Microplastics in sewage sludge spread on land to come under microscope
Research is intensifying on the impact of spreading sewage sludge on farmland in spreading microplastics into watercourses.
Urban wastewater treatment plants were identified as one of the largest point sources of microplastics which are plastic particles less than 5mm in diameter.
They are formed either through the breakdown of large plastic particles or through intentional production for products such as cosmetics and cleaning agents.
The production of sewage sludge has increased over the years, and in 2015 more than 58,000 tonnes were produced in the Republic of Ireland.
Although there are many disposal and reuse pathways, in Ireland up to 80pc is currently reused on agricultural land.
Dr. Anne Marie Mahon of Galway Mayo Institute of Technology told an Oireachtas committee examining a proposed law prohibiting certain products containing such microbeads in Ireland, sewage sludge is used as a fertiliser for tillage, not for crops for human consumption.
"Microplastics, which are incorporated into the sewage sludge, may find their way back onto the land due to spreading of sewage sludge practices," she said.
She also noted that there are regulations or guidelines regarding the application of sewage sludge.