Cancer, a devastating disease with a significant impact on public health, is influenced by various factors, with environmental factors playing a pivotal role in its development. In India, for instance, the cancer burden has been steadily increasing. Understanding how environmental factors contribute to cancer risk is crucial in combating this widespread disease.


Dr. Devavrat Arya, who is a Medical Oncologist, Director, Cancer Care / Oncology at Max Hospital, Saket, New Delhi said that environmental factors play a significant role in developing cancer, especially lung cancer.


"In India there is a rising trend in incidence of lung cancer among smokers as well as non-smokers. Environmental pollutants like arsenic, chromium, nickel, asbestos, dioxins have to be addressed along with smoking being the major cause. Simply put, environmental exposures describes the totality of all substance that enters into our body – from the air we breathe, to the food and beverages we ingest and all things that enters through our skin via absorption, even sun rays. It is estimated that almost 85 – 90% of cancer have their roots in environment and lifestyle," he further added.


Environmental Factors That Pose A Risk Of Developing Cancer:


When we talk of environmental factors, we can slice and dice these into various segments. Dr. Devavrat Arya explained each of these segments and showed how they can be potentially harmful and can cause cancer. 


Radiation: 


Radiation emitted from X-rays (which forms electrically charged particles or ions) or CT Scans aka Computed Tomography can cause mutations and upto 10% of invasive cancers are related to radiation exposure. Radiation is typically associated with cervical cancer, breast cancer, Hodgkin Lymphoma- to name a few. Increased levels of screening in a radiation-exposure is known of the risk of cancer incidence.


Heavy Metals:


Exposure to various chemicals, heavy metals is also known to cause cancer of the breast, pancreas, lungs, gall bladder, etc, depending on exposed dose, genetics, people’s immune system, nutrition, resistance, age, overall health status. When metals enter the body through air, food, water, or any other means, they exert their enzymatic and genotoxic effects on different organs. Some heavy metals such as arsenic, cadmium, chromium, nickel, and zinc are known to develop cancer. Such metals are known sources of Carcinogens, the inhaling of which causes cancer.


It must be noted here that other Carcinogens that are found to be linked to cancer include wood dust, plastic containers, household cleaning products, naphthalene, soot- to name a few.   


Air Pollution: 


Vehicular pollution, emission from industrial processes, power generation, household combustion of solid fuel and other sources pollute the air across and is today having a global effect in the world. These air pollutants cause illness such as vomiting and even chronic diseases such as cancer as well as respiratory diseases. Prolonged exposure to these chemicals increases the risk of lung cancer.


Free Radicals:


In lay man’s language free radicals are highly reactive and unstable molecules that are made by the body naturally as a by-product of normal metabolism. Free radicals can also be made by the body after exposure to toxins in the environment such as tobacco smoke and ultraviolet (UV) light. Free radicals can come from normal metabolic processes in the body or from exposure to cancer-causing substances like Carcinogens or other harmful substances.


"Needless to say, avoidance of exposure to environmental cancer-causing hazards should be minimised to reduce the risk of being afflicted by cancer, the deadly C word can also be reduced by making healthy choices. Maintaining a healthy weight, avoiding tobacco, limiting the amount of alcohol intake, eating a healthy diet with plenty of fruit and vegetables, exercising regularly, practicing safe sex, reducing exposure to UV, etc, can all reduce to decreasing the risk of cancer," he added.


The Indian Scenario:


Dr Deepak Patkar, Director (Medical Services), Nanavati Max Super Speciality Hospital said, "Speaking of India, these factors are different in both urban and rural areas. In larger cities, where industries and vehicular traffic is prevalent, heightened exposure to pollutants and carcinogens from industrial emissions and vehicular exhausts may be potentially escalate the cancer incidence rates, although more research is required to substantiate this claim. On the other hand,  villages witness the rampant use of pesticides and chemicals in agriculture, possibly escalating the cancer risk among the populace. Moreover, the prevalent use of tobacco, a proven carcinogen, across both sectors significantly contributes to the cancer burden."


How Tobacco Smoking Poses A Rick Of Developing Cancer:


It is a well-known fact that smoking, be it active or passive, afflicts more than half the population around the world with Cancer. According to Dr Ramachandra, who is a Sr. Surgical Oncologist at Kamineni Hospitals, LB Nagar, Hyderabad, "Tobacco smoking is responsible for around 25-30% of cancer cases. It introduces numerous carcinogens into the body, leading to various forms of cancer, particularly lung cancer. Passive smoking is also a significant risk factor, underscoring the importance of smoke-free environments."


Other Environmental Factors For Developing Cancer:


Dr Ramachandra said, "Ultraviolet (UV) radiation from the sun is a common environmental factor that significantly increases the risk of skin cancer. Excessive UV exposure has been linked to melanoma and squamous skin carcinoma, highlighting the importance of sun protection measures."


"Chemical factors, including alcohol consumption and exposure to heavy metals like arsenic and cadmium, are additional cancer risk factors. Alcohol intake, even in small amounts, can elevate the risk of several cancers, including those of the mouth, throat, liver, and breast," he added.


Dr. Ramachandra also said, "Oncogenic viruses, such as hepatitis viruses, human papillomaviruses, and Epstein-Barr virus, are associated with the development of specific cancers. Vaccination and early detection methods are effective strategies for managing virus-related cancers."


While some cancer-causing exposures can be avoided through lifestyle choices, others, like air and water pollutants, are challenging to prevent entirely. Raising awareness, implementing public health policies, and conducting further research are vital steps in reducing the environmental factors that give rise to the potential risk of cancer. Ultimately, comprehensive strategies that address both individual behaviors and environmental factors are essential in the fight against this devastating disease.