In March 2011 an accident at the Fukushima nuclear reactor in Japan led to a release of radioactive elements into the atmosphere. A few days later, these unique elements were detected in Oxford in the UK. Given that Japan and the UK are on opposite sides of the earth, that accident must have filled the entire planet’s atmosphere and done so with astonishing speed.
The reason for this is that atoms, and the molecules made out of them, are very very small, move very fast and there are lots and lots of them. Chemist’s are familiar with this and have a number that expresses it. Avagadro’s number can be used to work out how many atoms in a particular weight of a particular substance. So for instance when you add 5g of sugar to a cup of coffee you are actually putting around 3,000,000,000,000,000,000,000,000 individual sugar molecules into it.
One of the consequences of molecules being so small is that they tend to turn up everwhere. As we get better at detecting things at lower levels we find more and more of them in all sorts of places. This can be made to sound very alarming if you don’t remember how small they are. For instance synthetic chemicals are often detected in what sounds like out of the way places. I remember DDT being detected in eskimo’s mothers’ breast milk for example. The implication being that if it had got that far how much have we got? In reality you’d expect it to become evenly distributed everywhere pretty quickly, which was exactly what happened.
Another way of yanking our emotional muscles is to look at unborn babies. If you analyse a sample of amniotic fluid with very sensitive techniques you will find all sorts of stuff there at a low level. We all live in a world full of small molecules and if they have got everywhere else they are going to be in everyone’s body including prior to birth. It is very hard to look at data like that and not find it worrying. All of us have a predisposition to chemophobia. And this is especially so when you talk about unborn babies, about which all of us have protective feelings.
It is easy to spot scaremongering scoundrels talking about ‘pre-polluted babies’ of course. The choice of language gives away their nefarious intentions. It isn’t so easy to dismiss the Royal College of Obstetricians and Gynaecologists though. I think their sincerity at least is beyond doubt.
The trouble is that their recent advice on what pregnant women should avoid really isn’t particularly helpful. My ear’s pricked up when the radio coverage included shower gel in a list that also warned against new cars, ready meals and tinned food. Although not much of the shower gel you use is going to get through the skin, Avagadro’s number ensures that at least a few molecules will. But avoiding shower gel will only minimise your exposure a little. If your partner is using shower gel some of the same molecules will be shed in his skin cells which you will inhale.
Luckily, there is no evidence that all the chemicals that we are exposed to from personal care products are harmful. In fact there isn’t much evidence of any harm arises from low levels of any kind of chemical. Given that we are all living longer and healthier lives and the world population is growing, it looks most likely that there is nothing to worry about.
Sadly our brains aren’t good at absorbing this kind of logic and most of us, me included, will have nagging doubts in the backs of our mind. It’s a pity that there are so many news stories like this one that reinforce our groundless fears.