Impact of air pollution on lungs and precautions to be followed

Well, with every breath we inhale, we take in tiny particles that can damage our lungs and eventually leads to changes in heart, and brain and can result in a host of health conditions. The most harmful of these particles include soil, dust, sulphate, and fine particles 2.5 microns or less in diameter. Though air pollution is a global burden, it strangely affects those living in developing countries and strikes the most vulnerable sections -women, children, and the elderly.

Air pollution is a mixture of tiny particles and substances which are man-made like vehicles or coal/wood burning and natural sources such as wind-blown dust. Particulate matter is mainly regarded in terms of causing damaging health effects. And it’s no surprise that air pollution has been strongly associated with lung cancer risk.

What Is Lung Cancer?
Lung cancer, like other cancers is an uncontrolled mutation of cells in the lungs. The lungs are vital organs for maintaining inhalation of oxygen and exhaling carbon dioxide gas, thereby controlling respiratory functions. The main cause attributed to the development of lung cancer in individuals is smoking which damages the lungs. Upon inhaling cigarette smoke, toxic substances called carcinogens enter the respiratory tract. These change the genetics, structure, and function of healthy lung cells, apart from causing damage to the lining of the lungs. Constant exposure to tobacco vapours will also lead to abnormal growth of lung cells at a fast pace, giving rise to tumours, which eventually evolve into spreadable or malignant cancers, that can prove to be fatal.

Other triggers which increase the chances of lung cancer are persistently being subjected to second-hand smoke, radon gas, and asbestos, as well as a family history of the disease. There are 2 types of lung cancer depending on the histopathological/biopsy type: small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
It is a proven fact that smoking increases the risk of lung cancer but it also can occur in people who have never smoked or smoked less than 100 cigarettes in their lifetime. It is observed that non-small cell lung cancer was seen in people who never smoked but these people lived in regions where air pollution exceeded more.  
 
Symptoms:
Lung cancer does not exhibit any obvious signs in the initial stages. The characteristic symptoms of lung cancer only appear in the later stages, generally in older adults above the age of 40 and include:
•        Persistent coughing, such as in COPD (Chronis Obstructive Pulmonary Disease)
•        Phlegm discharge with blood
•        Difficulty breathing
•        Acute discomfort in chest
•        Sudden loss of weight
•        Bone pain and tenderness
•        Headaches

How Air Pollution Impacts Lung Cancer
Cancer is a disease where the cell mutates and divides in its genetic makeup leading to uncontrolled and non-regulated cell production. Several pieces of evidence reveal a strong correlation between particle pollution as the definitive cause of lung cancer, heart disease, and asthma attacks. However, the risk of lung cancer from air pollution is lower than from smoking. It was found that exposure to pollutant particles (PM2.5) leads to changes in mutation in Epidermal Growth Factor Receptor (EGFR) gene and in another gene linked to lung cancer known as KRAS genes. This finding supports that air pollution is not just correlated to lung cancer, but it may cause it.
Exposure to air pollution results in an inflammatory response involving interleukin -1 beta (IL1B) that changes the lung epithelial cells into a progenitor stem cell state. If the stem cell has the EGFR or KRAS mutation, then the risk of tumour being initiated is higher.

Who Are at Risk?
The fact is most people still are unaware that particulate pollution is a risk factor for lung cancer. These fine particles support alterations in the EGFR gene which is associated with NSCLC. Those people living in a polluted environment are at an increased risk of fighting lung disease including lung cancer. Vulnerable sections of people prone to lung cancer include children, older people, people with pre-existing lung or heart disease, and diabetes are highly prone to infection. Additionally, people who work outdoors are at huge risk of developing aerosol/particulate matter-induced lung changes including lung cancer.

Precautions Cancer Patients Needs To Take
Cancer patients have low immunity and are highly prone to catching infection easily compared to healthy people. Patients suffering from lung cancer should be very cautious and try to refrain from outdoor activity/traveling except if unavoidable. They should be wearing a face mask that has the ability to filter out dust and particulate matter. Thus, lowering air pollution levels needs urgent consent and it has become very evident that “climate health and human health are closely related.

Prevention
If you are a smoker, quit it right now. It is witnessed that quitting smoking delivers quick results, boosts lung power, and significantly reduces the risk of lung cancer. If you are a passive smoker, stay away from it. Safeguard yourself from getting exposed to hazardous carcinogenic gases at the workplace. Avoid going out if the air is polluted. Grow some indoor plants for circulating fresh air in the house. Engage in regular workouts to augment lung health. Practice yoga and other breathing exercises. Practice mindful eating habits and adopt a healthy lifestyle. Eat fresh vegetables and fruits that are a storehouse of various vitamins, minerals, antioxidants, and other nutrients. 
If you notice any of the above-mentioned symptoms, consult a medical professional immediately. 

Authored by:
By Dr. Trinanjan Basu, Senior Consultant – Radiation Oncologist at HCG Cancer Centre, Mumbai