This headline explains my general aversion to "chemicals". This, despite the fact that everything is a chemical and that we are all little chemical machines.<p>The human physiology is unfathomably complex and the advent of synthetic chemistry has meant that we are now exposed to new molecules which have arisen at a rate tens, hundreds of thousands of years too early for our bodies to evolve to accommodate for them. Our exposure to these chemicals is also incredibly opaque: even eating "clean" by eating fruit and veg exposes us to a multitude of chemicals that come along the pipeline including fertilisers, pesticides and preservatives.<p>Nature is exquisitely sensitive to chemistry - I recall reading that natural systems have evolved to exploit and dispatch behaviour based on the isotopic composition of carbon-based molecules: naturally synthesised molecules also have a different isotopic profile to artificially synthesised molecules. For the record, Carbon-13 represents ~1% of the natural isotopic abundance.<p>If something as granular as the isotopic distribution of elements is important to physiological systems, how can we be so complacent as to constantly pile chemicals into every aspect of our lives?<p>Businesses will wantonly and irresponsibly use any method to increase their bottom lines and it falls to regulators to moderate this behaviour. As an example, I recall McDonald's doping their chip oil with a known toxic organic chemical to lower the rate of thermal decomposition of their oil. This is something they could as easily avoid by replacing their oil more often, but this is costly: they instead defer this cost onto our health by exposing us to unnecessarily dangerous chemicals.<p>In my opinion the FDA's (or indeed global regulators') thresholds for the use of chemicals is not stringent enough - humans are living longer, how do we know that prolonged exposure to any of these individual chemicals (let alone the cocktail of all of them) over a 50-100 year period are worth the risk?<p>For another anecdote of irresponsible chemical usage - the onset of lung cancer through smoking underwent a stepwise increase after the tobacco industry started using phosphate fertilisers to increase their crop yield: a side effect of the fertilisers was to enrich the soil in radium which would decay down to Pollonium-210, an alpha source of Russian-assassination fame. Studies have been done on characterising the sievert profile of tobacco leaves, highlighting the risk of this but no action on the tobacco industry has been taken to mitigate this.