Environmental effects on health are a hot topic of discussion among the political and medical communities around the world. Every 14 seconds a person dies from air pollution in the Western Pacific, and over 90
per cent of people breathe unhealthy levels of outdoor air pollution, largely resulting from the burning of the same
fossil fuels that are driving climate change.
Amid the global pandemic, a polluted planet, increasing rates of diseases like cancer, asthma and heart disease, on World Health Day this year, WHO will focus global attention on the urgent actions needed to keep humans and the planet healthy and foster a movement to create societies focused on wellbeing. This World Health Day 2022, the focus was on climate change and its effect on life.
The environmental factors affect health in several ways both in severity and clinical significance. For example, the effects of environmental degradation on human health can range from death caused by cancer due to air pollution to psychological problems resulting from noise.
In India, the clinical significance of environmental detriments is related more to the exposure to air pollutants
(particularly in North India) and chemicals in the environment. Burning of stubble and industry pollutants are
major causes of air quality problems and are on the increase, with serious repercussions for human health.
Sources of environmental pollution
There can be various sources of exposure to chemicals, which can reach the environment through emissions from industries, anti-fouling paints on marine vessels, agricultural pesticides, waste incineration and leakage
from waste disposal sites etc. While emissions of chemicals can be reduced, they can have a long term impact on the environment after the emission has stopped. Feed additives and medication for livestock are some of the other sources of chemicals which can cause harm to humans. Residues in the form of chemicals that remain in fruit, grains, vegetables, meat and dairy products also impact humans.
As mentioned earlier, unsafe livestock feeding practices make toxins reach the food chain unintentionally. Dioxins contaminating the poultry feed can reach the food chain of humans once they consume the contaminated meat.
Reference can be made to the mad cow disease in livestock which has been linked to a new form of CreuzfeldtJacobs disease in consumers. The effects can be dangerous and can lead to serious allergies and also cancer.
Although one cannot find a direct link between exposure and disease, in some cases a direct causal relationship
can be found. In some cases, low levels of urban air pollutants in the long term can cause asthma, allergies, respiratory diseases and cardiovascular diseases. Heavy metals may lead to neurological disorders and various
cancers and sometimes birth defects and reproductive disorders. Noise is another form of pollution that
can impact human health, leading to decreasing quality of life and in some cases depression. It may be noted that ozone-depleting substances (ODS) are used in cooling systems and spray cans. Ozone layer depletion has led to increased exposure to UV radiation and a greater risk of skin cancer.
During the ‘90s, the huge worldwide toll of CVD was attributed primarily to lifestyle factors such as poor diet, lack of exercise, lack of medical care, smoking and exposure to secondhand smoke. Similarly in India, demographic and health transitions, gene-environmental interactions and early life influences of fetal malnutrition were enumerated as the likely causes of increased
CVD burden, failing to recognise the additional harmful effects of rising pollution levels in urban India. Although the rapidly expanding evidence appears to be carrying the newly recognised field of environmental cardiology into ever-widening areas of influence, research in the area remains in its infancy. Yet there has been much growth in the west in the last few years. One group that is beginning to embrace environmental cardiology is
the American Heart Association (AHA), an 80-year-old organisation that has traditionally focussed on risk factors
such as poor diet and lack of exercise as some of the most important contributors to CVD. In the 1 June 2004 issue of Circulation, an expert panel of 11 researchers and physicians published an AHA Scientific Statement that concluded that air pollutants, one of the major environmental exposure sources under investigation by environmental cardiologists, pose a “serious public health problem” for CVD. This is the first official AHA acknowledgement of such links.
A few other US government agencies, such as the National Heart, Lung, and Blood Institute (NHLBI), have also
begun to address the links between environmental agents and CVD, as have advocacy organisations such as the American Lung Association and the Natural Resources Defense Council. And the NIEHS, one of the original players in the environmental cardiology arena, has ramped up its efforts to explore this area of research.
Organisation for Economic Co-operation and Development (OECD) countries are safe when it comes to direct exposure to chemicals or air pollutants. Although OECD countries have taken steps to decrease the production of ODS, xposure levels to UV radiation are still above acceptable levels in many regions of the world.
What experts say
According to a report by WHO more than seven million people across the world lose their lives due to diseases
linked with PM2.5 pollution. India, being a rapidly developing country with an increasing population is suffering from severe air pollution; among the world’s 10 most polluted cities, nine of them lie in India. The increasing air pollution in most of the Indian megacities over the last few decades and its consequential human health impacts (such as asthma and cardio-respiratory illness) has drawn prominent attention in recent years.
Climate change and air pollution have been a matter of serious concern in India in the last few decades. The expanding urban areas with extreme climate events like high rainfall, extreme temperature, floods, and droughts are posing human health risks. The intensified heatwaves because of climate change have led to the elevation in temperature levels causing thermal discomfort and several health issues to urban residents.
Says Dr Harsh Dhar, Consultant Head Neck and Skull Base Surgeon, Medica Superspecialty Hospital, Kolkata, “With the growing industrialisation and lack of proper laws regulating chemical waste disposal, we stand the risk for exposure to chemical toxins. Of the most devastating elements of this pollution is that plastics take thousands of years to decay. Besides, these pollutants cause an increase in harmful algal blooms that produce toxins that accumulate in seafood. The ingestion of these toxins in humans can further cause cancer, amongst many other harmful diseases. There is definite evidence that the incidence of cancer is rising and a certain proportion of this can be attributed to the rise in environmental toxins.
“Being more conscious of pollution and chemical exposure may lead to better health and the prevention of chronic health conditions.”
Dr Kakoli Lahkar, consultant- Medical Oncology, Manipal Hospital, Old Airport Road, Bangalore toxins.”
Environmental pollution by industries especially, air pollution or particle pollution is one of the most important
causes of cardiovascular diseases apart from usual culprits such as gender, hypertension, smoking, diabetes and obesity.
According to Dr Raghavendrra Chikatoor, Senior Cardiothoracic Surgeon, BGS Gleneagles Global
Hospital, “Though we do not have Indian studies, indirect evidence could be seen in the increased incidence of
heart attacks, strokes etc, in urban population. Anti-fouling paints used in ships contain a large amount of
copper which is shown to accumulate in marine life forms and gets passed up in the food chain including fishes. It also contaminates water near the dockyards and high levels of copper can cause damage to solid organs like the liver and kidney. The chronic exposure can lead to cancers of solid organs too.”
Dr Lahkar said, “The environment we live in has a direct effect on our health. Chemicals like pesticides and emissions from industries cause inflammation and oxidative stress leading to cardiovascular, respiratory, and other diseases. Air pollution resulting from diesel fumes can cause various respiratory illnesses including cancer. Being more conscious of pollution and chemical exposure may lead to better health and the prevention of chronic health conditions.”
How to remain safe
Humans should take precautionary measures to overcome the challenges of pollution. Safe practices should
be adopted to live a pollution-free environment. After all that we sow today will reap tomorrow. According to Dhar the only way to be safe from these risks is to eat healthy foods, increase immunity, completely avoid processed foods as much as possible, stay hydrated, have safe household water storage, better hygiene measures, and limit the use of unknown chemicals, especially plastics.
Dr Kandaswamy says, “Strategies available for pesticide reduction include agronomic practice, resistant crops, natural pesticides, integrated pest management, agroecology, organic farming etc.”
There can be many ways we can minimise pollution which is harmful to not only humans but also other
living beings. Not using pesticides in agricultural activities, using chemical feeds for livestock can bring a sea
change in human health in the long run and thus reduce the impact of harmful diseases. How we can control the
environment today will tell us what we will be getting tomorrow.