PCB testing for communities living near contaminated land 

Published on: 21 Sep 2026

Public Health Wales supports the Welsh Government’s view that historical contaminated land in Wales should be addressed as a priority and we acknowledge the concerns of local communities affected by this. We are aware that calls have been made for PCB testing for communities living near contaminated land. However, testing PCBs in blood is not recommended as a public health action. This is because it does not provide a reliable means of assessing an individual’s exposure to contamination or the potential health impact.  

What are PCBs? 

PCBs, or polychlorinated biphenyls, are a group of toxic, human-made, hazardous organic chemicals that have dangerous effects on the environment and our health. There are many different types of PCBs and they vary widely in their potential toxicity and health effects. The harms associated with PCBs mean that their production was banned in 2001. But, they persist in our environments and everyone in the world is likely to have some level of PCBs in their body.  

We can be exposed to PCBs through inhalation, ingestion, or by skin contact. There are many potential sources of PCBs in our environment, including the food that we eat, particularly fish, dairy and meat. We can also be exposed to PCBs in our homes and other buildings because they can be released from the materials used to construct the buildings we live and work in.   

If a particular place is found to have elevated PCB levels, that does not necessarily mean it is the source of PCBs in someone’s body. In addition, two people could eat the same diet and visit the same places, but individual differences, for example the amount of fat in our bodies, can influence the amounts of PCBs that stay in our bodies. Some evidence also suggests that diet, smoking, or levels of physical activity can affect the potential harms associated with PCBs. 

Testing for PCBs in blood does not tell us how or where people may have been exposed to them. We also do not currently have a good understanding of how different PCBs interact in the body. And factors like diet, smoking, physical activity, level of exposure and genetics mean that PCBs can affect everyone in different ways.  

There are also some risks in introducing blood testing for PCBs. For example, causing worry among people who have are found to have PCBs in their blood. There is no way to treat or manage a particular PCB level in someone’s blood, even if we measured it.   

Public Health Wales is working with partners, including Welsh government, on how to address problems linked with contaminated land.