I made a statement that much of the microplastics works is not credible. Having reviewed many studies, it is some of the worst “science” I have ever seen. Those are bold statements, so now I will explain why I made them by looking at several publications individually and explaining why the science is either invalid or, in some cases, fraudulent.
First comes this warning from scientists who point out that many of the studies are not done under realistic conditions.
Microplastic exposure studies should be environmentally realistic
R. Lenza, K. Endersa, and T. G. Nielsen, Proceedings of the National Academy of Sciences, 113(29), E4121 – E4122 . . DOI: 10.1073/pnas.1606615113
The authors warn that:
“Experimental exposure concentrations tend to be between two to seven orders-of-magnitude higher than environmental levels.”
Meaning that many articles are using 100x and 10 million times more more plastic and toxin than are found in the environment. Dose is very important for toxicity. For example, breathing 20% oxygen keeps us alive where 100% oxygen is lethal. Therefore, they go one to say:
“Microplastic research is an emerging field, and there is a lot of misunderstanding and in some cases over- reaction or misinterpretation of results from MP science in the public. We therefore strongly suggest that future studies of MP impact on marine ecosystems should also include concentrations that have been documented in the environment to yield more realistic estimates of sublethal effects.”
Another article points out that the studies are usually done on the wrong kinds of plastic. Many studies are done on polystyrene when that is not at all common in the ocean. Polystyrene is just 1% of microplastic in the ocean so why focus on that? The reason is that polystyrene particles are easily obtainable making it convenient for the scientists to order them.
Studies of the effects of microplastics on aquatic organisms: What do we know and where should we focus our efforts in the future?
“Analysis of the available data revealed that 1) despite their widespread detection in field-based studies, polypropylene, polyester and polyamide particles were under-represented in laboratory studies; 2) fibres and fragments (800–1600 μm) are the most common form of MPs reported in animals collected from the field; 3) to date, most studies have been conducted on fish; knowledge is needed about the effects of MPs on other groups of organisms, especially invertebrates. Furthermore, there are significant mismatches between the types of MP most commonly found in the environment or reported in field studies and those used in laboratory experiments.”
They correctly noted that studies are done on the wrong plastics and on the wrong shapes. In the oceans fibers and fragments are found, whereas all the studies are on perfectly round particles.
Now let’s look at a couple of studies that make plastics out to be a problem…
Chemical Pollutants Sorbed to Ingested Microbeads from Personal Care Products Accumulate in Fish
The abstract for the article states:
“This work provides evidence that microbeads from personal care products are capable of transferring sorbed pollutants to fish that ingest them.”
Later, the article says:
“The bioavailability of PBDEs sorbed to microbeads that did accumulate in the fish is of concern, considering the large volume of MBs (and other microplastics) entering the aquatic environment and their largely unknown environmental fates. Implications for the food chain, including the human diet, from this very fine fraction of plastic debris demand further investigation.”
That sounds like it could be a problem, so I read the article in detail. First, they showed that polyethylene beads from facial wash had no effect on fish that ate them. Then they soaked the beads in known toxins so that they beads absorbed the poison. They fed the toxin loaded beads to the fish and confirmed that a small proportion of the toxins was transferred to the fish.
What does this mean? Let’s picture what would happen in the ocean. The PE beads (proven to be harmless alone), will absorb toxic chemicals. That means less toxic chemicals in the water that the fish are in. That’s great news. What happens if the fish eat the plastic beads? Just 0-12% of the toxin is released by the beads because the toxic chemicals prefer to stay inside the beads. That’s more good news! The plastic beads are purifying the water and protecting the fish. The title of the article could have been “Microplastics miraculously effective at sequestering toxins and purifying seawater”.
I hope this shows you how desperate the environmentalists are to do studies that are unrealistic, improperly performed and incorrectly interpreted. It’s shocking.
In fact, at least two studies have proven that microplastics are very effective at binding toxins and protecting marine wildlife (polypropylene study, nylon study). Yet another study directly tested the hypothesis that microplastics (MP) would lead to accumulation of toxins in fish. What they found instead was:
“Contaminant concentrations in the muscle tissue were unrelated to the MP levels in fish, suggesting a lack of direct links between the levels of HOCs and MP ingestion. Thus, despite their ubiquity, MP are unlikely to have a measurable impact on food intake or the total body burden of hydrophobic contaminants in Baltic herring.”
Source: Hydrophobic organic contaminants are not linked to microplastic uptake in Baltic Sea herring, M. Ogonowski, V. Wenman, S. Danielsson and E. Gorokhova
Oyster reproduction is affected by exposure to polystyrene microplastics
Sussarellu et al., PNAS March 1, 113 (9) 2430-2435 (2016)
The authors state:
“This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring.”
I then noticed this:
“analyses on extracted micro-PS particles detected bibenzyl and 1(2H)naphthalenone,3,4,dihydro4phenyl with >90% correspondences”
This means that the PS spheres they used contained toxins not found in household polystyrene. The beads used contain added surfactant and are cross-linked with divinyl benzene, which explains the toxic extractibles found (see manufacturer’s description).
In conclusion, this experiment cannot be trusted because it was not performed properly. They used polystyrene beads when only 1% of plastics in the ocean is polystyrene. They also used a special type of polystyrene that contains toxic chemicals not found in normal polystyrene.
Next is a study on worms that feed on sediment.
“Biouptake in worms was lower by 76% when PCBs were associated with polypropylene compared to sediment. The presence of microplastics in sediments had an overall impact of reducing bioavailability and transfer of HOCs to sediment-ingesting organisms. Since the vast majority of sediment and suspended particles in the environment are natural organic and inorganic materials, pollutant transfer through particle ingestion will be dominated by these particles and not microplastics. Therefore, these results support the conclusion that in most cases the transfer of organic pollutants to aquatic organisms from microplastic in the diet is likely a small contribution compared to other natural pathways of exposure.”
Differential bioavailability of polychlorinated biphenyls associated with environmental particles: Microplastic in comparison to wood, coal and biochar
Another study states the following about microplastics (MP):
“Thus, despite their ubiquity, MP are unlikely to have a measurable impact on food intake or the total body burden of hydrophobic contaminants in Baltic herring.”
Hydrophobic organic contaminants are not linked to microplastic uptake in Baltic Sea herring
Both polyethylene, and polypropylene, by far the most abundant microplastics in the ocean, have been proven to absorb toxins from water and sequester them, thereby protecting marine wildlife. Nylon has been shown to do the same, the PA (polyamide) particles were themselves harmless and reduced the amount of BPA in the water:
“The PA particles themselves did not induce negative effects, while the effects of BPA alone followed a typical dose-dependent manner. Sorption of BPA to PA particles prior to exposure led to a reduction of BPA in the aqueous phase.”
Microplastics Reduce Short-Term Effects of Environmental Contaminants. Part I: Effects of Bisphenol A on Freshwater Zooplankton Are Lower in Presence of Polyamide Particles
For the next article, I did a search of the title to find a link to share here and Google revealed this hit, which was quite a surprise:
“We wish to report a strong suspicion of research misconduct in the following study by researchers at Uppsala University, published in the journal Science on June 3 2016”
Lönnstedt OM and Eklöv P (2016) Environmentally relevant concentrations of microplastic particles influence larval fish ecology. Science 352: 1213-1216. doi: 10.1126/science.aad8828
“Regarding point #4 above, we have evidence including witness reports, photos of the experimental setup, and email correspondences that the experiments reported in the paper were not performed as described by the authors. To be clear, there is a significant mismatch between what is described in the paper and how the experiments were actually performed. Examples include:
- The exposure times of eggs and larvae reported in the paper are longer than the actual duration of the experiment at the Ar research station in Gotland, Sweden.
- The actual number of replicate tanks and fish is lower than what is stated in the paper.
- Aquaria maintenance and monitoring were not conducted as described in the paper.
For these and other reasons, we strongly suspect that this study constitutes a case of research misconduct.”
You read that correctly. Apparently, these researchers were so desperate to make plastics look bad that they falsified their results. After an investigation, the article was retracted.
I have many more articles that I will be reading and commenting on here.
There is one meta-analysis on this topic but unfortunately, they did not properly screen the articles they included. I checked with the lead author and she admitted that even the studies where they intentionally soaked the plastic in toxins were included. I hope that they do a new meta-analysis only on articles that have been conducted properly. Even with the inclusion of those suspect studies, the meta-analysis showed surprisingly few adverse effects.
Microplastics in fisheries and aquaculture – Status of knowledge on their occurrence and implications for aquatic organisms and food safety
One may wonder whether creatures containing plastic could be eaten by people and whether any harm would result. I found one detailed report on that topic and they concluded:
“As an example, a worst case estimate of exposure to microplastics after consumption of a portion of mussels (225 g) would be 7 μg of plastics. Based on this estimate and considering the highest concentrations of additives or contaminants reported in microplastics, and assuming complete release from microplastics, the microplastics will have a negligible effect on the total dietary exposure to PBTs and plastic additives. These contaminants are estimated to contribute only <0.1 percent of the total dietary exposure to these compounds.”
I have not seen a single credible article showing microplastics to be toxic. When reading such studies we should ignore studies based on polystyrene, ignore studies using 100-10 million fold more particles than are actually present in the ocean and ignore studies where the plastic used was intentionally loaded with poison. Realistic, professionally designed experiments are needed if we are to draw meaningful conclusions and so far those realistic studies show no harmful effects.