How silently the tiny plastic particles steal food from the plate

The tiny plastics scattered on the earth not only pollute the oceans and landscapes, but also actively disrupt the process of feeding humans. A groundbreaking study shows that microplastics have greatly hindered photosynthesis globally and have a shocking impact on global food production.

The study, published on March 10 in the National Science (PNAS), quantifies for the first time how these tiny pieces of plastic (less than 5mm each) reduce the photosynthesis efficiency of terrestrial plants and aquatic algae by 7-12%, thus threatening food security at a global scale.

The study, a professor at the Institute of Soil Sciences, Chinese Academy of Sciences, and a Chinese professor at Nanjing University, analyzed an extensive data set of 3,286 records using meta-analysis and machine learning techniques.

Their findings paint a disturbing picture: The estimated photosynthesis damage caused by microplastics will result in global losses of 1.0973–3.6087 million tons per year for key staples including rice, wheat and corn. This represents a 4-13% reduction in the production of food billions rely on every day.

In the marine environment, the impact is equally worrying. The researchers estimate that the loss of net primary productivity is 0.31–7.24%, which is the rate at which plants and algae produce organic compounds – the trend of seafood production declines by 10,500 to 24,33 million tons per year.

Although previous studies examined the microplastic effects on specific organisms or ecosystems, the study provides the first comprehensive assessment of the land, oceans and freshwater environments, thus resolving contradictions in early discovery.

“Although people are increasingly aware of this environmental hazard, the impact of microplastics on photosynthesis at the ecosystem level remains unclear.” This knowledge gap has made complex efforts to address the UN Sustainable Development Goals related to hunger, health, consumption and marine resources.

The timing of this study is particularly relevant, as microplastics are found almost everywhere on Earth, from deep-sea sediments to mountain glaciers, and even in human blood and placental tissue. Their ubiquity makes these discoveries even more shocking, which is even more shocking to the global food system that is stressed by climate change and population growth.

However, this study also offers hope. The team estimates that reducing the level of environmental microplastics by only 13% may reduce photosynthesis losses by about 30%. This will prevent global losses of 22.15-11.73 million tons per year in major crops and 32-7.39 million tons in seafood production.

These figures emphasize both the magnitude of the problem and the potential benefits of effective mitigation strategies. As international negotiations on the global plastics treaty continue, the study provides policymakers with key evidence on the hidden costs of plastic pollution.

The study calls for additional data collection on the effects of microplasticity and improved remote sensing technology to better monitor problems. It also highlights the importance of integrating plastic pollution reduction into a broader food security program.

For consumers who have already focused on the impact of pesticides and climate on food production, the study adds another dimension to consider – the invisible threat of microplastics gradually reduces the Earth’s ability to produce food through the fundamental process of photosynthesis.

As a senior researcher who was not involved in the study said: “We have long been worried about what happens when plastic enters our food. Now, we need to worry about whether plastic stops that food from growing in the first place.”