Smog : History, Types, Causes and its Effects

Here's the difference between fog and smog and how the smog is formed. Why smog is formed in winters?
Realtion of Great smog of 1952 and London smog disaster of 1952 with sulfurous and photochemical smog.

1. SMOG
AND
ACID RAIN

2. SMOG

3. What is SMOG?
■Smog is a kind of air pollution.
■It occurs when smoke combine with
fog.
■It is yellowish or blackish in color.

4. BRIEF HISTORY
■1943-First recognized photochemical smog in Los Angeles
■1947-California Governor Earl Warren signs a law setting up an Air
Pollution Control
■1948-Caltech chemistry professor Arie Haagen-Smit discovers the source of
ozone
■1952-Sulfurous smog led to 4000 deaths
■1963-Congress accepted the primary Clean Air Act
■1975-Catalytic converters with three way catalyst were designed to lessen
discharges of hydrocarbons, carbon monoxide and oxides of nitrogen
■1990-President George Bush signs into law the Clean Air Act Amendments
of 1990
■2010-The Pak-EPA drafted the National Air Quality Standard (NEQS) for
ambient air quality

5. DIFFERENCE BETWEEN FOG AND SMOG
■FOG
✓Fog is formed when moist air is cooled
✓Disperse light and reduce visibility
✓Visibility less than 1000 meters
■SMOG
✓Formed when organic compounds and
nitrogen oxides chemically react with
sunlight
✓Cause choking coughing and other
health problems

6. FORMATION OF SMOG

7. ■Smogisformedduetothereactionthattakesplacebetweensunlightandemissions
frompowerplants,factories,cars,andothersources

8. Why Smog Is Formed In Winter?
■It is caused entirely by pollution
■Pollutants released in air reacts with sunlight
and heat as a result, smog is formed in the
atmosphere
■During winter months, the speed of wind is
slow and is mostly stagnant, this causes
smoke and fog to accumulate at a place, lead
to the formation of smog

9. TYPES OF SMOG
■There are two types of smog:
Sulfurous
Smog Photochemical
Smog

10. Difference between
SULFUROUS SMOG
■Industrial smog or London smog
■First observed in London in 1952
■Greyish in color
■Cause-burning of coal or oil at
large power plants
■Cause lung problems
PHOTOCHEMICAL SMOG
■Los Angeles smog
■Frist observed in Los Angeles in 1950
■Brownish in color
■Cause-automobiles
■Cause eye irritation

11. SULFUROUS SMOG
■AlsoknownasLondonsmogorIndustrial
smog
■Greyishincolor
■Reducinginnature
■Producedduetohighconcentrationofsulfur
dioxideandparticulatematterproduced
fromfuelcombustion
■Usuallyformedinwinterparticularlyin
morninghourswhentemperatureislow

12. GREAT SMOG OF 1952
■Great smog of London
■Severe pollution event that affected
British capital of London in early
December
■Sustain from 5 to 9 December
1952
■12,000 dead
■200,000 injured

13. LONDON SMOG DISASTER OF 1952
■Early on 5th of December 1952 the London sky was clear
■The weather was considerably colder than usual
■People of London were burning large amounts of coal and smoke bellowed
from the chimneys
■The winds were light and the air near the ground was moist
■Hence, cold stagnant air trapped under a layer of warm air
■The resultant fog that was a persistent smog blanketed London for few days
until the weather changed