A concerning “strong odour” at Fendrod Lake in Swansea has left vistors feeling ill.
Emergency services rushed to investgate after several visitors reported symptoms including dizziness, sore throats, headaches and sharp pains.
The foul smell – described as being similar to “paint thinner” or a solvent – was first noticed on Saturday, December 28, particularly near the lock bridge area of the popular beauty spot.
One unnamed hiker said: “The smell was strongest around the little bridge.
“People were lightheaded and dizzy, with sore throats. Some even spotted a slick in the water.”
Firefighters quickly responded to the scene and referred the incident to Natural Resources Wales (NRW).
Ioan Williams, NRW’s operations manager, confirmed that teams were dispatched on Saturday evening and returned the next morning to continue their investigation.
“We are working to identify the source of the odour and any potential risks to the environment or public health,” Williams said.
Visitors have raised concerns over the potential health implications, and some fear the smell may indicate hazardous material in the area.
The sighting of a possible slick in the water has added to these worries, though no official cause has been identified yet.
The incident has also brought attention to the dangers of strong, unusual smells in other contexts, such as within homes.
Experts warn that odours like rotten eggs, burning, or metallic scents emanating from boilers or heating systems could indicate gas or oil leaks.
Joshua Houston, a boiler specialist at GreenMatch, said: “Smells that seem innocent can be signs of serious danger, like a gas leak, which is extremely hazardous.
“On average, 40 people in the UK die each year from boiler-related incidents. Recognizing these smells and acting quickly can save lives.”
NRW is continuing its investigation into the Fendrod Lake odour. Authorities advise the public to avoid the area until further notice and to report any concerning symptoms after visiting the lake.