“Black cloud”, a mass of polluted air that darkens the skies of the Egyptian capital in October and November, is less severe this year, but efforts to reduce the pollution that leads to this phenomenon should continue if a disaster is to be avoided, an environment official said.
“Last year the cloud appeared for 20 hours [in October and November] compared with more than 100 hours in 1999.
“Nevertheless, efforts to combat pollution should continue, otherwise it might last 100 to 150 hours next year or the year after, triggering serious health concerns,” said Ahmed Abul Sa’oud, undersecretary at the Ministry of Environment, from Cairo.
Human activity has saturated the air with pollutants over Cairo, and meteorological conditions lead to acute air pollution or what is locally called “the black cloud”.
Smoke caused by the annual burning of rice hay is also a major factor in the cloud’s formation, Sa’oud said.
“This is the time when farmers start burning rice hay to prepare their land for the next season. Farmers burn at least four tonnes of hay in a very short time, making its smoke account for at least 40% of the pollution,” he said, adding that 6% of pollutants come from burning waste in the open, 23% from vehicle emissions, and the same percentage from factory emissions.
“In autumn the wind drops and thermal inversions happen more frequently. The warm air holds down the cold air, preventing pollutants from rising and scattering,” he said.
Topography aggravates the situation. “The city is located between two elevated areas, Moqattam Mountain on one side and the 6 October heights on the other, which keeps emissions trapped in the middle”.
Burning rice hay
Rice hay can be used as animal feed, as an organic fertiliser or in paper production, said Ahmed Gabr, professor of animal production at the University of Mansoura.
“Farmers are willing to recycle hay, but the problem is that there aren’t enough hay balers at governorate level, not enough to deal with the huge quantities of rice planted annually,” he said.
Last year too much rice was planted. “Farmers had no choice but to burn the hay, causing serious pollution,” he said.
Media reports said the government would stop fertiliser subsidies to those who burnt rice hay.
Vehicle emissions are also a major cause of air pollution in Cairo, which has 2,1-million vehicles, Sa’oud said.
The Ministry of Environment is working to curb vehicle pollution.
“We are encouraging people to switch to natural-gas-fuelled cars. Today we have more than 85 000 natural-gas-powered vehicles and more than 115 natural-gas pumps in 17 governorates.
“We are also encouraging people to use public transport, and taxi drivers to trade in their old vehicles for new ones. We give them incentives like exempting them from customs and sales tax,” he said.
Health risks
According to health workers, the cloud has an adverse effect on people’s health, causing respiratory problems. “The number of bronchial asthma patients doubles at this time of the year,” said Mahmoud Abdel Majeed, head of Abbasiya Chest Diseases Hospital.
People suffer from breathing difficulties, coughing and sometimes respiratory failure, which requires artificial respiration.
“Cairo in general is witnessing an increase in the number of bronchial asthma and respiratory obstruction patients, and respiratory system tumours because of pollution,” Majeed said, adding that children and the elderly are most at risk. — Irin