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How closely is human health linked to ocean plastic pollution?

“Do a conference on oceans and human health”, said a good friend of mine to me a couple of years ago. “That’ll get people’s attention” he said, referring to the overall pollution crisis the world’s oceans face, which he and I care quite a lot about. We were discussing what it would take to drive more business interest in the subject.

His point was that most people only really care about the environment when it directly affects them. Or, to be more nuanced, is visible and inescapable. Look at climate change. It hasn’t yet affected most of our lives in a really significant way (unless you live on a low lying pacific island or are a rare/vulnerable species expert) but we’re starting to see its impacts around us.

So, a couple of years after my friend’s suggestion, we’ve tweaked his idea to make it about ocean plastics pollution, and we’re running a debate/science/solutions based conference called: “How business can tackle ocean plastic pollution” on 26-27 October in London. We’ve had lots of big companies, key NGOs and others sign up already, so that’s nice. Join us if you can.

Back to the title of this post, in our research for the conference, we came across this document by the Netherlands-based Plastic Soup Foundation.

Here’s a few scary excerpts:

  • In 2013, scientists at the Plymouth Marine Laboratory in England filmed plankton, the base of the food chain, consuming plastic.
  • Researchers at the University of Lund (Sweden) have demonstrated that nanoplastics can move through the food chain and affect the animals at the top it.
  • Microplastics are found in 63% of the prawns in the North Sea.
  • Japanese oysters filter microplastics out of the water, the consequences of which are fertility problems and deformed offspring.
  • Italian research shows that the consumption of polyvinyl chloride (PVC) can damage the intestines of sea bass.
  • American scientists have discovered that microplastics can cause liver cancer in fish kept under laboratory conditions.
  • A quarter of the fish bought at local fish markets has plastic in their digestive tracts. Scientists concluded this from researching fish from fish markets in Indonesia and California.
  • And very recently, in July 2016, scientists demonstrated for the first time that microplastics can leak toxic chemicals in the bodies of fish. Scientists at three Japanese universities had previously linked chemicals in the tissue of sea birds to plastics in their stomachs.There’s a lot more in the PDF document linked to above. The document goes on to highlight research around how all this may impact human health:”There are enough reasons to do more scientific research into the health risks for humans. In June 2016, the Dutch scientists Dick Vethaak and Heather Leslie addressed this issue in a pioneering publication in the Environmental Science & Technology journal entitled ‘Plastic Debris is a Human Health Issue’. They looked at three core issues:
    • Plastic contains several added chemicals, including hormone disruptors. What damage do these chemical substances cause and/or what are the physical consequences?
    • Plastic can be a carrier of viruses and parasites. What is this doing to our bodies?
    • Nanoplastics can pass through our cell membranes. What are the consequences?Vethaak and Leslie estimate that the damage caused to human health can amount to billions and they link this to the overproduction and over consumption of plastic coupled with a lack of knowledge.”

The Plastic Soup Foundation then draws links between the chemicals found in the plastics in the oceans and research that they say shows that such chemicals are harmful to human health, such as hormone disruptors and persistent organic pollutants. They note that:

“In 2013, 89 international scientists issued a warning. They signed the Berlaymont Declaration in which they stated that there had never been so many endocrine-related diseases before. They pointed to the huge increase in breast-, prostate- and testicular cancer and other hormone-related conditions in Europe.”

Now, I’m not a scientist. Nor am I someone who takes everything they see from campaigning NGOs at face value, but you can see where I’m going here. I suspect the answer to my question in the title “How closely is human health linked to the oceans?” is probably “quite a lot”, if you consider the health of fish populations, which after all, according to the UN, are vital to nearly half the world’s population: “Oceans serve as the world’s largest source of protein, with more than 3 billion people depending on the oceans as their primary source of protein“.

Of course, if the studies cited above, particularly that carried out by the Berlaymont Declaration signatory scientists, are right, we’ve got another big, related, problem on our hands, which is a chemicals-related hormone disruption/health crisis looming somewhere in the near future. I’ve published and edited a number of articles on the dangers of chemicals (or the exaggeration of the dangers) in the last fifteen years, and I know it’s a minefield of an area. One study will show one thing, another, the opposite.

Scarily the scientists behind the Berlaymont Declaration (and they may all be left wing ideologues perhaps, but I doubt it) also write this:

  • “For many endocrine disrupting effects, internationally agreed and validated test methods do not exist, although scientific tools and laboratory methods are available.
  •   For a large range of human health effects, viable laboratory models are missing altogether. This seriously hampers progress with understanding the full extent of risks.”

That’s not good, and surely needs addressing.

We do know that in general, consumers are not comfortable knowing that Persistent Organic Pollutants or flame retardants or glyphosate are prevalent in the environment or our bodies. We’ll find out eventually, I suppose, just how damaging these things are.

Back to oceans specifically, after some time searching for further credible research (you could argue the Plastic Soup folks are cherry-picking stats and findings to suit their cause, so I’ve been looking for peer reviewed scientific papers or summaries of these, and disregarding many ‘sources”) I’ve found this:

“Rolf Halden, associate professor in the School of Sustainable Engineering at Arizona State University and assistant director of Environmental Biotechnology at the Biodesign Institute has undertaken a survey of existing scientific literature concerning the hazards of plastics to human health and to the ecosystems we depend on. His findings, which appear in the latest issue of the Annual Review of Public Health, are sobering.”

To save you reading time, what’s sobering is essentially a repetition of what’s posted above in terms of potential health risks. So what are the conclusions from a 50 year review of the dangers of plastics in the oceans to human health from his work?

“What are the overall effects of the plastics we unwittingly ingest? The literature Halden surveyed is ambiguous on this point, despite more than half a century of study. Part of the difficulty lies in the absence of good controls for studying health outcomes, as plastic exposure is a global phenomenon, and finding unexposed subjects for comparison is nearly impossible. It is known however that health effects vary depending on who is exposed-and when. Infants and pregnant or nursing mothers are at heightened risk for toxic exposure or passage of BPA and additives like DEHP.”

So we don’t really know for sure, but we know it’s not good. That’s my answer to the question that serves at the title of this post. Is that good enough? It is when it comes to climate change, for example. The infographic I found and have posted below has one statistic in it that on its own ought to be enough for us to focus on cleaning up the oceans.

That stat? “70% of the oxygen we breathe is produced by marine plants”.

My conclusion is that ocean plastics are a crisis we can see, and perhaps we can do something about. It should lead us to tackle the bigger crisis of overall ocean health, which is clearly linked to human well-being, and doing so may be a useful first step in that direction. The concern of course is spending too much time on one issue (oceans plastics), to the detriment of something more significant (say, ocean acidification and climate change).

As to the human health impacts, we’ll be discussing those in more detail on October 26-27 in London, I hope you can come along and join the dialogue.

Our forthcoming events