This past winter has been very harsh on our lungs. The thick inversion layer trapped dust and smog in the air for weeks and Kathmandu recorded dangerously high levels of
pollution with the unfinished road expansion project making the city’s air more unbreathable. And if you
smoked during this time, you made yourself doubly vulnerable to a host of chronic lung disease such as COPD (chronic obstructive pulmonary disease) as proved by studies by doctors like Mark Zimmermann and Paban Sharma from Patan Hospital.
But to better understand air pollution and figure out ways to protect ourselves, we need to understand aerosols. Aerosols are a collection of particles that remain airborne for a substantial period of time. Many pollutants exist in this form and their pattern of deposition in the lung depends on the size. Larger particulate matters above 10 microns (PM 10) are trapped in the nose and upper airways, but the finest and most deadly particles, PM 2.5, find their way into the inner recesses of the lungs.
Most Kathmandu residents don masks or cover their mouths with handkerchiefs when out on the streets. But PM 2.5 which is about 30 times thinner than human hair can easily penetrate these generic masks. While many of us know how harmful air pollution is to our lungs, the relation between pollution and cardiovascular diseases is not talked about too often. Many people are surprised to find out how these small particles lead to an increased susceptibility to heart attacks and strokes.
However, outdoor air pollution is not our only enemy. Thousands of households across Nepal still burn wood and dried cow dung to use as cooking fuel in their kitchens.
Inhaling this exhaust is as worse as smoking five packs of cigarette a day and women who are in-charge of the kitchen are at most risk. In a recent study conducted by Mountain Medicine Society of Nepal, Nepal International Clinic, and our Italian colleagues in Khumbu, a non-invasive ultrasound revealed that the inner lining (endothelium) of the arteries of a large number of inhabitants of this region was impaired. Derangement of endothelial function of the arteries leads to atherosclerotic disease, the hallmark of heart attacks and strokes. Although Khumbu has clean air, most people here still use bio-mass in homes which causes the damage in the endothelium.
The good news is that both outdoor and indoor pollution are reversible, but we need to create awareness and the political will to make a change.