MEXICO

-- The world's most
polluted metropolis, Mexico
City, had to perforce observe
a smog emergency for three
days in the last week of
January after ozone levels
shot up to 269 points - 19
points higher than the safe
leveL In spite of clear skies,
the smog levels remained
high. While smog emergencies are nothing new -
Mexico has seen 20 such
emergencies in the last three
years - environmentalists
are sbouting hoarse that the
city authorities are as usual
giving the health of the 20
million inhabitants of the
capital a low priority by
allowing the emergency
threshold to remain so
low. The World Health
Organization considers 100
points to be the safe limit.

Thousands of cars were
kept off the streets and factories cut down their production by 30 per cent in a bid to contain the threat by bringing down the ozone level.
Hundreds of gas stations
were also closed down. The
restrictions paid off as the
ozone levels were brought
down, reducing the intensity
and the quality of airborne
pollutants. High concentrations of ozone, an invisible
gas, can cause respiratory
problems, headaches, sure
eyes and nausea.