MEXICO CITY -- It's a dirty job, but someone's got to do it. About 100 women, in this case.
The Mexico City police department has created the female unit to help combat pollution in the world's smoggiest city. Women are believed to be less corrupt and less likely to get punched in the nose.
"The government wanted women for the job because we have a better reputation in the public for not accepting bribes," says Esperanza Galicia Carillo, the unit's commander. "If we are ever going to make any progress in fighting air pollution, then we can't have police officers taking bribes and then letting violators go on their way."
Until January, most of the unit's officers directed traffic in Mexico City's busiest intersections. But now the Eco-Cops, whose cars are painted green and white, are posted at those intersections to pull over cars and trucks that spew blue and black smoke.
Once pulled over, the vehicles are examined by a technician, who checks the fumes coming out of the tail pipe and looks under the hood to look for oil leaks. If the technician determines that a vehicle is polluting the air, the Eco-Cop asks its driver to remove the license plates.
In the three months since the force was created, the officers have taken the plates off 5,272 vehicles. Another 124 drivers have been stopped for violating Mexico City's "day-without-driving" law, which requires that drivers go without their car at least one day per week.
"Sometimes people get really upset when we take their plates. You can see it in their eyes," says Officer Juana Elisalde, whose deep blue eye-liner matches her uniform. "They may even say JJTC few curse words, but they rarely get violent or aggressive with us."
Indeed, most of the drivers stopped during a recent sweltering day seemed to bite their tongues when their license plates were taken away.
"I suppose this is something that should be done because the smog in this city is killing us," said Rogelio Mihualtec, who was hauling a load of bricks on a rusted flat-bed truck. "I'm not angry."
But his body language sent a different message. He snatched the baseball cap off his head, threw it to the ground and then walked a few hundred feet with his hands on his hips.
When he returned, Officer Maria Aldonez Hernandez softly explained that he can have his plates back without paying a fine providing the truck is fixed within 30 days.
"We don't want money," she says. "We want to help clean the air."
Those are not words that many expect to hear from officers of Mexico City's police department, infamous for accepting bribes instead of enforcing laws.
Extortion has become so widespread among police officers that Mexico City Mayor Manuel Camacho Solis threatened to resign if he and the head of the police department were unable to stop corruption.
"I don't know what it is because men and women have grown up in the same homes, learning the same rules," said Ms. Elisalde. "But for some reason women rarely accept bribes, and the men take them.
"Maybe because most of the people we stop are men," she added. "It is easier for men to make these secret deals with each other. Women want to follow the rules."
Not that some don't try.
"This isn't my truck and the owner is really going to be angry with me when he sees those plates are gone," truck driver Jose Luis Duran explained to officers when they stopped him along the north edge of town. "He's going to ask me why didn't I just offer something to the officers and promise them that I would get the truck fixed."
Officer Delia Silva Carmona smiles and explains, "It doesn't make sense for us to accept money from you. We are paid by the police department to stop pollution. We can't take money from you to ignore pollution."
But the occasional stomping, grumbling or bribe attempt are not the most irritating parts of their job, say Eco-Cops. What bothers them most is the constant exposure to their greatest foe: noxious fumes.
At the end of a shift, most of the officers return to their headquarters with hacking coughs and watering eyes.
"I hope we beat the contamination before it beats us," says Lilia Fijada Perez.