Beginning Monday, cars with even-numbered plates will be banned from driving into the city of Paris. Public transportation will also be free at least through Monday, and possibly longer if necessary. The only vehicles exempt from the ban are taxis, electric cars and ambulances.
The decision was reached after Paris and a number of other northern cities sufferd with a heavy, choking smog. The very same measures were required last year, when on March 17, 2014, the city experienced a particularly bad spike in pollution levels.
On Wednesday this past week, the concentration of particulates went over the recommended levels, prompting Mayor Anne Hidalgo to ask authorities to take the emergency action. On Saturday, the particulate matter (PM) levels again reached higher than recommended levels, and Hidalgo authorized the Monday car ban.
In Paris, authorities measure the concentration of dangerous particulates with a diameter of less than 10 microns, or PM10, to determine pollution levels. This difference in particulate matter concentrations is because PMs are divided into two groups, coarse and fine PMs. In Beijing, only fine Particulate matter concentrations of less than 2.5 microns are measured.
According to the standards for PM10 concentrations, the safe limit is 80 micrograms per cubic meter (mcg/m3). According to the World Health Organization, in 2011, the Earth’s most polluted city was Ahvaz in Iran. Ahvaz had an average of 372 mcg/m3. The city’s air quality is not only due to high levels of industrial pollution, but the frequent sandstorms that hit the city. The average for Paris in 2011 was 38 mcg/m3.
