Are plastics killing us?
Jumping into the future head first, blindfolded, handcuffed, and in darkness
Plastics have been a feature of our world since the time they started being produced on a large scale during the 20th century. They are one of the several giant experiments that we are performing on ourselves. As usual, we are jumping into the future head first, without thinking of what we are doing. (Image by Dall-E)
If you are a scientist, you may like doing experiments on mice. Not so much if you are a mouse. And yet, we are going through a series of planet-wide experiments in which we are playing the role of mice. Right now, humankind is engaged in determining the value of the climate sensitivity factor. That is, how the temperature of the atmosphere reacts to the CO2 concentration. Discovering it may involve killing us all, but on the other hand, that’s the normal destiny of laboratory mice.
However, climate change is not the only experiment we are engaged in. Several others aim to test how humans react to chemicals not normally present in nature. One is plastics.
Plastic waste is seen as ugly and obnoxious but not really dangerous. It is supposed to be inert, and, indeed, it normally is. You may occasionally bite off a piece of plastic from a wrapper while eating a sandwich, but nothing bad will happen to you — not immediately, at least. But plastics are not as inert as they seem to be.
Plastics are carbon-based polymers made by assembling smaller molecules, “monomers,” to form chains; the result is a solid that’s normally stable. Chains can degrade, releasing the monomers, molecules that are not inert at all. In addition, plastics contain all sorts of additives. A few are inert fillers, but most are not.
You may take a look at this review of the most common additives used in plastics. I tried to count those they listed, but I gave up; too many of them. However, the “common additives” are just a tiny fraction of the total. According to a recent UNEP review, some 13,000 additives are used in plastics. In addition, there are many non-intentionally added substances (NIAS).
So, what’s the effect of these additives on human health? Interesting question. The answer is clear: nobody knows for sure.
How would you test the effects of plastics on health? You cannot do a randomized controlled trial (RCT) of potentially harmful chemicals on people; it would be unethical. Testing on mice will tell you how some substances affect mammals but won’t give you quantitative data about humans. You can conduct correlation studies; that is, you can correlate pathologies with the amount of plastics-derived chemicals in the urine or in the blood of people. This approach tells you something about the effect of chemicals on health but can’t tell you where exactly the chemical came from, what concentration caused the pathology, whether there is a threshold dose, whether there are other factors at play, and the like.
But it is much worse than that. How would you test for the combined effect of 13,000 chemicals combined? And at different concentrations? And over a long time? It is simply impossible. The UNEP report says that “Many chemicals in plastics, including additives and NIAS, are poorly characterized and have large data gaps regarding their chemical properties and toxicity” and that “the problem of missing or highly uncertain data on the properties of many chemicals persists and has been identified as a major challenge to the successful implementation of the regulation.” Nice to know that nobody knows anything, right?
The only sure thing is that every one of us is exposed to harmful substances produced by plastics when they degrade. We use plastics, we throw plastics away, and they end up in the food chain. Then, we eat what we threw away in the form of minuscule particles that release their components into our metabolic system. Even nicer, right?
At this point, you could say, “But people are not suddenly dropping dead on the street. It means that plastics cannot be that harmful.” Yes, plastics don’t kill you right away. But how about long-term effects? Some data are worrisome; take a look at the figure, below. A similar correlation occurs for other pathologies, such as diabetes and a decline in sperm counts.
Of course, correlation doesn’t mean causation. Let me stress that I am not claiming that it is certain that plastic degradation is causing the obesity epidemic. I am just saying that there is no causation without correlation, so we are considering a plausible hypothesis.
But what could be the culprit, exactly? Let me focus on just one of those 13,000 plastic components: “BPA,” that is, bisphenol-A.
If you know just a little about these matters, you’ll immediately recognize the two hexagonal things as “benzene rings.” Benzene is a very common organic molecule; it is called “aromatic” because it smells bad, which, in turn, is related to its chemical structure. Benzene compounds are chemically active and often carcinogenic.
Bisphenol-A is a monomer used to create polycarbonate chains, one of the most common forms of plastic. It is also used to make epoxy resins, vinyl ester resins, and other substances. You find it everywhere, not just in plastics but also in coatings for the inside of food cans, clothing, shop receipts, and dental fillings.
Now, the problem with BPA is that it is known to be a xenoestrogen. That is, it has hormone-like properties that mimic the effects of estrogen in the human body. Estrogen, as you know, is one of the fundamental hormones in the endocrine system. If you are a man, excess estrogen (or xenoestrogen) will make you develop a fat belly, grow breasts, and lower your sex drive. In addition, for both males and females, it may increase your risk of cardiovascular disease, type 2 diabetes, high blood pressure, and infertility. Nice, right? Ah… by the way, BPA is also carcinogenic. Are you surprised?
So, the obesity epidemic in the US and elsewhere in the world is what you would expect if an endocrine-disrupting additive, such as BPA, were having its known effects on the entire population. Unfortunately, we could prove it only if we were able to phase out BPA, and then, years later, we saw the obesity trend reversing. But do we need proof in order to suspect that a known xenoestrogen is wreaking havoc with people’s delicate and fine-tuned endocrine systems? Wouldn’t it be a good idea to phase out — or at least curb — its production as soon as possible?
The same idea would be good for many other harmful chemicals contained in plastics, and that leads to the idea of curbing all kinds of plastic production. But that’s anathema in a world where growth is supposed to be the perfect thing in a perfect world. Look at the projections. The production of plastics is supposed to triple in the next 40 years, and most people seem to think it will be a good thing.
Some feeble attempts are being made by the United Nations to rein in plastic production. However, the negotiations are slow, ineffective, and continuously sabotaged by the plastics industry. Just note that an initial version of the proposed international agreement said that the objective was “to end plastic pollution.” That was changed into “to protect human health and the environment from [the adverse effects of] plastic pollution.” The ocean plastic islands can keep growing because there is no evidence that they have adverse effects on human health.
And not just that. Some well-intentioned actions against BPA are backfiring. Producers are proudly rolling out “BPA-free” plastics. Nice, but these products normally contain other forms of bisphenols, such as BPS or BPF. They have been found to have the same effects as BPA. This is not surprising: they are very similar molecules containing aromatic rings. Why should they be safer?
So, there is not much we can do as individuals. Avoiding all kinds of plastics may help, although it is very difficult to do that in our world. One good thing is that BPA does not seem to accumulate in the body, and perhaps there is a “threshold level” that will trigger bad effects only if it is overcome. So, even a modest reduction of the exposure may help a lot. Maybe.
In the end, we may wonder why humans are so stupid that they damage themselves by inventing things that they don’t really need and they don’t know how to get rid of afterward. The strangest thing of all is that everyone is affected by plastic pollution, even those who make money from its production. So, you wouldn’t expect such a strong resistance to curbing the damage. But no; apparently, many people value money more than their own health. Maybe they think they are invulnerable? It is the same thing for climate change: it affects everyone, even those who are lobbying against measures to curb it. But that doesn’t stop them.
That’s how humans are. They keep jumping into the future head first, blindfolded, handcuffed, and in darkness.
See also this article on FT about the decline of sperm counts. It mentions PBA and other endocrine disruptors
In the following, a post by Lukas Fierz, MD, republished here with his kind permission. One sentence by Fierz that I find especially enlightening is “ the political right, which claims to be fighting this ‘woke-culture’ is actually at the root of it, because they are defending the freedom of the industry to poison our food and environment.”
The insidious castration of all men
by Lukas Fierz
Men seem to become less testosterone-driven. This decreases sperm count and threatens reproduction. While this is perhaps not a bad thing it also blurs sex and gender.
Born in 1941, I spent my early youth with toys made from wood and tin. Electrical appliances were insulated with rubber, textiles or ceramics. Tinned food came in glass or uncoated tin cans. There were no ready meals or plastic. It wasn't until the 1950s that the first plastic toys were marketed as ‘hygienic’.
Boys were still boys and fought with fists. Girls giggled, they had aprons and pigtails that we boys could pull on. We didn't hear about homosexuality until we were seventeen: An acrobatically gifted schoolmate was given a small role in the theatre ballet. After a tour, he told us about the sexual customs with his eyes wide open: ‘Everyone does everything with everyone!’ We didn't know whether this was a free choice, a sin or a crime.
Hormones and behaviour
Towards the end of the century, it became clear that male behaviour depends on there being enough testosterone around birth. If it is then absent or if the receptors cannot perceive it, the individual will not behave as a man, even if he later has enough testosterone and a male body: Homosexuality is neither a choice nor a crime. It is a hormone-determined behavioural trait that cannot be changed by doctors or laws. Despite the talk of gender roles as an exclusively social construct, there is irrefutable evidence that testosterone not only promotes virility and muscles, but also has behavioural effects such as aggressiveness, dominance, territorial behaviour or a preference for ball games and firearms over dolls.
Since the 1970s, reports have appeared on disorders of sex differentiation in fish and amphibians. They no longer seemed to know whether they wanted to be male or female, and there was an increased incidence of intersex behaviour. Hormones and hormone-active substances in the wastewater are blamed. Disorders are now even found in alpine waters that have not come into contact with wastewater.
Decline in human fertility
And what about us? The sperm count of Western men has fallen to less than half since the middle of the last century - by around one per cent per year. Alarmingly, this decline has now been confirmed worldwide and has accelerated to almost two per cent per year (1). If things continue at this rate, it can be calculated that natural human reproduction will become increasingly impossible from around 2045. It will then only be possible in the retort.
It is surprising that hardly a word is said about this well-known finding in the discussions about population development or old age pensions. And when you consider the clamour raised by opponents and supporters of abortion, it is actually strange that nobody cares about the fact that we are killing the majority of sperm. After all, they are living beings too.
It is not only the sperm count that is decreasing. Sperm volume, male testosterone levels and the fertility of men and women are also declining in a similar way. The number of unintentionally childless couples is increasing, as is the number of fertility treatments.
For thirty years, Professor Shanna Swan of the Mount Sinai School of Medicine in New York has been researching this problem in all directions (2). Based on evidence from the animal kingdom, she systematically measured the distance from the anus to the genitals in newborns. This distance is testosterone-dependent, and it is much greater in boys and men than in girls and women. Men with a smaller distance have a smaller sperm count and lower fertility.
However, this difference in the so-called anogenital distance between boys and girls has also decreased in recent decades. The boys are less masculine - an indication that there is also less testosterone effect in unborn boys. Not only fish, but also human beings apparently no longer always know whether they want to become male or female.
Environmental toxins
According to the studies by Professor Swan and others, chemicals that block the testosterone effect or enhance that of the female hormones are responsible for this. Of particular importance to humans are phthalates and bisphenols, which are contained in almost all plastics as plasticisers or hardeners, as well as certain pesticides and fire retardants. Some of these substances are extremely persistent, present everywhere and even in breast milk, and accumulate in the body. Not only do they disrupt hormone balance and sperm production in men, they are also likely to play a role in breast cancer and painful endometriosis in women.
Professor Swan and toxicologist Professor Wilks from Basel are therefore unanimous in their advice to avoid all food packaged in plastic, be it dairy products, meat, ready meals, frozen food or tinned food in plasticised tins. For milk and yoghurt, this is impossible in many places. Retailers should therefore switch back to glass packaging. Coated pans should be replaced by uncoated iron pans. In France, many of these substances are to be banned from 2026. In the parliamentary debate there, the comparison with the asbestos scandal was quite apt.
Blurred gender roles
As already mentioned, sex hormones have a formative effect on male and female behaviour. Over the past twenty years, an unprecedented gender debate has emerged about the definition, categorisation, roles and rights of the sexes. It goes right down to the finer points of language. As an old man, this seemed irrelevant and incomprehensible to me for a long time. Like many right-wing politicians former Swiss Federal Councillor Ueli Maurer feels the same way, and he and his like-minded colleagues are fighting against this so-called woke culture.
But if you really think about it: According to the physical findings mentioned, men are subject to a mild but increasing chemical castration across the board, both before and after birth. It cannot be otherwise than that male behavioural patterns are also weakened as a result. And what if many young men become less masculine? Do young women perhaps miss the ‘right’ man? Do traditional gender roles still fit in with the chemically blurred gender types?
On a subjective level, the young people concerned will deal with their changed state of mind in endless discussions about what it means to be a man or a woman or something in between. That's exactly what we're seeing.
And the political right, which claim to be fighting this"woke-culture", is actually at the root of it, because they are defending the freedom of the industry to poison our food and environment, e.g. recently in Switzerland by downing the popular initiatives on poison-free drinking water and pesticides - the fox guarding the henhouse...
(2) Shanna Swan, ‘Count Down’, Scribner 2021
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Labels: anogenital distance, bisphenols, boys, fish, Gender, girls, phtalates, sex, sexual differentiation, sperm, sperm count, testosterone, Woke, woke-culture
Even if conducting RCTs on human subjects to learn more about the effects of plastics was considered ethical, at this point it seems like it would be virtually impossible. So many things humans consume come into contact with plastics somewhere in the supply chain, often with the end user unaware of it.. Goods that reach the consumer that are sold in cans or jars may have been produced using bulk ingredients from plastic containers, or may have been sourced from producers who make use of plastics in their handling, processing and/or bulk packaging. And even all that would not account for the casual environmental exposure that food has to plastics that have already found their way into nature (e.g., meat or fish that already contain microplastics consumed by the creatures in their native habitats).
I am old enough to remember when soft drinks first started appearing in non-returnable bottles, and how strange it felt to toss those containers after just a single use. But going back to returnable bottles may not be the answer either—there are other costs, such as hauling those containers back and forth, washing and sanitizing them, inspecting each one for damage, etc.—all energy consumers. I now buy milk in returnable containers that carry a deposit; the milk itself is from an in-county dairy. Purchasers take them back to the store after rinsing them out. But this is not a choice available to most people.
Years ago I first read of the theory that ancient civilizations (Rome comes to mind) fell because they slowly poisoned themselves by the use of lead drinking vessels. Wouldn't it be ironic if a millennium or two from now, historians were saying the same thing about us and plastic vessels!
Ugo and Lucas; thanks. Very good.
I remember getting interested 40y ago in bioaccumulation as one route that resulted in increased toxicity. (Chemical changes of organochlorines in lower temperature combustion was another.) It will be good if this can be ruled out for the more obviously active compounds / residues. But an other issue for substances new to the biological environment, one that is related to persistence, is the absence of natural full degradation. A whole range of plastics become so physically finely divided in the environment they are seen for instance in the guts of micro-plankton animals and even in cells and tissues.
PS I remember finding black plastic sheeting poisoning my plant growth experiments. This kind of sheeting did get removed from food packaging along with other types after they had been tested, but I take your point about the impossibility of defining 'safety'.