Odour levels at a Pembrokeshire landfill site have fallen below World Health Organisation annoyance levels, it has been revealed. However Wales' First Minister, Eluned Morgan, has said that it is crucial that this is not just a temporary change.

Public Health Wales said that the latest monitoring of air quality in the areas around Withyhedge Landfill Site did not exceed the World Health Organisation (WHO) odour annoyance level of 5ppb / 7ug/m3.

This is in contrast to the period between March and April this year when levels of hydrogen sulphide, a colourless gas with an eggy smell, were above WHO guidelines.

Public Health Wales (PHW) said it had undertaken a health risk assessment of air quality data collected at the Spittal School monitoring station between July 1 2024 and August 26, as well as data collected at other sites between June 4 and 2024 August 5.

This monitoring has recorded no exceedances of the WHO odour annoyance level.

Although the body said that it was reassuring that were are no exceedances it acknowledged that individual sensory responses can vary, and intermittent odours may have been experienced even at concentrations below this level.

“For some, bad odours or smells can lead to headaches, eye irritation, nausea, dizziness, and unusual tiredness, even when the substances that cause the odour are themselves not toxicologically harmful to health,” said PHW.

“These are common reactions, and these effects should usually pass once the odour has gone. The long-term (lifetime) health risk remains low.”

PHW recommended closing windows and doors when nasty smells occur, or when the wind is blowing from the landfill. However, residents should not block windows or vents completely and should open windows and doors once the smell has passed.

PHW said that it would continue to review and update the health risk assessment as more monitoring data is made available.

The news has been welcomed by politicians. However, they say more needs to be done.

“It is crucial to remember that this situation should never have arisen in the first place,” said Henry Tufnell MP.

“The impact on our community has been profound, and people have endured far too much suffering.

“Even when levels are deemed compliant, odours can still have a noticeable impact on those living nearby.”

He added he was committed to working closely with the Welsh Government to identify and implement stronger regulations around landfill management to ensure that such a situation does not occur again.

Welsh First Minister Eluned Morgan MS said it was crucial that these improvements are not temporary.

“We must ensure that these lower odour levels are maintained consistently,” she said.

“Close monitoring and proactive measures will be essential to prevent any recurrence of the issues that have caused so much disruption to residents.”

The First Minister said that she would continue to work with all relevant parties to ensure long-term solutions were in place.

Anybody wishing to report an odour from the landfill site can do so via https://bit.ly/reportasmellwithyhedge or by calling 0300 065 3000.