Winter has not set in yet and the dirty winter smog has already enveloped north and central India. And with it comes the threat of a long list of diseases to which new ones are added every few weeks.
My health concern of the week is the study that shows long-term exposure to diesel fumes and particulates — tiny dirt particles in polluted air — increases the risk of deep vein thrombosis. This is a condition in which blood clots formed in the thighs or legs break and clog blood vessels, causing heart attacks and stroke in sedentary workers and people on long-haul flights. Particulate matter consists of solids in the air in the form of smoke, dust and vapour that remain suspended for extended periods, and is also the main source of smog that reduces visibility.
Particulates smaller than 10 micrometers in diameter (1/40th the width of a human hair) are found in the exhaust fumes of vehicles, especially those with diesel engines, and when fossil fuels are burned. When inhaled, these particles cause lung damage and respiratory problems such as asthma. Particulates are also an established risk factor for heart attack and stroke.
One in 10 people in urban India has asthma — a breathing disorder characterised by recurrent wheezing attacks. Children and people over 65 years are at a higher risk of acute attacks. The smog, along with the temperature drop, can trigger wheezing in non-asthmatics who smoke or have respiratory infections. The cold combined with chest infection can worsen symptoms and cause respiratory failure in the elderly.
According to the World Health Organisation, pollution causes 777,000 deaths worldwide, 531,000 of them in Asia. A Central Pollution Control Board and All India Institute of Medical Science survey showed that eye irritations and shortness of breath affected a majority of Delhi residents. The study found that pollution also affected lung capacity, with nearly everyone doing poorly on lung functions tests such as forced expiratory volume, forced vital capacity and peak expiratory flow.
Most of us don’t find this worrying enough to leave our cars and take the metro or bus. But if we want the smog to go, new challenges have to be addressed such as the boom in the number of private vehicles, in particular, diesel vehicles. Delhi already has over 52 lakh registered vehicles, with another 1,100 added everyday. Efforts such as introducing Euro II standards, lowering sulphur content in fuel, implementing CNG for public transport and banning trucks in the city made some difference but the sheer number of new vehicles negated the gains in two years. Steps have to be taken to ensure our lungs continue functioning a decade from now.