There’s even more bad news about microplastics.
Microplastics are rapidly becoming a major problem. They are the end result of poorly disposed plastic items. Discarded plastic eventually breaks down in the environment due to UV exposure, temperature changes, water exposure, or mechanical action. Ultimately, it becomes plastic “dust” that easily blows around the planet and lands basically anywhere.
3D prints are made from a variety of plastics. When those prints (or failed prints, support structures, leftover filament, etc.) are discarded, they will ultimately become microplastics.
There is no proper way to recycle 3D prints because local recycling centers require specific marks on objects to indicate the type of recyclability. Virtually all 3D prints — and especially support structures and other scraps — do not carry these marks, so any 3D print placed in the recycling bin will be instead routed to the landfill.
There are a few ways to clean out microplastics from water, for example. Dirt and other contaminants can settle out or float on top, but microplastics are mixed in the water and cannot easily be removed.
Because of this, we find microplastics in every corner of the world, and that widespread coverage means it is also getting into your food, water, and ultimately your body. A recent study suggested that most people now carry a noticeable amount of microplastics in their brains from this accumulation over many years.
The risk here is that the chemistry of the plastics themselves is now being exposed to the body directly over long periods. Most plastics carry a data sheet that describes their toxicity, which varies considerably. Some are definitely not something you want in your body.
But new research now shows that microplastics have a strong tendency to adsorb toxic metals.
The researchers exposed polypropylene (PP), polystyrene (ABS), and polyethylene (PET) to levels of metal contaminants similar to public waterways and found disturbing results:
“Polypropylene had the highest adsorption capacity of the nanoplastics, but all three showed a strong capacity to grab onto the metals. Lead was adsorbed the fastest, with 99% of it being adsorbed within 5 min by all three types of nanoplastics.”
The problem now isn’t just that these microplastics introduce plastic chemicals to the body, but now they also can bring toxic metals into the body, including lead, cadmium, manganese, and zinc.
This is getting worse, and I’m wondering what things will look like in 20 years when the concentrations and exposures will be even higher.
This is one of the reasons I am looking forward to developments in properly sustainable 3D print materials.
