Last month, Monash Council granted Wilson Transformer Company, in Wilson Road, a permit to extend its building. As part of the extension, the company will move an existing substation on the south side of the factory to the east side, about 12metres from residential properties, and increase its power capacity by more than a quarter.

A resident, who did not want to be named, said she was "seriously concerned" about living near an electro-magnetic field.

She and her husband, who have lived in neighbouring Jordan Grove for about 40 years , have been diagnosed with different forms of cancer in the past decade. They are concerned there may be a link between their ill health and the substation after reading studies that linked electro-magnetic fields of more than 4milligauss to an increase in the likelihood of childhood leukaemia.

The Journal spoke to four other residents in Jordan Grove who were diagnosed with cancer in the past decade. Three other residents have died from cancer in the past four years.

Two women living in the same house complained of headaches which started only after they moved to the street. One of the women, Tasneem Yousuff, was concerned about her severe headaches that were different to what she had experienced in the past.

The new substation will be about 12 metres from her house, and she called for it to be built on the western side, further away from residences.

WTC managing director Robert Wilson said it was "not practical" to build the new transformer further away from neighbouring properties.

Mr Wilson said that, as a result of residents' concerns, a consultant had been employed to measure electro-magnetic fields emanating from the existing substation. He said the electro-magnetic field level measured less than 4milligauss at a 10-metre distance because of metal shielding and cable screening. WTC was prepared to guarantee levels would be less than 4milligauss on average, but he expected the result to be less than 1milligauss.