People around the world are constantly exposed to nanoparticles mostly emitted by vehicle exhaust, but the risks are greater in crowded Asian cities, which are seeing a dramatic rise in the number of vehicles on the roads.
In the study — the results of which were published on 26 April in ACS Nano — healthy volunteers exposed to gold nanoparticles were shown retaining them in the body for as long as three months. Experiments on mice also reveal that nanoparticles accumulate in the liver and blood vessels.
“Vehicles contribute up to 90 per cent of the total in polluted environments such as busy roads.”
Prashant Kumar, University of Surrey
Gold particles detected in surgical specimens of diseased carotid artery from patients at risk of stroke and at sites of vascular inflammation, under the study, may explain the link between environmental nanoparticles and cardiovascular disease, the researchers say.
While the study was conducted with gold nanoparticles, the researchers believe that the results can be extended to nanoparticles in vehicle exhaust. “This is something we are investigating further in our current research,” says Mark Miller, senior research scientist, University of Edinburgh, UK, and the corresponding author of the study.
Nanoparticles in ambient air come from both natural and artificial sources, but vehicles are the main culprit says Prashant Kumar, professor of air quality and health at the University of Surrey. “They contribute up to 90 per cent of the total in polluted environments such as busy roads,” he says.
In Europe, tighter emission norms have reduced the number of nanoparticles emitted by diesel engines. However, the situation is different in developing Asia Pacific countries where older vehicles are still widely used, and the burning of solid fuels for cooking already adds to particulate matter in ambient air. Nanotechnology is expected to touch human lives in many ways, but the risks associated with new engineered nanomaterials are poorly understood.
“A comprehensive toxicology screening needs to be performed with all new nanomaterials, especially with attention to the cardiovascular system,” says Miller.
This piece was produced by SciDev.Net’s Asia & Pacific desk.