Power Lines

Overhead power transmission lines are classified in the electrical power industry by the range of voltages:

• Low voltage (LV), less than 1000 volts (1 kV), used for connection between a residential or small commercial customer and the utility.
• Medium voltage (MV), between (1 kV) and (69 kV), used for distribution in urban and rural areas.
• High voltage (HV), less than (100 kV) at voltages such as (115 kV) and (138 kV), used for sub-transmission and transmission of bulk quantities of electric power and connection to very large consumers.
• Extra high voltage (EHV), from (345 kV), up to about (800 kV), used for long distance, very high power transmission.
• Ultra high voltage (UHV), often associated with (≥ ±800 kVDC) and (≥ 1000 kVAC) power transmission.

The overhead transmission lines are generally categorized into three classes, depending on their length:

• Short transmission lines, are less than 50 km.
• Medium transmission lines, are between 50—150 km.
• Long transmission lines, are more than 150 km.

This categorization is mainly done for the ease of performance analysis of transmission lines by power engineers.

According to the “World Health Organization” (WHO), there is no established evidence that exposure to magnetic fields from power lines, substations, transformers or other transmission networks, regardless of proximity, causes negative health effects. Although, the recommended distance from high voltage lines stands at 200 m.

Houses that are 200 m or more from a high voltage power line usually have typical radiation effect levels that are insignificant on humans. While you can still live within the 50 m limit for low voltage lines and still be safe from harmful radiation, a significant association was observed with brain tumors for people with prolong exposure.

Analysis by “The National Center for Biotechnology Information” (NVBI) reveal that people who live close to power lines have more days off work and significantly suffer more from headaches or migraines.

EMFs disturb the immune function through stimulation of various allergic reactions, inflammatory responses, and tissue repair processes. Such disturbances evidently increase the risks for various diseases.

It has been found that 'Radiofrequency Electromagnetic Fields' (RF EMFs) can induce changes in the central nervous system nerve cells, including neuronal cell apoptosis, changes in the function of the nerve myelin, and ion channels.

To this end, studies have shown that living near high voltage power lines and other parts of electrical transmission networks increases the risk of cancer, childhood leukemia, and other health hazards…

Food for thought!