Dozens of Tesco's fish, dairy and meat products have been found to contain chemicals linked to liver problems and cancer, according to an 'alarming' new analysis.

Researchers from campaign group Foodrise and the University of Birmingham tested 30 everyday food items from the supermarket – including tinned tuna, sausages, steak, salmon, eggs, milk and cheese – and detected per- and polyfluoroalkyl substances (PFAS) in every single sample.

PFAS – a group of more than 5,000 man-made chemicals found in everything from food packaging to clothing – are known for their persistence in the environment and their ability to build up in the human body over time. 

This has earned them the nickname 'forever chemicals'. 

They have been associated with pregnancy complications, liver damage and cancers such as kidney, testicular and, in some studies, thyroid cancer, with risks increasing as the chemicals build up in the body over time.

PFAS can enter the food chain through contaminated water and soil – particularly affecting fish – as well as through food packaging and processing. 

In the new study, the highest concentrations of PFAS were found in cod fillets, sardines, smoked mackerel, turkey sausages and tinned hotdogs.

Carina Millstone, executive director of Foodrise, said the findings were 'shocking', adding that Tesco is selling food containing potentially harmful PFAS to millions of customers.

'Tesco must stop profiteering on the back of the nation's health and take immediate steps to remove all forever chemicals from its products.' 

The researchers measured PFAS concentrations in nanograms per gram (ng/g). While these amounts are tiny – billionths of a gram – scientists warn the chemicals can build up in the body over time, raising concerns even at low levels. 

Topping the list were Tesco's boneless cod fillets, which contained 1.198ng/g of PFAS, followed closely by the supermarket's own sardines in brine at 1.192ng/g, turkey sausages (0.899ng/g), Kingsfood brand hotdogs in brine (0.838ng/g) and Tesco smoked mackerel fillets (0.605ng/g).

Dr Mohamed Abdallah, chair in environmental chemistry at the University of Birmingham, said it was 'alarming that PFAS were detected in every single food sample tested'.

PFAS were found most commonly found in the test among fish and seafood items, as prawns and sea bass also contained them. 

Most meats, eggs and cheeses showed lower levels, though whole milk ranked relatively highly with 0.564. 

The European Food Safety Authority declared in September 2020 that average intake of certain PFAS should not exceed 4.4 nanograms per kilogram of body weight per week. 

For context, a 70kg adult would have a tolerable intake of around 300 nanograms of PFAS per week under current guidelines.

But some scientists have argued that even these limits may not fully reflect the risks, given the chemicals' ability to accumulate in the body over time and widespread exposure from multiple sources. 

Researchers said the most concerning finding was that the chemicals were detected in every sample tested, rather than the concentration in individual items.

Ms Millstone said: 'We were absolutely not expecting that [finding PFAS in every sample] and it's really worrying that they are present in fish in particular. 

'We know the government tells us we should be having two portions of fish a week.

'They were also in family favourites such as turkey sausages or hot dogs, and in milk. The vast majority of the nation will have been exposed to these PFAS if they're purchasing these products.

'We don't know if it's just the 30 here and bad luck, but probably not. Our research does suggest it's ubiquitous across product ranges.

'It's entirely possible that if PFAS are in Tesco's products, that this is also the case with other supermarkets.  

'I think what's scary is that we all as a nation have been eating the products that we now know contain PFAS.'

Campaigners have previously written to supermarkets including Tesco – also Aldi, ASDA, Co-op, Iceland, Lidl, Morrisons, Marks and Spencer, Sainsbury's and Waitrose – urging them to remove PFAS from UK food packaging after uncovering it was in most of the ones analysed. 

Now, Ms Millstone is urging supermarkets and the UK government to do more to tackle the problems caused by PFAS, after it unveiled a plan to 'protect the nation' against them earlier this year.

Environment minister Emma Hardy said in February: 'The persistent nature of 'forever chemicals' means they pose a long-term challenge for not only our health, but that of the nation's vital ecosystems.

'It's crucial that we protect both public health and the environment for future generations. Through our PFAS Plan, we will act decisively to reduce their harmful effects while transitioning to safer alternatives.

'We will work in partnership with regulators, industry and local communities to deliver co-ordinated action to ensure 'forever chemicals' are not a forever problem.'

A spokesperson for Tesco said: 'We take the safety of our products very seriously. Our products and packaging are safe and comply with relevant UK and EU legislation.

'We have reviewed the claims from Foodrise and the products they tested are below EU legal limits for PFAS. Own Brand products tested for PFAS as part of our own testing programme comply with relevant EU legal limits.

'We are also working closely with our Own Brand suppliers to meet the incoming EU legislation for food packaging.'