Things That Are Killing Us: Microplastics
Often it is difficult for us to conceptualize how the things around us directly impact us. We produce, use, and consume at rates that are too fast for us to truly understand just how far-reaching the effects of our innovations are. We have to go through each of these issues one at a time to truly understand the scale of everything that's wrong. For this week, let’s take a look at:
There are few things quite as present in the world as microplastics. It is everywhere. There are 51 trillion microplastics in our sea. It’s in our food and water. It’s in our rain. It’s in the deepest trenches of our oceans and it’s also at the summit of our tallest mountains. Microplastics are, well, really small pieces of plastic, typically less than five micrometers, or around 0.0002 inches. Though we have billions of tons of plastic sitting in landfills, microplastics have also made it into our food chain. Smaller animals, like birds and fish, consume the microplastics, which then make their way up the food chain to us and accumulate as the plastics go up the food chain.
Microplastics are a mix of hydrogen and carbon polymer strands, and they also contain chemicals like phthalates (known informally as plasticizers) and polybrominated diphenyl ethers. Phthalates are used to make plastic more durable while polybrominated diphenyl ethers are used to reduce the fire risk of the plastic. As a result, plastic is not biodegradable, and they stay in the ecosystem for decades and can stay there for upwards of hundreds of years. Similarly, when eaten, they can stay in the body for a long time, and they continue to build up. For years.
Microplastics are spread through the use and consumption of plastic, and take two forms. First, there are primary microplastics, which make up between 15-31% of the microplastics found in the ocean. These microplastics are purposefully manufactured, and they’re used in many products that are major parts of our life. It’s in cosmetics and beauty products, fishing nets, microfibers in our clothing, as well as in facial scrubs and toothpaste and much more. The remainder of the microplastics are secondary microplastics. These result from degradation of larger plastic products in the environment, like plastic bottles and plastic bags. These are broken down by environmental factors, such as ocean turbulence and ultraviolet radiation.
The specific composition of microplastics as well as their large surface areas makes them more prone to adhere to organic pollutants in water as well as to more toxic plasticizers that are likely present in the water. One study estimates that the yearly human adult intake of microplastics is 458,000 microplastic particles for treated tap water and 3,569,000 microplastic particles for bottled water. Additionally, studies have found that microplastics can be spread as aerosols, including clear microplastic particles. These get swept up by wind into the atmosphere, which in turn leads to us breathing in air that has microplastics in it. The measurements of the microplastics in aerosols also has measurement error, severely undercounting the actual amount of microplastics that are in the air.
The result is that microplastics became part of our consumption without us realizing. For example, a meta-analysis (analysis of multiple studies on a specific subject) of microplastic presence in salt for human consumption found that the microplastics were in the majority of the samples that were analyzed. This includes sea salt, lake salt, rock salt, and table salt.
The consequences of microplastic consumption are dire. Microplastics can affect immune responses, cause allergic reactions, affect cell membranes, and even cause oxidative stress that leads to cell and tissue damage. Multiple studies have indicated that microplastic exposure can lead to cell death. It is unclear how many people die as a result of microplastic exposure, but the only thing we know for certain is that it is indeed killing us.