Human health is being impacted by plastic ingestion and that’s likely to worsen, with scientists predicting the rate of the pollutant entering the ocean could seriously accelerate in the coming years.
By 2040, the damaging plastics are projected to be entering the ocean at a rate 2.6 times greater than today. The warning comes after researchers detected a “rapid and unprecedented” increase in ocean plastics from 2005 onwards. The study, published in PLOS ONE on Thursday, estimated up to 358 trillion plastic particles were floating in the ocean in 2019, leading them to call for “urgent international policy interventions”.
Responding to the study’s findings with concern, University of Technology Sydney scientist Dr Charlene Trestrail said while scientists have known for a long time that microplastics are a major problem, the research suggests the scope of the issue has been worryingly underestimated.
Plastics are a cocktail of hazardous materials
The study was published just days after Australian scientists revealed they had identified a new disease in birds called plasticosis that causes stomach tissue to scar.
Dr Trestrail, who specialises in the impact of plastics on marine creatures said tissue damage and inflammation has previously been identified in other creatures including mussels.
She warns plastics can interfere with reproduction, and stunt growth because the they can interfere with the production of digestive enzymes in the stomach, preventing animals from absorbing nutrients. But the bad news doesn’t end there — plastics can also contain endocrine disruptors that interfere with chemical signalling as well as neurotoxins that harm the nervous system.
Scientists are only beginning to understand the impact of microplastics because they are a cocktail of substances. “That’s really hard for us to imagine because plastic is solid, but they are actually composed of many different chemicals that we add in during the manufacturing process,” Dr Trestrail said. “Over time those chemicals leach out into the environment, and that environment can be the insides of animals.”
How humans can ingest microplastics
Opening a bag of chips
Drinking from a plastic water bottle
Breathing in dust
Eating contaminated seafood
Using plastic cutlery
Plastics found in human bloodstream
While Dr Trestrail’s research has been limited to animals, she doesn’t see a reason why microplastics couldn’t also impact humans. “We are already full of plastic particles,” she said. “There are [research] papers that have found them inside human faeces and insider our blood.”
While larger microplastics generally pass through the digestive system, as they continue to break down into smaller pieces they are able to pass through intestines and into the bloodstream, allowing them to travel through the body.
“It would be so nice to think that the plastic would just get smaller and smaller, and then it would go away and stop being a problem. But the reality is… it just gets more problematic.”
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