For those of you residing in metropolitan cities will know the pros of travelling by metro trains. Commuting by metro train is one of the quickest way to get to your destination. I am sure most of you would agree to it.
Well, what we were considering was just one side of the coin. But, a new study has come out with some startling fact about metro trains that will seriously blow your mind.
In what can be considered a landmark study, researchers have found that, commuting regularly by underground metro trains may pose hazardous health risks.
This is because the air inside the compartments have higher concentrations of cancer-causing agents, says the study.
The study was recently published in the journal Aerosol and Air Quality Research.
So What Is The Exact Cause?
The study showed that people are exposed to significant amounts of airborne particulate matter (PM) during their daily commutes, which often exceed 30-60 minutes each way.
Polycyclic aromatic hydrocarbons (PAHs) and hexavalent chromium, the two major compounds found in airborne particulate contains carcinogens which can cause chronic non-cancer health risks like heart and respiratory diseases.
Owing to the high levels of exposure to carcinogenic transition metals hexavalent chromium, for a person travelling in the underground trains, the maximum "excess lifetime cancer risk" was found to be 10-times higher than the acceptable threshold of one-in-a-million, set by the World Health Organization (WHO) and the US Environmental Protection Agency (EPA), the researchers said.
Despite these electric-powered trains operating with mandatory closed windows and a mechanical ventilation system, airborne hexavalent chromium gets built up due to dust from friction on the steel tracks, as well as the lack of ventilation.
The researchers suspect that individuals who spend more time in the subway, particularly those who work there, would also have a significantly higher health risk.
For the study, the team collected air samples using battery-operated devices with particle sensors on both train platforms and inside train cars in Los Angeles.
The cancer and non-cancerous health risks were calculated based on a lifetime of exposure commuting one hour a day, five days a week, for 50 weeks a year, and assuming 30 years of employment.
(With Agency Inputs)