We breathe it regularly in Hong Kong, and can often see it shrouding our skyscrapers, but what does smog taste like?
That is the question being posed on Saturday at the Ideas City Festival, at the New Museum, in New York, where free synthesised-smog meringues will be dished out.
"Some people react to them with disgust but, when we explain, 'You are breathing the air [these are made with] every day,' most people are willing to give it a try," says Zack Denfeld, co-founder of the Centre for Genomic Gastronomy, the artist-led think tank that created the cautionary culinary treats.
The smog tasting cart will serve meringues in four flavours: the London peasouper; 1950s Los Angeles; present-day Atlanta; and Central Valley, California, agricultural smog. Each flavour represented a certain type of smog.
"The meringues each taste different," says Nicola Twilley, co-creator of the project. "The LA one has an ozone-y, bleach-type note, whereas the London one is a little sulphurous, like the smell of a struck match."
One can only imagine what a Beijing smog meringue would taste like, given that city's pollution index.
The team chose to use the cloud-shaped treat to raise awareness of air pollution because up to 90 per cent of egg foam is air; pollutants, harvested in a smog chamber, can easily be trapped in the mixture at the whisking stage.
So are the meringues safe to eat?
"Inhaling smog over extended periods of time is extremely dangerous to health," says Twilley, "but scientists have told us the human digestive system is more robust than our respiratory system. The sugar in these meringues is probably more harmful."
While Denfeld's team has no plans to bring smog tasting to China, in truth it's already here.
We call it alfresco dining.
For this story and more, see Post Magazine, published with the Sunday Morning Post, on May 31