July News: Toxic gas invasion poses cancer risks to everyone
In the air which we breathe in every day, there are pollutants from automobile exhaust, emissions from factories and coal-burning power plants. Those that we can breathe in include particulate matter (PM10, PM2.5), Nitrogen dioxide, ozone, Sulphur dioxide etc. PM2.5 in particular, of which the particulate diameter is less than 2.5 µcm, is in the main concern of the medical industry. When these tiny particulates enter the nasal cavity, not only will it provoke rhinitis, but they can also enter into the lungs via trachea and even blood, affecting cardiopulmonary health. In the long term, the risks of having chronic lung diseases, cardiovascular diseases, lung cancer and even early death will be inflated.
Can breathing in these pollutants and health risks be prevented?
Whenever on smoggy and foggy days with low visibility, the number of patients visiting surges due to tracheal sickness.
Nasal cavity is the first to be defeated by polluted air
‘If there is a vast amount of pollutants (e.g. PM) in the air, the first to be affected is the nasal cavity. The pollutants will be carried in the air that we inhale into our nasal cavity, stimulating the nasal mucosa and hence swelling and inflammation there arise, allergic rhinitis is particularly common’, Otorhinolaryngology specialist, Dr. Kin Ming Chan, said.
The rhinitis caused by air pollution is unrelated to sources like pollens or dust mites. From his clinical practice, he noticed there is a close relationship between the city environment where the patient usually resides in and the seriousness of the patients’ conditions. ‘In a classic and common case, when a patient with rhinitis went to study abroad in a city where air pollution level is low, his condition became less serious or the disease is cured naturally. On the other hand, some patients only started to suffer from allergic rhinitis after moving to cities like Beijing, Shanghai to work where there was heavy smog. If they are rhinitis patients, their conditions can only become worse there. At night, especially, they will suffer from postnasal drip syndrome, stuffy nose, breathing difficulty etc. thus poor sleeping quality is resulted. In this way, they won’t have enough energy for daily work due to the lack of sleep and will be more vulnerable to suffer from cold because of low immunity,’ he explained. Those experiencing allergic rhinitis as a result of severely polluted working and living environments require long-term prescriptions for controlling their illness. They only start to recover after giving up their work and relocating to where there is cleaner air.
He pointed out that allergic rhinitis should not be ignored. If it was not properly treated, sinusitis would arise simultaneously. In the worst case, the pathogens could spread to the eye orbit and even attack the meninges, upsetting the eyes and brain.
Breathing through the mouth can hurt your pharynx
It is observed that there is a rise in the number of patients with pharyngitis on heavily polluted days. He added, ‘they turn to mouth for breathing since they cannot do so properly with a stuffy and sick nose. Consequently, the pollutants in the air are taken in into the pharynx, leading to inflammation, pain in the throat and accumulation of mucus there.’
Aside from these, asthma can be induced in an even worse case. Symptoms such as tightened bronchi and difficulty in breathing can be easily triggered by external stimulant i.e. air pollutants in patients suffering from asthma. This can be deadly if they are not treated promptly.
Particulates slip into the lungs
Aside from the immediate and short-term impact on the respiratory system, the functioning of the cardiopulmonary system can be affected in the long term when inhaling air pollutants.
‘PM2.5 is very tiny; they can pass through the respiratory barrier and enter the lungs. The elderly with declining body functioning are more easily affected whose functioning of the lungs may be influenced. Patients with chronic lung disease e.g. bronchi dilation, chronic bronchitis are especially vulnerable as well’, he said.
In addition to the elderly, extra care should be taken for children. Research Professor, Prof. Tze Wai Wong, from The Jockey Club School of Public Health and Primary Care at the Chinese University of Hong Kong pointed out that if children at the growth stage were exposed to a heavily polluted environment for a long time, their vital capacity would be affected. Research in Hong Kong and other countries also found out that the vital capacity of children living in heavily polluted cities was smaller, possibly affecting the proper growth and health of their lungs.
‘It has long been proved in the medical industry that there is an obvious relationship between PM2.5 and the risks of having lung cancer. This is caused by a carcinogenic substance called PAH (Polycyclic Aromatic Hydrocarbons) in particulate matter. They often come from diesel car exhaust or factory emissions,’ he continued, ‘On top of that, when PM2.5 enters the blood, the inner wall of blood vessels will be stimulated, inducing blood clotting which can lead to blockage in the cardiovascular vessel and thus heart disease. Therefore, the risk of early death from having heart and chronic lung disease will be raised when inhabiting an environment with high PM2.5 concentration.’