Pollution and cancer

Diesel emissions from cars are proven to increase the risks of cancers, primarily of the respiratory system. The United States had conducted a study on the matter and has proved the link. An environmental protection agency started a campaign to decrease levels of such products in the air and a reference concentration was established in 1993. In 1996 the World Health Organisation recommended that "urgent efforts should be made to reduce emissions... by changing exhaust train techniques, engine design and fuel composition".

Benzene is present as a gas in motor vehicle emissions which has also been proven to be a cancer-causing product. Benzene is primarily implicated in cancers in the blood such as leukaemias. Butadiene is similarly implicated as a cause of leukaemias. The latter condition results in a defective production of cells from the bone marrow. This will lead to a number of life threatening problems such as anemia which means that our organs will be unable to receive enough oxygen to continue functioning properly. The patient will become very pale, lethargic and breathless and will require blood transfusions.

Leukaemia also decreases the amount of platelets in the body. These are small cells which control bleeding. Without them the patient will start bleeding and will develop many bruises. A life threatening condition will result if this bleeding occurs in the brain or in the abdomen.

Leukaemia can also affect the function of white blood cells which defend us from infections. Without them the patient is very prone to have all types of infections and a simple one which is easily cured in a normal person may be a life threatening condition to such a patient. This is why such patients are kept in isolation throughout their illness.

Formaldehyde is another toxin found in vehicle exhaust and was also found to cause cancers. Effect is mostly on the nose, sinuses and pharynx (the area at the back of the mouth). The patient may suffer bleeding from the nose or nasal blockage which is resistant to treatment.

Strategies to reduce vehicle emissions are multiple but include four key components. There should be stringent emissions standards for new vehicles, clean fuels, programmes to assure proper maintenance of in-use vehicles (the VRT test) and, last but not least, traffic and demand management. New vehicles are now able to run with unleaded petrol. New motorcycles with highly polluting two-stroke engines may also be banned. Electric motorcycles and cars are also being introduced in our county. Cleaner fuels have been introduced and leaded petrol has been banned. Petrol should have a specific content of benzene and sulphur.

The VRT testing should include control of vehicle emissions and commercial vehicles should be removed from circulation after a number of years, say 15 years. Limits on carbon monoxide, nitrogen oxides, particulate matter and hydrocarbons must be imposed.

The number of cars on our roads is always increasing (at present over 260,000) and this inevitably is increasing the concentrations of pollutants. Improving public transport may encourage people to use less their own cars, at least to go to work. This will decrease considerably the amount of vehicles on the road at a given time of the day.

The principal cause of lung and laryngeal (the place where our vocal cords are) cancer is cigarette smoking, both active and passive. Malignant tumors of the larynx occur almost exclusively in smokers. It is estimated that a person sitting next to a smoker may inhale up to three quarters of the smoked cigarettes. This is to prove the selfishness of smokers who are polluting the air around them. It is essential that cigarette smoking is restricted in all public areas and that their cost continues to rise. At least the revenue by the government could be used by the health department to make up for the costs of hospitalisation and treatment.

Symptoms of lung cancer include coughing, producing blood-stained catarrh, shortness of breath, loss of weight and appetite. Symptoms of laryngeal cancer include hoarseness which may persist as the only symptom for many months, earache and difficulty to swallow.

Many people seem to think that cancer is a recent disease. About one of every four persons is affected by cancer. I think that the truth is that technology and improved diagnostic machines make it easier for us doctors to recognise the presence of these cancers before death. Having said that, it may be that technology is also leading to an increasing amount of waste material which finds itself in the same air that we breathe. So a worrying question arises from all this: Is technology and development making our life more comfortable or is it contributing to our death sentence?

Dr Farrugia Randon is a committee member of Din l-Art Helwa. This contribution is part in a series aimed at raising awareness on the topics addressed.