EMFs - Should you throw out your microwave oven now?

TODAY, ENVIRONMENTAL HAZARDS are a plenty. They vary from pesticides to radon. Some are visible, others are not. A few are preventable, many are not. To start off the discussion, just a simple brain-teaser.

What do a hair-dryer, an iron, a microwave oven, a personal computer, a cellular phone and an automated teller machine have in common? They are all appliances which have become part and parcel of our everyday life. Imagine having to go through a single day without them.

However, the benefits that you gain are not without a price. These high technology innovations consume electricity and consequently generate electromagnetic fields (EMFs). In fact, these low energy fields emanate from anything electrical, including electric power stations and high voltage power lines.

While we enjoy the various comforts of modern life, we also expose ourselves to the EMFs these appliances produce. The EMFs pulse imperceptibly through the air and through our bodies.

In the early 1980s, the American public began to take notice of EMF-related effects following a handful of studies linking weak EMFs to certain cancers and other health problems. These studies suggested that there might be an increased risk of leukaemia, lymphoma and cancer of the nervous system in children living near high-voltage power lines.

In other studies, elevated risks of these diseases were reported in electricians and telephone line workers. In addition, there were also studies which linked miscarriages and birth defects in pregnant women exposed to high levels of EMFs on the job. EMFs were also thought to contribute to the rising incidence if breast cancer. On a more extreme note, EMFs have been linked to depression and suicide. Are these concerns far-fetched and unsubstantiated?

Although it has been speculated that the risks of getting cancer from EMFs is about one in 1,000, it is relatively low on the list of life-threatening risks. The risk of dying in a car accident is approximately one in 50. But practising disease prevention means trying to minimise as many known hazards or health risks as you can for you and your family, just as you would wear a seat belt while in a car.

So the next question on EMFs is, how serious is it? Certainly, the health effects associated with EMFs are not as dramatic as those seen with exposure to electromagnetic radiation from, for example, radioactive materials.

Nevertheless, concerns have been raised by several sensational news reports, including the claim in 1993 by a Florida man on CNN's Larry King Live that his wife's fatal brain cancer was caused by her frequent use of the celluar phone. What are the underlying physical and biological mechanisms associated with the health hazards of EMFs? Some of hte possibilities proposed thus far are:

• EMFs alter the movement of calcium ions in cells . Calcium is one of the main messengers that shuttle vital information across cell membranes. It is also responsibie for maintaining many processes including cell growth and division.
• EMFs suppress the production of melatonin. Melatonin is a hormone which is produced in the brain and acts to regulate our biological clock. It may also play a major role as a tumour growth-inhibiting factor.
  A suppressed level of melatonin has been linked to different forms of cancer, particularly prostate and breast cancers. Scientists have found that exposure to EMFs can decrease night time production of melatonin and they believe that this reduction may allow cancerous cells to proliferate unchecked.
• EMFs may stimualte growth and repair of both normal and cancerous cells. Low frequency radiation has been used as a therapy to help broken bones heal faster, and some scientists believe that EMFs might likewise cause tumours to grow faster.
  EMFs cause changes in the production of a number of hormones and neurotransmitters and, consequently changes in brain activity. This may lead to alterations of most of our body's functions.
• EMFs may induce changes is the genetic material, ribonucleic acid (RNA), which is copied from deoxyribonucleic acid (DNA) and transmits genetic information that cells use to make proteins.
• EMFs change the activity of immune cells.
• EMFs slow down the heart.

These subtle effects are just begining to be revealed in the laboratory. They do not necessarily reflect health problems in real life.

However, while citizens of many developed countries have taken a rather aggressive stand on this issue, the scientific community is still deeply divided over the issue of the safety EMFs.

One school of thought believes that the association between EMFs exposure and cancer, no matter how small, is very real. Their adversaries argue that these studies have not been able to rule out other possible confounding exposure factors. Using the same data from the EMFs study, this group of scientist found that the incidence of childhood cancer was associated with traffic density. The odds of this associations were greater than those reported earlier for EMFs and cancer. One potential consequence of high traffic density is a high level of benzene, which is known to cause cancer, in particular, leukaemia.

Others criticised that the consistency of findings of the various epidemiological studies was indeed rough, in the sense that the description to exposure levels in these studies are clearly inconsistent. Thus, it is thought that the variability and complicated nature of EMFs characteristics would not allow researchers to even design definitive studies of EMFs health effects.

Although the main concern of the hazards of EMFs have focused on the exposure we get from electrical high-voltage power lines, for the majority of us who do not live near power lines, most exposure comes from appliances and electronic equipment in the home as well as household wiring.

EMFs are typically measured in milliGauss (mG). One milliGauss is 1/1000 of a Gauss. What is the level of EMFs in an average house? According to a survey of 1,000 homes conducted by the Electric Power Research Institute of America, about 90% of homes had EMFs measurements under 2mG when readings were taken at a distance from appliances. The median reading for all rooms was 0.5mG.

Kitchens generally has higher fields, 0.7mG, which could still be considered as a safe level.

However, the remainder of the homes surveyed had all-room median readings of 1.9mG or more, which is high. Half of those 1,000 homes had readings of 2.7mG or more. This can be considered as bordering a potentially dangerous level as the recommended upper level of exposure of EMFs for children is 3mG. Some countries have adopted an even more conservative standards and have recommended that we avoid exposure to magnetic fields that are higher than 2mG.

Some general measures for avoiding EMFs emissions from all appliances and electrical equipment are:

• The simplest and most effective measures which you can take is to keep your distance from electrical appliances. EMFs drop off significantly as you move from their source. An appliance with EMF of 3,500mG might be reduced to 150mG at 15cm and drop again to just 1.5mG at 1m. So, the golden rule is: Try to stay at least one metre away from all appliances when they are turned on (see Table 1).
  

  Table 1 : Examples of EMF levels (mg) from household appliances at distances of 15 cm and 30 cm :
  	At 15 cm	At 30 cm
  Microwave oven	200	40
  Portable fan	8	0.5
  Colour television	not available	0 - 8
  Stereo equipment	1	0 - 1
  Fluorescent ceiling lights	20 - 100	0 - 30
  Iron	6 - 20	1 - 3
  Washing machine	4 - 100	1 - 30
  Analog clock	not available	15
  Hair dryer	300	1 - 7
  Refrigerator	0 - 40	0 - 20

• Be aware of the EMFs levels in places where you and your family spend most of your time, for instance the bedroom, your desk at work, or where you sit to watch the television in the living room. You should try to avoid spending long periods of time anywhere that has consistently high EMFs levels.
• Be wary of old appliances. The newer appliances normally have more sophisticated designs and reduced EMFs emissions.

The writer is the head of Education and Prevention Unit, National Poison Centre and a lecturer of the School of Pharmacy, Universiti Sains Malaysia.