I talk about microplastics a lot with my students. This is mostly in the context of marine food chains, including fishes that are eaten by people. Microplastics themselves are toxic but they also act as tiny magnets for other toxins such as PCBs (a known carcinogen), mercury and other heavy metals (neurotoxins), BPA, phthalates, and pesticides like DDT (a carcinogen that also interferes with reproductive systems; banned here, but not in other countries). These toxins are all fat soluble. That means that once they are in your body, they hunker down in your fat cells instead of being flushed out of your body with your water-based liquid wastes. The greater the concentration, the greater the effects. The higher up in the food chain you are, the more of these toxins you have stored up in you. Science teacher moment: on an individual level this is called bioaccumulation (building up in a lifetime) on a food chain level it’s called biomagnification, with the top levels having higher (magnified) amounts built up in them because they eat a lot more.
A study published recently in the peer-reviewed journal Environmental Science and Technology compiled data on microplastics in bottled water, seafood, sugar, honey, alcohol, and air and analyzed that data in the context of average consumption rates of Americans and activity levels (summary here; note that this summary does not report on inhalation of microplastics, only consumption). While the analysis makes a number of assumptions and was not able to include major dietary factors such as grains, meats, and dairy, the results are alarming and, even more alarming, are likely a gross underestimate of the amount of microplastics that enter the human body annually. The average American adult male may ingest nearly 60,000 and adult female nearly 54,000 microplastic particles annually, most of that through bottled water and seafood. Bottled water averages 94 particles per liter, while tap water averages 4 particles per liter. Another very compelling reason to ditch the bottled water habit (see some other reasons in my April 12 post, “#banthebottle”). Of course some towns and cities have to do some work to ensure safe tap water for their citizens, but that’s a whole other story. In terms of seafood, of course, the more you eat, the more microplastics enter your body (bioaccumulation!). What you eat also makes a difference. Big predatory fishes such as tuna and swordfish will likely have more plastics in them than planktivorous fishes such as anchovies (biomagnification!). Consumption is not the only route for microplastics to enter your body. Males may inhale an additional 60,000-120,000 (females 48,000 to 100,000) microplastic particles per year. Many plastics are volatile, meaning that they spontaneously emit particles to the atmosphere or to the liquids they are immersed in. You know that new car smell? Airborne plastic particles. Just one example of thousands.
So, what is the solution? We are stuck with all the plastics that have ever been made (over 8,300,000,000 metric tons of it) so they will remain a problem forever. We need to move away from producing new plastics. I don’t see this happening any time soon, since global production in 2015 was 380 metric tons and the annual production growth rate is high (8.4%; Geyer et al. 2017). We have become a “throw away” society and a society in which both convenience and consumer demand for cheap products are driving product manufacturing and development. Think about the packaging that is on nearly everything now. I’m hard-pressed to find items in my grocery store that do not have some sort of plastic wrapping or container. I’ve been buying a few things in bulk lately to cut back on the plastics that I have to throw away at home, but that is really just a drop in the bucket. We need a whole new system.
Consumers need to start demanding a return to glass bottles and start eating whole, unprocessed foods. Random small example: I stopped buying a particular brand of salad dressing years ago when they went from glass bottles to plastic ones. When I e-mailed the company to complain, I got the response that the plastic bottles were recyclable. Of course, I wrote back about how plastics can only be down-cycled and glass can be recycled forever and then expressed my intent never to buy their products again. I did not get a second response from them. Now I buy salad dressing from Trader Joe’s (all glass bottles!...but many other items in plastic, you can’t ever really win) or mix up some olive oil and vinegar. There are plant-based, compostable alternatives to plastic but those of course are more expensive now because of low demand. Of course, packaging is not the only place plastics are used. Many vehicles today have bumpers made of plastic and interiors composed mostly of plastic. There is plastic furniture. I’m looking across my room at a plastic fan. It’s kind of crazy how many things we use are composed of plastic.
Back to the question of what do we do? For a start (shooting for the stars here) I would like to see federal legislation requiring manufacturers to replace fossil fuel plastic packaging with compostable, plant-based products and I would like to see federal legislation requiring all take out containers, single-use straws and utensils and shopping bags to be compostable. These things exist. They just need to be cheaper for stores, companies, restaurants, and consumers to purchase than fossil fuel plastics. That means we need to create a greater demand for those plant-based products in tandem with taking away the fossil fuel industry subsidies. If plastics were more expensive at the source, the market would naturally shift to alternatives. It’s back to my common theme: money drives everything. You can start by taking small steps like I have to try and cut back on plastic packaging. What you put out in the environment will come back to you in your food, water, or air (karma!). You can also support plastic banning legislation in your town, city, or state and let your federal legislators know that you’d like them to take some action too. Write e-mails, make phone calls, go to town meetings. Collective consumer action is a critical piece.