#yield reductions

Microplastics are now a ubiquitous part of our daily physical reality. These minuscule fragments of degrading plastic now suffuse our air, our soil, the food we eat and the water we drink. They’re being detected everywhere researchers look, from Antarctic sea ice to human brains. As scientists develop a better idea of where microplastics are accumulating in the environment, they’re just beginning to understand how these pollutants affect one of the most essential and widespread kingdoms of life on Earth: plants. A new study, published on Monday in the Proceedings of the National Academy of Sciences USA, reveals how microplastics hinder photosynthesis across a wide range of plant species—including crucial food crops. “It’s really scary,” says Marcus Eriksen, a marine scientist at the 5 Gyres Institute, a nonprofit plastic pollution research organization, who was not involved in the study. The researchers found that the presence of microplastics (plastic particles that are less than five millimeters in size) can reduce photosynthesis by as much as 7 to 12 percent, on average. That could range from 6 to 18 percent in terrestrial crops, 2 to 12 percent in marine plants such as seaweed and 4 to 14 percent in freshwater algae. “The exposure to microplastics was not surprising at all,” Eriksen says. “What surprised me was the level of impact.” A generalized reduction in photosynthesis at such a scale could have major implications for the global food supply, according to the study’s researchers.