We now know that both titanium dioxide nanoparticles (used in sunscreens, cosmetics, food packaging, paints, clothing and more) and carbon fullerenes (used in high end anti-ageing creams and mooted for use in medicines, solar cells and superconductors) can be passed from pregnant mice to their offspring, with consequent harm to health (see here and here). Now a startling new study has shown that rice plants exposed to carbon fullerenes also transmit these nanomaterials to the next generation. Exposure to both carbon fullerenes and carbon nanotubes also delays the onset of rice flowering by at least 1 month and reduces seed set.
The US researchers note that: “Black aggregates were frequently found in the seeds and roots, and less frequently in stems and leaves” of rice plants grown from seed exposed to a mixture of C70 fullerene and natural organic matter. “Remarkably, black aggregates were also spotted in the leaf tissues of the second-generation plants, though much less frequently.” Rice flowering was delayed in the C70 fullerene-exposed rice plants by at least 1 month and the seed setting rate was reduced by 4.6%.
The researchers observed that: “It is also very likely that plant cell-nanoparticle interaction could lead to the modification of plant gene expression and related biological pathways, and consequently impacting plant development”.
In contrast to the rice plants exposed to fullerenes, the uptake of multi-walled nanotubes (MWNT) into plants was found to be insignificant and almost none appeared in the plant tissues. Nonetheless, MWNT were found to be adsorbed to plant root surfaces. Flowering of rice plants incubated with MWNT and natural organic matter was also delayed by at least 1 month, and their seed setting rate was reduced by 10.5%.
The researchers point out that over half the world’s population relies on rice as a staple crop. They conclude that the environmental and food safety implications of observed results “are important subjects to understand”.
For a useful detailed look at the study, and interview with one of its authors, read Nanowerk’s article “Starting to explore nanotechnology’s impact on major food crops” available at: http://www.nanowerk.com/spotlight/spotid=9516.php
Another interesting related Nanowerk article “Nanoparticle uptake by plants” is available at: http://www.nanowerk.com/spotlight/spotid=6331.php