The race for a greener Earth

From waste to water, humankind has its work cut out to achieve the eco-friendly world of tomorrow…

Air pollution 

Studies from the World Health Organization show that the majority of large cities fail to meet minimum air quality guidelines. But numerous technologies are trying to pull pollutants directly out of the urban air. Walls, roof tiles and billboards coated in tiny particles of titanium dioxide can break down the nitrogen dioxides that impair lung function. A series of towers being trialled in China collect two types of particulate matter, called PM2.5 and PM10, which are known to contribute to smog. And in Canada, large walls of fans extract carbon dioxide from the air.

Ageing population 

There will soon be more people on the planet aged 65 and over than there are children under the age of five, and an ageing population brings challenges for urban planners. Researchers have developed ‘age suits’ that mimic the physical challenges associated with ageing, such as sight loss or physical impairment. These are being used to help design better roads and pavements. And high-speed internet is being used to develop better links across generations in cities.

Housing demand

Around 80 percent of Latin America’s population now live in cities, and housing developers can’t keep up with demands. But a Bogota-based architecture firm may have a solution. They are constructing safe, secure houses using building blocks made from waste plastic. The raw material is collected from landfill, before being cleaned and ground into a powder. Then it is melted and extruded to form beams, blocks and pillars that lock together to form buildings. A two bedroom plastic house can be built in five days, at a cost of approximately $5,000 (£4,000).

A mountain of e-waste

Electronic waste is the name given to the discarded electronic devices and domestic appliances that litter landfills across the world – in 2016 we dumped 40 million tons of it. But inside every smartphone and computer are small quantities of rare-earth metals. They are difficult to extract from the ground, so researchers are developing ways to ‘mine’ them from landfills. Their first success was in extracting neodymium from scrapped memory devices, and their work is ongoing.

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