Integrating grounded fences may be a good short-term solution to minimise electrical threats for building sites in proximity to the high-voltage power lines or transformer stations.

Workers inspect transformers which are in unsafe distance to a high-rise building in HCM City. In reality, many houses in HCM City are located near power lines fail to maintain the minimum distance.

Exposure at higher levels can lead to brain damage and cancer.

Bao said the electromagnetic fields emitting from power lines with the voltages above 110KV were capable of causing damage. The electric discharge at the 15KV voltage could cause death.

“The discharge safe distance between electrical stations and surrounding buildings such as offices and private houses ranges from one to three metres depending on whether the wire is insulated or not.

“According to the law, the safe distance from magnetic fields is at least two metres with 15KV stations and four metres with overhead 110KV power lines. However, to really ensure safety, building sites should be at least eight metres far away,” said Bao.

In reality, many houses located near power lines fail to maintain the minimum distance. In an investigation taken last month, the HCM City Electricity Company discovered nearly 6,000 cases that violated the safety corridor of high-voltage power grid. The common violation is inhabitants using corrugated iron roofing in front of their places, or utilising the transformer stations to run their business, or encroaches closer to the safety corridor.

One particular case was Phong Lan Hotel at Ben Nghe Ward, District 1 in HCM City, where corrugated iron was the only thing separating the transformer station there from the hotel since 2006.

“Many people think that by putting up corrugated iron roofing, their places could be safe from electromagnetic fields but it’s totally wrong,” said Bao.

Insulated metal pieces have to be properly earthed. But even when grounded, corrugated iron is still electrically charged. In reality it actually adds much more danger if a discharge in the station nearby occurs because corrugated iron is a conductive material, he said.

Bao advised those who dwell too close to the high-voltage electricity sources to carefully install earthing systems in their walls or grounding fences. Electricity discharged from the power line will go into the earth via those systems. The grounding fences should be made of steel or iron and the grounding part must be at least half a metre, beneath which is activated carbon and salt.

Tran Khiem Tuan, deputy director of the HCM City Power Company said administrative fines had not proved a stiff enough deterrent. Although the pavement is supposed to two metre wide, its width in fact is often one metre due to encroachment. In addition, the overlapping responsibilities between the company and local authorities in handling the cases dilutes punishments.

Tuan said that the company has distributed 6,600 flyers outlining the Electric Law which regulates the electrical safety code. It also replaced bare wires with insulated wires to enhance safety and implement earthing roofs. About 500 premises have had to improve their conditions.

VietNamNet/Viet Nam News