A vast and rapidly expanding array of engineered nano-products are flooding the consumer market unregulated as evidence of toxicities accumulate. First cases of nanotoxicity occupational exposure

Seven young women (aged 18-47yrs) working in a paint factory and exposed to nanoparticles for 5-13months fell ill and were admitted to hospital. Two subsequently died. Pathological examinations of the patients’ lung tissue showed nonspecific inflammation, fibrosis and foreign-body granulomas (tumours resulting from inflammation) of the pleura (membrane around the lungs). Transmission electron microscopy revealed nanoparticles of polyacrylate lodged in the cytoplasm and the nucleus of cells and in the chest fluid. The polyacrylate nanoparticles were confirmed in the workplace.

These first suspected cases of nanotoxicity from occupational exposure have heightened concerns over the huge and rapidly expanding array of nanotechnology products in the market that remains unregulated despite accumulating evidence that many nano-ingredients, including those most common in commercial use, are indeed toxic. Common nano-ingredients are toxic

Nanotechnologies are technologies at the scale of nanometres (10-9m), where new quantum effects can alter the chemistry and physics of elements and compounds, offering exciting new possibilities in industrial applications, and for exactly the same reasons, posing unprecedented risks to health and the environment.

It was difficult to separate hype from reality when it all began, and almost no one worried about safety and nanotoxicology became established as a discipline in 2005 (Nanotoxicity: A New Discipline, SiS 28). By then, many serious health impacts had already been observed in laboratory experiments; and more appeared in subsequent years.

In 2009, researchers at University of California Los Angeles Jonsson Cancer Center led by Robert Schiest reported that titanium dioxide nanoparticles (TiO2), found in “everything from cosmetics and sunscreens to paint and vitamins” (see Box), caused DNA damage when fed to mice. They induced breaks in DNA, damaged chromosomes, and caused inflammation of tissues; “all of which increase the risk of cancers.”

The mice were exposed to the nanoparticles in their drinking water, and genetic damage started showing up on the fifth day, equivalent to occupational exposure in humans of 1.6 years. Once taken into the body, the TiO2 nanoparticles accumulate in different organs because the body cannot eliminate them, and they are so small that they can go everywhere.

These latest findings confirm the results of numerous other studies indicating that nano-TiO2 increases cell death, DNA damage, and genome instability in the short-term and the risk of cancer in the longer term. A team of researchers at several institutes in Taiwan showed that exposing mammalian cells to TiO2 nanoparticles at 10 ppm in the short-term (days) resulted in enhancement of cell growth and survival, and increase in reactive oxygen species (oxidative stress). In the long-term – after 12 weeks – a dramatic increase in transformed (cancerous) cells was observed, resulting from a disturbance of cell division and genome instability. Similar toxicities have been found for other nanoparticles often used with TiO2, such as ZnO2 and SiO2.