[co-author: Salvatore Badala]
Corporations produce more than 400 million metric tons of plastic per year. With that number set to triple by 2060, the growing amount of microplastics in the environment is of increasing concern to public health. Microplastics are virtually everywhere, leaving little to be done to safeguard human health unless widespread cleanup efforts are swiftly implemented.
A Plethora of Health Effects
Microplastics are fragments of any type of plastic measuring less than 5 millimeters long. They are the result of degradation of larger plastic products like textiles, tires, paint, artificial turf, and plastic pellets. Nanoplastics, which are even smaller than microplastics, are especially worrisome; measuring less than 1 micrometer long, they are small enough to enter the bloodstream and accumulate in cells and organs.
A recent study linked the presence of nano- and microplastics in the carotid artery tissues to an increased risk of heart attack, stroke and early death. Alarmingly, microplastics are even able to cross the robust defenses of the blood-brain barrier. Accumulation of microplastics in the brain may lead to cognitive decline, behavioral changes, and altered motility.
Microplastics can also contain heavy metals and “forever chemicals” such as per- and polyfluoroalkyl substances (PFAS). As their name suggests, forever chemicals are hard to get rid of, accumulating in cells and organs. PFAS are linked to increased rates of kidney cancer, testicular cancer, hypertension, high cholesterol, and preeclampsia in pregnant women. PFAS are also known endocrine disruptors, meaning they can interfere with the normal function of hormones, leading to thyroid disorders, early puberty, low birth weight, birth defects, fertility problems, and more.
Multiple Exposure Channels
Due to their small size, microplastics can pass through water treatment systems and end up in drinking water. They can also transfer onto food from food packaging. Microplastics have been found in fish, beef, chicken, pork, and even breastmilk. When ingested orally, microplastics can cause gastrointestinal distress, including nausea, vomiting, and abdominal pain.
When inhaled as airborne fragments, microplastics can damage lung tissue and cells, leading to negative impacts on the immune system. Additionally, they can accumulate on the skin from cell phone cases and from the use of personal care products like toothpastes and facial cleansers containing exfoliating microbeads.
The full extent of the impact of microplastics on human health is yet to be discovered. If no clean-up effort is made, we can anticipate microplastics becoming a wider public health crisis, especially if the top global plastic producers are not held accountable for their far-reaching impact.
