Unlike many other pollutants, toxic metals do not break down in the environment. Although they may become diluted over time, they can remain in landscapes for centuries, posing potential risks to wildlife, livestock, ecosystems and people.
Exposure to these metals can have both immediate and long-term health effects. Acute exposure to high concentrations can result in poisoning incidents, while chronic exposure to lower concentrations has been linked to more subtle health effects.
Lead, one of the most common contaminants associated with historical mining in England and Wales, is of particular concern. According to the World Health Organization (WHO), there is no safe level of lead exposure below which adverse health effects would not be expected.
Led by Dr Lisa Yon, Dr Andrea Sartorius and Professor Malcolm Bennett from the School of Veterinary Medicine and Science and Professor Matthew Johnson from the School of Geography, the Nottingham team identified and reviewed 255 documents spanning more than 150 years, from 1874 to 2025. The review included peer-reviewed scientific papers, government reports and other publicly available evidence to assess the potential impacts of historical metal contamination on animal and human health.
The researchers found consistent evidence that elevated metal concentrations in the environment are reflected in increased metal levels in local wildlife, livestock and human populations. Although many of these studies measured exposure rather than health outcomes, and therefore fell outside the review's inclusion criteria, they demonstrate the transfer of contaminants from the environment into living organisms.
The review also found evidence that chronic exposure to metals associated with former mines and smelters has been linked to adverse health effects in terrestrial and aquatic invertebrates, fish, rodents, livestock and humans. However, the researchers identified relatively few studies directly examining health risks in animals exposed to historic metal contamination in England and Wales.
While health effects associated with metal contamination have been reported in livestock, the review found that no peer-reviewed studies investigating health incidents linked to historical metal mining or smelting in mammalian livestock in England or Wales have been published in the past 70 years. The authors highlighted that this represents an important evidence gap that warrants further investigation.
Risk assessments conducted at or near former metal mining and smelting sites have also identified a number of locations in England and Wales where environmental metal concentrations may present potential risks to human health.
Dr Andrea Sartorius, one of the lead authors of the review, said: "Historical metal mining has left a long-lasting environmental legacy across many parts of England and Wales. By bringing together more than 150 years of published and unpublished evidence, this review provides a clearer understanding of where the evidence is strongest, where important knowledge gaps remain, and how historical contamination may continue to affect both environmental and public health. We hope the findings will help inform future research, monitoring and policy."
The review provides one of the most comprehensive assessments to date of the evidence surrounding historical metal mine and smelter contamination in England and Wales. The findings will support future research and help inform approaches to managing the long-term environmental and health impacts of historical mining.
Dr Lisa Yon, a lead author on the review, said: "By bringing together the numerous disparate sources of (published and unpublished) information on this topic, this review served to highlight potential areas of risk or concern, and those knowledge gaps where further research is urgently needed. It is only by having a thorough and integrated understanding of the potential risks (to animal, human and ecosystem health), that appropriate methods of mitigation can be developed to effectively reduce the health risks for those living in areas impacted by current or former metal mining activities."
