Tap water at a community near Lamphun's Northern Region Industrial Estate exceeds the safety limit for lead and copper by four times, and is eight times over for zinc, the environmental group Greenpeace claims.

The organisation held a campaign yesterday morning at Ban Nong Ped tap water station in Tambon Ban Klan in Muang Lamphun to get government officials to inspect the water which it claimed was contaminated by dangerous substances from nearby industrial factories.

Members posted "toxic" signs on a water tank and informed residents about the toxins in the water. They invited representatives from the Pollution Control Department to collect samples for testing.

Greenpeace Southeast Asia's Ply Pirom said the group found Ban Nong Ped, located near the industrial estate, had unsafe drinking water, he said.

Ply said the health and general development of local children were also lower than average.

Residents called for the government to inspect and improve water quality in the area. Janfong Maneechote said the Greenpeace survey, conducted six weeks ago, confirmed the contamination. Some local residents were reluctant to use it and bought bottled water instead, while others boiled it.

Ban Nong Ped village headman Jamnong Janthaklang said there were about 100 residents in the village and none had fallen sick from drinking the tap water.

However it was decided to tell residents to stop drinking the water pending an investigation as some children had complained about "pain in their bones", he said.

The director of the Pollution Control Department's Industrial Wastewater Division, Anukun Suthaphan, said water samples would be collected for testing. It could take some time as officials had to check if the contamination was natural or caused by factories.

When the results were known, the department would take water samples from other villages around the industrial estate, he said.

Public Health official Danai Sarapreuk said people would be stopped from drinking the questionable tap water and related authorities contacted to provide them with safe water.

He said the local authorities had undertaken random tests of the water quality in the area but had never found such high levels of contamination.