Shutterstock image: Hand Holding soil sample in a tube on the field for chemical analysis and ph test. Agrochemical analysis soil and greenhouse soil for fertil. Soil quality monitoring concept______ .jpg
Over the years I have been working in the pollution space I’ve come across the term “regrettable substitution” numerous times. It’s used to describe when a chemical acknowledged to have unacceptable impacts to human health and/or the environment is replaced by another, only to find that the replacement chemical too has unacceptable impacts. This discovery seems to only come after years of monitoring human and animal populations The history of sheep and cattle dip chemical use in Australia is one replete with examples of regrettable substitution, starting with arsenic in 1895 and followed by chemicals like DDT, BHC, and dieldrin, all of which were banned in the 1960s after decades of use.
The story of regrettable substitution is bigger and more complex than one chemical replacing another. It is not just the substitution of one problem chemical with another problem chemical. I believe it’s the substitution of whole materials (articles for those in the pollution space) and ways of life that is a major driver of chemical pollution around the world.
It can be argued that humans by their very nature have always been generators of waste and pollution. The archaeological record abounds with examples of artefacts that are effectively the waste of previous civilisations. One could also argue that fossils and coprolites are too a form of waste left in the permanent geological record by extinct species. With both previous civilisations and extinct species, rocks and sedimentary profiles tell the story of massive water pollution events occurring as species’ populations shrank to zero in the mass extinction events that mark geological boundaries, such as the Permian-Triassic extinction. These boundaries are called unconformities in geological parlance and are evidence that huge amounts of sediment erosion and deposition has occurred concurrently with what must have been catastrophic water quality impacts in Earth’s geological past. Not to mention that all animals poop and pee and thus have potential to negatively impact water quality; eutrophication by dinosaur dung must surely have been a sight to behold.
The difference between the waste and pollution generated by our ancient human ancestors and other long extinct species and that generated by humans in the industrial and post-industrial ages, I believe, is a result of behavioural and material differences that resulted from the industrial revolution. With few exceptions, resources such as medicines, bowls, and tools used by ancient peoples entered one of two pathways when they became waste products. In the first pathway, materials derived from plant or animal material decayed via the process of respiration (undertaken by humans or microbes) to become some form of carbon (e.g., CO2, CH3), nitrogen (e.g., NO2, NH4), or similar organic by-product. In the second pathway, little breakdown occurred and the material became the stone-like waste products that we now consider to be artefacts—things like bone knives and ceramic plates.
With the advent of the industrial revolution, chemicals were developed synthetically, creating products that entered a pathway previously unused in the Earth’s history. Like the respiration pathway of prior times, these synthetic products followed a pathway into the ecosystem. Unlike organic products entering the respiration pathway, synthetic products were not broken down into their molecular parts—carbon dioxide, humic acid, or other organic by-products. Instead, many synthetic products that entered the ecosystem were not broken down at all. But they were not inert like the stone-like waste products of the pre-industrial era either. Instead, these synthetic materials altered organisms in the ecosystems to which they were exposed, accumulating in their tissues to cause disease; impeding their respiration and digestion; and preventing the way of life to which these organisms were adapted.
But synthetic chemicals also altered the way in which people interfaced with the world. People changed to no longer consume for survival—creating the tools necessary to hunt, eat, and provide shelter. We consumed for pleasure. Synthetic chemicals gave us bold, beautiful dyes; roads sealed with tar, bitumen, and asphalt; and lights. They give us machines, and fabric, and medicine. Indeed, a complete list of products created via synthetic chemicals is probably impossible to compile.
Millions of items have been developed using the synthetic chemicals developed in the industrial and post-industrial eras, almost none of which were developed for the sake of survival. This, I think, is a part of the pollution story that must be acknowledged if we are to decouple ourselves from the pollution crisis. Not only do we need to use green and sustainable chemistries that can pre-empt the regrettable substitution of chemicals that all‑too-frequently occurs. We need to change the regrettable behaviour that the consumerism introduced by the industrial revolution has created. This is not revolutionary thinking—consumerism has long been cited as a driver of biodiversity loss, habitat destruction, and the waste crisis.
What might be new is thinking of consumerism as a key driver of a separate issue: the development of synthetic chemicals that enter the ecosystem and cause harm. This problem is not one of chemical innovation in itself, but instead of the sheer number of synthetic chemicals that is far beyond the ability of science to assess and the drive that innovation and consumerism creates to create more chemical solutions to all our problems. Stickier tape, more run-proof dyes, pesticides that can kill pesticide-resistant pests, more durable shoes, nicer smelling shampoo. Not to mention the chemical inputs—rare earth elements and iron in batteries, plasticisers, UV blockers, stabilisers, pigments―that go into all the new gadgets and fuels under development for computerised technologies. Our human impulse to purchase new things drives the chemicals manufacturing sector to create chemicals, with no technology currently available to realistically assess the impact of these chemicals as they are emitted into the environment.
While I think consumerism is a key driver of the chemical pollution problem and a key driver of regrettable substitution—of chemicals, materials, and ways of life alike―I can see no way off this path. As humans sleepwalked into agriculture without realising the catastrophic environmental impacts this innovation would bring, humans have and are sleep walking into chemical manufacturing crisis. Just as humans can no longer live without the agriculture that causes so much of the environmental damage seen today, we can no longer live without the chemicals industry that enables the agriculture, the roads, the houses, and the medicines we now depend upon.
More on this, next time.