Inquiry over River Berem heating oil spill in Pontyberem
A clean-up operation is under way after hundreds of litres of heating oil spilled into a Carmarthenshire river in an act of suspected vandalism.
Environment body Natural Resources Wales (NRW) said 300-400 litres entered the River Berem in Pontyberem, at the weekend.
The pollution was traced to a nearby residential heating oil tank on Mynachlog Road.
Dyfed-Powys Police and NRW are investigating.
The spill happened late on Saturday night and caused a sheen to affect more than 1.5km (0.9m) of the river.
NRW said it did not expect the oil to have a serious impact on water quality and wildlife and it had not entered the River Gwendraeth.
Huw Brunt, from Public Health Wales, said contact with or breathing in fumes from this type of heating oil could cause eye, skin and respiratory irritation as well as drowsiness.
Anyone who experiences such symptoms should contact Public Health Wales on 02920 402 478.