Microplastics may harm human cells

Ingesting high levels of microplastics may have harmful effects, a new study by the University of York reveals. 

The researchers compared the concentrations of microplastics that affect cell viability to the concentrations that humans are exposed to by ingesting contaminated food and water.

The team then compared these levels to the doses that have caused adverse effects on human cells within the toxicology studies. 

The toxicology studies reviewed tested for five categories of effects which were: cytotoxicity (cell death/viability); immune responses (including allergic reactions); whether microplastics can affect the cells membranes in any way or cross inside them; the cause of oxidative stress (leads to cell and tissue damage) and genotoxicity (damage genetic information in cells).

The first four were found to be affected by exposure to microplastics at certain levels.

Evangelos Danopoulos, the lead author and PhD student at Hull York Medical School, said: ‘Our research shows that we are ingesting microplastics at the levels consistent with harmful effects on cells, which are in many cases the initiating event for health effects.

‘However, the biggest uncertainty at the present time is how ingested microplastics are excreted from the body. This is a crucial point to understand the true level of risk. Our analysis of the data showed that cell viability depends on the shape of the microplastics. Irregularly shaped microplastics, which are the majority found in the environment, are more hazardous than spherical.

‘So far, most toxicology studies have been testing spherical microplastics. There needs to be a shift to testing irregularly shaped ones.’

 Researchers said that although tests have shown effects on cells in toxicology tests, no research is yet available showing what happens to microplastics after they enter the human body.