A useful method of repairing sewage and underground water pipes in a way that avoids digging large trenches is actually to pump tiny plastic particles into the air, often in densely populated urban areas, found. scientists from Purdue University in Indiana.
When a pipe breaks, contractors previously had to dig a trench big enough for crews to cut out the broken section and replace it with a new one.
Now, a more surgical approach called cure-in-place allows them to insert a stent into the pipe in the form of a resin-soaked fabric tube or sock, and then inflate the stent with pressurized steam to so he can seal the pipe.
The technique takes a lot of time and hassle out of it, but the plumes of steam it sends into the air contain polluting chemicals, including what scientists say are “significant” volumes of nanoplastics.
Nanoplastics are particles measuring 100 nanometers or less in diameter. A nanometer is 0.000001 mm.
Microplastics – particles less than 0.5 mm in diameter – and nanoplastics were thought to enter air, water and soil primarily when the plastic degrades and wind or other disturbances break parts.
“What we are showing here is that there is a process commonly used throughout the modern world that releases nanoplastic pollution into the air,” said study leader Alexander Laskinprofessor of analytical chemistry at Purdue’s College of Science.
His team collected the condensate from the steam plumes and subjected it to full chemical analysis.
This they wrote in the magazine Nature’s nanotechnology“revealed the abundant presence of insoluble colloids, which after drying form solid organic particles with a composition and viscosity compatible with [nanoplastics]”.
Studies show that we accumulate nanoplastics into our bodies by breathing, drinking and eating them, although scientists are not yet sure of the long-term health effects.
Andrew Whelton, a Purdue professor of civil, environmental and ecological engineering who contributed to the study, has studied on-site pipe repair methods for nearly a decade.
He said they often saw workers standing in the plumes of steam, sometimes for warmth in the winter.
“This new study indicates that these workers and those who preceded them likely inhaled microplastics and nanoplastics,” he said.
He Told Indiana radio station WBOI said the problem could be solved by either capturing the steam plumes or changing the chemicals used in the process.
“That’s the problem here,” he said. “There are technologies and approaches to solving the problem that are quite simple, but nothing changes because there is no driving force to change it.”