JOHOR BARU, June 23 — The Department of Environment (DoE) will beef up its monitoring of an illegal dumpsite in Pasir Gudang tomorrow, to aid its investigations into the actual cause of the breathing difficulties experienced by students at several schools since Thursday. 

DoE director Wan Abdul Latiff Wan Jaffar said the department would also undertake checks again in the Sungai Kim Kim area which was the scene of chemical waste contamination in March.

Expressing concern that "something” may have been dumped again, he said the department would be employing drones and mobile air quality monitoring units to assist in its monitoring, he told Bernama when contacted today.

An estimated 150 enforcement personnel are expected to be involved in the monitoring operation.

For the moment, DoE monitoring activities are focused on the schools affected in this latest incident, as well as nearby factories — checks are being undertaken every four hours with the aid of multi-gas detectors. — Bernama