Camilla Jessen
Cases of colorectal cancer are rising among younger adults, even as many other types of cancer decline worldwide.
While overall cancer rates have declined in many parts of the world, colorectal cancer has been moving in the opposite direction, becoming one of the most common cancers globally.
A major scientific review led by researchers at the University of Southern California (USC) points to microplastics as a potential culprit.
Widespread exposure
The researchers warned that constant exposure to microplastics, combined with their ability to accumulate in the body, could pose serious health risks.
“Due to ubiquitous exposure and bioaccumulative characteristics of microplastics, the extent of human health impacts due to microplastic exposure is of great concern,” the team said.
“We concluded that exposure to microplastics is ‘suspected’ to adversely impact the colon and small intestine in humans.”
They also described microplastics as “a suspected link to colon cancer, using the key characteristics of carcinogens approach.”
Beyond the colon
The review found potential associations between microplastic exposure and damage to the lungs, as well as effects on sperm quality and testicular health. The particles were also identified as a possible hazard to the respiratory system.
“Microplastics are widespread and mobile in the environment, being detected in air, surface water, costal beaches, sediment, and food,” the researchers wrote.
“They have been discovered in remote and pristine locations, including the Antarctic, deep ocean trenches, and Arctic sea ice.”
Because of their small size, the particles can enter the body more easily than larger debris. Researchers noted they have been detected in human placenta, breastmilk and liver tissue.
Calls for action
Tracey J. Woodruff, professor of obstetrics, gynaecology and reproductive sciences at UCSF, said: “These microplastics are basically particulate matter air pollution, and we know this type of air pollution is harmful.”
Although many of the studies reviewed were conducted on animals, researchers said the biological similarities suggest the findings may be relevant to humans.
Nicholas Chartres, PhD, one of the study’s authors, urged policymakers to respond. “We urge regulatory agencies and policy leaders to consider the growing evidence of health harms from microplastics, including colon and lung cancer,” he said.
Sources: University of Southern California study, UCSF.
