Air Pollution and the Railways, threat to human life

Air Pollution and the Railways, threat to human life


During our fight with the deadly coronavirus, we heard another terrible news where some reports suggested that Air Pollution can intensify COVID 19, it may alter lung cells to increase the number of SARS CoV 2 virus receptors. Air Pollution is not a new problem that we are facing, it is a  global health emergency and there is no doubt that if we are moving with this pace it will become more dangerous in the coming years.

Graph showing major risk factors to human health


Air pollution is a silent killer it does not attack directly, but it made us sick day by day. Many people lost their lives due to air pollution every year and many are suffering from serious health consequences due to this. If we look at the report of 2019 released by WHO Air pollution kills an approximate 7 million people worldwide every year. WHO data shows that 9 out of 10 people breathe air that contains a high level of pollutants. The health hazards that can cause due to Air Pollution are:-

  •  Lung Cancer
  • Cardiovascular disease
  • emphysema
  • Pneumonia
  • Respiratory diseases 


In the last few decades, awareness among the people regarding environmental concern had come. But whenever we thought about reducing air pollution one of the most important things we are suggesting is of using public transport as much as possible. The railways, along with the positive influence on the economic development of the regions have also caused irreparable damage to the environment. Railways are the lifeline of millions of people, but are also responsible for causing Air Pollution in both direct and indirect ways. We know that the rail engines are run through Electricity, Coal or Diesel.  In most of the countries, Diesel fuel has preferred to use as a fuel for railway locomotive because of its lower volatility, lower cost, and common availability but, it releases polluted air. Trains are more energy-efficient than automobiles, but they have their own effects on the environment, including major pollutants emitted from the diesel-powered locomotives are:

  • Carbon dioxide (CO2)
  • Methane (CH4)
  • Carbon monoxide (CO)
  • Niisgen oxides (NOx),
  • Nitrous oxide (N2O), 
  • Sulphurusesoxide (SO2)
  • Non-methane volatile organic compounds (NMVOC)
  • Particulate matter (PM)
  • Hydrocarbon (HC)

It contributes to air pollution and negative health effects. Coal is used for producing electricity which later on uses for this engine. Pollution from electric trains can also lead to poor air quality due to the production of metal-rich ultrafine particles from brake linings, friction between wheel and rail, and from overhead pantographs.

Many studies reported higher levels of PM10  and PM2.5 near railways, higher than the standard level allowed. Trains are complex pieces of machinery, and it’s not as simple as a car which starts just by turning the key. Trains can be left idling on platforms, spewing particulate matter into an enclosed environment. It creates disturbances and has bad consequences on air, soil and water pollution, as well as noise and vibration, which may alter species. The two most known disturbances of railways are the noise and vibrations caused by passing trains. Apart from these, railways are also responsible for a large number of emissions that cover a wide range of pollutants and toxic substances that affect the atmosphere.  

The emission of toxic gases is the main source of environmental pollution all over the world.  These emissions depend mainly on the type of transport and fuel. Possible sources of contaminants related to railways include diesel exhaust, and the abrasion of brakes, wheels, and rails, as well as dust from the transport of minerals and treated railway ties.


Recent occupational health standards are not suitable for enclosed railway stations and need to be reconsidered. More measurements of the levels of particulates and nitrogen dioxide in enclosed railway stations need to be undertaken. Air pollution from diesel emissions is becoming an increased international concern, and whilst attention has been primarily focused on the automotive industry, concerns have also been raised about emissions from diesel rail vehicles has initiated major steps to address pollution. 

Globally, air pollution is responsible for more deaths than any other serious risk factors such as malnutrition, alcohol, physical inactivity etc. And for combat, this crisis we should move forward to reduce dependency on traditional resources. Hydrogen can be produced using other methods and from renewable energy sources, e.g. electricity from solar photovoltaic and electrolysis of water. We also have to encourage more sustainable transportation.

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