Villagers who have suffered as a result of a gold mining operation are to submit a letter to the Department of Primary Industries and Mines (DPIM) tomorrow.
They will ask the firm to pressure a gold mine operator near their communities to reveal a list of villagers who have health problems caused by mining activities.
The mine is operated by Akara Resources Plc.
Suekanya Theerachartdumrong, who represents villagers in Phichit province, said locals from Phichit, Phitsanulok and Phetchabun provinces who are suffering from the environmental effects of the mine will hand over a document to DPIM director-general Suraphong Chiengthong.
It will ask him to order Akara to disclose a list of 250 villagers who were found to have high levels of heavy metals in their blood.
She said the mine operator claimed that it took responsibility by taking villagers with health problems to receive treatment from a hospital. But villagers had not been told about the treatment provided by the mine, she said.
The group will also ask the DPIM to check injury and illness records of villagers in three provinces to see whether the number of people who fell sick increased after the mine began operations in the area, Ms Suekanya said.
The DPIM issued a 30-day suspension order over the mine on Jan 13 after blood tests on locals showed they contain higher than normal levels of toxic heavy metals.
Sitang Philaila, a lecturer in water resources engineering at Kasetsart University, is also a member of a subcommittee overseeing the environmental effects of Akara's mining activities.
He said an initial examination showed ground water samples taken from communities covered by the mine were contaminated with heavy metals.
Meanwhile, Deputy Public Health Minister Somsak Chunharas and his subordinates yesterday toured mining operations at Akara in Phichit's Thap Khlo district led by Cherdsak Attha-Arun who represents the mine.
He has asked the Department of Health to collect vegetables in the area for tests on whether they contain toxins.