Mumbai’s air quality worse than Delhi, AQI dips to 156 due to development projects
Mumbai’s air quality worse than Delhi, AQI dips to 156 due to development projects
Subject :Environment
Section: Pollution
Major Air Pollutants:
CO:
- By incomplete combustion of carbon based fuels, Automobile exhaust, Cigarette smoke
- Combines with hemoglobin to form carboxy haemoglobin, which is highly stable & reduces oxygen carrying capacity of blood
- Slow our reflexes & make us confused & sleepy
CO2:
- Major greenhouse gas formed by respiration, burning of fuels, decomposition of lime, volcanic eruption.
CFCs:
- Released mainly from air conditioning systems & refrigeration
- Detrimental to Ozone layer present in the stratosphere as CFC + UV >> Cl (Chlorine radicals which causes breakdown of Ozone)
Lead:
- Present in petrol, diesel, lead batteries, paints, hair dye products etc. (Affects children in particular)
- Damages nervous system & cause digestive problems & in some cases causes cancer
O3:
- Formed when NOx particle from vehicle exhaust & volatile Hydrocarbons interact with each other in presence of sunlight
SPM:
- SPMs in air, when breathed in causes lung damage & respiratory problems
SO2:
- Produced from burning coal (60 %), mainly in thermal power plants + Petroleum products + in production of paper & smelting of metals
- Major contributor to smog causing lung diseases
CH4:
- Mainly CH4 burns in fossil fuels + produced by burning of vegetation / rotting
Acid Rain:
- Ph< 5.6 (Rain with oxides of sulphur & nitrogen (SO2 & NO2)) – HNO3 + H2SO4
NOx
- NO3- → Acts as a fertilizer to the soil
- Automobile exhaust produces NO2 which damages plant leaves & retard rate of photosynthesis + also causes red haze & lung irritation
Classical Smog
- Occurs in cool humid climate
- Chemically reducing hence called reducing smog
- Smoke + fog + SO2.
AQI
(AQI) is A tool for effective dissemination of air quality information to people. An Expert Group comprising medical professionals, air quality experts, academia, advocacy groups, and SPCBs was constituted and a technical study was awarded to IIT Kanpur. IIT Kanpur and the Expert Group recommended an AQI scheme.
There are six AQI categories, namely Good, Satisfactory, Moderately polluted, Poor, Very Poor, and Severe. The proposed AQI will consider eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb) for which short-term (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed.
Based on the measured ambient concentrations, corresponding standards and likely health impact, a sub-index is calculated for each of these pollutants. The worst sub-index reflects overall AQI. Associated likely health impacts for different AQI categories and pollutants have been also been suggested, with primary inputs from the medical expert members of the group. The AQI values and corresponding ambient concentrations (health breakpoints) as well as associated likely health impacts for the identified eight pollutants are as follows:
