Nanoparticles may compromise crops

Image: Priester et al. 2012, PNAS.
Image: Priester et al. 2012, PNAS.

Advances (ever an optimistic notion!) in technology take many forms and may have unanticipated consequences. Take, for example, the emerging discipline of nanotechnology, which works with structures that are intermediate between isolated atoms and bulk materials – in the range of 1–100 nm, and which often display physical attributes substantially different from those displayed by either atoms or bulk materials (e.g. Zhong Wang). Not surprisingly, therefore, concerns have been expressed about the effects that manufactured nanomaterials (MNMs) may have on human health or other biota if they ‘escape’ into the environment.

John Priester et al.  examined the response of a major crop – soybean – to farm soil amended with two ‘high-production’ metal oxide MNMs, nano-CeO2 and nano-ZnO. Amongst other findings, they show that plant growth and yield diminished with nano-CeO2, and nitrogen fixation was shut down at high nano-CeO2 concentration. As the authors chillingly – but calmly – conclude, ‘these findings forewarn of agriculturally associated human and environmental risks from the accelerating use of MNMs’. You have been warned!

However, and not that I’m cynical or anything like that, I’m a little exercised by the fact that the manuscript was received for review on 1st April (2012). I don’t know about the rest of the world, but there is a tradition in the UK of playing what are euphemistically termed ‘pranks’ – ‘practical jokes’ and the like – on April Fool’s Day, 1st April. But those antics are only permitted up until 12 noon on that date. So, I’m hoping that the paper was received during the afternoon of that day. Plus, having been published in such an august organ as PNAS some months after that date, I’m guessing that this is a genuine piece of science. Further reassurance comes from the fact that it has subsequently elicited a letter that challenges the study’s conclusions. Co-authored by Rothamsted Research’s Professor Steve McGrath (UK PI for a transatlantic consortium set up to investigate the environmental and human health implications of nanotechnology), that epistle needs to be taken seriously. And it has been, in the robust rebuttal by way of reply thereto by the original paper’s authors. Consequently, we should be rightly concerned about those nanomaterials (or not, per Lombi et al.…).

[One of the most famous April Fool’s Day hoaxes in the UK – and which is coincidentally botanical! – was the BBC’s news item in 1957 that purported to show the ‘harvesting’ of spaghetti in Switzerland. And it has even been voted ‘the top April Fools prank in history’ – Ed.]