In the height of daytime, the sky suddenly blackened, and day became night in Sao Paulo.

Sure, smog is bad in the Western Hemisphere’s largest city, where traffic jams can stretch for dozens of miles. But not this bad. What was going on? Was the end near? — The Washington Post

Cars and trucks on one of Europe’s most notoriously congested and polluted urban highways would not only be obliged to drive more slowly, they’d have less room to do it: The number of beltway lanes open to all traffic would also be slashed from eight to six. One lane will be reserved for public, emergency, and zero-emissions vehicles. The other one is to be devoted to trees. — CityLab

A colourful mural of a 35m-tall tree in Mexico City is one of three environmentally friendly new public works made using Airlite paint, which purifies polluted air in a process similar to photosynthesis.

[...] the mural aims to increase oxygen levels in one of the western hemisphere’s most polluted cities, where ozone concentration levels remain high despite government regulations on fuel and cars. — The Art Newspaper

House Observations of Microbial and Environmental Chemistry—was the world’s first large-scale collaborative investigation into the chemistry of indoor air. [...] The experiment’s early results are just now emerging, and they seem to show that the combined emissions of humans and their daily activities—cooking, cleaning, metabolizing—are more interesting, and potentially more lethal, than anyone had imagined. — The New Yorker

Shit, I Smoke! was created by Brazilian-born designer Marcelo Coelho and Paris-born app developer Amaury Martiny in just a week, after they read a study that analyzed air pollution and its equivalent to cigarette smoking. [...] Using the formula in [the study], [the app] uses live pollution data from hundreds of air quality stations in cities around the globe and converts the station’s PM2.5 number into the number of cigarettes being inhaled by a person in real time. — Citylab

An experimental tower over 100 metres (328 feet) high in northern China – dubbed the world’s biggest air purifier by its operators – has brought a noticeable improvement in air quality, according to the scientist leading the project, as authorities seek ways to tackle the nation’s chronic smog problem. [...]

The head of the research, Cao Junji, said improvements in air quality had been observed over an area of 10 square kilometres (3.86 square miles) in the city over the past few months [...]. — South China Morning Post

Beijing will suspend construction of major public projects in the city this winter in an effort to improve the capital’s notorious air quality, official media said on Sunday, citing the municipal commission of housing and urban-rural development.

All construction of road and water projects, as well as demolition of housing, will be banned from Nov. 15 to March 15 within the city’s six major districts and surrounding suburbs, said the Xinhua report. — Reuters

Birds fly in and out of the eight-storey "Green Office Building" in Shenzhen, China, because a third of its walls are completely open to the air. It's a clever natural design that enables the building to stay cool without air conditioners.

Across town, in a vast campus known as the "Low Carbon Park", mist is sprayed into the air to cool the streets down and remove dust. — The BBC

The Chinese capital issued its highest red fog alert for a second day on Wednesday, keeping highways closed in and around the city which is already under a smog alert after weeks of choking winter pollution.

China's weather bureau warned of visibility of less than 50 meters in some areas, leading many airports to cancel flights. — Reuters

Tens of thousands of “smog refugees” have reportedly fled China’s pollution-stricken north after the country was hit by its latest “airpocalyse” forcing almost half a billion people to live under a blanket of toxic fumes.

Huge swaths of north and central China have been living under a pollution “red alert” since last Friday when a dangerous cocktail of pollutants transformed the skies into a yellow and charcoal-tinted haze. — the Guardian

The true impact of air pollution has been obscured by the failure to consider people’s exposure as they move around during the day...

The research cites air pollution as “the world’s single largest environment and human health threat” but laments that the problem has not previously been “considered spatially and temporally”, with most studies basing a person’s pollution exposure on where they live. — the Guardian

In a new paper, economists and public health researchers have found that not even working indoors in an office can protect people from the deleterious impacts of polluted air and particularly fine particulate pollution — defined as tiny particles that can travel deep into our lungs and even get into the bloodstream and eventually reach the central nervous system. — the Washington Post