After heart diseases, strokes etc. cancer is among the leading causes of death worldwide with approximately 8 million deaths in 2012 alone. This includes deaths due to all type of cancer and one such type is oral cancer. It is a type of cancer that develops in the tissues of mouth or throat and belongs to a larger group of cancers called head and neck cancer. More than 4 thousand patients are diagnosed with oral cancer every year in USA only. It further has types – lips, tongue, inner lining of the cheek, gums, floor of the mouth, hard and soft palate. There are many reasons which can lead to oral cancer like repetitive sun exposure, family history of oral cancer, smoking, poor nutrition, HPV infection etc. but the most common reason is consumption alcohol and tobacco in excess. It is shocking that men are twice as likely to get oral cancer as women are.
Before we understand the association of oral cancer with air pollution let us understand few things about oral cancer. There are four stages of oral cancer:-
Stage 1:- In this stage the tumor is less than 2 cm and the cancer has not reached to lymph nodes.
Stage 2:- In this stage the tumor has grown more than 2 cm (2-4 cm) but cancer cells have not spread to lymph nodes.
Stage 3: – In this stage the tumor has grown larger than 4 cm and may or may not have spread lymph nodes but not to other parts of the body.
Stage 4:- In this stage the tumor can be of any size but the cancer cells have spread to nearby tissues, the lymph nodes, or other parts of the body.
There are various ways to fight oral cancer and some of them are:-
1) Surgery – This is for the early stages where the tumor is removed with the help of a surgery from lymph nodes.
2) Radiation therapy – Tumor is treated with radiation beams. This is practice in higher stages of oral cancer.
Other methods are chemotherapy and targeted therapy.
It is very disappointing to know that out of 30 most polluted cities across the world 22 cities are in India and this air pollution is one of the leading factors causing oral cancer. As per a study by researcher Shou-Jen Lan, Professor at the Asia University, in Taiwan, high levels of air pollutants which are fine particulate matter-PM2.5 and to a lesser extent, ozone, may be linked to a higher risk of getting diagnosed with oral cancer. Oral cancer can also be developed with the emission of harmful gases from heavy metals and petrochemical plants. There was also a significant relation between oral cancer development and ozone levels.
The study also said that there was no “safe level” of air pollution. Researchers collected data from 66 air quality monitoring stations in Taiwan in 2012-13 and compared it to 2009 data and after analyzing the health records of more than 4, 80,000 males aged 40, it was found that around 11000 men were diagnosed with mouth cancer. It was also found that men exposed to higher level of air pollution (PM more than 2.5) are 43% more likely to develop oral cancer than those exposed to average level of pollution (PM less than 2.5). As per the World Health Organization (WHO) annual levels of PM 2.5s should not be more than 10 μg/m but still the average annual level of PM2.5s in Kabul is 86 μg/m3, while in Beijing it is 85 μg/m3 and in Delhi it has been recorded at 122 μg/m3 making them dangerous cities to live. Before this study high air pollution level was linked with only health problems like asthma, heart strokes and other types of cancers like breast, liver, lung and pancreatic cancer but now oral cancer is the major issue.
Although this study has limitations, including that it is does not consider the men’s previous exposure to air pollution over their lifetime – which may have been higher or lower than their recent exposure and hence requires further investigation. Also it was practiced in Taiwan only, therefore it should be conducted in other parts of the world as well. But this raises a concern that we are living in an environment which is full of harmful chemicals, gases, diseases and we are exposed to some dangerous diseases. Pollution is man made and if we had the ability to create it then we only have to put a stop to it. Little changes in our routine can make our mother earth much more habitable not just for us but for our future generations as well. It is our responsibility to take initiatives to reduce air pollution and make this world a better place.