MEXICO CITY -- A famous Mexican cartoonist once proposed a brilliant idea for ridding Mexico City of its choking smog.
Abel Quezada's plan would go into effect during Easter vacation after millions flee the city for the beaches and countryside.
Upon their return, the vacationers would find all access roads blocked and their cars forever barred from the city.
Now with the Easter vacation at hand, the late cartoonist's satirical solution seems like a sensible plan. The Mexican capital is now in the third week of its worst pollution crisis.
While rains and wind have improved the situation slightly, the only real end in sight is the Easter holiday when many of the city's 3 million cars -- the source of 77 percent of the pollution -- leave to foul someone else's air.
The smog crisis has led to finger-pointing, fears of "ecocide" and a substantial dent in the presidential ambitions of the city's mayor.
Indeed, Mayor Manuel Comacho Solis' bid for the presidency in 1994 is up in the air. He's had seven years to fight the dreaded smog, first as federal environment minister and then as head of the world's most polluted city.
The current crisis began March 16 when ozone reached a record "very dangerous" level on the pollution scale -- nearly four times the amount considered safe by the World Health Organization.
Ozone causes bronchitis, sinusitis, eye irritation and lethargy and can also permanently damage the lungs.
Data from the national statistics institute show that more than 50,000 capital residents died of respiratory diseases in 1990, at nearly double the rate of some rural states.
And a recent study by a prominent hospital here found evidence of another pollutant -- lead. One of four schoolchildren in heavily polluted southern Mexico City had alarmingly high levels of lead in their blood, enough to produce learning disorders, the study found.
When the current crisis hit, schools were ordered closed for a day, industry was told to cut production 30 percent, and people were deprived of the use of their cars two days a week instead of the usual one mandated by earlier anti-pollution efforts.
But the ozone level still has hovered at or near the "dangerous" level, leading to charges of widespread cheating, government incompetence and contamination of gasoline by PEMEX, the state oil monopoly.
The crisis also produced the usual round of panicky panaceas, from removing a third of the metropolitan area's 18 million people creating a new national capital in a rural state.
The core of the government's program rests on taming the automobile, but like many things in Mexico, it is subject to corruption and cheating.
Since 1990, the government has required all new cars to have catalytic converters so that they can use unleaded gasoline. But many people with new cars buy cheaper leaded gasoline, which ruins the converters after one tankful.
(Unlike U.S. cars, Mexican-built models can use the pump nozzles for both unleaded and leaded gasoline.)
Another weak point is the annual inspection to determine if a car meets pollution standards.
Since the average Mexico City car is about 8 years old, many junkers stand little chance of passing. So the owners resort to the Mexican tradition of the mordida, or bribe. In February, an anti-corruption undercover operation shut down nearly 10 percent of the 680 testing stations because they were taking bribes, Fernando Menendez Garza, the city's smog czar, says.
Other smog suspicions rest on the the composition of PEMEX's unleaded gas. Humberto Bravo, a pollution specialist at the National Autonomous University of Mexico, says that ozone levels rose dramatically after 1986 when the company introduced "something" to its unleaded gasoline to reduce lead and sulfur.
Professor Bravo says that the number of hours that ozone exceeded the World Health Organization norm each year has grown from 740 in 1987 to 1,536 in 1991.
Still others say there is an urgent need for more public transportation. Luis Manuel Guerra, a member of the metropolitan pollution commission, says that the city needs to increase its fleet of 3,000 large buses by up to 15,000. He suggested paying for them with a 30 percent increase in gas taxes.
City officials say that they are studying a gas tax increase but that it would be politically impossible this year.
About 1,500 more buses will be introduced soon, along with a mid-size bus to replace the current mini-buses, Mr. Menendez said.
Mayor Camacho is the first to admit that the city is in an ozone crisis, but he also notes that in the past two years the levels of three other major pollutants -- sulfur, nitrogen dioxide and carbon monoxide -- have remained within WHO norms.
Mr. Guerra, a chemical engineer, says that the city daily produces about 11,000 tons of pollutants, about the same level as in 1990, even though there are now 200,000 more cars. He figures anti-pollution measures are preventing another 2,000 tons day from entering the air.