“There’s more plastics in the ocean than fish,” the headlines on my social media feeds scream on a daily basis, and with depressing certainty. As a regular user of social media it is hard not to be swamped by the daily horror stories, links to mainstream media reports, brief two-minute videos and clever memes warnings about the evil plastics menace that is killing the planet.

Is there – or will there be – really more plastics in the ocean than fish? Is this on a per unit or per kilo basis? Where’s the data? It doesn’t seem to matter; there is no doubt that there is a huge amount of plastics polluting our oceans, so wouldn’t it make a great meme? At the risk of being labelled a ‘heretical denier’ (or worse) I took a sceptical deep dive into some of the more recent headlines.

Fake science

In June 2016, a paper, which at the time was heralded as a ‘landmark breakthrough’ claiming to show the devastating impact of microplastics on fish, was published in the prestigious US journal Science. The study claimed that fish became “smaller, slower and more stupid” when exposed to tiny plastics fragments in the marine environment. It also suggested that perch larvae favour eating plastics over their natural prey “like teenagers eating junk food”.

Widespread mainstream media coverage, and an avalanche of social media memes, quoted the work in June 2017 and helped cement the case for banning microbeads in cosmetics and clothing. But it was entirely fake science.

Uppsala University’s Josefin Sundin was one of seven researchers in five countries unconvinced by the paper. They claimed shortly after its publication that it contained fabricated data.

Sundin was at the Ar Research Station on Gotland, an island in the Baltic Sea, with Fredrik Jutfelt of the Trondheim Norwegian Institute of Science and Technology at the time Lönnstedt supposedly carried out her research there. Both said the research simply never took place.

Sundin and Jutfelt claimed the authors hadn’t spent enough time at the station to do the studies described in Science. They pointed out many other problems in the paper, including the fact that the full data wasn’t posted in a public repository, as Science requires – the authors, Lönnstedt and Eklöv, subsequently claimed the data was on a laptop that was stolen from a car soon after the paper was published.

Although a preliminary investigation by the university published in August 2016 dismissed the doubters’ claims, an expert group at Sweden’s Central Ethical Review Board (CEPN) hired fish researcher Bertil Borg of Stockholm University to delve into the case.

His report, sent to CEPN in February 2016, made clear that Lönnstedt and Eklöv didn’t have answers to many problems and said they had made false statements. But Borg’s conclusion was somewhat ambiguous: “The suspicions of deceit cannot be denied.”

The CEPN group dismissed that ambiguity. The statement said that answers provided by the accused “have been, in all essentials deficient, at times contradictory and have not infrequently given rise to further questions”. It declared the duo “guilty of scientific dishonesty” for not having posted the data, and also for making false statements about obtaining ethical approval for the study, both in the Science paper and in their contacts with the committee.

Although Lönnstedt was responsible for carrying out the experiments, Eklöv didn’t actually visit the research station and the report does not absolve him, noting “in his role as a senior researcher, [he] bore significant responsibility for what transpired”.

The CEPN panel also had some stern words for Science: In its view, the journal was “deficient” in enforcing its open data policy. They add that even if the research had been conducted as described, it would not have proved anything. The microplastics supposedly used in the study were mixed with detergents, according to the report, and the authors didn’t say they had removed these detergents. They, and not the plastics beads, could have caused the effects on fish larvae. That Science even accepted the paper for publication is “remarkable”, the group said.

All of that went largely unreported and the memes just keep coming, even the fact that just six months after publication, on 3 December 2016, Science published an ‘editorial expression of concern’ – that’s code used when a paper has come under suspicion, and deputy editor Andrew Sugden subsequently published a retraction after the authors were found guilty of scientific misconduct.

Plastics soup

Microplastics clearly have become the ‘hot topic’ and research funds for PhD students are readily available globally. Now we have reports that apparently the food we eat, our tap water, flying insects, the beer we drink, the clothes we wear and even all the air that we breathe are contaminated with microplastics. It is even in human stools, according to a study suggesting the tiny particles may be widespread in the human food chain.

That requires some explanation: The small study examined eight participants from Europe, Japan and Russia. All of their stool samples were found to contain microplastics particles. Up to nine different plastics were found out of ten varieties tested for, in particles of sizes ranging from 50 to 500 micrometres. Polypropylene and polyethylene terephthalate were the plastics most commonly found.

On average, 20 particles of microplastics were found in each 10g of excreta. Based on this study – of eight participants – the authors were able to extrapolate data to estimate that “more than 50 per cent of the world population might have microplastics in their stools, though they stressed the need for larger-scale studies to confirm this. Meanwhile, a recent Italian investigation also found microplastics present in soft drinks.

Not proven

A study published by Elsevier in April 2018 entitled Risk assessment of microplastics in the ocean: Modelling approach and first conclusions, by Gert Everaert, Lisbeth Van Cauwenberghe, Maarten De Rijcke, Albert A Koelmans, Jan Mees, Michiel Vandegehuchte and Colin R Janssen suggests that the case against microplastics, as Scots Law would have it, is ‘not proven’.

While the researchers do not contest the existence or volume of microplastics, according to the study’s introductory paragraph, “it is then often inferred that microplastics do cause adverse ecological effects and, hence, are an imminent threat to the marine environment”. The report continues: “However, these types of statements and the classification of microplastics as contaminants of concern have often been made without adequate, scientific confirmation. “Given the rise of microplastic-related studies our knowledge of microplastics pollution in the marine environment has significantly increased over the past decades, but the environmental or ecological (including human) risks of microplastics in marine environments have, to date, not been addressed and quantified.”

The authors, instead of going out and analysing the oceans, air, water, beer, insects and excreta, analysed the scientific reports themselves and the methodologies by which conclusions were drawn. In total it is an interesting insight into the process of scientific modelling, but between the formulae and data charts lays the authors’ criticism: “Numerous monitoring campaigns of different marine systems have revealed that microplastics are ubiquitous and can be present at very high concentrations.”

In comparison to these monitoring efforts that result in exposure concentrations, effect studies aiming to quantify the (adverse) effects of microplastics are much more rare and may suffer from a number of shortcomings: The data collected does not always allow for the evaluation of the potential effects of microplastics (if environmental risk cannot be assessed solely based on monitoring or ingestion data); most of the laboratory studies are poorly standardised; and few of these studies are performed with the aim of establishing a concentration-response relationship (needed to derive effect thresholds).

Additionally, (adverse) effects of microplastics exposure have mostly been investigated by administering unrealistically high (usually single-dose) concentrations of microplastics to test organisms (Van Cauwenberghe, 2015; Koelmans et al, 2017). Most effect-oriented laboratory studies were aimed at demonstrating the ingestion or uptake of microplastics by marine organisms (Lusher et al, 2015). The presence of microplastics in the marine environment has been an issue of concern for more than a decade. A great number of studies conclude that microplastics are a threat or risk to these systems.

However, these conclusions are mostly based on conjecture and inadequate data sets (that is, ingestion data sets are only part of the risk-related research question). Plastics remediation projects can help at a local scale, but mentality shifts that prevent plastics from being used and emitted into the environment, sustainable alternatives for plastics, and science-based policy guidelines on safe concentrations are urgently needed.