A lawyer and a professor of environmental law are taking Mexico City authorities to court over changes to vehicle emissions testing, claiming that a less rigorous procedure puts more polluting vehicles on the road.

Professor Bernardo Bolaños and lawyer Gunnar Hellmund decided to take action after the new city government eliminated one of two tests carried out in the city’s vehicle verification program after it took office in December.

One is onboard diagnostics testing, or OBD, which continually monitors engine performance, including its emissions. The second, which has been eliminated, is an analysis of tailpipe emissions.

An estimated 169,000 vehicles that would have been restricted from circulating in the city on certain days will be able to circulate freely every day.

Bolaños claims that allowing additional vehicles on the road has produced more air pollution and that relaxing testing standards is a violation of the right to a healthy environment.

Named in the suit are Mexico City Mayor Claudia Sheinbaum and the environment secretary.

The city defends the testing change by arguing that the OBD test is the only one required by federal law for vehicles manufactured after 2006.

Bolaños began the suit by looking for residents who had suffered respiratory problems during the recent environmental contingency triggered by poor air quality levels at the end of March.

He posted an invitation on Twitter to anyone who had suffered a respiratory ailment to contact him if they wished to take legal action at no cost.

Of the hundreds of people who replied, 12 have been selected to be part of the suit, whose protagonists say is the first of its kind in Mexico City.

In 2017, Mexico City’s air was only considered “clean” on 81 days, according to the capital’s Environment Secretariat during the previous administration.

A study found that city residents breathe 50,000 tonnes of contaminants annually.

Source: El País (sp)