IT'S the pollution season in Mexico City.
"Today air quality will be unsatisfactory between 11 a.m. and 6 p.m.," reads a typical smog forecast carried in the daily newspapers.
Thermal inversions trap noxious gases in this mountain valley during the winter months. More than half the days in February registered ozone pollution levels above internationally accepted health norms. And March is usually the worst month of the year, environmentalists reminded officials here this week.
Since holding your breath isn't much of an option, in the last two years the government has adopted a vast array of measures to combat the problem. Industries are being sanctioned or shut down. Catalytic converters are mandatory on new cars. Trucks and buses are being converted to natural gas. When the air gets bad - as it has of late - the Phase One emergency measures kick in. Some 200 factories must cut production by 30 percent. Government vehicle use is curbed. Schools keep the children inside at rece ss. If the air gets worse, further restrictions are imposed. Day Without a Car program
As the brown haze thickens over the metropolis, the public clamor to "do something" once again is rising. And the government now finds even the World Bank voicing criticism of its antipollution programs.
This year, the innovative Day Without a Car program has come under attack.
It is a "palliative that isn't solving the problem," complained German Pina Villalpando, a Mexican scientist speaking last month at an environmental conference. "The Day Without a Car program stopped the contamination in the first year, but now it's ineffective because of the increase in the number of cars overall," he said.
Since late 1989, Mexico City residents have been prohibited from using their cars one day per week. But four years of double-digit car sales have blunted the program's effectiveness, according to Gunnar Eskeland, a World Bank economist. The solution "may actually have backfired, as many households responded by buying an additional car," he writes in a recent World Bank report.
Criticism from the World Bank is taken seriously here. Since President Carlos Salinas de Gortari took office in 1988, Mexico has received a broad range of development loans totaling $8.9 billion from the bank. And Mexico has a $1.5 billion open line of credit with the bank to finance environmental projects.
During a visit here last week, World Bank President Preston Lewis praised Mexico as "an example for the world in its programs of change and adjustment." But he added that in light of the North American Free Trade Agreement, Mexico will have to spend more on the environment.
Fernando Menendez Garcia, director of Mexico City's antipollution program, says there are no plans to end the Day Without a Car program, which takes 20 percent of the cars off the road each day. With all due respect, he refutes the World Bank economist's findings.
"I've asked for the data that supports his conclusions," Mr. Menendez says. "Our figures show the growth of vehicle sales in Mexico City parallels sales growth nationwide. The Day Without A Car program has not boosted sales here above the national average," he says.
Mr. Eskeland declined to be interviewed. But Menendez explains car sales throughout Mexico have been stimulated by low inflation, growing middle class buying power, and expanded credit available to consumers. Proposed gasoline tax
World Bank economists also suggest Mexico and other developing countries adopt a gasoline sales tax as a means of reducing vehicular usage and thereby pollution.
"Policymakers can discourage the use of cars through a variety of means, including high-occupancy vehicle lanes, car-free zones, and parking fees. But one of the simplest most effective ways is through a gasoline tax," Eskeland writes. He calculates a 10 percent price hike produces a 4 percent drop in gasoline consumption.
Mexican officials reject this solution as contrary to one of the government's overriding economic goals: reducing inflation.
Menendez argues Mexico City is implementing a more effective, non-inflationary plan. Since December, all vehicles are being required to pass two exhaust emission standards inspections annually.
"We have already taken 10 percent of the worst polluting cars out of circulation. We are obliging people to invest in their cars to bring them up to standard. That's applying the `polluter pays' principle," Menendez says. His studies show 20 percent of the vehicles produce 80 percent of the pollution.
Menendez claims Mexico is now applying the strictest standards in the world. "California only requires a smog check on cars every other year. The only city in the US with this caliber equipment is Phoenix. There are 92 US cities that violate carbon monoxide norms. Nearly 100 violate ozone norms. Many US city officials are considering using the exhaust emissions verification equipment already in place here," he boasts.
Moreover, city records show a decline in most air pollutants, Menendez says. Unleaded gas consumption has increased to 25 percent of the total gasoline sold in three years.
But environmentalists here note that rising gas consumption requires tougher methods or the marginal improvements will not last. And they say verification of exhaust emissions is only as effective as the operator.