Can Brexit be blamed for high mercury levels in UK blood?

Recently, 17 high-profile Britons, including a number of MPs (like Caroline Lucas and Philip Dunne), as well as various Lords, philanthropists and campaigners, had their hair and blood sampled by Wildlife and Countryside Link (WCL), a coalition of 83 environmental organisations, like the National Trust, Woodland Trust, Greenpeace, Forest Stewardship Council (FSF), and WWF, working on conservation in England. The readings for a plethora of toxins, from PFAS to phthalates to mercury, were less than heartening – and potentially, demonstrate the real impacts of Britain’s regulatory climate diverging from that of the European Union.  

The study found that more than half of those sampled had blood levels of PFAS that exceeded the European Food Safety Authority’s safe threshold (>6μg/L of combined PFOS, PFOA, PFNA and PFHxS)¹ and that the majority had combined levels of endocrine-disrupting chemicals (bisphenols and phthalates) above expected or ‘normal’ levels.² In addition, concentrations of mercury were 37% higher than average concentrations found in international studies, which WCL’s report puts at 0.27 ng/mg of hair, with the average in the study’s sample group being 0.372 ng/mg – but that’s just the group average. Out of the 12 sampled for mercury, 7 (that is, over half) showed concentrations above this international average, one of which had levels that were 450% greater. With the World Health Organisation’s recommended limit of 1 ng/mg (or, more properly, 1 mg/kg)³, this latter participant would be just over this threshold but the rest don't have too much to worry about – well, perhaps a little more to worry about than their European neighbours! 

In 2017, the House of Commons ordered the Environmental Audit Committee to investigate the UK’s regulations on commercial chemicals. In 2019, the Committee published its report, warning that ‘current regulation does not account for the cocktail of chemicals we are exposed to’ and that, in certain respects, ‘[o]ur Regulations should be brought in line with the rest of the world’.⁴ Yet, promised updates and reviews of the UK’s regulatory environment, particularly the new UK Chemicals Strategy⁵ that was promised by Theresa May’s government back in 2018, have not yet materialised. By contrast, since Britain left the EU, Brussels has passed new regulations and bans on PFAS, and has been toying with the idea of a comprehensive ban on all PFAS following a proposal made to the European Parliament by Denmark, the Netherlands, Norway, Sweden and Germany. On mercury, the EU has been equally as ambitious, having recently announced that the European Council had approved a new manufacturing, export and import ban on certain mercury-containing products, including dental amalgams and lamps, from 2025.  

These results from WCL show, in a limited way, of course, given its tiny sample size, that this lag is having some impact on public health. Perhaps, then, it’s time for some urgency and ambition on more firmly regulating mercury and other ubiquitous toxic chemicals.  

¹ Outcome of a public consultation on the draft risk assessment of perfluoroaklyl substances in food. European Food Safety Authority. 2020. 

² The Sleeping Giant of Pollution: Why the UK Must Wake Up to the Impact of Toxic Chemicals. Adler et al. Wildlife and Countryside Link. 2024. 

³ Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication. Kim et al. Annals of Occupational and Environmental Medicine. 2016. 

⁴ Toxic Chemicals in Everyday Life. Environmental Audit Committee. 2019. 

⁵ A Green Future: Our 25 Year Plan to Improve the Environment. HM Government. 2018.