Plastic is the most prevalent type of marine debris found in our ocean and Great Lakes. Plastic debris can come in all shapes and sizes, but those that are less than five millimeters in length (or about the size of a sesame seed) are called microplastics. They come from a variety of sources including cosmetics, clothing and industrial processes. Two classifications of microplastics currently exist: primary microplastics are manufactured and are a direct result of human material and product use, and secondary microplastics are derived from the breakdown of larger plastic debris. Because plastic does not readily break down, plastics persist in the environment at high levels, particularly in aquatic and marine ecosystems. If you've ever taken part in a beach clean, you'll know that about 80 percent of the waste that washes up on the shore is plastic.
Petroleum-based plastics don't decompose the same way organic material does. Wood, grass and food scraps undergo a process known as biodegrading, which means they're transformed by bacteria in the soil into other useful compounds. But bacteria cannot degrade plastics. Plastics are synthetic (artificially created) chemicals that don't belong in our world and don't mix well with nature. And we're making most of it from oil—a non-renewable resource that's becoming increasingly expensive. It's been estimated that 200,000 barrels of oil are used each day to make plastic packaging for the United States alone. We use it for mostly disposable, low-value items such as food-wrap and product packaging, but there's nothing particularly disposable about most plastics. Discarded plastics are a big cause of pollution, cluttering rivers, seas, and beaches, killing fish, choking birds, drowning sea turtles, blocking the digestive systems of marine mammals and making our environment a much less attractive place. It takes hundreds of years for plastics to decompose depending on the type of plastic. On average, we use plastic bags for 12 minutes before getting rid of them, yet they can take fully 500 years to break down in the environment (quite how anyone knows this is a mystery, since plastics have been around only about a century).
Some cosmetic companies have replaced natural exfoliating ingredients with microplastics, usually in the form of microbeads. They are often found in face washes, hand soaps, and other personal care products, so the beads are usually washed into the sewage system immediately after use. Their small size prevents them from fully being retained by preliminary treatment screens at wastewater treatment plants, thereby allowing some to enter rivers and oceans. In 2015 The Obama administration banned the use of microbeads and many nations are also banning them as well.
Studies have shown that many synthetic fibers, such as polyester, nylon and acrylics, can be shed from clothing and persist in the environment. One load of laundry can contain more than 1,900 fibers of microplastics, with fleece releasing the highest percentage of fibers.
The World Health Organization (WHO) has announced a review into the potential risks of plastic in drinking water after a new analysis of some of the world’s most popular bottled water brands found that more than 90% contained tiny pieces of plastic. A previous study also found high levels of microplastics in tap water. Analysis of 259 bottles from 19 locations in nine countries across 11 different brands found an average of 325 plastic particles for every liter of water being sold.
In one bottle of Nestlé Pure Life, concentrations were as high as 10,000 plastic pieces per liter of water. Of the 259 bottles tested, only 17 were free of plastics, according to the study. The most common type of plastic fragment found was polypropylene – the same type of plastic used to make bottle caps.
Jacqueline Savitz, of campaign group Oceana, said: “We know plastics are building up in marine animals and this means we too are being exposed, some of us every day. Between the microplastics in water, the toxic chemicals in plastics and the end-of-life exposure to marine animals, it’s a triple whammy.”