MercoPress. South Atlantic News Agency

First environmental alert of year issued in Chilean capital

Santiago is under its first environmental alert of the year Monday in an effort to reduce air pollution and protect the health of the Chilean capital's nearly 6 million residents.

City officials said the measure was preventive in nature and designed to protect residents, especially children, the elderly and pregnant women.

The alert restricts the use of 40 percent of the vehicles without catalytic converters that operate in the city and bans the lighting of chimneys in residences across the metropolitan region.

Although the air quality index is still in the "good" range across the city, thermal inversion and lack of air circulation are expected later Monday.

Thermal inversion, in which hot air is concentrated in the upper layers of the atmosphere, combined with the absence of wind during the fall months of March to June impedes the dispersion of particulates.

Santiago Mayor Victor Barrueto said Monday that the plan for fighting pollution required "structural changes," since issuing an environmental alert only reduces emissions by 1.5 percent.

Due to this atmospheric phenomenon, environmental authorities set up a three-level system of alerts, with the first level being an environmental alert.

The second level is an environmental pre-emergency, and the third level an emergency. Santiago has not declared an emergency, under which the operation of 60 percent of the automotive fleet, including vehicles with catalytic converters, is restricted in more than four years.

When an environmental emergency is declared, the emissions of 30 percent of industries are also prohibited.

During the Southern Hemisphere fall and winter from March to September, atmospheric conditions can lead to the formation of a so-called "toxic mushroom cloud" over the Chilean capital.

Santiago's propensity for high levels of air pollution stems from the nearly 1 million vehicles in circulation, its geographic location - ringed by mountains, practically windless - and the fact that the city is surrounded by an industrial belt.