Long-term exposure to diesel pollution bad for health, according to experts

Prolonged exposure to diesel pollution, which includes a complex mixture of pollutants, can have serious health effects on humans, said experts here even as the government contemplates a ban on diesel vehicles. A government panel formed by the Ministry of Petroleum and Natural Gas has recommended banning the use of diesel-based four-wheelers by 2027 in cities with a population of over 10 lakh people.

Pollution from diesel exhaust mainly includes soot or particulate matter (PM); oxides of nitrogen (NOx) which contribute to the production of ground-level ozone (smog) and acid rain; hydrocarbons (HC), carbon dioxide (CO2), and carbon monoxide (CO).

Short-term exposure to diesel exhaust can cause irritation of the nose and eyes, changes in lung function, respiratory changes, headache, fatigue, and nausea. Long-term exposure has been shown to result in prolonged cough, sputum production, and poor lung function.

"One common contributor to air pollution is vehicular smoke, with diesel exhaust particles accounting for a significant percentage of the particles emitted in many towns and cities," Vivek Nangia, Principal Director and Head-Pulmonology, Max Super Speciality Hospital, Saket, told IANS.

"Exposure to fumes causes significant inflammatory changes in the airways, which may be even more detrimental in people with chronic lung diseases such as bronchial asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, etc. It is also postulated that diesel exhaust particles are an important factor contributing to the allergy pandemic as they act as adjuvants to allergens and increase the sensitisation response," he added.

A recent study by the Universities of British Columbia and Victoria in Canada showed that common levels of traffic pollution are capable of impairing brain function in a matter of hours.

Another study of 1.4 million kids aged under 10 by Universities of Manchester in the UK and Aarhus in Denmark showed that exposure to high levels of nitrogen dioxide and PM2.5 increased their odds of self harm in adulthood by 50 per cent.

These two pollutants are also among the most commonly linked with heart and lung diseases, as they get into the bloodstream and cause inflammation.

Air pollution contributes to about 6 million preterm births each year globally. Exhaust emitted by diesel engines have also been linked to increased rates of neuro-developmental disorders, such as schizophrenia and autism.

"Diesel engines emit a complex mixture of pollutants. Obviously, those are very small carbon particles which are known as diesel particulate matter. So if their sizes are small, they will enter deep into our organs, especially lungs," said Kuldeep Kumar Grover, Head of Critical Care & Pulmonology, C.K. Birla Hospital, Gurugram.

"Diesel exhaust contains more than 40 cancer causing substances, thus diesel engine emissions are believed to be responsible for so many cancer related contaminants. That is why various factors exaggerate the health risk of diesel particulate exposure," he added.

A possible solution is switching to electric and gas-fuelled vehicles, as suggested by the government panel.

A latest study by the University of Southern California used real-world data to provide evidence that increase in electric vehicles may result in better air quality and better health.

The study found that when electric vehicles increased, air pollution and health problems went down.