Tuesday, July 23, 2024

Trash talk: are microplastics truly the horror story we are being told?

Those of you who subscribed to BIG Media Ltd. in the news platform’s inaugural year of 2021 might remember a piece I wrote about the power of critical thinking. I examined the idea of a “Great Pacific Garbage Patch” (Taking a critical look at the ‘Great Pacific Garbage Patch’) – an area in the Pacific Ocean reportedly the size of a small country, and so densely packed with floating garbage that it presents a massive environmental hazard.

Natural skepticism and a bit of critical thinking led me to question the existence of the garbage patch, so I undertook a couple of Google searches and a few elementary calculations. I quickly discovered that the patch is a fictional construct, through which one could sail without noticing any particular concentration of human-made debris.

I was reminded about that bit of critical thinking recently when I saw an opinion piece claiming that recycling plastics is harmful, largely because of the release of microplastics (Recycling plastic is doing more harm than we realise – so what’s the alternative?). The author expounded upon the many dangers of microplastics, to the point that he claimed he tries to avoid using plastics at all – a difficult task in the world today.

Of course, there are headlines aplenty about plastics pollution and the many, many dangers of microplastics. “The Effect of Microplastic on the Human Health”, recently released online says:

“The small particles of microplastics serve as carriers for bacteria and persistent organic pollutants, which are toxic organic compounds that take years to degrade. Moreover, they consist of chemical materials that are hazardous to human and animal health in high concentrations. The humans ingest microplastics by eating marine animals that have consumed the material or through drinking water or breathing air. Therefore, it is very important to have idea and information about microplastics and how to avoid or eliminate their effect on our life.”

WebMD, an online publisher of news and information pertaining to human health and well-being, quotes a researcher calling microplastics “a plastic time bomb,” and expressing the belief that “we are likely facing a public health emergency.” (Microplastics and Health Risks: What Do We Really Know?)

In response to these concerns in public discourse and mass media, Canada’s federal government commissioned an assessment that “found that plastic is polluting our rivers, lakes and oceans, harming wildlife, and generating microplastics in the water we use and drink.” Never wanting to let a good crisis go to waste, the Trudeau government decided to “pursue actions to reduce the amounts of macroplastics and microplastics that end up in the environment, in accordance with the precautionary principle.” (Single-use Plastics Prohibition Regulations – Overview) Canadians are now drinking through paper straws and trying to remember to bring their reusable grocery bags to market to avoid paying for a paper or plastic bag.

What struck me in reading about microplastics was the similarity to the “Garbage Patch” articles – everybody knew about it, everybody knew it was just terrible, but there appeared to be few published facts to back up the rhetoric. Just as critical thinking led me to ask, “How much garbage is really floating out there?” I also wondered “Why are microplastics so terrible? Are there really cases of environmental destruction or disease outbreaks associated with microplastics in the environment?”

As a geologist, the first question that popped into my mind was “What is the difference between the many microplastic particles floating around and the far larger quantities of other microparticles in our environment?” There are billions of grains of sand on a beach – does it matter how many are silica, how many are carbonate, and how many are plastic? There are innumerable silt- and clay-sized particles suspended on our oceans, lakes, and rivers – does it really matter what they are made of? Our bodies are already riddled with microparticles and micro-organisms – so do microplastic particles make a difference?

Exercising my ever-improving search-engine skills, I found that the World Health Organization (WHO) recently compiled a comprehensive assessment of the implications for human and ecosystem health arising from the presence of nano- and microplastic particles (NMP) in drinking water, air, food, and beverages (Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health). They found reasonably extensive literature, with 640 references listed in the report, and they reached some interesting conclusions, including:

  • NMP are distributed across the planet, but in highly variable concentrations
  • There are only crude estimates of human exposure, with insufficient data for a quantitative assessment of total human exposure
  • Evidence is insufficient to determine risks to human health
  • This lack of evidence does not necessarily imply that exposure to NMP is safe or without risk.

WHO notes that there are well-documented health consequences arising from occupational exposure to high concentrations of particular NMP types, but that these findings cannot be extrapolated to background NMP exposure for the general population. As well, there is little evidence to suggest that NMP in food and beverages expose people to hazardous levels of plastic-associated chemicals or pathogens.

The WHO report reminds me of IPCC reports on climate – they compile a lot of relevant scientific research, and attempt to reach appropriate conclusions from that research. Risks and hazards are identified, and best efforts are made to assess their severity. Areas for additional investigation are identified, with the expectation that more reliable results will be obtained in the future.

Very notably, however, neither IPCC nor WHO investigators forecast doom, gloom, or dire consequences based on incomplete information. Horror stories and crises are instead invented by the news media and others who gravitate to such ideas, selecting worst-case outcomes from a wide range of scenarios and deciding that the world must put all else aside to address these highly unlikely developments. In the two articles referenced at the top of this essay, the authors are correct in seeing microplastics everywhere, but they fail to make a case that those tiny particles represent a hazard to people or to the environment.

That said, as with climate change, it is wise to observe the precautionary principle when it comes to microplastics – which means realizing that there are potential hazards, and working toward better understanding and reducing those hazards. But plastics serve many purposes supporting human health and well-being, so regarding them as time bombs or health emergencies is short-sighted and simply wrong.

Brad Hayes
Brad Hayes
Brad Hayes has a PhD in geology from the University of Alberta and is president of Petrel Robertson Consulting Ltd., a geoscience consulting firm addressing technical and strategic issues around oil and gas development, water resource management, helium exploration, geothermal energy, and carbon sequestration. He is an adjunct professor in the University of Alberta Department of Earth and Atmospheric Sciences.

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