When
Jenny Linden, an air quality scientist, tried to measure the pollution
in Burkina Faso’s capital city, one of her instruments clogged up. It
was designed for road dust in Arizona, but the dust in Ouagadougou far
exceeded the machine’s limit, and it had to be sent to the United States
for repair.
The
instrument “could not take the level of pollutants they had there,”
recalled Dr. Linden, who took measurements in Ouagadougou between 2003
and 2007 and is now a research associate in urban climatology at the
University of Mainz, in Germany. So intense was the dust, she added,
that “you don’t have a cold but you have an irritated nose the whole
time.”
Read the full article @ NY Times
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| Gridded Anthropogenic OC Emissions in 2030 in Africa |
Air
pollution in Asia and Europe has grabbed headlines. But as Dr. Linden’s
experience suggests, the problem is pervasive across Africa as well.
Africa is urbanizing quickly, and pollution from sources like vehicle
exhaust, wood burning and dusty dirt roads has reached worrisome levels
in many cities. Equally or more troubling is air pollution inside homes,
caused by cooking with wood or other sooty fuels. But few nations
outside South Africa have imposed regulations to address the problem,
experts say.
“We
do know that in Africa, there’s a very major problem with indoor air
pollution,” said Dr. Carlos Dora, an official with the World Health
Organization’s Department for Public Health and Environment. Data for
outdoor air pollution in cities, he added, is less available and may not
capture the scope of the problem.
Dirty
air can cause lung damage as well as heart disease, strokes and cancer.
Last month the W.H.O. estimated that one in eight deaths worldwide
resulted from air pollution. The organization found that air pollution
in African homes contributed to nearly 600,000 deaths in 2012. Africa
had the third highest level of deaths per capita from indoor air
pollution of any region of the world, though it was still well behind
areas of the western Pacific region (including China) and Southeast
Asia.
The
W.H.O. figures for deaths per capita from outdoor air pollution in
Africa are well below the world average, but the lack of data is a
barrier. Pollution monitoring is minimal on a continent that is mostly
focused on other problems. Instruments are expensive, and academics say
they often struggle to get grants to study the problem. The W.H.O.
assesses outdoor pollution in Africa by drawing from satellite data,
inventories of pollution sources, air-current modeling and occasional
ground monitors, Dr. Dora said. Continentwide data is stronger than that
for individual countries, he added.
In
Nairobi, the Kenyan capital, normal levels of fine dust (meaning
particles less than 2.5 micrometers in diameter, about 1/30 of the width
of a human hair and a significant health threat) are usually five times
as high as those in Gothenburg, Sweden, according to Johan Boman, a
professor of atmospheric science at the University of Gothenburg. The
Nairobi pollution doubles near the central business district, he said,
reflecting high pollution from vehicle exhaust.
“It’s
certainly not as bad as what we see from China,” he said. “On the other
hand, in China it’s very much seasonal,” whereas Nairobi, with its
relatively stable climate, has less variation. A
survey several years ago by the W.H.O. showed Gaborone, Botswana, as
having the eighth-highest level of particulate pollution (particles of
up to 10 micrometers in diameter) among a list of world cities. But the
W.H.O. stresses that it is an incomplete list, since many cities did not
provide data — including some of the most polluted.
The
outdoor pollution problem is growing, as more Africans move to cities.
Ms. Linden, who did research in Burkina Faso until 2007, said that “the
situation is likely worse now” because Ouagadougou’s population has
swelled by more than 50 percent since then. Major outdoor sources of
pollution include old vehicles; the burning of wood and trash;
industrial activities; and even dust from dirt roads, a serious issue in
Ouagadougou. In West Africa, a wind called the harmattan adds to the
problem in the winter, coating the region in Saharan desert dust.
One
recent study, published in the journal Environmental Research Letters,
estimated that Africa could generate 20 percent to 30 percent of the
world’s combustion-driven sulfur dioxide and nitrogen oxides by 2030, up
from about 5 percent each in 2005. Other pollutants are growing too:
Organic carbon from Africa could rise to over 50 percent of the world’s
combustion output, from 20 percent, the study said. The authors did
their calculations using estimates about fuel consumption, growth and
other emissions factors, and warned of “a considerable increase in
emissions from Africa” in the absence of regulations.
One
of few countries to put regulations in place is South Africa, where
ozone and tiny particles are particular worries. Air quality standards
went into effect in 2009. Restrictions on particles will tighten in 2015
and 2016, according to Rebecca Garland, a senior researcher at the
Council for Scientific and Industrial Research in Pretoria.
Elsewhere,
action is lacking as African nations grapple with other problems. Dr.
Dora of the W.H.O. said that in countries like China, the pressure to
stem pollution comes from businesses, and “from what I know, there’s
still not that pressure from businesses in Africa,” he said. However,
some leaders are aware of the issue and want to address it, he added.
One
initiative that has gotten considerable attention is cleaner
cookstoves. The current fuels, including wood, charcoal, animal dung and
crop residues, create smoke and soot. The W.H.O. is releasing
information soon about how various technologies can improve indoor air
pollution. The concept of cleaner cookstoves has been getting
high-profile attention; however, some experts caution that some of the
new cookstoves may be focused less on reducing air emissions than on
other benefits like increased energy efficiency and preventing forest
degradation.
“I
don’t think anybody’s really demonstrated that they’re clean enough” to
play a serious role in improving public health, said Darby Jack, an
assistant professor at Columbia University’s Mailman School of Public
Health.
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