Who knew? Much has been written about the Great Garbage Patch in the Pacific Ocean, where a Texas-size swill of plastic bags, bottles, wrappers and other debris floats. Now, scientists are finding that home washing machines seem to be a major source of "microplastic" ocean pollution.

Bits of polyester and acrylic smaller than the head of a pin are likely rinsing off garments during the wash cycle and ending up on shorelines, according to a study published this month in the American Chemical Society's Environmental Science & Technology.

An international team of researchers, including Mark Browne, looked for microplastic contamination along 18 coasts worldwide and found it was it was more common in densely populated areas. After testing this microplastic, they concluded that wastewater from home washing machines was the probable source, noting that more than 1,900 fibers can rinse off a single garment. They say this debris contains potentially harmful ingredients that fish can ingest and then transfer to people who eat them.

"Designers of clothing and washing machines should consider the need to reduce the release of fibers into wastewater and research is needed to develop methods for removing microplastic from sewage," the study concluded. The research, done by Irish, Canadian, British and Australian scientists, received funding from the Leverhulme Trust, University of Sydney and Hornsby Shire Council.