Peter Gellert
MEXICO CITY — This city's legendary air pollution problem is bad and getting worse. City authorities have responded with an emergency plan to address partially the deteriorating environmental situation in the world's largest city.
In 1991 the Mexico City metropolitan area had 170 days officially recognised as being above the danger level on air pollution indexes, more than at any time in the city's entire history.
The metropolitan air quality index — the Imeca Scale — judges air quality based on six criteria: solid suspended particles found in the air, sulphur dioxide, ozone, carbon monoxide, nitrogen oxide and a term measuring the reaction between sulphur dioxide and other chemicals such as lead.
For the past few days, for example, the Imeca reading has hovered around 282 points. Above 200 is considered "dangerous", above 300 "very dangerous". Last year, levels above the 300 mark were registered on nine days.
There were 10 thermal inversions: warm, more contaminated air is trapped in the lower layers of the atmosphere, producing record-breaking pollution levels and increasing bronchial diseases in the population, particularly among children and the elderly.
According to Martin Becerril, of the Allergies and Immunology Department of the La Raza Medical Centre of the Mexican Social Security Institute, "at least 10% of the population suffers from respiratory diseases such as pulmonary asthma".
Two years ago, the Federal District Department (DDF) — Mexico City's government — put into effect a "day without a car program". Every car has a sticker indicating that one day during the work week it cannot circulate. Weekday traffic would, theoretically, be reduced by 20%.
Since then, however, the number of cars on the road has increased by 600,000, in effect cancelling out the original idea of reducing contaminants by 14,000 tons per day. Many middle and upper class families simply purchased another car to avoid the bother of the "day without a car".
According to Alfonso Cipres, a leader of the Mexican ecologist movement, the program has, in fact, reduced air pollution by only 1%, although it has had a positive effect in terms of increasing grassroots consciousness on the seriousness of the situation.
Part of the problem is objective. The city is located in a valley surrounded by mountains, which tend to trap polluted air. The spectacular and unplanned growth of Mexico City — from 12 million inhabitants in 1977 to over 18 million in 1990 — is an additional factor. Air pollution was not recognised as a problem until recently, authorities devoting time and energy to tackling what were conceived of as more pressing problems.
However, a series of sweeping measures was announced last month by Mayor Manuel Camacho Solid for the winter 1991-92 period.
Among the most important are eliminating the industrial and commercial use of petrol that contains more than 2% sulphur; reducing energy production in thermoelectric plants inside the metropolitan area by almost a third; allowing businesses to remain open at night to cut down on daytime traffic.
Also, the school day is to begin an hour later so that children can avoid the early morning hours, when pollution is at its worst. There are additional minor measures aimed at restricting the use of metallic paint, allowing petrol stations to fill their storage tanks only at night etc.
If pollution levels go above 350 on the Imeca Scale and the thermal inversions continue, as will most likely be the case, cars will be allowed to be used on only three weekdays per week, and school might be suspended until the situation improves.
If the contamination levels go above 400 points — which has so far never happened — all work in Mexico City will come to a halt. At that point, the city will be truly uninhabitable.
For really the first time ever, the population, burdened by the struggle for daily existence, is paying attention to the pollution problem and its long-term effects.
Everyone is beginning to notice that more and more people are calling in sick on the job; everyone complains of headaches and burning eyes; athletes complain that they cannot run or train inside the city limits.
The DDF also announced that it will provide the population with regular news bulletins on levels and tendencies of each contaminant in the Imeca Scale. Ten electronic billboards will be installed on major thoroughfares to keep residents posted on the air quality.
Activists from the small but growing ecology movement, social organisations and opposition political parties, while generally supporting the city government's plan, feel the response is too little, too late.
Mexico, rich in oil reserves, has paid little attention to alternative energy sources, and there is a complete dependence on hydrocarbon fuels.
Ecology movement activists say that one problem that has not been adequately addressed is that the quality of petrol, responsible for the high ozone levels, is far from optimum.
Some argue that not enough pressure has been brought to bear on the motor car industry to use technologies which would reduce emissions.
Public transportation is still deficient, and there are still large ere the clean and modern, if crowded, metro does not even reach.