The cloud, which first appeared in 1999, is a mixture of vehicle emissions, industrial pollution, incinerated garbage, and smoke from the annual burning of four million tons of rice chaff in the Nile Delta region. Dr. Saleh El Haggar, professor of the environment and energy at the American University in Cairo and author of several books on the subject, says the cloud is formed by atmospheric inversion. When fall approaches, warmer air is trapped closer to the ground, along with pollution that would normally be dispersed during other months. Heavy smoke from the burning rice fields floats south to combine with the city’s normal high levels of air pollution, creating the eponymous black cloud that damages historic monuments and causes an estimated $2 billion in health problems, according to data provided by El Haggar.

Photo of Qasr Al-Nil Bridge from Garden City, by Daniel Mayer.

“The problem,” says El Haggar, “is lack of awareness.” Farmers in the Nile Delta believe that the rice chaff has no value and that the only way to dispose of it is to burn it. In fact, rice chaff can be transformed into paper, used as animal fodder, converted into electrical energy, or simply turned into compost. El Haggar contends that the only solution is for the government, along with the media, to inform farmers of the waste material’s uses and promote recycling.

El Haggar cites a similar problem that occurred in San Francisco in 2003. There, as in Cairo, a black cloud caused by burning rice chaff in surrounding farms formed over the city. State and federal authorities instituted an aggressive campaign to eliminate the burning of agricultural waste and the problem disappeared within four years. El Haggar believes a similar aggressive program would work in Egypt, but that the government is unwilling or unable to enact it.

However, the solution is not that simple, according to Dr. Mounir Labib, a chemical engineer with the Egyptian Environmental Affairs Agency who has published a number of papers on the black cloud. “The economy of collecting [the rice chaff] is not worth it,” Labib says. One 50-kilogram bale of compressed chaff brings in only two Egyptian pounds (about 34 cents). That is not nearly enough for the region’s thousands of small farmers to cover labor, equipment rental, and transport of the waste to far-away processing centers, even if they wanted to.

Nevertheless, the government has made efforts to collect and process the chaff which are reducing the effects of the black cloud, according to a recent study Labib undertook in 2010 in conjunction with the Desert Research Institute in Nevada. El Haggar disputes this claim, saying efforts are not enough and the black cloud is appearing sooner and sooner every year. But both scientists do agree that the solution is a long way off and that the black cloud shall make its annual visit to Cairo for years to come.

Conal Darcy is a writer and student living in Cairo