Air pollution in Mexico City

In the 20th century, Mexico City's population rapidly increased as industrialization brought thousands of migrants from all over the world.

The Mexican government has several active plans to reduce emission levels which require citizen participation, vehicular restrictions, increase of green areas, and expanded bicycle accessibility.

It is the eighth largest cause of death, after factors such as diet, overweight, high blood pressure, alcohol and drugs, smoking and lack of exercise.

Some of the programs included removal of lead from gasoline and the implementation of catalytic converters in automobiles, reduction of sulphur content in diesel transportation fuel, substitution of fuel oil in industry and power plants with natural gas, reformulation of liquified petroleum gas used for heating and cooking.

[4] This improvement in air quality was achieved through the Mexican government's requirement that gasoline be reformulated, that polluting factories be closed or moved, and that drivers be prohibited from using their car one day per week.

In addition, the stations have a meteorological tower, equipped with sensors that measure the ambient temperature, wind speed and direction, precipitation, solar radiation, relative humidity and barometric pressure.

Over the past two decades, ozone levels gradually fell below government limits as authorities moved factories out of the capital and tightened regulations on fuel and cars.

However, in all stations the concentrations of this pollutant as a daily average are above the guideline value recommended by the World Health Organization, which is 0.008 ppm.

However, this NOM has not been updated since 1993 and the World Health Organization recommends as a guide that the limit of the hourly average for NO2: be set to 0.106 ppm.

On 16 May 2019, The government of Mexico City declared an extraordinary atmospheric environmental contingency, which indicates that the level of harmful particles in the air has exceeded the accepted standards (160 ppm for PM2.5).

The Head of Federal government of Mexico, Claudia Sheinbaum, commented that the main cause behind the current levels of pollution were a series of Fires that have affected regions near the capital since the weekend.

"The Government knows that these particles generate problems in those with lung diseases, those who suffer from allergies, rhinitis, conjunctivitis and also for those who do not have regular discomfort: irritation of eyes or runny nose, because the body defends itself from these toxic elements", explains the expert in environmental toxicology and respiratory damage Carlos Falcón.

"They are not taking it seriously enough, they have simply kept things as they go and we do not see a substantial advance in all the measures that have been proposed to improve air quality", says the researcher at the Science Center of the Atmosphere, Ricardo Torres.

There are bad conditions of dispersion of pollutants, but also a slow response from the authorities: during this weekend and until this Tuesday we had problems of atmospheric turbidity and according to what we have calculated, in one week we passed the World Health Organization standard 150 times", adds Torres.

In 2005, a survey was administered by members of the BMC Public Health with the purpose of finding out the levels of awareness from the general population in Mexico City about air pollution and its consequences.

This study consisted of randomly selecting 800 individuals from Mexico City using a polling company named Parametria and asking them some Spanish-translated versions of the United States 2005 Behavioral Risk Factor Surveillance System.

The demographic information recorded by respondents in terms of gender and age distribution mirrors that of publicly available Mexico City census data.

To gauge this application of IMECA knowledge among respondents, the number of days modified, defined as avoiding exercise or strenuous activity outdoors in response to poor air quality over a 12-month period, was assessed.

[11] In efforts to reduce the pollution, in 1989 the Mexican Government introduced "No-Drive Days", or Hoy No Circula, which prohibited drivers using their vehicles on one weekday per week, and in 2008 this was changed to include Saturdays.