Nano-worries

The Council of Canadian Academies has written a report for the Canadian federal government recommending greater regulation on the use of nanomaterials in consumer products. Their reasoning being that a chemical compound, when incorporated into a nanoparticle will oftentimes display different properties than when it exists in its other forms.

I do not have a problem with the recommendations of the report as listed in the article. The whole purpose of developing nanoparticles is to create a material with different chemical properties than would be observed if the compound were simply a bulk solid or in solution. Therefore treating each nanoparticle as a separate chemical entity that needs an individual assesment of its environmental and toxicological effects only makes sense.

However, I can’t help but detect a bit of nano-hysteria in the article itself. The author seems to be suggesting that there is a danger posed by nanoparticles because of the fact that they are so small, which is a gross over-simplification.

Sure, nano is small, but it is quite large on the molecular scale. In terms of size, nanoparticles are more comparable to proteins or polymers, which are much larger than many of the individual chemical species found in your blood like sugar, caffeine, nicotine, ethanol, vitamins, minerals, hormones, etc.

It may be that titanium oxide nanoparticles found in sunscreen are more likely to enter your system perhaps than the bulk form found in house paint, especially when the former is applied directly to your skin and the latter, typically, is not. However, it’s rarely the solid form of a chemical that we’re concerned about. The problem with lead pipes isn’t that you’re likely to absorb lead into your system by simply touching them, it’s that water-soluble, oxidized forms of lead enter your body by means of the water the lead pipes are transporting. Water-soluble, oxidized forms that are smaller than any nanoparticle.

What needed to be stressed in this article is that there can be substantial differences in the chemical properties of compounds when alone or incorporated into a nanomaterial. Instead, it is suggested those differences are simply related to nanoparticles being so darn small.

They even mention drug delivery in the article, which is where multiple molecules of the drug are incorporated into a single nanoparticle. The goal is to achieve timed release of the drug from the nanoparticle structure to maintain a more consistent concentration of the drug in the blood stream as opposed to taking a pill of the bulk solid form which, after ingestion, results in a significant spike in the blood concentration of the drug. The chemical properties of the drug do not change, and the difference in how the drug is introduced into the blood stream is in no way related to the difference in size between a single nanoparticle and a drug tablet.

The field of nanoparticles is varied and complex, in some cases the difference in size may be a critical factor in the different properties of the materials while in other cases size may play little to no role at all. This is point where journalism and science commonly clash. Journalists aim for accuracy, yet when writing about science look for a simple, generalized way to present the concept to their readers. Science, however, in its own quest for accuracy, can rarely comply.

Kids’ Brains

I found a recent study that suggests that children’s brains are programmed to elicit empathy upon seeing someone get hurt, accidentally or intentionally.  The researchers performed MRI scans on 17 children while showing them an animation of people getting hurt.  They found the same areas of the brain that light up in the adult brain were also activated in the children studied, including the area responsible for moral reasoning.

It is an interesting finding, but perhaps not that surprising.  I think anyone who’s worked with a large number of children believes not only that children are capable of empathy, but also most kids, regardless of their upbringing, are inherently good and decent people.   At least in the age range of the children of this study, who were between 7 and 12 years old.

However, therein lies the problem with this study’s main conclusion, in my view.  The researchers are suggesting empathy is hardwired, not taught, but they didn’t study any children of the age when you would be teaching them about empathy.  In a daycare, the three-year-old who hits their playmate is made aware of the fact that they’ve hurt their friend and asked how they would feel if their friend hit them.   Is that not teaching empathy?

It’s a good question as to whether the child is capable of responding to such reasoning because their brain is programmed to do so, or whether scolding the child in this manner is actually creating the wiring that will allow the child to respond empathetically later in life.  A question this study, unfortunately, does not address.