Tires and degrading garbage shed tiny pieces of plastic into the air, creating a form of air pollution that UC San Francisco researchers suspect may be causing respiratory and other illnesses.
A review of some 3,000 studies implicates these particles in a variety of serious health problems. These include male and female infertility, colon cancer and poor lung function. The particles also may contribute to chronic pulmonary inflammation, which can increase the risk of lung cancer.
"These microplastics are basically particulate matter air pollution, and we know this type of air pollution is harmful," said Tracey J. Woodruff , PhD, MPH, a professor of obstetrics, gynecology and reproductive sciences at UCSF.
Woodruff directs the Program on Reproductive Health & the Environment (PRHE) and is the senior author of the study, which appears Dec. 18 in the journal Environmental Science & Technology .
Small particles, big problem
Microplastics are less than 5 millimeters - smaller than a grain of rice - and they are ubiquitous in the environment. Each year, companies around the world produce nearly 460 million metric tons of plastic. That is projected to reach 1.1 billion by 2050.
A major source of plastic in the air is driving. Friction wears down tires along with the road surface, sending plastic fragments into the air.
