ENVIRONMENT-CHILE: First Emergency in Santiago Since 1992

By IPS Correspondents Reprint | | Print |

Gustavo Gonzalez

SANTIAGO, May 23 1998 (IPS) - While authorities in Mexico and Honduras urge people to stay indoors to avoid the smoke of forest fires raging out of control due to the El Nino weather phenomenon, good old-fashioned smog forced officials in the capital of Chile to declare the first environmental emergency since 1992.

After seven years of anti air pollution policies and frequent alerts which have become all but routine, Santiago, famous for its smog, remains in serious trouble.

A total of 942 industries in the Metropolitan Region were ordered to cease operations, 350,000 vehicles running on leaded gas were banned from circulation, preschools and primary schools were closed in three municipalities, and phy-ed classes and sports activities were suspended in all primary and secondary schools in the 34 municipalities of the greater metropolitan region.

The last environmental emergency in Santiago – a city of more than five million set in a valley surrounded on all sides by the Andes mountains – was declared Jul. 8, 1992, shortly after the democratic transition government of Patricio Aylwin (1990-94) began to implement systematic anti-pollution measures.

An environmental emergency is declared when the local air pollutant index measuring the concentration of carbon monoxide and other toxic agents exceeds 500, as occurred Sunday in three municipalities on the westside of Santiago.

The declaration of a state of alert has become routine from April to September – the southern hemisphere autumn and winter – when the air pollutant index frequently exceeds the threshold of 200, above which air quality is considered poor.

Twenty percent of vehicles running on leaded gas are normally banned from circulating in fall and winter, through an alternating system based on license plate numbers. That proportion rises to 40 percent under an environmental alert, and to a full 80 percent in a state of emergency. Vehicles with catalytic converters – which use lead-free gas – are exempt from the restrictions.

Deforestation on the outskirts of the capital resulting from urban and industrial sprawl, an irrational public transport system and a boom in the number of motor vehicles all contribute to the smog, which has a hard time escaping the valley due to Santiago’s unique location.

The haze thickened over the weekend due to a ronounced “thermic inversion,” a phenomenon that frequently affects the capital at this time of year. Thermic inversion occurs when a layer of hot air settles in at high altitudes, holding down the cold air in the valley, keeping air from circulating and preventing winds from blowing away pollutants.

The thermic inversion was aggravated over the weekend by another phenomenon, masses of hot air blown in from the Pacific ocean which is located some 100 kms from Santiago. When that occurs, the lowest-lying sectors along the westside of Santiago are affected: the poor municipalities of Pudahuel, Cerro Navia and Lo Prado, where air quality measuring stations detected a level of 551 Sunday.

The 942 factories – which account for 50 percent of the total emissions released by fixed sources in the city – that were closed down Monday were mainly industrial boilers.

All new vehicles sold in Santiago since 1992 are lead-free, and authorities have been gradually retiring old buses and taxis as part of their attempt to improve air quality.

Anti-pollution measures began to go into force under the Aylwin administration, which shortly after taking office in March 1990 created the Special Commission for Decontamination of the Metropolitan Region, which was to come up with proposals for policies and measures.

Although the commission was dissolved, its work served as the basis for successive environmental programmes in Santiago, the last of which was presented by President Eduardo Frei in 1997.

The programme outlines long-term objectives, such as major investment in public works including new freeways and avenues that prevent traffic jams and expanded capacity for the Metropolitan Railway and other clean forms of transport.

Other plans are downtown areas limited to vehicles running on electricity or natural gas, more pedestrian-only areas, reforestation projects on the outskirts of Santiago and an expansion of parks and green areas in the capital.

Bu environmentalists are opposed to the construction of new freeways, and criticise the government for failing to adopt firm measures to encourage public transport.