This column appears as part of the Winds of Change newsletter.

The circular economy is a fantastic idea. Let’s all stop sending them off to landfill or incinerators and make them into something useful - money-making, even - instead.

What’s not to like? Except when it doesn’t work, and when it is a cause of the dissemination of pollution, rather than a clean, safe answer to the problem.

I wrote about an example of when the circular economy stinks last week when I recovered a new report by the Environmental Rights Centre Scotland (ERCS) and the environmental charity Fidra, which highlighted growing concerns over the spreading of sludge, a by-product of wastewater and sewage treatment on agricultural land.

Over half a million tonnes of this 'low-cost fertiliser', was spread on Scotland's fields between 2020 and 2024. But, according to the report, this type of fertiliser contains plenty of toxic and polluting substances, including PFAS (often dubbed forever chemicals), microplastics, heavy metals, bisphenols, pathogens, pharmaceuticals, antibiotic-resistant bacteria and antibiotic-resistance genes.

It also points out that the spreading of sewage sludge has been banned or restricted in other countries, including the Netherlands, Switzerland, and parts of the United States, because of concerns about the risks.

The sewage sludge problem struck me as very similar to the 'end of life' tyres issue which I wrote about a few years ago.

Used car tyres are a challenge. Every year, more than 50 million end-of-life tyres are generated across the UK. The seemingly good news is that,........

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