MEXICO CITY -- In a dramatic move to combat this city's deepening air pollution crisis, President Carlos Salinas de Gortari ordered yesterday the immediate closing of the city's largest government-operated oil refinery.
The decision to close the March 18 Refinery, which sprawls over 430 acres in the north of the city, will cost an estimated $500 million and will reduce the country's crude-oil refining capacity by more than 100,000 barrels a day.
In addition, oil industry officials said it will force Mexico to import some kinds of gasoline until new refining capacity can be built.
But the action will abruptly eliminate what environmentalists have long considered one of the worst sources of pollution in the mountain-ringed capital, which is now suffering under one of the most dangerous periods of contaminated air in its history.
Mr. Salinas declared that the giant refinery would be replaced by public parks and other green spaces to help head off a still graver environmental crisis.
"The government is prepared to impose upon itself the most severe measures to protect public health and to respond to social demands," Mr. Salinas said, announcing the decision at a ceremony marking the 53rd anniversary of the nationalization of Mexico's oil industry. "Let's plant trees where today there is nothing but pipelines."
The announcement came after weeks of growing public concern about the medical effects of recent pollution levels, which have reached nearly four times the maximum limits established by the World Health Organization for key pollutants.
The decision reflected the intense political pressure that the government has felt as it has tried to cope with the city's visibly deteriorating air quality without bringing its vital industries to a halt.
The director of the state-run energy monopoly, Petroleos Mexicanos, said yesterday that the giant Mexico City refinery, which was first opened in 1933, had served as the "backbone of production and distribution of fuels" for the capital and that extensive studies were made in an effort to keep it open at lower levels of emissions.
The refinery accounted for roughly 7 percent of overall national refining capacity, oil officials said.
But the director, Francisco Rojas, said that government officials had concluded that the refinery, which was named in honor of the date on which the oil industry was nationalized in 1938, should be shut down completely and immediately with the exception of minor storage and distribution facilities that will be preserved.
Officials of the energy monopoly, which is commonly known as Pemex, said the refinery employed 5,429 workers, 3,206 of whom were directly involved in the refining process.
But they said that no workers would be laid off as a result of yesterday's decision, and that the company would accelerate plans to build a new, 300,000-barrel-a-day refinery outside the capital region.
The gravity of the air pollution crisis has provoked growing discussion of dramatic measures to cut emissions and bring clean, fresh air into the Mexico City valley.
One radical plan that has been discussed recently is a proposal to cut deep man-made passes through the high mountains that surround the capital. But that idea has been harshly criticized by environmental experts.