Madrid City Council replied on 3 February 2017. In its reply, it sent a report on the measures taken to combat nitrogen dioxide (NO2) pollution, which is produced mainly by road traffic, but it also referred to other pollutants.
It gave an account of the Protocol of measures to adopt during high nitrogen dioxide pollution episodes, and of evaluation of the implementation of the protocol and the procedures for informing the community.
As regards the protocol, the Council has an air quality Observation, Prediction and Information System that makes it possible to know pollutant concentrations continuously and in real time. Since this system was created in 2010, the nitrogen dioxide alert threshold has exceeded the hourly limit value in several of the stations of the network. As a result, a division is established in zones of the municipal area, so that the alert situation can be declared in smaller areas with high population density. Likewise, action scenarios are defined according to pollutant concentration levels, the length of the episode and weather forecasts, by virtue of which measures are adopted for restricting traffic in the city and its accesses to reduce the level of pollution and avoid the alert situation from being reached.
These measures are associated with additional information mechanisms, addressed both to the general public and to public opinion.
There are also population information and alert procedures for tropospheric ozone pollution episodes, and the population is informed when a high level of particles is reached (PM10 and PM2.5).
Evaluation of the implementation of the protocol and the information procedures is done through the Council’s Air Quality Committee.
The Council provided information in this respect about the nitrogen dioxide pollution episode that took place from 26 December to 2 January 2017.
It was an intense and long episode with a greater number of instances of exceeding 200µg/m3 than in the episodes in 2015. There were instances of exceeding the hourly
limit value of N02, coinciding with higher levels of particulate material (PM10 and PM2.5). Consequently, scenario 3 measures were applied for the first time and, hence, number-plate traffic restriction inside the M30. This measure, which was applied on 29 December, brought about a decrease, with respect to the previous year, of 24.40% in the number of vehicles that came inside the M30 ring road.
Likewise, considerable decreases were recorded in the average speed of traffic on the M30 on the days when the protocol was applied. The direct consequence of these large decreases in the intensity and speed of the traffic was the reduction of pollutant emissions into the atmosphere, which has avoided higher levels of concentration from being reached and the general public from suffering greater exposure and, therefore, greater health effects.
As for the protocol, it stipulates that it will be assessed annually and, where applicable, be reviewed.
Lastly, the system for informing the community is described, through the different resources that the Council makes available to the general public (web page, telephone, alerts via SMS, Smartphone applications, Twitter, etc.).
