Microplastic could be reducing photosynthesis rates by up to 18% — study

Microplastics, omnipresent across various ecosystems, pose an unclear environmental threat. Recent findings, however, have begun to articulate the potential scale of this threat, particularly concerning the reduction in photosynthesis. An international research team, after reviewing 157 prior studies and employing machine learning techniques, suggests that photosynthesis rates could diminish by as much as 18 percent due to microplastic contamination. The study’s results have been published in the journal PNAS, highlighting the urgency and scope of the issue.

The study reveals that the effect of microplastics varies depending on the type of plant and its environment, with average reductions in photosynthesis ranging from 7.05 to 12.12 percent among terrestrial plants, marine algae, and freshwater algae. Notably, the levels of chlorophyll a, crucial for photosynthesis, dropped by up to 18.25 percent in freshwater algae.

By applying these findings across global agriculture, the researchers have estimated significant impacts on food production. From wheat in Europe to maize in the United States, the projected annual losses could range between 109.73 and 360.87 million metric tons for crops, and 1.05 to 24.33 million metric tons for seafood. These figures underscore the potential for increased food insecurity and health deficits if microplastic pollution continues at its current rate.

Although the study is based on rigorous analysis, it does incorporate some assumptions and extrapolations from smaller-scale studies. As such, more research is needed to refine these predictions and fully understand the complex interactions within the global food supply chain.

Nevertheless, the implications of the findings are stark, signaling that the adverse effects of microplastics could extend from food security to broader ecological and planetary health. Photosynthesis supports not only the food supply but also vital ecological functions. This research serves as a call to action for reducing microplastic pollution and integrating plastic mitigation strategies into global hunger and sustainability initiatives. Such measures are essential for mitigating the ongoing impacts of plastic reliance and protecting future food supplies.