Pollution and infections

Pollution may be a cause of increasing morbidity and mortality caused by infections. Most types of pollutants damage cells which are found on the lining of the nose, throat and bronchi (airways which transport air from the throat to the lungs). These cells possess very small hairs called cilia which have the function to move up to the mouth any mucus (a slimy substance produced in the throat and bronchi). These cilia are also damaged by pollutants and so the mucus which forms as a reaction to the pollutants is not easily disposed of by the body. This mucus will therefore accumulate in the bronchi and if it becomes infected it could lead to severe medical problems. Effects could be high fever, shortness of breath, production of greenish catarrh, permanent damage to the lungs and sometimes also death.

We call such infections bronchitis if they effect the airways only and pneumonia if they effect the lung tissue. The latter condition is more serious than the former. Children seem to be more at risk of suffering from lung infections including bronchitis and pneumonia secondary to air pollution.

Malaria is a disease of humans caused by infection with protozoan parasites belonging to the genus Plasmodium. It is characterised by high fever, jaundice due to liver problems, mental impairment and, if left untreated in severe cases, will lead to coma and cause death. The parasites are transmitted by the bite of female mosquitoes (the vector of the parasite). It has been eradicated from Europe but is still present in African countries where levels of hygiene are still low.

The word "malaria" means literally "bad air". This makes evident the ancient concept that smelly air carries impurities which may be a threat to human health. In fact, in order to "disinfect" the smelly air, it used to be recommended to make use of agreeable smells derived from burnt herbs, tar and resins of pine and larch.

The concept of "bad air" was also recognised as a cause of bubonic plague. During outbreaks of plague which hit Europe in the 14th century, bonfires were lit in the streets of affected areas in an attempt to purify the air. People were instructed to burn rosemary shrubs in their homes to counteract the contamination of the air brought about by the plague. Rain was welcomed as it was seen as another way to clean the air.

Paul Cassar, author of History of Medicine in Malta (1969), writes that one of the worries of the Order of St John after the siege of 1565 was the possibility of an outbreak of pestilence from the odours of the putrefied bodies of the Turks who died during the attack on Vittoriosa. Vittoriosa was also invaded by swarms of flies to such an extent that they had to resort to gunpowder to destroy the insects.

In September 1754 a number of inhabitants of Mdina were suffering from fever (a cardinal sign of an infective disease) and this was blamed on the fouling of the air by the surrounding fields and gardens under cultivation in the area. In 1801 another epidemic of such fevers broke out in Mdina and this was taught to arise from the "poisonous emanations" in the air arising from stagnant waters in the valley behind the city.

Such examples show that since many years man has noticed a relationship between polluted air and illness.

Summer is a time of the year which many people look forward to in Malta because the temperature of the sea rises to about 28°C and swimming becomes a relaxation and a way to cool down from the high temperatures during this time of the year.

Influenza is less common during the warm months but doctors notice a considerable increase in external ear infections. The majority of these infections are acquired from pools.

The water in pools warms up easily as there are no currents and the body heat of bathers heat it further; organic material such as skin, sweat and urine end up in the pool.

The latter two factors encourage the growth of bacteria, especially of Pseudomonas aeruginosa which is the most common infecting organism. Such infections may also be acquired from polluted sea and I personally noticed that the majority of patients swam along the coast in the vicinity of Mount Maghtab.

The patient presents himself about one to two days after the infection is introduced into the ear, complaining of severe pain especially at night, inability to hear from the affected ear, a sensation of fluid in the ear canal when moving the ear lobe and a discharge which is usually whitish to greenish.

Treatment involves local antibiotics instilled into the ear canal and sometimes requires oral antibiotics.

Living in a cleaner environment will help us live a happier and healthier life. We should all be aware that smoking next to others or driving a car which is producing a lot of noxious exhaust may be harmful to others and to ourselves.

Dr Farrugia Randon is a committee member of Din l-Art Helwa and the articles forms part of a campaign by Din l-Art Helwa in favour of the environment and to raise environmental awareness.