On Tuesday, January 13, the Guardian ran an article alleging “bombshell doubts” about the validity of methods used to detect micro and nano-plastics (MNPs). The article cited criticism from a former Dow researcher and a scientist in Germany. Noting that seven microplastics studies had received published critique, the article questioned “what is really known today and how concerned people should be about microplastics in their bodies.”
For what it’s worth, over 6,000 peer-reviewed articles on microplastics were published in 2024 alone, with hundreds of studies touching on human exposure and detection. This suggests a large denominator for a numerator of seven.
A flurry of push-back ensued, with physicians, scientists, and others penning letters to the editor and on social media. Authors (including this one) pointed out that microplastics are unquestionably present in the human body, and that magnifying uncertainty by elevating fringe dissent is a well-worn tactic from the Tobacco Industry Playbook. While we know normal scientific method relies on healthy debate, we also know that industry stakeholders will readily exploit it to forestall regulation.
Doubling down on doubt
The Guardian soon doubled down on its assertion that MNP science may be bunk. Congratulating its own “extraordinary reporting,” the article opened by placing concerns about microplastics in the human body in the past tense. What once seemed like groundbreaking discoveries, claimed editor Aamna Modin, have now been eroded by “a steady drip of criticism.”
For what it’s worth, the “drip of criticism” that Guardian writers have described focuses mainly on a single detection technique, Pyrolysis GC/MS, which has been used to detect plastics in human tissue – including in the brain. After dissolving the tissue in solvent, investigators identify the material that is left by heating it until it vaporizes, then identifying the molecules in the fumes.
The trouble, some reviewers point out, is that polyethylene (PE) and polyvinyl chloride (PVC) molecules can look the same as those derived from fatty acids such as triglycerides. This is true, and investigators readily note that PE and PVC are likely over-represented, but not to the point of invalidating the findings. Plastics – including an abundance of other resins beyond PE and PVC – are present in the human body and their concentrations are likely increasing over time.
“Exactly how science works”
On the Friday after the original “bombshell” piece was published, Washington Post journalist Shannon Osaka opened the conversation to numerous independent scientists with an article interviewing several researchers in the field. While acknowledging that no method is perfect, Osaka’s interviewees emphasized that multiple detection techniques — including infrared spectroscopy and pyrolysis — have repeatedly detected a range of plastics in human tissues.
The basic fact of human exposure is undeniable. What seems like controversy, they pointed out, is actually the normal process of science. Osaka gave the last word to developmental pediatrician and researcher Christos Symeonides: “This is exactly how science works in tackling a new problem.”
But this was not the last word, at least not yet. On Sunday, the Guardian came back with another editorial, this one chastising microplastics researchers for bringing controversy onto themselves by publishing work that could be subject to critique.
“Given that there is immense public and media interest in plastic pollution,” opined the paper, “it is unfortunate that scientists working in this area did not show more caution.” It is worth noting that by this logic, the dust-up initiated in the press occurred because scientists working on new methods allowed room for critique. “Hopefully the spotlight trained on the field last week will prompt reflection and future caution.”
Hopefully it will, but not necessarily in the ways the Guardian editors intend. The controversy that the paper stirred may seem novel to readers concerned about microplastics, but it is part of a well-worn series of tactics deployed by industries seeking to delay regulation on dangerous materials, from lead to asbestos to opioids and hazardous chemicals. Not by accident, we refer to this as the “Tobacco Playbook,” and manufacturers have used it successfully for over a century.
Controversy on cue
Here are a few maneuvers we can all recognize:
- Magnify or manufacture uncertainty: Emphasize limitations, variability, and unanswered questions, while ignoring converging lines of evidence.
- Shift the burden of proof: Demand impossible standards of certainty before action, despite acting decisively in other domains with less evidence.
- Promote false balance: Elevate fringe dissent to suggest scientific division where little exists.
- Delay through research: Call for more studies as a substitute for policy, even when evidence already supports harm reduction.
The logic in utilizing these tactics is straightforward and the successes for industry are dazzling: regulatory delay preserves market access, and public doubt weakens support for science and policy. The millions of lives lost to opioids, tobacco, lead, asbestos, and other products even decades after science and medicine understood how deadly they could be are testament to the tactics’ effectiveness.
So the more relevant question may not be whether doubt is being amplified, but why now?
A few elements may be worth noting. The Guardian article emerged on the same day that a conference on Microplastics Exposures and Human Health had drawn approximately 250 researchers together in New Mexico, including reporters from national press outlets that would have covered exciting new findings. None of them did, however, focusing instead on the “bombshell” of controversy that the Guardian claimed to have uncovered.
In a news cycle already saturated with mistrust of experts and fatigue from overlapping crises, the suggestion that microplastics might be “one less thing to worry about” was news that many were likely to embrace – and circulate.
We know enough to act
What now? Science communicators have continued to speak out, largely with the message that the so-called controversy of microplastics research methods is not hullaballoo, but science. Scientists review each other’s work and offer insights and critique, which in turn are used to sharpen the original work, the questions going forward, and the development of better techniques. This is how science does science.
They are also making clear that, to quote Mark Twain, reports of the death of microplastics science were greatly exaggerated. There is no question that microplastics are present in the human body. The challenge for scientists is to understand how many, and what the mechanisms of harm may be. (This charismatic messaging from the Environmental Working Group makes the point nicely.)
For the rest of us, the challenge may be how to implement the precautionary principle while there is still potential to do so. We have enough data to understand that human exposure to plastics is chronic and universal, and that many of the potential health harms are potentially catastrophic. We have enough data to act. Advocacy in this respect is not political – it is an extension of ethical practice. We cannot let manufactured doubt fill the news cycle when there is already so much clarity.
Introducing: The Merchant of Doubt Award
This award recognizes extraordinary commitment to sowing doubt, undermining consensus science, and postponing protections for human and environmental health—often while claiming the mantle of responsibility.