Air pollution levels soared to dangerous levels in Mexico City, already one of the world's smoggiest cities, as smoke from the fires mixed with the daily output from 3 million cars and 60,000 factories to form a deadly canopy. The emergency order will force nearly half the cars off city roads today. In addition, schoolchildren will be banned from playing outside and factories will be asked to cut production by a third.
Authorities in Mexico's second city of Guadalajara also declared an environmental alert and asked motorists to leave their cars at home.
Dense smoke from an estimated 11,000 brush and forest fires covered nearly the entire country, despite fire-fighting helicopters and equipment that has begun to arrive from the United States. The smoke was so thick in southern Oaxaca state that firefighting helicopters were grounded yesterday and air traffic into the state capital suspended.
The fires have spread in the past week to Mexico's last remaining tracts of tropical rainforest - Chimalapas and the Lacandon jungle, home to such rare species as the jaguar, quetzal bird and howler monkey.
The US offered help last week after smoke from the fires drifted as far north as Chicago and prompted health warnings in Texas. But a lack of wind this week has caused the smoke to build up inside Mexico's borders.