Confirming reports of carcinogenic heavy metal presence in the waste material thrown up by the Coca-Cola plant at Plachimada in Palakkad district, the Kerala State Pollution Control Board on Wednesday said its sample analysis showed presence of cadmium in much higher concentration than permissible levels.

Releasing the results, PCB chairman Paul Thachil said the sample was found to contain 201.8 mg of cadmium per kg of dry weight, against the tolerable limit of 50 mg.

The factory had been asked to stop supplying the sludge as fertiliser to farmers in the locality and keep it in seepage proof condition, Thachil told a press meet in Thiruvanthapuram.

Also Read 'Sludge at Coke factory is deadly' Probe ordered into Coke plant 'toxic sludge' Coke accused of supplying toxic fertiliser to farmers All soft drinks banned in Parliament

The presence of lead at 319.0 mg per kg was, however, lower than the tolerable limit of 500 mg per kg, Thachil said.

The samples were tested earlier this week at PCB's Central laboratory at Kochi.

The Hindustan Coca-Cola factory has, of late, been in the eye of a storm, with BBC recently reporting that the sludge thrown up by the plant contained heavy concentration of cadmium and lead.

A local campaign was also on, alleging that the factory caused depletion of ground water in the arid region.

A routine test conducted by PCB in January this year could not detect the presence of heavy metals at hazardous levels in the waste material of the plant, Thachil said.

A detailed inquiry would be held to ascertain how this 'serious deviation' took place within a few months.

He said it was not within the PCB's powers to probe whether the soft drink itself contained hazardous material. It was for the health department to probe this, he said.

The concentration of cadmium at below detection limit of 2 MG per litre and lead at 0.1 mg per litre in the effluent was within the tolerance limit, Thachil said.

"The results indicate that the concentration of cadmium in the sludge is high and hence the sludge may have to be classified as hazardous waste," he said.

The board had asked the company not to use the sludge as manure, even within the plant premises and the company had complied with the instruction, he said.