Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what estimate his Department has made of the average amount of microplastics present in sewage sludge.

Research has been performed to improve the understanding of microplastics in sewage sludge. Defra has contributed to the design and development of the UK Water Industry Research funded and led Chemicals Investigation Programme (CIP) in this area. While the third CIP phase, reported in 2022, estimated an average mass of microplastics in final sludge products (generated from the sewage treatment processes), it was noted there could be large differences in the estimated values, and in sludge products from different works, and between sludge product samples taken at different occasions from the same treatment works.