Daniela Estrada
SANTIAGO, Mar 27 2008 (IPS) – It s as if we were swimming at a beach unfit for bathing. For four or five months a year, the air is unfit to breathe in the Chilean capital, and the government throws out a lifejacket when people are in difficulties, so that they don t drown, Patricio Pérez of the University of Santiago told IPS.
The expert was referring to the latest measures against air pollution announced Wednesday by the authorities in Santiago, which he described as merely palliative.
Pérez s forecasts about air quality for Santiago s 6.5 million people are not very favourable. So far there is no indication that this year will be any better than 2007, which was the worst since 2002, the researcher said.
Santiago, which is home to 40 percent of the Chilean population, has particularly poor ventilation, because it is surrounded by mountains.
Vehicles and factories are the main culprits of air pollution, although in recent years wood smoke from residential fireplaces has made an increasing contribution.
Other factors conspiring against air quality this year are the lack of rainfall due to the cyclic climate phenomenon known as La Niña, and greater use of oil to generate electricity for industry, because of the continuing cuts in exports of natural gas from Argentina.
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Transantiago, the public transport system inaugurated a year ago, also plays a crucial role. Dissatisfaction with overcrowding and inconvenience has led to private cars taking to the streets in droves, and the use of old, polluting buses to make up for the initial shortage of vehicles.
The government also reduced taxes on gasoline, which has acted as another incentive to buy and use cars.
Every year, under the Air Pollution Prevention and Decontamination Plan for the Santiago Metropolitan Region, designed in 1998, the mayor s office announces measures to deal with the most critical period of the year, from April to August.
Some of the measures announced this week by Santiago Mayor Álvaro Erazo are permanent and others are transitory, to be applied only if a state of environmental alert, pre-emergency or emergency is decreed.
As a permanent measure, owners of cars without catalytic converters with licence plates ending in four specified, alternating digits will be forbidden to drive from Monday to Friday between Apr. 1 and Aug. 31.
Restrictions will be increased to six digits in pre-emergency situations, and to eight in environmental emergencies.
Burning crop stubble is prohibited from Apr. 1 to Aug. 31 (the ban used to be effective as of May 1 in previous years). Four new air quality control stations will be added to the seven that already exist, and government monitoring is to increase.
Since 1998, the government has used an air quality index based on the quantity of particulate matter (PM), known as ICAP, to determine critical episodes of pollution.
The indicator reflects the daily average content in micrograms of PM 10 (solid or liquid particles measuring less than 10 micrometres, or microns, in diameter) in each cubic metre of air.
The four ICAP air quality categories are good (less than 100 micrograms of PM 10 per cubic metre), moderate (100 to 200 micrograms per cubic metre), poor (200 to 300) and critical (300 to 500).
If the ICAP is above 200, a state of environmental alert is decreed, if it is over 300, a pre-emergency , and if it is above 500, an emergency , because of the damage these particles can do when inhaled by the human respiratory system.
What the government wants to achieve with this package of measures is not very ambitious: its goal is not to exceed the 22 environmental alerts and six pre-emergencies that were recorded in 2007.
Before the measures were made public, there was controversy between the environmental and transport authorities over restrictions to be enforced on cars with catalytic converters during pre-emergency periods.
The Transport Ministry won the dispute, as instead of imposing a four-digit ban, as was stipulated for this year by a 2007 decree, the government instead ordered restrictions on two digits.
Mayor Erazo argued that a ban on four digits for cars fitted with catalytic converters would lead to a further 250,000 people using the fragile public transport system, which would collapse under the strain, especially the metropolitan subway network.
It was also expected that the authorities would prohibit wood burning in all fireplaces, but this measure was confined to periods of environmental alert only.
Environmental organisations are demanding solutions at a more fundamental level, such as halting the city s expansion, improving public transport, increasing green areas, and using cleaner fuels in industry.
In Pérez s view, the government should provide companies with incentives to encourage them to move to other cities.
The expert also criticised the fact that standards have not yet been set for fine particulate matter (PM 2.5, or less than 2.5 microns in diameter), which are a greater health hazard than PM 10, and that the public is not informed about PM 2.5 levels in the capital.