Almost 200 residents contacted healthcare services complaining of headaches, dry coughs, dizziness and anxiety.
The findings have been published of an investigation carried out by consultants RSK Stirling on the prevalence of carbon dioxide in disused mineral mines in Scotland and the implications for residential buildings.
In high concentrations, carbon dioxide can pose a serious risk to humans, leading to headaches, dizziness and confusion and, in extreme cases, loss of consciousness.
Commissioned by the Scottish Government, the research was prompted by incidents in 2013 and 2014 affecting a new-build estate built by Lovell Homes in Gorebridge, a former mining village in Midlothian. Almost 200 residents contacted healthcare services complaining of headaches, dry coughs, dizziness and anxiety.
An NHS Lothian investigation found that carbon dioxide had seeped through disused mine shafts, natural cracks and gravel columns used for house foundation. Midlothian Council demolished the 64 properties and re-housed the residents.
A report on the incident advised that building regulations should be changed and that mine gas mitigation measures should be mandatory in new residential developments in former mining areas. It also called for the national investigation whose report has now been published.
The RSK Stirling investigation considered incidents involving mine gas and carbon dioxide and included a comprehensive literature review and consultations with stakeholders.
It has made recommendations in eight areas: • Use of planning conditions and building standards to ensure adequate risk assessment and construction and verification of gas protection measures • Further research and preparation of supplementary technical guidance relating to risk assessments of new and existing developments • The consideration of mine gas issues and constraints at the planning stage, especially related for large-scale developments • Improved coordination and communication between planning, building standards and environmental health/contaminated land staff in local authorities • Research on the effectiveness of granular fill and perforated pipe ventilation below slab construction • Further consideration of mandatory mitigation measures in former coal and oil shale mining areas • Additional liaison between the Scottish Government, Scottish local authorities and Northumberland County Council • Validation of risk assessment and mitigation design within the developers’ procurement process.