Microplastics have become an inescapable part of our environment, and Pennsylvania is no exception. But a recent study offers a glimmer of hope: the tide may be turning. While the problem is far from solved, the research provides a fascinating insight into the movement and accumulation of microplastics in our waterways, and it suggests that human behavior can make a difference.
As environmental engineers and scientists, we set out to map the journey of microplastics across Pennsylvania. What we found was striking: microplastics are nearly everywhere, with their concentration in sediment doubling every 20 years since the 1950s. This mirrors the rise of global plastic production, which has doubled every 20 years since the 1950s. The world now produces over 500 million tons of plastic annually, and the U.S. is a leading producer of plastic pollution, generating over 48 million tons of plastic waste annually.
What makes this particularly fascinating is the sheer scale of the problem. Microplastics are now found in the air, water, soil, food, and living organisms, including humans. They enter our bodies through ingestion, inhalation, and skin contact, and studies have found them accumulating in our blood, brain, and reproductive systems. This raises a deeper question: how do we classify and understand the health threats posed by plastics?
Plastics are sorted by the resin identification code system into seven categories in the U.S. However, the mystery of missing plastic remains. More than 80% of mismanaged plastic waste is estimated to be transported by rivers to coastal environments, yet there is still far less plastic in the ocean than models predict. Our study, which focused on Pennsylvania's Raystown Lake, Conemaugh River Lake, and the John Heinz National Wildlife Refuge, aimed to investigate this paradox.
What we found was surprising: microplastic levels in rural areas were similar to those in densely populated regions. On average, we found about 1,125 microplastic particles per pound of sediment, but concentrations varied widely. Reservoirs and estuaries do trap microplastics, but not enough to account for the ocean's missing plastic. The most abundant types of plastic we found were polypropylene and polyurethane, both single-use plastics.
One thing that immediately stands out is the role of land use. While land use alone can't reliably predict microplastic concentrations, it's clear that different land uses have varying impacts. Urban areas, for example, may have higher concentrations due to increased plastic use and waste. However, our study also found that estuaries, which are partially enclosed coastal bodies, do trap microplastics, offering a glimmer of hope.
What this really suggests is that human behavior can make a difference. In the most recent sediment layers, we found a small but measurable decrease in microplastic concentration, which could reflect better recycling rates and broader awareness of plastic waste. This is modest, but it suggests that the problem is at least partially responsive to human behavior.
So, what can you do to decrease your exposure to microplastics and help decrease their spread? Stay informed about which plastics carry the greatest health risks and check the recycling number on the bottom of containers before you buy. You can also swap out single-use plastic cups, straws, and food containers for alternatives, such as glass, stainless steel, or unbleached paper. These small changes can make a big difference in reducing your exposure to microplastics and helping to protect our environment.
In my opinion, the study highlights the urgent need for action on plastic pollution. While the problem is complex and far-reaching, it's clear that human behavior plays a crucial role. By staying informed and making small changes in our daily lives, we can all contribute to reducing our exposure to microplastics and helping to protect our environment for future generations.
