Britain has launched its first major study of the so called forever chemicals building up in people's bodies, a story covered across our news pages and first reported by the BBC. Scientists will test blood and urine samples to find out how widespread exposure has become, and at what levels these long lasting substances are present in the population. The work is being run by the UK Health Security Agency, known as UKHSA, and its first findings are expected in 2027.
The study focuses on PFAS, short for per and polyfluoroalkyl substances. These are a large family of human made chemicals that have been used since the 1940s and 1950s in industrial processes and consumer products. They resist heat, grease and water, which is why they turn up in non stick cookware, waterproof clothing, food packaging, firefighting foams and many other everyday items. The same toughness that made them useful also makes them hard to break down, in the environment and in the body, and that is how they earned the nickname forever chemicals. There are thousands of types, with one UKHSA background note putting the family at more than 15,000 substances, which makes studying them a large and complicated task.
Rather than recruiting a new group of volunteers from scratch, the study will use samples already collected through the Health Survey for England, an established national survey. UKHSA says analysing those samples for PFAS will establish baseline levels across the UK population. That baseline matters because, without it, scientists cannot tell whether exposure is rising or falling, or whether particular groups carry higher levels than others. Alongside PFAS, the samples will also be tested for lead, arsenic, bisphenols, phthalates and flame retardants, giving a broader picture of the chemicals people carry in their bodies. The programme sits within a wider body of work on public health and chemical exposure, and UKHSA has also published an evidence review on PFAS and health outcomes to sit alongside the testing.
Scientists working with samples in a laboratory, illustrative image
Credit: Esculab, Wikimedia Commons, CC0. Illustrative image.
Why the study matters now
Concern about PFAS has grown steadily over the past decade, and the UK is not alone in trying to measure the problem. Other countries have run their own biomonitoring programmes, as covered in our homepage reporting, and the results have fed into tighter rules on some of the best studied chemicals. Two of the most closely studied PFAS, PFOA and PFOS, are already banned in the UK. The World Health Organization's cancer research agency has classified PFOA as carcinogenic to humans, while PFOS is considered possibly carcinogenic. Those classifications reflect the state of the evidence on those specific chemicals, not on all PFAS as a group, and scientists are careful to draw that line. Most of the thousands of PFAS types have been studied far less, which is one reason a broad baseline study is useful: it shows what is actually present in people, rather than what researchers assume is present.
The UK government has previously told Parliament that most people in the UK are likely to have measurable levels of PFAS in their blood, but that it is not possible to tell where any individual's exposure came from. That is an honest statement of the limits of the science. PFAS can reach people through food, drinking water, household dust, consumer products and workplaces, and a blood test cannot trace a chemical back to a single source. The new study will not change that for individuals, but at population level it can reveal patterns, such as whether levels differ by age, region or occupation, and those patterns can guide policy and further research.
Dr Edward Wynne-Evans, UKHSA's director of radiation, chemicals, climate and environmental hazards, has spoken about the gaps in current knowledge. In an interview with BBC Radio 4's Inside Health, he said there are gaps around what different levels of exposure mean for an individual's long term health. That framing is important. Finding a chemical in blood does not by itself mean a person will become ill. Dose, duration, the specific chemical and a person's overall health all matter, and for many PFAS types the evidence is still thin. UKHSA's own assessment is that the evidence available to date suggests any health effects are likely to be limited. The strongest evidence from large population studies so far points to possible associations with raised cholesterol and potentially lower birth weight, but the agency stresses that further work is needed to understand those findings and what they mean.
What the study will not do
One point UKHSA has made repeatedly is that it is not recommending routine blood testing for PFAS for individuals, guidance that matters for readers following health advice on this site. That may surprise people who would like to know their own level, but the reasoning is practical. At present there is no established clinical intervention linked to a particular PFAS blood level, so a test result would not change the medical advice a person receives. A high result could cause worry without offering a treatment, and a low result could give false reassurance, since testing usually covers only a subset of PFAS types. The agency's position is that population level testing, where results inform research and policy, is more useful than individual testing at this stage. People who are concerned about a specific local exposure, for example living near a site known to have used PFAS, should speak to their GP or local health protection team rather than seeking a private test and trying to interpret it alone.
It is also worth noting what the study cannot prove. A baseline survey shows exposure, not harm. Linking a chemical level to a health outcome requires long term studies that follow people over time, control for other factors, and look at large numbers. The independent Committee on Toxicity is carrying out a detailed review of the available evidence on PFAS and health, and its conclusions, together with the biomonitoring results, will shape how seriously particular exposures should be taken. The first findings, due in 2027, will be a starting point, not a final verdict.
A local story behind the national study
The launch also follows local concern in parts of the country, and in world reporting on chemical regulation. In September, blood tests found what were described as really high levels of PFOA in dozens of people living near a major chemical factory, according to reporting on the study. That kind of local finding sharpens public interest in a national programme, because it shows that exposure is not evenly spread. A national baseline helps put local results in context, showing whether a community's levels are unusual or in line with the wider population. It also helps regulators decide where closer investigation is warranted, and whether controls on industrial use or on contaminated land need to change.
Prof Tony Fletcher, from the London School of Hygiene and Tropical Medicine, has noted that low levels of PFAS likely show up in everyone's blood, and that the important questions concern higher levels in larger populations, a point also made in independent coverage. That distinction, between background presence and levels that might matter for health, is at the heart of the study. Simply detecting PFAS is not the story. The story is how much, of which types, in whom, and whether those levels are changing.
What happens next
The samples will be analysed over the coming months, with initial findings from the biomonitoring programme expected in 2027. Those findings will give the first proper national picture of background chemical exposure in the UK, covering PFAS and the other substances in the panel. Researchers will then be able to compare future samples against that baseline, track trends, and test whether policies such as bans on PFOA and PFOS are reducing levels in the population. The results will also feed into the Committee on Toxicity review and into decisions about whether further controls are needed.
For the public, the most useful outcome may be clarity. Forever chemicals have attracted alarming headlines, and some of that coverage has overstated what the science can say. A careful, government backed measurement programme will not settle every argument, but it will replace guesswork with numbers, and that is a step forward for a debate that has too often run ahead of the evidence. People do not need to wait for the results to take simple, sensible steps, such as following product safety guidance and checking local advice where a specific contamination issue is known, but they should be wary of anyone selling a test or a detox that promises to solve a problem science has not yet fully described. The UK study, reported in national coverage and in science and health reporting, is a reminder that good public health work often starts not with an answer, but with a proper measurement. Further background is available in independent reporting and in a detailed summary of the programme.
