Agricultural mulching films are potential sources of microplastics (MPs) in soil. Some farmers resort to the use of biodegradable plastic films that are supposed to break down more easily and have a better environmental impact. However, it is still unclear whether these biodegradable plastics are safer for terrestrial invertebrates compared to MPs from conventional mulching films.
In this study, researchers tested MP particles from two types of regular plastic films and two types of biodegradable films on two common soil animals: woodlice and mealworms. They wanted to see if the biodegradable plastics caused less harm.
The main finding was that there was no clear difference between the effects of biodegradable and regular plastics. Neither type caused obvious harm to the animals over two to four few weeks, even when the plastics made up 5% of the soil. But, some small changes were noticed in the woodlice’s metabolism and immune system, suggesting the animals were reacting to the plastics. The study also found that both kinds of plastics could change how the soil holds water and its acidity.
In summary, biodegradable plastics can still affect soil animals and soil health, hence more research is needed to fully understand their environmental impact.
Read the full study here: https://www.sciencedirect.com/science/article/pii/S0048969724055293?via%3Dihub