Plastic pollution is a growing environmental concern, with tiny plastic particles infiltrating various ecosystems, including the human body. The gut is crucial in this process, serving as the main gateway for microplastics and nanoplastics to enter the body. A recent study found that human colorectal cancer cells can absorb microplastic particles, raising concerns about their potential effects on health.

Researchers exposed four human colorectal cancer cell lines to polystyrene micro- and nanoplastics of various sizes (0.25, 1, and 10 micrometers) and concentrations. They tracked the particles' uptake into cells and monitored their behavior during cell division.

They found that all the cancer cells absorbed micro- and nanoplastics, with the highest uptake observed in HCT116 cells—a type of cells commonly used to study various aspects of tumor biology. Notably, the cells didn’t eliminate the absorbed particles. Instead, they passed them on during cell division, sharing them between the original and new cells. Even short-term exposure to the smallest particles (0.25 micrometers) increased the cells' movement, which could facilitate metastasis.

These findings suggest that micro- and nanoplastics accumulate in cells and pass into progeny cells during cell division. Once inside the cells, they promote cell migration, potentially enhancing the spread of cancer. Some harmful effects of microplastics may be due to compounds commonly used in plastic manufacturing, such as bisphenol A, phthalates, and heavy metals. Learn more about microplastics in our overview article.