I’ve just finished some research about the use of biosolids (human sewage sludge) as farm manure. The results will keep me awake at night.
¾ of biosolids in the UK are spread on farmland. The rules about what it can contain are not fit for purpose. Please read and share this 🧵

Biosolids typically contain a wide range of synthetic chemicals, including antibiotics and other pharmaceuticals, personal care products, microplastics and persistant organic pollutants, among them “forever chemicals”. Yet testing is restricted to a small number of contaminants.

Spreading them across the land means spreading them through the foodchain and the ecosystem. There’s plenty of evidence of uptake of many of these chemicals by crops, earthworms and other soil animals, and of large-scale antibiotic resistance developing among soil bacteria.

When soil is blown or washed off the land, these chemicals enter the air and water. Some seep into groundwater. We're likely to eat, drink and breathe them. It’s hard to say what the health thresholds are, or what the combined impact of this cocktail of synthetics might be.

Yet the issue has been wilfully neglected by governments. Regulation is negligible. Farmers in the UK are “responsible for knowing the levels of any potentially toxic elements” before spreading sludge. But how? With an on-farm lab that can test for 80,000 possible contaminants?