Exposure to microplastics in soil can impair the immune function of soil-dwelling organisms (Image provided by Professor Yoon-Joo Ahn)
DAEJEON, April 23, (Korea Bizwire) — Exposure to microplastics in soil can impair the immune function of soil-dwelling organisms, according to new research published by a South Korean team, marking the first study to link microplastic contamination with reduced immune activity in earthworms.
On April 22, 2025, the National Research Foundation of Korea announced that Professors Ahn Yoon-joo of Konkuk University and Hyun Young-min of Yonsei University had jointly discovered that Eisenia andrei earthworms exposed to polystyrene microplastics exhibited significantly weakened immune responses — specifically, a reduction in phagocytic activity, a key function of immune cells.
In laboratory tests, the worms were exposed to 1-micrometer-sized polystyrene particles. Within 30 minutes, their immune cells, known as amoebocytes, internalized the microplastics. While 24-hour exposure did not result in cell death, phagocytosis — the cells’ ability to engulf and destroy harmful bacteria such as E. coli — dropped significantly at concentrations as low as 1 mg/L.
A follow-up soil experiment found that even in microplastic-contaminated soil with a relatively low concentration of 0.1%, earthworms exposed for two weeks showed no change in survival rate but experienced a 40% reduction in immune cell activity compared to the control group.
Exposure to microplastics in soil can impair the immune function of soil-dwelling organisms (Image created by AI/ChatGPT)
Although research on microplastic pollution in soil has increased in recent years, studies focusing on immune toxicity — especially in soil-dwelling organisms like earthworms — remain limited. This study is the first to provide empirical evidence that microplastic exposure weakens phagocytosis, a fundamental immune defense mechanism.
The findings were published online in the March 20, 2025 edition of the international journal Journal of Hazardous Materials, shedding new light on the ecological risks of microplastic contamination beyond aquatic environments.
Lina Jang (linajang@koreabizwire.com)
