A world with stronger building structures, vegetables that grow faster, and more effective medical treatment - this is what nanotechnology has promised, and to some degree delivered.

Dr Saji George, a senior lecturer at Nanyang Polytechnic's School of Chemical and Life Sciences, wants to make sure these advantages are not negated by the tiny particles' harmful effects on humans.

Nanotechnology is the science and art of manipulating structures as small as a billionth of a metre, and harnessing the special properties they have at those scales.

Such particles are so tiny that it would take some 100,000 of them to make up the width of a human hair.

Being very tiny means the biological responses they induce in us are very different from those of the materials we are familiar with, and this could sometimes make them toxic to human health, said Dr George.

Gold, for example, is typically inert - it does not react with the human body even when swallowed.

At the nano scale, however, gold particles can penetrate the different layers of tissue barriers, and could become toxic. This happens with other nanomaterials as well, and there are growing concerns that nanoparticles could cause problems like organ damage and cancer.

This is why the 37-year-old is studying how nanomaterials interact with the human body, focusing on the use of nanomaterials in food and agriculture.

Growing up on a farm in Kerala, south India, Dr George was exposed to science and its relationship with agriculture from a young age. He describes his father as a farmer who had the outlook of a scientist.

"He would understand the pest or plant pathogen, and then find a remedy for that. His farm was always better than his neighbours' farms.

"So I knew if you understood the science behind a problem and found a way to solve it, you could make a difference," Dr George said.

His quest to understand nature and the environment has taken him from farm animals to microbiology, and now to nanotechnology.

He studies nanomaterials such as zinc oxide and titanium dioxide nanoparticles, which are found in personal care products and food, and used to enhance the growth of plants like corn.

His research projects include using nanomaterials to deliver a vaccine into fish gills, removing the need to inject them individually, and studying the nanomaterials in outdoor and indoor air.

"Whether we like it or not, we are now eating and breathing nanomaterials," he said.

Researchers estimate that people living in urban areas are each exposed to a trillion nanoparticles in their food every day.

Dr George believes that if you cannot avoid contact with nanomaterials, then what is most important is to make sure they are safe. To determine this, a person needs to consider both the toxicity of the material and his degree of exposure to it.

To this end, he and his team at Nanyang Polytechnic are developing a catalogue of nanomaterials with information on their potential applications and potential toxicity.

"We want to develop sustainable nanomaterials - both economic (economically viable) and safe."