Calle 30 Natura: vertical gardens and air quality sensors combat pollution in the M-30 in Madrid

A pioneering project that combines vertical gardens and pollution sensors to improve air quality and reduce emissions in Madrid.


Madrid City Council sought to improve air quality and adapt to climate change in the city. To do so, they launched the innovative “Calle 30 Natura” project, consisting of the installation of highly durable vertical gardens with the capacity to absorb pollutants along 400 metres of the M-30 road. This section is one of the busiest in Spain, with 1.1 million vehicles travelling on it every day, which makes it a critical point for road traffic emissions and noise pollution.

With Calle 30 Natura, works were carried out on 3,250 m² of the M-30, transforming concrete walls into vertical gardens with 23 resistant and pollutant-absorbing plant species. In addition to beautifying the city, the project aimed to reduce traffic emissions and noise pollution, reduce the heat island and eliminate graffiti.


The solution deployed in the “Calle 30 Natura” project is an innovative combination of vertical gardens with advanced air quality sensor technology for environmental pollution monitoring. The plant walls, composed of highly durable species with a high capacity to absorb pollutants, are complemented by Kunak AIR Pro pollution sensors, strategically placed in the vertical gardens. These sensors allow continuous and accurate measurement of key air pollutant levels such as CO, CO2, NO, NO2 and PM.

The sensor technology provides valuable information on the pollutant uptake of the gardens and its evolution over time. In addition, the data obtained is compared with general pollution measurements to assess the positive impact of the project on air quality. This unique combination of nature and technology highlights Madrid City Council’s commitment to sustainability and improving the urban environment.


Thanks to the installation of vertical gardens and the continuous monitoring of pollution with Kunak AIR Pro sensors, the “Calle 30 Natura” project achieves a significant improvement in the air quality of the urban environment. The gardens act as green lungs, absorbing pollutants and reducing emissions from road traffic, which helps to dampen the heat island and eliminate graffiti.

Sensor technology provides accurate data on pollutant levels, enabling more effective and rapid management if problems are detected. These combined efforts result in a healthier and more sustainable environment, protecting the health of citizens and moving towards a more environmentally friendly Madrid.