New group of environmental pollutants detected in Swedes’ blood for the first time
Synthetic phenolic antioxidants (SPAs) – a group of man-made chemicals – have been detected in the blood of 30 donours in Stockholm, according to a new study by researchers at the Department of Environmental Science at Stockholm University.
The concentrations found are comparable to – and in some cases even higher than – levels of the more widely known PFAS chemicals. Several of the SPAs were detected in every individual tested. Some of these substances are known to accumulate in the body and may affect fertility or disrupt hormonal systems.
This is the first time these substances have been identified in the blood of Swedish individuals. Previous studies from China and the United States have reported the presence of SPAs in both human and environmental samples – in some cases at high concentrations.
“Our study provides the first indication that people in Sweden are also exposed to high levels of SPAs. To fully understand the extent of the issue, we need to examine a broader group of individuals across different regions of the country,” says Josefin Engelhardt, former doctoral student and lead author of the study.
SPAs are added to a wide range of everyday products to increase their durability and shelf life. They are commonly found in plastics, food packaging, clothing and skincare products. Several of these substances have been flagged as potentially hazardous by the European Chemicals Agency and are included on the EU’s Candidate List of Substances of Very High Concern due to their links to reproductive toxicity, hormone disruption, and/or their potential to accumulate in the body.
One reason SPAs have gone undetected in blood samples until now is due to the challenges posed by analytical methods. As these substances are also present in plastic laboratory materials, particular care must be taken to ensure that the levels measured come from the blood itself – not from contamination introduced during sample handling. Now that a robust analytical method is in place, more samples can be tested to better understand how widespread these chemicals are.
“We still don’t know the long-term health effects of exposure to SPAs, but the fact that they appear in such high levels in the blood is reason enough to take action – in line with Sweden’s national environmental objective of achieving a non-toxic environment,” says Josefin Engelhardt.
Going forward, it will be important to identify the main sources of exposure and investigate the health effects of these substances, to help prevent further harm to people and the environment.
The study forms part of Josefin Engelhardt’s doctoral thesis, which was publicly defended on 28 March 2025 at Stockholm University.
About SPAs
SPAs are synthetic antioxidants added to materials to extend their lifespan. Compared to natural antioxidants, these man-made chemicals often have additional properties that make them concerning from a health and environmental perspective. Some have been shown to interfere with hormonal systems, reduce fertility, and persist in the body over time. SPAs are found in disposable food packaging, clothing and certain skincare products.
Two commonly used SPAs – BHT (E321) and BHA (E320) – are also approved for use in food, such as chewing gum and cooking oils (not to be confused with BHA acid, which is found in some cosmetic products). In 2024, Nordic Ecolabelling decided to prohibit the use of BHT and BHA in Swan-labelled cosmetic products.
About the study
This study is part of a project in which new risk chemicals were prioritized for chemical analysis in the Products Register, maintained by the Swedish Chemicals Agency. The Products Register is a register that includes chemicals produced and used within Sweden. By using different models to predict chemicals of concern, SPAs were identified as potential environmental pollutants to which humans could be exposed. The prioritization was performed on behalf of the Toxicological Council and financed by the Swedish Environmental Protection Agency. The chemical analysis was performed within the project RiskMix (FORMAS No 2018-02264).
The EU Candidate List of Substances of Very High Concern for Authorisation
Link to the study
Last updated: April 10, 2025
Source: Department of Environmental Science