Evaluation of tolerance of climate-adapted plant species planted in green walls to air pollutants using APTI index in Mashhad city

Today, air pollution, with an impact on a global scale, is an important concern of the modern world. It has many adverse effects on human health and the environment. Therefore, it is necessary to find sustainable and environment-friendly solutions that prevent the increase of pollution levels and help eliminate them. One of the newest ways to reduce air pollution and absorb particulate matter, as well as improve air quality, is to use green walls in urban spaces. The present study investigated the potential of green walls in reducing air pollutants.  

In this research, two green walls were installed at the Khayyam intersection in Mashhad for three months. Finally, the Air Pollution Tolerance Index was determined for all the plants by measuring chlorophyll, ascorbic acid, leaf-related water content, and pH.

Results:

 All of the plant species planted on the walls were classified as intermediate in the tolerance. Among all the plants, Carpobrotus edulis and Rosmarinus officinalis had higher APTI, which makes them more resistant and suitable for planting in polluted areas. Considering the statistical analysis, the APTI of the plants was correlated with ascorbic acid and leaf-related water content.

Our findings suggest the suitability of the above-mentioned plants for plantation in areas with high levels of pollutants.