According to the World Health Organisation, eighty percent of the people living in the city are breathing polluted air. Air pollution levels are increasing faster than ever. Air pollution is one of the biggest problems in developed and developing cities. Every year at least 7 million people die from air pollution.
While many cities are battling to reduce the emission levels, few cities have already come up with buildings that will help to bring down the pollution levels. These special buildings constructed using special concretes (called smog-eating concrete) that would neutralize the pollutants in the atmosphere.
How does Smog Eating Concrete Work?
This special concrete is also called as the Smog eating concrete. A photocatalytic additive called Titanium dioxide is added to the cement. This additive in the presence of sunlight gets activated and reacts with the pollutants to neutralize them into harmless salts.
This concrete purifies the air surrounding the building. These salts will deposit on the building surfaces and will be washed away during the rain and mix with the soil. Since these salts are inert, it will not pollute the soil in return.
Carbon dioxide, Nitrogen dioxide, and Sulphur dioxide are some of the major pollutants that can be neutralised using this technology. The pollutants emitted by the vehicles and industries can be neutralized by this concrete.
Examples of Smog Eating Buildings
1. Manuel Gea González Hospital – Mexico
Mexico is a densely populated country and has high air pollution levels. Manuel Gea González Hospital constructed at the heart of the city not only gives a stunning look but also reduces the air pollution levels. The façade of the hospital is made up of titanium dioxide which neutralizes the pollutants in the vicinity.
The façade is spread over an area of 2700 square feet. The façade is said to counteract the pollutants emitted from at least 1000 cars per day. Apart from providing clean air to the patients inside the hospital, this façade also acts as a natural light filter and solar blocker thus keeping the hospital cool and reducing the energy bills.
2. Palazo Italia – Milan
Milan is known for its extraordinary architecture and rich heritage. This smog-eating building not only complements the city’s architectural stigma but also reduces air pollution. The building was inspired by the concept of the urban forest – A modern forest that would reduce air pollution.
The design of the cladding is in such a way that it resembles the branches of the trees signifying the green concept of the building. The cladding made of 80% recycled materials and made up of titanium dioxide acts as the biodynamic skin of this urban forest that reduces pollution.
3. Smog Eating Poem - UK
This building in the UK has dedicated one of its walls to a smog-eating billboard that features a song that emphasizes the importance of air. This billboard is also made of titanium dioxide that reduces air pollution. This billboard is said to eliminate the pollution caused by at least 20 cars every day. Following this, smog-eating billboards are emerging in various parts of the world including a recently unveiled one in Peru.
Smog Eating Paints
Simply adding titanium dioxide to the paint will help in reducing air pollution. Scientists are working on compatible and competent smog-eating paints that could solve the air pollution problem in the cities forever. Applying this paint to any surface that comes in contact with the sunlight will be a significant step in reducing air pollution.
This is by far the most economical way of incorporating titanium dioxide into a building. However, this paint will be available only in white color.
Other inventions include smog-eating roof tiles, pavements, and paver blocks.
Drawbacks of Smog Eating Concrete
The drawbacks of this technology include
- High cost – nearly 5 % increase in the cost of the project.
- These buildings should be adopted widely to have a positive impact on pollution.
- The photochemical reaction between the titanium dioxide and pollutants in some special cases produce ozone as a by-product of the reaction.
- The titanium dioxide is classified as “Possibly carcinogenic to humans” by inhalation.