest they be left behind, creating a new scientific divide similar to the technology and genomics divide that already exists.