Mobile phones, vehicle exhaust and obesity

Two disparate health issues received mention in recent editions of The Times and they deserve comment. These were a letter about the perceived hazards of mobile phone base stations (Health Hazards, May 23) and an excellent editorial on obesity on May 28. Another serious health threat to the future health of the present young generation is vehicle exhaust - and this has not featured lately in the media.

While it is very wholesome for people to query what is perceived as a threat to health, there is much misunderstanding about mobile telephony, which needs to be put right. We otherwise run the risk of distracting attention from other proven true threats to our collective health.

Cellular telephony works simply on microwaves. Microwaves are not to be confused with, say, radioactive (X-ray) radiation, which is manifestly dangerous, or electromagnetic waves from high-tension cables, which are highly suspect.

Apart from the heat which microwaves induce, there is no known or suspected mechanism whereby microwaves can cause damage to living creatures. As we all know from our kitchen experience, microwaves cause things to get hot. This heat is not much different to that achieved from immersing something in hot water - and (provided the water is not too hot) no more harmful than this.

Another misunderstanding is the question of base antennae; a telephony antenna emits microwaves but these will only affect (warm up) objects immediately near to it - but not at a distance.

The scientific crux of the matter, which must be strongly emphasised, is therefore this: If microwaves do pose a health threat, this would sooner be from hand-held telephones and not from the base antenna. People don't seem to realise that hand-held telephones emit microwaves and that they are pressed tightly against the ear - literally within one inch of our hind-brain.

Mobile phones can have a power output as high as one watt; roughly calculated, this exceeds the maximum allowable leakage from a microwave oven by a factor of three. This (unlike a base antenna) can raise the temperature of the user's brain by as much as 1°C.

Though there is no scientific evidence linking mobile antennae to harmful health consequences, one could reasonably argue that the jury is still out on the question of mobile telephony, but with an estimated ownership of nearly one billion mobile phones worldwide, some adverse effect would have become apparent in scientific surveys by now. To date, the only clearly-proven danger of mobile telephony is a significantly increased likelihood of a traffic accident resulting in injury (to drivers or pedestrians) when drivers use a mobile phone while at the wheel; curiously, this applies to hands-free phones too.

Even though there is no evidence to support other deleterious effects, there is still some concern that microwaves from hand-held mobile telephones could be harmful in some as yet undetected way. Hand-held mobile phones are suspected of occasionally causing minor symptoms such as sleep disturbance, memory problems, headaches, nausea, dizziness etc - but the chief concern is that hand-held mobile telephones might induce serious ill effects, particularly in children since their brains are still in a growth phase. A precautionary approach to the use of hand-held mobile phones by children is therefore recommended. The official recommendation is to limit the use of mobile phones by children, namely, not to give children mobile phones and - if they already possess them - to allow them to use them as little as possible.

On the other hand, very few people seem truly concerned about the two proven serious threats to our national health - these are pollution from vehicle exhaust and obesity. In both of these, Malta seems to be one of the highest ranking in the world.

The seriousness of the exhaust pollution in our streets should be keeping us awake at night. The density of traffic in parts of Malta is now so great that vehicle exhaust fumes (especially diesel exhaust), to which most of our youngsters will be exposed for much of their life from birth onward, will almost certainly be responsible for a significant future increase in adult cancer rates in our children and young adults over the coming years. This possibility is supported by results from large scale studies, which have repeatedly confirmed that people living in areas with heavy traffic are at a greatly increased risk of getting lung cancer. This pollution also causes, or aggravates, other lung diseases.

There is a number of reasons for Malta's complacency in the face of the inconvenient truth that motor vehicle exhaust fumes are a cause of cancer.

Firstly, we are too addicted to the convenience and comfort of our cars to accept the truth. Secondly (as in the case of cigarette smoking), owing to the delay of many years before the cancer becomes evident in its unlucky victim, the risk of cancer from exhaust emissions is too remote to grasp.

Thirdly, traffic pollution is perceived as less of a threat because it is not (usually) visible - but phone antennas are highly visible.

Overweight (obesity) has also been shown beyond doubt to be associated with premature death from heart disorders, high blood pressure and diabetes and poses a very serious threat to health, both to adults and, especially, to the future health of our obese children.

In spite of all this we all continue using our car more than is necessary, overfeeding ourselves and our children and being physically inactive, as though tomorrow didn't exist. As the editorial of The Times rightly says, a drastic change in attitudes and lifestyle is imperative if the serious consequences of obesity - and transport pollution - are to be mitigated or avoided.

The government seems to be waking up to the threat of obesity. Traffic pollution, which might well pose the greater threat of the two, is already at crisis level; yet nobody - and that includes our government - seems particularly worried or inclined to do anything about it. In any case it is also up to you, the public, to do something about it. Using your car less and walking more will do yourself and everybody else a world of good.