Study finds microplastics inhibit growth of 'ecosystem engineers'

02/03/2022
According to foreign media reports, a new study published in the journal "Environmental Science and Technology" shows that the presence of microplastics can hinder the growth of earthworms and even cause them to lose weight, which may have serious impacts on soil ecosystems. It is also the first measurement of the effects of microplastics on worms living in the topsoil.

    Academics at Anglia Ruskin University (ARU) have studied the effects of biodegradable polylactic acid (PLA), high-density polyethylene (HDPE), and microplastic clothing fibers (acrylic and nylon) on earthworms living in soil and planted in Effects of ryegrass on soil.

    The researchers found that earthworms (Aporrectodearosea) lost an average of 3.1 percent of their weight after surviving for 30 days under high-density polyethylene commonly used in plastic bottle and plastic bag production. In contrast, earthworms living under normal control conditions gained 5.1 percent of their body weight over 30 days.

    At the same time, the study found that the presence of high-density polyethylene led to a decrease in soil pH, while the soil containing biodegradable plastic polylactic acid led to a decrease in the shoot height of ryegrass (Lolium Perenne), and both polylactic acid and lint fibers caused ryegrass seeds to germinate. less.

    The study's lead author, Dr. BasBoots, a lecturer in biology at Anglia Ruskin University, said: "Earthworms lost weight overall in the presence of some microplastics and in the absence of added microplastics. Earthworms significantly increased their body weight in the soil, however, the specific reasons for this weight loss need to be unraveled. Earthworms may respond to microplastics by mechanisms similar to those previously studied for water earthworms. These effects include obstruction to the digestive tract and stimulation, limiting nutrient absorption and reducing growth."

    The researchers note that earthworms can be called "ecosystem engineers" because they help keep soil healthy. Their digging activity improves soil structure, helps with drainage and prevents erosion. Therefore, any pollution that affects the health of soil animals, such as earthworms, is highly likely to have knock-on effects on other aspects of the soil ecosystem, such as plant growth.