FINALLY - the Truth about Plastics & the Environment
By Dr. Chris DeArmitt FRSC
World-class plastic materials scientist
Microplastics have attracted a huge amount of attention. People tend to be afraid of the unknown and especially so about things that they cannot see with their own eyes. As a scientist, I decided to review all the science I could find on the topic to see whether or not we have genuine cause for concern. That meant reading a huge amount of material, not just skimming through but also checking how the science was done, to make sure that it was professionally conducted. What I found shocked me…
What are microplastics?
Microplastics are defined as plastic fragments of 5mm or less across. They first came to the public’s attention when articles started showing up about the polyethylene microspheres used in some facial scrubs as a mild exfoliant. There was a huge uproar, as this was perceived as a major problem and now the PE spheres are no longer used. A recent report gives an excellent overview (see Primary Microplastics in the Oceans- a Global Evaluation of Sources IUCN 2017). The report says that the global release of primary microplastics in the oceans is estimated to be about 1.5 Mtons/year.
So, we know that microplastics are real and the quantities are enough to be concerned about. I looked for the data and it turns out that just 2% of the plastic particles in the sea were from in facial scrubs. I was surprised at how low the amount was, in light of the huge amount of attention the topic received. If not facial scrubs, what is responsible for the microplastics in our oceans?
Microplastics are abundant – but are they causing harm?
For a substance to present a danger, it has to be toxic and there has to be an exposure route. For example, a bottle of poison on the moon would not be a threat to people on Earth so there would be no danger. In that example, there is toxicity but no exposure. Conversely, we may be exposed to something but if it turns out to be harmless, then there is no cause for concern.
I looked at many studies and we know for sure that birds and fish do eat plastic. Microplastics can be found in their digestive system.
“Plastic was detected in 49 out of 64 fish (77%), with 2.3 pieces on average and up to 15 pieces per individual” and “Most were polyethylene (52.0%) or polypropylene (43.3%).”
So, the exposure component is there. What about the toxicity aspect? Are these plastic particles harmful to the marine wildlife?
It is interesting to see that PE and PP are the main plastics. It should not be too surprising, as they are the two most commonly used plastics and they both float on water, making them more visible and more likely to be ingested by fish. PE and PP are also two very safe plastics that we use all the time to package food. PE is used for sealable food bags in the kitchen and PP is used for sealable food containers. Both have been used safely for several decades.
The press has drawn the public’s attention to studies claiming that plastics leach toxins, but when we look at those studies, it turns out that the plastic was shown to be safe and only released toxins after the plastic was intentionally soaked in toxins by the experimenters. These studies are not only misleading but irresponsible. We could soak more or less anything in poison and then show that it released some poison once placed in clean water. Interestingly, other workers showed that plastics absorb toxins from water and hold them tightly so that even when ingested by fish, they are able to protect the fish. Have you ever seen a headline highlighting those studies? I have not. Why is that?
So, it is a myth that microplastics are toxic. You can see details of the various studies in the myths tab in the section below. To summarize, having read many studies, here is what they say:
- Several studies show that microplastics are non-toxic to marine life
- Some studies show that microplastic intentionally pre-soaked in poison are somewhat toxic – but so is any substance
- Some studies state that microplastics protect marine life by binding poisons from the ocean and preventing exposure
- Other studies claim microplastics cause harm but none of them are credible because they use the wrong type of plastic, they use the wrong shape of particle, they use 100-10 million times too much plastic and they use fluorescent colored plastic which is completely unrealistic
Conclusion – microplastics are not toxic
Careful consideration shows no credible evidence that microplastics are causing harm. Some of the data even points to a protective effect whereby the plastic particles absorb toxins in the sea and shield marine animals from exposure.
There is a shocking amount of bad science whereby the experiments were so poorly designed that they should never have been accepted for publication. I have refereed articles for major publishers and I would not have allowed many of the environmental papers to be released. I would encourage people to take the challenge of doing good quality research so that we can learn more about the facts and take appropriate action.
Debunked Microplastics Articles i.e. Junk Science
Here is a partial list of articles claiming that microplastic is toxic along with the reasons that they are not valid experiments. The main reasons these studies are invalid include: using the wrong polymer type, using particles that are the wrong size, the wrong colour, particles that contain toxins and particles that are made artificially to be fluorescent. Many studies use thousands or millions times more microplastic, compared to actual amounts in the ocean.
Size‐dependentproinflammatory effects of ultrafine polystyrene particles- a role for surface area and oxidative stress in the enhanced activity of ultrafines They used polystyrene particles, i.e. the wrong kind of plastic and did not specify exactly which type (no product number was given). The particles were from Polysciences, meaning they are cross-linked, probably coloured and unlike real polystyrene. Another invalid study.
This study is quite different to others. They exposed gastropods to commercially available PP pellets and polymer pellets randomly collected from a beach. They found that the plastics were non-toxic but the gasptrods were slower to respond to a threat when they were in water exposed to the plastic pellets. Beached plastics had a larger effect than virgin, clean PP pellets. It seems that somehow the chemicals from the plastic confuse the ability of the gastropod to sense danger. The study was done well but the conclusions were incorrect. To understand the relevance of this, we need to consider the whole picture. In the real ocean situation the gastropods would be in water containing toxins that confuse them. Adding microplastics to that system would absorb those toxins and potentially help the gastropods sense chemical danger. Therefore, this experiment was not designed in a way that tells us what would happen in reality.