After the announcement out of Brown University last week that the jagged edges of graphene can cut into cells and find themselves inside of them, the news cycle has been non stop with headlines like “Jagged Graphene Can Rip Human Cells Apart” and “Graphene Sheet Jagged Edges Easily Pierce Cell Membranes”. Of course, it’s not clear from the research that graphene “rips human cells apart” or can “easily pierce cell membranes”, but this is how these stories are typically covered.
This is important research, and published in the prestigious journal Proceedings of the National Academy of Sciences, but it is preliminary research and is not conclusive evidence that graphene is toxic to humans. This distinction is made at least implicitly clear in the press release:
“From here, the researchers will look in more detail into what happens once a graphene sheet gets inside the cell. But Kane says this initial study provides an important start in understanding the potential for graphene toxicity.”
These stories always take the same track in the media, whether it’s the technology press, the mainstream media or the NGO-related opinions. We even have a pretty clear blueprint of how these stories play out from a news item five years ago that reported that carbon nanotubes longer than 20 micrometers lead to the same pathogenic effects in the mesothelium as asbestos fibers.
In this five-year-old example, we got big headlines about how carbon nanotubes are like asbestos followed by self-righteous indignation that research into nanomaterials is still allowed and fallacious arguments that nanomaterials companies were defrauding investors by dissimulating this asbestos-like threat. But outside a few notable exceptions, it seemed hardly worth mentioning by most of the media that the underlying research that started the uproar didn’t even address the issues of dose and exposure—pretty important elements in discussing the toxicology of anything.
Perhaps the worst aspect of how these stories develop in the media is that virtually nobody covers the news that comes years later that the whole problem is resolved by ensuring that carbon nanotubes are not longer than 20µm.
Another issue that very rarely gets discussed when these stories land in the media is the formula for determining the risk of anything: Hazard x Exposure = Risk. We live every day with all sorts of hazardous materials but if we are not exposed to them there is little risk to us.
In the case of the Brown University research, the graphene had to be placed in Petri dishes along side human lung, skin, and immune cells. That’s not the kind of exposure that at the very least will be common.
I think somewhat to the discredit of the research, Robert Hurt, professor of engineering and one of the study’s authors, is quoted in the press release announcing the research: “These materials can be inhaled unintentionally, or they may be intentionally injected or implanted as components of new biomedical technologies.”
You really would have to be working with these graphene microsheets at a research lab or factory setting to unintentionally inhale these particles. This was the point made in the now nearly decade old report from the Royal Society report “Nanoscience and nanotechnologies: opportunities and uncertainties”: Workers making products out of nanoparticles are in more danger than those who buy and use the products made from the nanoparticles. But the implication that we can be walking down the street now and be inhaling graphene microsheets is planted like a demon seed in peoples’ heads.
The second point made in Hurt’s quote that a graphene-based biomedical device injected into our bodies could result in graphene microsheets piercing cells like they did in the research is just fear mongering. It would seem to me that there would have to be a lot of lifecycle studies to determine whether graphene would detach itself from the rest of the composite material making up the device and even then whether it would take on the jagged form that proved such a hazard in the study.
It’s hard to tell at this point whether there is any point to being circumspect about these preliminary toxicology reports on nanomaterials; it’s a bit like trying to swim upstream. But as hard as it may be for some to accept, this kind of careful approach to these kinds of stories probably serves the interests of science—and our health and safety—more than alarmist news stories and hyperbolic rhetoric.
Image: Kane Lab/Brown University