Sometimes when a scientific or technological breakthrough is made, it can take a long time for its full ramifications to reach the public.
This is particularly true if it is going to challenge or change the way that people look at or consider things.
Here is an example. When I went to mining school, we had courses in fire assaying and in chemical assaying or quantitative analyses. The idea was to take some ground up rock and figure out what it was made of.
In fire assaying, you use a furnace to turn things molten and then you could determine how much gold and silver was in the rock, down to 1/10 of an ounce of gold. Anything below that was considered trace or not detected. Chemical tests for individual elements could take hours or even days and were far from accurate. One could also use a microscope and estimate percentages but overall, determining what elements were in a sample was a long, labourious process. Much the same was true in the other sciences.
Then the atomic absorption machine and process was developed. One could take a sample, put it into solution in a beaker and stick in a probe to get results in parts per million for any given element. Suddenly, there was a fast, easy and inexpensive way to determine what a sample contained. Today I can get a 32-element assay of a rock sample for what it use to cost to get a one element assay. They are now giving results in parts per billion and parts per trillion.
That was truly amazing breakthrough and it fundamentally changed the way we see the world around us. People started testing all sorts of stuff and found that most things contain a number of trace elements people hadn't thought about or been able to detect before. This was true for rocks, soils, water, plants, foods and all sorts of critters and organisms.
The world suddenly became a whole lot more complex and even interrelated. The concept of a pure substance became obsolete because it would be extremely difficult to create a pure substance when these trace elements are so wide spread on the planet and in most things.
It really is hard to wrap one’s mind around around the parts per million, per billion and per trillion concept. The numbers are just too big to really visualize.
Imagine you have a million grains of salt sitting on your table. You know there are a million because you counted them. Now, take away one of those grains and substitute a grain of black pepper. That is one part per million. Now take away the black pepper, which is easy to see, and substitute a grain of something white like silica. Now mix them up and try to find that grain of silica. Now you can see why it is hard to make a pure substance. Finding and removing all the trace elements is almost impossible.
Scientists discovered many of these trace elements also had an important part to play in how things work. They discovered having none - or too little - of them could be just as dangerous to your health as having too much of them.
Consider a pizza or a chocolate cake. If you are starving and have too small of a piece it isn’t very satisfying but if you have too much of them, you are going to make yourself sick.
Now there is a lot of talk in town arsenic, which is a naturally occurring element. Too much of it is certainly dangerous but so is too little of it. What is really needed is better explanations of what is going on and putting things into a context that people can understand. You want the right balance of arsenic in the environment just as you want the right amount of chocolate cake. I know some people aren’t going to like the pizza or cake analogy, but what the heck, science should be fun as well as informative.