"Please write letters to Captain uncle and Khattar uncle and say, 'Please think about our health and use machines for treating stubble'," Kejriwal told the children at a Delhi school this Friday, referring to the smoke from stubble burning in Punjab and Haryana #SundayScience 
Conventionally, farmers in Punjab & Haryana burnt the crop residue after harvesting paddy (Oct / Nov), to clear their fields for sowing wheat. #SundayScience
That’s the time winds blow from India's north and northwest towards east. This aerial view shows India's annual crop burning, resulting in smoke and air pollution over Delhi and adjoining areas. #SundayScience
There you go with science of air pollution, with respect to one of the pollutants. Spatial source of a pollutant in a given season and the direction of wind at that time #SundayScience
Let’s examine what aggravates this problem and the science behind it, and then move on to other such sources and locations of pollutants in different seasons #SundayScience
During winter in North India, atmospheric inversion occurs, viz. warmer air is held above cooler air, unlike the normal atmosphere, where temperature decreases with an increase in altitude. An inversion traps air pollution, such as smog, closer to the ground. #SundayScience
Black line shows height vs temp under normal atmospheric conditions. When the layer from ~8 km (A-B) descends dry adiabatically (let’s deal with this word in another #SundayScience) inversion occurs near the ground ~2 km (C-D).
The particulate emissions in other seasons (from one or the other sources) are more or less the same, but comfortable convective upward atmospheric air circulation is able to disperse the pollutants. #SundayScience
When upward-displaced air parcels become buoyant and experience a further upward force, atmospheric convection occurs. #SundayScience
Let’s get to some basics now. Particles <=10 micrometers in diameter are so small that they can get into the lungs, potentially causing serious health problems. Ten micrometers is less than the width of a single human hair. #SundayScience
Coarse dust particles (PM10) are 2.5 to 10 micrometers in diameter. Fine particulate matter (PM2.5) are tiny particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated #SundayScience
An IIT Kanpur study says that the two most consistent sources for PM10 and PM2.5 in Delhi are secondary particles and vehicles. For traffic related sources, growth in vehicle numbers seems to outpace efforts to reduce emissions. #SundayScience
An old study in Delhi concluded that tempos contribute maximum amount of concentration of NOx and PM, followed by trucks, buses, cars / taxis, and small trucks in that order. #SundayScience
Delhi’s air quality monitoring grid allows granular tracking of pollution across its thirty eight neighbourhoods, allowing action by hot spots. #SundayScience
For example, many of the unorganised plastic recycling units in Mundka resort to open burning of plastic waste, causing unacceptable toxic exposure! Other hot spots include regions that house a number of unregulated industries and their emissions. #SundayScience
Wind blown dust from loose soil is a major contributor to air pollution. Unpaved roads and digging activities for various infrastructural construction expose the loose soil, resulting in an increase in the hazardous PM2.5 #SundayScience
Closing this week’s #SundayScience with a link to “4 studies on Delhi’s pollution and 4 different conclusions” pointing to the need for more granular ongoing data collection round-the-year to solve the problem comprehensively. indianexpress.com/article/explai…
#Telugu Poem by @ivak99 on today's #SundayScience feature #DelhiAirPollution #సండేసైన్సుదశకం
ఊపిరితిత్తులు కొలిమి
ఊపిరివ్యాధుల చెలిమి
ఊపిరితీతకి బలిమి
ఊపిరియాడని తాలిమి!
తాలిమి = ఓర్పు!
ఊపిరితిత్తులు కొలిమి
ఊపిరివ్యాధుల చెలిమి
ఊపిరితీతకి బలిమి
ఊపిరియాడని తాలిమి!
తాలిమి = ఓర్పు!
