Monday, April 21, 2014

Comparing Air Quality Classifications in China and USA

Here are two simple charts, neither of them brand-new but both easily comprehensible, that help dramatize how different the situation is there. The first, by Steven Andrews for China Dialogue via ChinaFile, compares official Chinese classifications of "good" air conditions with those in Europe or North America. Read the full article @ Atlantic Cities


Here is the point of this graphic: The green and yellow zones in the left-hand column, showing official Chinese government classifications, are for "good" or "OK" air—while those same readings would be in the danger zone by U.S. or European standards. When you're living in China, it's impossible not to adjust your standards either to ignore how dire the circumstances are, so you can get on with life, or to think that any day when you can see across the street is "pretty good."

Here's the other chart, comparing the 10 most-polluted Chinese cities with the 10 in America. It is from The Washington Post a few weeks ago:


Read the full article @ Atlantic Cities

Nobody Lives Here

There are plenty of visualizations based on population data, but nothing quite like what designer Nik Freeman has created: a map of where no one lives. Using data from the 2010 U.S. census, Freeman shades green the nearly 5 million census blocks with zero population. The resulting map highlights the 47 percent of the U.S. that remains unoccupied. Read more @ Atlantic Cities

Saturday, April 19, 2014

Measuring Air Pollution in African Cities

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

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.

Anthropogenic CO2 Emissions in Africa
 
“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.

A factory in Kenya Producing Improved Cookstoves for Africa
 
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.

Explosive Growth in Africa's Combustion Emissions
 
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.

Measuring and Characterizing Pollution in Accra
 
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.

Air Pollution in Ouagadougou
 
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.

Air Pollution in Kampala
 
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.

From Gridlock to Brain Damage in Lagos
 
“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.

Wednesday, April 16, 2014

Zero-Waste to Landfills in Pune by 2015


Pune aims to become a zero-landfill city by 2015. With a range of solid waste management options like localised biogas plants and composting facilities, and policies that encourage door-to-door waste collection and segregation, the target does not seem too ambitious. However, the city municipal corporation needs to ensure it does not fall into the trap of easy answers as it seeks to enhance its waste processing capacity. Read the full article @ Down to Earth

115,000 MT of Waste Generated in India, Every Day

The 600-square metre compound that shares its boundary with the Pune Municipal Corporation (PMC) ward office in Aundh, an affluent suburb, gives no sign of what happens inside. Strollers cheerfully walk past it. Behind its green steel gates is the city’s cleanest weapon to fight garbage. The five-tonne per day (TPD) biogas plant silently operates all day decomposing organic waste—vegetables, fruit rejects and stale food—and converting them into methane. The gas is injected into a generator to produce electricity. The leftover is excellent organic manure. Yet, passers-by have nothing to complain. There is no stench around; no flies or eagles hovering above food. Life goes on, the way it would with any other commercial compound there.

Composting Wet Waste in the House

The plant is Pune’s experiment to ensure that no waste goes to the city’s landfills. “The aim is to make the 244-sq km municipal area zero-landfill by 2015,” says Sanjay Gawade, additional commissioner, municipal solid waste, PMC. Pune generates about 400 grams of solid waste per person per day. The 2011 Census puts the city’s population at about 3.5 million. Another 0.5 million come into the city every day. This translates into 1,400 to 1,600 tonnes of municipal solid waste (MSW) every day, say PMC officials. Of this, 65 per per cent per cent comes from residences, hotels and restaurants (see ‘Waste contributors’). Wet waste accounts for about 70 per cent.