Published: 15 November 2024
Public Health Wales is continuing to evaluate air quality data, to improve our understanding of the potential for harm to health of people living around Withyhedge landfill site. This air quality monitoring began earlier this year, after Natural Resources Wales received large numbers of complaints from members of the public about smells linked to the site.
Our most recent health risk assessment relates to air quality data collected at the Spittal School monitoring station between 1st October and 3rd November 2024. During this time, there were occasions when hydrogen sulphide concentrations in the air were above the WHO odour annoyance guideline value (5ppb / 7ug/m3).
We have also reviewed air quality monitoring by Geotechnology at other sites in the community between 7th September and 22nd September 2024. These monitoring data have not recorded any occasions when hydrogen sulphide concentrations in the air were above the WHO odour annoyance (5ppb / 7ug/m3) level. Air monitoring undertaken by Geotechnology using diffusion tubes has not identified levels of hydrogen sulphide above longer term guideline (1ppb – based on a lifetime exposure).
The long-term (lifetime) health risk remains low, however we understand that bad smells in your community can be upsetting and even at very low concentrations, bad smells can lead to headaches, nausea, dizziness, watery eyes, stuffy nose, irritated throat, cough or wheeze, sleep problems and stress. This can happen even when the substances that cause the smell are not directly harmful to health. These are common reactions, and these effects should usually pass once the odour has gone.
Closing windows and doors when smells occur can help to stop them coming inside homes. Remember not to block windows or vents completely. This is because they provide air to vent cookers or heaters and can help to control damp. Once an outdoor smell has passed, opening windows and doors will help get rid of any smells that remain.
Multi-agency partners review and check monitoring data together. Public Health Wales then use it to inform a health risk assessment before sharing our conclusions with the public. The health risk assessment will continue to be reviewed and updated as more monitoring data is made available to us.
We recognise the real stress and anxiety that local people are under as a result of these smells. However, PHW does not have regulatory responsibilities or powers around the management or enforcement of a site, including carrying out monitoring. We can advise regulators, the public and other partners, and contribute to public health risk assessments.