London: Washing machines are polluting seas with polyester and acrylic bits, smaller than a pinhead.
Mark Anthony Browne from the University College Dublin School of Biology and Environmental Science said the accumulation of microplastic debris in oceans has raised health and safety concerns.
"Inhaled microplastic fibres are taken up by the lung tissues and can become associated with tumours while dispersive dyes from polyester and acrylic fibres have been shown to cause dermatitis," added Browne.
As many as 1,900 fibres can wash off a single piece of clothing during a machine wash cycle and end up on the shoreline, Browne said, the journal Environmental Science and Technology reports.
These bits of plastic contain potentially harmful ingredients which go into the bodies of animals and could be transferred to people who consume fish, according to a Dublin statement.
Scientists looked for microplastic contamination along 18 coasts around the world and did some detective work to track down a likely source of this contamination.
They found more microplastic on shores in densely populated areas and identified an important source - wastewater from household washing machines.
The problem, they say, is likely to intensify in the future. "Designers of clothing and washing machines should consider the need to reduce the release of fibers into wastewater.
"Research is needed to develop methods for removing microplastic from sewage and determine which fibres pose less of a problem for habitats, animals and humans," concluded Browne