Study: Microplastics Harm Land Ecosystems

A study has found that microplastics affect the growth of plants and animals on land. Many studies have looked into how microplastics affect marine life, but scientists know little about the impact of these plastic particles on land ecosystems. A team from Anglia Ruskin /ˈæŋ gli ə ˈrʌs kɪn/ University in the United Kingdom conducted a study to find out more about the impact. The team observed soil containing a plant known as perennial ryegrass /pəˈrɛn i əl ˈraɪˌgræs/. The team added three types of microplastics to the setup. These included PLA, a biodegradable plastic commonly used to pack food; HDPE, which is used in making plastic bottles and bags; and clothing fibers, such as acrylic and nylon. They also put rosy-tipped earthworms, which can disperse the microplastics, in the soil. The team found that PLA hindered the growth of ryegrass. This type of microplastic, as well as clothing fibers, stopped the ryegrass’s seeds from sprouting. Meanwhile, HDPE caused the soil to become more acidic. The study also revealed that earthworms exposed to microplastics for over 30 days lost 3.1% of their weight. The researchers have not pinpointed the reason behind the worms' weight loss, but the study’s lead author speculated that the earthworms react to microplastics in the same way as aquatic lugworms do. Previous research found that in these aquatic worms, microplastics obstruct the digestive tract, causing reduced growth. The researchers said that the results are alarming because earthworms are important to the ecosystem. The worms consume dead organic matter and help nourish the soil. In addition, they also create holes in the soil, allowing oxygen and water to enter. A previous study even concluded that soil will be less fertile without earthworms.