Microplastics critique is a damp squib, not a bombshell exposé of faulty science

What is a lethal dose of plastics poisoning? We don’t know yet, but some day we will.

Last week, The Guardian framed a recent critique of early-stage studies into the extent of microplastics in the human body as a “bombshell”, and one study in the field as “a joke”.

The broader field of research that’s being challenged here is young. It’s trying to establish the extent to which tiny shards of plastics are collecting in human tissue, mostly in our livers, kidneys, arteries, blood, hearts, placental tissue and even our brains. The Guardian’s supposed exposé raises red flags about the methods used for collecting and testing samples, particularly those relating to blood and brain samples. It concludes that the findings are too error-prone to be taken seriously.

The Guardian’s reporting here is misleading, and only serves to confuse the public.

Just as science needed time to quantify the harms of long-term tobacco use, we need time to measure the extent to which microplastics are accumulating in our bodies and what the public health consequences will be.

Yes, this is an emerging field of research, and should be subject to the same scientific rigour and journalistic critiques as any other. But this fast-evolving area must be communicated responsibly, and with the public good in mind.

Dismissing the first-round findings of such a greenfields area of scientific research as “scaremongering” will also play into the hands of those stalling global efforts to settle on a UN Environment Programme plastics pollution treaty.

As we’ve seen with communicating other complex areas of science – carbon pollution driving climate collapse; food-like products polluting our bodies with the “oil spills” of obesity, diabetes and the supposedly self-inflicted cancers of lifestyle – the public often reaches for simple truths and silver-bullet solutions amid the often confusing messages that come through with early-stage scientific findings.

How many readers will now dismiss the whole field of research, and slip into the kind of hopeful denialism that many of us default to when we’re overwhelmed by the consequences of big polluting systems that seem too enormous for us to change?

The “bombshell” term that The Guardian introduces into the article comes from the chemist Roger Kuhlman, who previously worked at the Dow Chemical Company – the kind of company that might benefit from downplaying the public health risks of microplastics in our bodies.

A more appropriate expert to approach for comment on this issue would be someone schooled in public health, with a more intimate knowledge of the biology at work, and no vested interests.

Consider the less-sensational, but more responsible framing by Dr Stephanie Wright, associate professor of environmental toxicology at the School of Public Health, Imperial College London. Yes, this field of research is young, she says in an interview with the BBC in 2025. Yes, the tech for measuring the build-up of microplastics in human tissue is prone to error. But this merely shows how urgently we need to speed up the work and get more robust results.

Why dismiss some researchers’ work as “a joke”? Another sensational – dare I say, click-bait – term that doesn’t work in the service of a well-informed public.

Wright’s more measured framing is to introduce into our discourse the fact that we need to consider what the possible toxicity from microplastics pollution in our bodies could be. Like all toxins, she argues, how damaging it is is dose-dependent. Dose, in this case, depends on how much plastic is in our tissue, which polymers, their size and surface area, how hazardous these are, and how long they remain in the body.

Yes, there are big gaps in knowledge here. But until we’ve filled these gaps, she urges us towards taking a precautionary approach.

The Guardian’s reporting informs public understanding and policy response at a global level. How the publication frames a matter as important as this will inform policymakers here in Africa.

Even well-informed people find it hard to understand a field as complex as this. How much more so for those who may not have the technical or scientific background to appreciate how scientific consensus evolves from greenfields studies to textbook knowledge?

The scientific method is a tool to help understand the world. It has steps built into it to tease out observer bias and wishful thinking, and it has self-correcting measures to help us go from emerging, rough-grained knowledge to solid theory. Journalism has similar processes for vetting evidence and self-correcting.

Communicating this evolving knowledge needs to be done with skill and care. Yes, let’s call for good science, but let’s not throw shade on early science in a way that’s inaccurate, misleading, and harms the public good. DM

Leonie Joubert is a multi-award winning science journalist and author in South Africa, where she reports broadly on pollution issues relating to climate collapse, the food system and plastics, among others. She is a research associate with the Stellenbosch University School for Climate Studies and a grant recipient of the Henry Nxumalo Foundation which supports investigative journalism in Africa.

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