Air pollution is rife in cities worldwide.
A 2014 study entitled Particulate air pollution and cardiovascular disease – it’s time to take it seriously stated that 3 million deaths worldwide were attributed to exposure to excessive levels of particulate air pollution in 2010.
“Globally, ambient particulate air pollution was the ninth leading cause of premature deaths, and most of the disease attributable to exposure to ambient particulate air pollution is cardiovascular disease,” the study found.
The World Health Organisation 2014 database contains results of ambient (outdoor) air pollution monitoring from almost 1,600 cities in 91 countries and, according to its figures, only 12 per cent of the people living in those cities breathe air that complies with WHO air quality guideline levels.
“About half of the urban population being monitored is exposed to air pollution that is at least 2.5 times higher than the levels WHO recommends - putting those people at additional risk of serious, long-term health problems,” the WHO said.
When looking for pollution-reducing solutions, nature offers some of the best. Greenery reduces carbon and offers improved air quality while decreasing the temperature in urban centres. Where land is scarce, facades themselves house flora.
Here are five viable projects that could be applied to cities across the world in a bid to reduce pollution:
1. Phoenix Towers, Wuhan
UK-based Chetwood Architects in conjunction with the Hua Yan Group last year released a proposal for two Phoenix Towers that would combat pollution in Wuhan, China.
The towers are planned to be completed by 2018 and would be part of a larger environmental master plan for the city.
Phoenix Towers would rise one kilometre on the Yangtze River at the crossroads of nine provinces and will operate as a renewable energy source.
The towers' design was drawn from Fenghuang, a mythological bird in Chinese culture. One tower will be known as Feng (male) and will serve as a mixed-use building, while the Huang (female) tower will house the world’s tallest vertical garden.
Feng will power both itself and Huang, with both towers delivering additional energy to the surrounding precinct.
The architects reveal the steel and lattice “superstructure” is made from lightweight photovoltaic cladding. The towers will also feature thermal chimneys, wind turbines and a water harvesting/recycling system along with waste recycling via biomass boilers.
2. Manuel Gea González Hospital, Mexico City
A hospital building in Mexico City is healing patients and the environment from the inside out.
In 2013, the Manuel Gea González Hospital had a façade installed that significantly reduces smog when activated by daylight.
The decorative facade is constructed from a superfine titanium dioxide coating (TiO2), a material by prosolve370e and designed by Elegant Embellishments. According to prosolve370e, TiO2 is already know for its self-cleaning and germicidal qualities.
“It requires only small amounts of naturally occurring UV light and humidity to effectively reduce air pollutants into harmless amounts of carbon dioxide and water,” prosolve370e said. “When positioned near pollution sources, the coated tiles break down and neutralize NOx (nitrogen oxides) and VOCs (volatile organic compounds) directly where they are generated.”
The massive “de-polluting” façade is designed to be applied to buildings close to traffic or in densely polluted conditions, and neturalises the effect of 1,000 cars every day for the growing city.
In addition, the façade acts as a natural light filtration system thanks to its molecular design, minimising solar gain and helping to reduce the building's energy consumption.
In Australia, the façade was also applied to a ceiling inside a Perth building, demonstrating its flexibility as an indoor/outdoor solution.
3. Palazzo Italia, Milan
This year will see the creation of the six-storey Palazzo Italia building for the 2015 Milan Expo, which will be clad in a pollution-reducing façade made of 900 panels of “i.active biodynamic” cement.
The pavilion was designed by Italian architectural firm Nemesi & Partners, and its cement façade features photo catalytic properties and Italcementi's (the creator’s) patented TX Active technology.
"In direct sunlight, the active principle contained in the material 'captures' certain pollutants present in the air and converts them into inert salts, helping to purify the atmosphere from smog," according to Italcementi.
The architects who were aiming for a “practically zero energy building” also used 80 per cent recycled aggregates, including scrap material from marble quarries in Carrara “that helps add more lustre than in traditional white cement.”
In addition, the roof will feature photovoltaic glass.
Each component contributes to a pollution-reducing solution and could be applied to other buildings.
4. Micro-Algae Façade
A vast 129 photo-bioreactors make up SolarLeaf, which utilises microalgae to shade the building and produce renewable energy.
The algae are fed by carbon via a combustion process taking place in close proximity, such as in a boiler in a nearby city.
The SolarLeaf façade system, created by Colt International, is based on a bioreactor concept developed by SSC Ltd with design work led by Arup.
It is currently installed on a four-storey residential building in Hamburg, Germany and provides around one third of the total heat demand for the building.
According to Arup, “the biomass and heat generated by the façade are transported by a closed loop system to the building’s energy management centre, where the biomass is harvested through floatation and the heat by a heat exchanger.”
Excess heat produced by the photo bioreactors can be used in other ways, such as heating water or providing heat for the building.
"If we can demonstrate that microalgae bio facades can become a viable new source of sustainable energy production, we can transform the urban environment, as well as providing architects with a new source of inspiration,” Jan Wurm, Arup’s Europe research leader said at the time.
5. Forte Building, Melbourne
Wood is one of the world’s oldest materials, and possesses great carbon sequestering qualities.
Melbourne currently holds the title for the world’s tallest timber building, the 10-storey Forte building in Melbourne, though that title will soon go to the 14-storey Treet building which is under construction in Bergen, Norway.
Forte’s 759 CLT panels can directly store 761 tonnes of CO2 according to the building’s website.
“When considering the emitted CO2 that would occur if an equivalent concrete or steel buildings was used, the advantage would increases to 1,451 tonnes of CO2 or the equivalent of taking 345 cars off the road for a year," the site says.
Wood for Good forecasted that the Treet building would utilise almost 900 cubic metres of lumber, resulting in savings of approximately 1,800 tonnes of CO2.
In a recent blog post, Narangba Timber in Queensland stated that for every cubic metre of timber, 235 kilograms of carbon is removed from the environment.