A case study on photochemical smog in Mumbai. Has many facts and figures and is very useful for the geography topic of climatic hazards.

1. MatthewMortimer
Mumbai Photochemical Smog Case Study
The Mumbai skyline,formingabackdropto the ocean,isone of the city’smosticonicsights.But
drive downMarine Drive or the Bandra-Worli sealinkthese daysandyou’re likelytosee the
skyscrapersonlythrougha thickbrownmist,particularlyinthe earlymorningoraroundsunset.
Mumbai receivesannual smogorhaze duringthe wintermonthsstartingNovember.However,over
the past couple of years,the haze seemstohave setin as earlyas October,a phenomenonthat
couldtriggera varietyof healthproblemsforthe residents.
Accordingto officialsof the Indianmeteorological department,haze like conditionshave begunto
appearin the monthsimmediatelyafterthe monsoon.There are avarietyof factorsfor this. One
reasonisthat post the monsoonthe windsthatblow throughthe cityare hotterand those bringa
lotof dust. Furthermore,anotherfactoristhat duringthe monsoonseason,alotof dustand other
particleshanginginthe atmosphere are washeddown tothe ground.Afterthe monsoon,asthe
weatherbecomesdryer,theseparticlescouldbecome loosenedandfloatuptothe air, causingthe
smog.
Increasingpopulationhasexacerbatedthe problemandevenmore pollutantsare beingreleased
intothe air. Thismeansthat the situationislikelytogetworse withthe onsetof winter.Seabreeze
isstrongerin summerbecause of the large temperature differencesbetweenlandandoceanwater.
As the seabreeze dropsinthe monthsfollowingNovember,itmeansthe pollutantshoveringinthe
air cannotbe blownawayas easilyasthose are insummer.
The MPCB regularlyputsoutair pollutiondata,classifiedaccordingtoacolour-codedairquality
index (AQI),fromitsstationinBandra.A lookat the data showsthe pollutionlevelsrisingsharply
postmonsoon.InOctober,readingsshootupdramaticallyoverthe 100 mark onthe scale,indicating
breathingdiscomforttopeople withlungandheartdisease,children,andolderadults.Oncertain
daystowardsthe endof the monthandthrough November,the level came dangerouslyclose to
200, a level thatindicatesbreathingdiscomforttoall people onprolongedexposure.
Doctors saidthe increasedlevelsof pollutionare mostlikelytoaffectchildrenandpatientswith
chroniclungdiseasessuchasasthma. The increasesinpollutantsmeansoverthe lastfew years,the
numberof patientsgoingtothe doctors withbreathlessnesshasheavilyincreased.