Saturday, December 22, 2012

Estimated 4,000,000 Deaths from Household Cooking Smoke - A Note from Dr. Kirk Smith

This was sent to the cook stoves email list server on December 21st, 2012

Dear Colleagues,
The recently released "Global Burden of Disease 2010," a new systematic analysis of all major global health risks, has concluded that household air pollution from cooking with solid fuels kills 4 million people annually worldwide. This figure is double the previous estimate, and includes 3.5 million deaths associated with indoor exposures and another 500,000 deaths from cookstoves' contribution to outdoor air pollution. Additionally, millions more are sickened from lung cancer and disease, lower respiratory infections, cardiovascular disease, and cataracts associated with household air pollution. The study was funded by the Bill and Melinda Gates Foundation and represents the work of 486 co-authors from 50 countries.
The Global Burden of Disease Study 2010 (GBD 2010), published On December 13, 2012, in the journal Lancet, is the largest ever systematic effort to describe the global distribution and causes of a wide array of major diseases, injuries, and health risk factors. GBD 2010 consists of seven articles, each containing data on different aspects of the study (including data for different countries and world regions, men and women, and different age groups).
The last of the seven articles reports the comparative risk assessment among about 60 risk factors, including household air pollution. It can be cited as:
A Comparative Risk Assessment of Burden of Disease and Injury Attributable to 67 Risk Factors and Risk Factor Clusters in 21 regions, 1990-2010: A Systematic Analysis for the Global Burden of Disease Study 2010. Lancet, 380: 2224-60, 2012. S Lim, et al. (Link) (Download is free, but registration is required)
Below are selected excerpts from a summary of the article by Kirk Smith of the University of California-Berkeley. A video of Dr. Smith's presentation about the GBD study is also available. To learn more about this study and efforts underway to address this serious global health challenge, visit the Global Alliance for Clean Cookstoves at

As chair of the skilled and dedicated expert group on Household Air Pollution (HAP), I here summarize four aspects of the assessment related to HAP:
First the numbers. The scale of HAP's health impact is quite large.
  • 3.5 million direct premature deaths annually in 2010 – compared to 3.3 million for outdoor air pollution (particles and ozone) and 6.3 million for active and passive smoking.
  • 0.5 million more from the outdoor air pollution due to household fuels — what one might call "secondhand cookfire smoke."
  • This makes ~4 million total attributable to HAP from cooking fuel.
  • 0.5 million of the total are child pneumonia deaths.
  • The rest are adult deaths (men and women) from lung cancer, cardiovascular disease (CVD), and COPD. Cataracts are also included, but they cause very few deaths.
  • In terms of absolute impacts, men are more affected than women. This counterintuitive result is because men have so much higher background rates of the major diseases. Thus, although women have higher exposures and higher elevations in risk for these diseases, men end up with the larger burden. In relative terms, as indicated below, however, women are more affected by HAP.
  • In terms of DALYs (lost healthy life years), HAP is the 2nd most important risk factor for women and girls globally among those examined and 5th for men and boys. It is 1st for both sexes in South Asia and for women and girls in most of sub-Saharan Africa. HAP is 6th for both sexes in East Asia.
  • HAP is the most important single environmental risk factor globally and in poor regions. Behind outdoor air pollution (OAP) in richer countries, of course, and in China, where OAP ranks fourth among all risk factors examined.
  • 2.8 billion people rely on solid fuels for their main cooking fuel in 2010, a number that seems to have been roughly stable globally for the last decade or so. This are now more people than anytime in human history relying on solid fuels for cooking.
Second, the bottom lines:
  • Most of the impact is now understood to occur in adults.
  • But still, Acute Lower Respiratory Infections (ALRI) (pneumonia)) deaths in children are significant — 500k globally — even with much lower background ALRI death rate globally.
  • Household cooking fuel emissions contribute substantially to outdoor air pollution in many countries — 25-30% in India, for example — "secondhand cookfire smoke."
  • The new integrated exposure-response (IER) analyses provide excellent new cross-risk-factor validation of the effects we find for a range of diseases — lung cancer, COPD, ALRI (IERs link epidemiological evidence across the four particle categories - outdoor air pollution, secondhand tobacco smoke, HAP, and active smoking).
  • HAP plays a large role in non-communicable diseases (NCDs) which are now understood to be so important in India and other low and mid-income countries.
  • It is important to remember that interventions that do not reduce all the way to the clean levels used for comparison (see next section) will not produce the full health benefits. Based on studies across combustion particle sources in the GBD, it is now believed that the impacts are highly non-linear at the levels commonly experienced in households cooking with solid fuels. Thus, for example, a reduction of a factor of two in smoke exposures at these high levels will produce far less than a reduction of 50% in health impacts. Need to reduce exposures down to levels in the range of the WHO Air Quality Guidelines to do so.
Third, many will wonder why the results show so much larger effects for HAP compared to what was found in the previous CRA for 2000 published in 2004 (1.6 million premature deaths).
There were actually factors that tended to decrease the attributable burden in the new estimates:
  • ~40% of the world use solid fuels for cooking in 2010, down from the ~50% estimated for 2000. This is based on much more robust estimate of global household solid fuel use for cooking informed by ~600 nationally representative household fuel use surveys compared to ~50 last time.
  • We were able to be more careful in separating out cooking fuel only. There is much less confusion with heating fuels than before.
  • The risks for COPD were less than before, based on the new systematic reviews and meta-analyses.
Fourth, there were other differences, however, that led to higher estimates:
  • Evidence now allows us to add estimates for two new categories of disease: cardiovascular disease (CVD) and cataracts.
  • As CVD is the chief cause of mortality in nearly all countries, the additional burden is substantial.
  • Evidence of effects in men now for all adult endpoints except cataracts.
  • We now using a low counterfactual (~7 ug/m3 annual PM2.5 — same as the OAP group used) — equivalent to cooking with gas.
  • This allows the HAP results to reflect the full benefit that could be expected from moving the 40% of households with solid fuel to the low pollution experienced by 60% of world population using gas or electricity for cooking.
The net result was a major increase in the estimated burden.

Kirk R. Smith, MPH, PhD
2012 Tyler Laureate
Professor of Global Environmental Health
Director of the Global Health and Environment Program
School of Public Health
747 University Hall
University of California

Tuesday, December 18, 2012

Shipping Industry Going Green (Singapore)

Read more on CNN


More than 700,000 Premature Deaths due to Air Pollution in South Asia

An explosion of car use has made fast-growing Asian cities the epicentre of global air pollution and become, along with obesity, the world's fastest growing cause of death according to a major study of global diseases.
Article from the Guardian, December 17th, 2012

In 2010, more than 2.1m people in Asia died prematurely from air pollution, mostly from the minute particles of diesel soot and gasses emitted from cars and lorries. Other causes of air pollution include construction and industry. Of these deaths, says the study published in The Lancet, 1.2 million were in east Asia and China, and 712,000 in south Asia, including India.

Worldwide, a record 3.2m people a year died from air pollution in 2010, compared with 800,000 in 2000. It now ranks for the first time in the world's top 10 list of killer diseases, says the Global Burden of Disease (GBD) study.

The unexpected figure has shocked scientists and public health groups. David Pettit, director of the southern California air programme with the Natural Resources Defence Council (NRDC), said:

"That's a terribly high number – and much more people than previously thought. Earlier studies were limited to data that was available at the time on coarse particles in urban areas only."

Anumita Roychowdhury, head of air pollution at the Centre for Science and Environment (CSE), a New Delhi-based environmental group, said: "There is hard evidence now to act urgently to reduce the public health risks to all, particularly children, elderly and the poor. No-one can escape toxic air."
The full effects of air pollution on health in Asian cities may not be seen for years, she said. "Toxic effects like cancer surface after a long latency period. Therefore, exposure to air pollution will have to be reduced today to reduce the burden of disease," she said.

According to the report, by a consortium of universities working in conjunction with the UN, 65% of all air pollution deaths are now in Asia, which lost 52m years of healthy life from fine particle air pollution in 2010. Air pollution also contributes to higher rates of cognitive decline, strokes and heart attacks.

If the figures for outdoor air pollution are combined with those of indoor air pollution, caused largely by people cooking indoors with wood, dirty air would now rank as the second highest killer in the world, behind only blood pressure.

Household air pollution from burning solid fuels such as coal or wood for cooking fell noticeably, but not having clean cooking and heating fuels remains the leading risk in south Asia.

Fine particle air pollution in India is far above the legal limits of 100 microgramme per cubic metre. This can rise to nearly 1,000 microgrammes during festivals like Diwali.

Improvements in car and fuel technology have been made since 2000 but these are nullified by the sheer increase in car numbers. Nearly 18m are expected to be sold this year alone. In Delhi, there are now around 200 cars per 1,000 people compared with 70-100 per 1,000 population in Hong Kong and Singapore.

Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change and director-general of the Energy and Resources Institute in New Delhi, this week suggested the need to "demand restraint measures" in Delhi, to put a check on the growing number of cars so that there was a check on pollution.

Monday, December 17, 2012

Air Pollution Responsible for 2200 Premature Deaths per Year in Tehran, Iran

Considering short-term effects, PM10 had the highest health impact on the 8,700,000 inhabitants of Tehran city, causing an excess of total mortality of 2194 out of 47284 in a year. Sulfur dioxide, nitrogen dioxide and ozone caused about, respectively, 1458, 1050 and 819 excess cases of total mortality.

Download the paper published in Iranian Journal of Environmental Health Science and Engineering

Saturday, December 15, 2012

Nearly 400,000 Bangkok Commuters are Suffering from Respiratory Diseases Due to Air Pollution

According to the BMA's medical division, the number of people suffering from respiratory diseases such as asthma and allergies has risen drastically over the past seven years, with about 20,000 to 30,000 Bangkokians developing symptoms every year.

Traffic in Bangkok is getting worse thanks to the government's first-car tax-rebate policy. As of October 31, car registrations in Bangkok had revved up to 7,384,934, of which 296,553 were for new cars bought under the first-car policy.

Though the number of cars registered has risen this year, the Pollution Control Department's director general Wichian Jungrungreung said the quality of air in the capital was still "good" and that the number of particles smaller than 10 micrometres had reduced over the past two years.

Read More at the Nation, December 15th, 2012

Friday, December 14, 2012

Rapid Rail Transit for the National Capital Region of Delhi

If the NCR Planning Board achieves its target of getting the three rapid rail transit systems operational by 2016, people living in the National Capital Region can hope to save Rs 1 lakh crore annually.

The board's member-secretary, Naini Jayaseelan, however, believes that the approved expenditure of around Rs 72,000 crore on the three rapid rail transit systems is only a trickle, compared with what an enterprise of this magnitude calls for.

The estimated value of the economic benefits accruing to the NCR after the Delhi-Alwar, Delhi-Meerut and Delhi-Panipat rapid rail alignments are completed will be around Rs 3.5 lakh crore, according the NCRPB.

Read more on Daily Mail

National Capital Region Planning Board

Global Burden of Disease Study 2010 (The Lancet)

The Global Burden of Disease Study 2010 (GBD 2010) is the largest ever systematic effort to describe the global distribution and causes of a wide array of major diseases, injuries, and health risk factors. The results show that infectious diseases, maternal and child illness, and malnutrition now cause fewer deaths and less illness than they did twenty years ago. As a result, fewer children are dying every year, but more young and middle-aged adults are dying and suffering from disease and injury, as non-communicable diseases, such as cancer and heart disease, become the dominant causes of death and disability worldwide. Since 1970, men and women worldwide have gained slightly more than ten years of life expectancy overall, but they spend more years living with injury and illness.

GBD 2010 consists of seven Articles, each containing a wealth of data on different aspects of the study (including data for different countries and world regions, men and women, and different age groups), while accompanying Comments include reactions to the study's publication from WHO Director-General Margaret Chan and World Bank President Jim Yong Kim. The study is described by Lancet Editor-in-Chief Dr Richard Horton as "a critical contribution to our understanding of present and future health priorities for countries and the global community."

Read more in the Lancet, December 13th, 2012

An article in the Times of India focusing on Asia and India.

A press release from Health Effects Institute.

Thursday, December 13, 2012

London Assembly Reports 4000 deaths per year due to Air Pollution

Up to nine per cent of deaths in the capital’s most polluted areas are attributable to air pollution, a new paper from the London Assembly reveals.

The percentage of deaths attributable to man-made airborne particles was highest in the City of London (9 per cent), Westminster (8.3 per cent), Kensington and Chelsea (8.3 per cent) and Tower Hamlets (8.1 per cent).  Bromley and Havering (both 6.3 per cent) had the lowest proportion in London, though are still above the England average of 5.6 percent.

The Assembly’s Health and Environment Committee's paper highlights the long-term health impact of toxic pollutants, which have been linked to life-shortening lung and heart conditions, breast cancer and diabetes.  It is estimated there are over 4,000 extra deaths each year in London from particulates and health costs are estimated at up to £20 billion a year – twice the cost of obesity.

Read More

Wednesday, December 05, 2012

Hairy Nose from Clean Air Asia (BAQ 2012)

The Hairy Nose campaign was launched at the three-day Better Air Quality (BAQ) 2012 conference, organized by Clean Air Asia, the Hong Kong SAR Environmental Protection Department and The Hong Kong Polytechnic University, which will kick off on December 5, 2012 in Hong Kong. The campaign which consists of a online video, a micro website where people can check pollution levels in their city and select their own nose hair styles will be rolled out after BAQ 2012 to a number of Asian countries where Clean Air Asia has regional offices and networks including China, India, Pakistan, Sri-Lanka and Vietnam

The Hairy Nose video can be seen
The Hairy Nose Micro site can be found at:

Top 100 cities with the worst air quality in the World (WHO, 2011).  

Sunday, December 02, 2012

Varieties of Carbon - Black to Green

from article published in Pacific Standard

Brown carbon: Brown carbon is a light-absorbing particle in the Earth’s atmosphere that has the unique characteristics of both cooling the planet’s surface and warming its atmosphere. It was originally distinguished from black carbon in a 2006 report by M.O. Andreae, who has a doctorate in oceanography, and A. GelencsÄr, a chemist. Research published in 2008 by Arizona State University professor Peter Crozier suggests that this nanoscale atmospheric aerosol species is abundant in the atmosphere over East Asian countries and should be explicitly included in models of radiative forcing (the gap between energy radiation reaching the Earth and that leaving through the upper atmosphere).

Green carbon: Green carbon is the carbon that is stored in terrestrial ecosystems such as forests, pastures and soils. This carbon can be released into the atmosphere through deforestation and fire. The U.N. Framework Convention on Climate Change noted in a 2008 report that increasing green carbon stores through reforestation and preservation efforts has great potential to combat global warming.

Blue carbon: Blue carbon is carbon that lives in the world’s oceans. An estimated 55 percent of carbon in living organisms is stored in mangroves, marshes, seagrasses, coral reefs and macro-algae. This carbon is cached for millennia, unlike green carbon, which may be stored for decades or centuries. A new report from UNEP, The Food and Agriculture Organization, and UNESCO’s Intergovernmental Oceanographic Commission highlights the alarming fact that blue carbon ecosystems are being degraded five to 10 times faster than rainforests. Coastal ecosystem services are valued at $25 billion per year — they provide vital nutrition for close to 3 billion people.

Black carbon: Last but not least, black carbon is the carbon formed through incomplete combustion of fuels — essentially soot. It is the most widely discussed form of carbon, and some scientists suspect it is second only to carbon dioxide as a contributor to global warming. Black carbon can be reduced through the adoption of clean-burning technologies.

Friday, November 30, 2012

Air Pollution News & Alerts - November 30th, 2012

Hindustan Times, November 30th, 2012
India tops China in air pollution level increase.

Pacific Standard, November 30th, 2012
Your Guide to the Carbon Rainbow.

The Indian Express, November 30th, 2012
Move to double fine for polluting cars.

TIME, November 30th, 2012
India’s Air Pollution: Is It Worse Than China’s?

Times of India, November 29th, 2012
Need curbs on the killer fuel: Environmentalists.

UC Berkeley News Center, November 28th, 2012
Let there be clean light: Kerosene lamps spew black carbon, should be replaced.

Shanghai Daily, November 27th, 2012
Alarming air pollution in Shanghai.

TUNZA Eco Generation, November 27th, 2012
Face to air pollution of Ulaanbaatar.

Mongolia News, November 25th, 2012
Air Pollution Killing Ulaanbaatar's Residents.

SEI, November 22nd, 2012
Transitioning away from large-scale power projects: A simple and effective fix for the CDM?

Times of India, November 21st, 2012
23 Delhiites die every day due to respiratory ailments.

WRI Insights, November 21st, 2012
The Trillion RMB Question: How Can China Fund its Sustainable Urban Transport Growth?

The Daily Climate, November 20th, 2012
We can slow near-term climate change.

Green Economy, November 20th, 2012
Beijing Makes Changes To Fight Air Pollution.

Indian Express, November 19th, 2012
Smog-hit city to penalise polluting cars.

Smart Planet, November 19th, 2012
Asian cities at highest risk to climate change.

Peoples Daily Online, November 19th, 2012
Air pollution hangs on another day in Shanghai.

Global Times, November 18th, 2012
Shanghai updates air pollution gauge.

The Independent, November 16th, 2012
Air pollution at dangerous level.

China Daily, November 16th, 2012
Air quality gets better test.

Hindustan Times, November 16th, 2012
To tackle pollution, focus on buses, BRT.

NRDC Switchboard, November 16th, 2012
Latin America Green News: Chile bikes to work, Costa Rica retires old refrigerators, and Mexico fights air pollution.

The Wall Street Journal, November 16th, 2012
Coal India Eyes Forests.

Chile News, November 16th, 2012
Chile Presents Plan to Reduce Greenhouse Gas Emissions.

Mongolia News, November 16th, 2012
Philippine company makes air-cleansing device in Ulaanbaatar.

South China Morning Post, November 15th, 2012
It's official: Hong Kong has poor air quality.

Hindustan Times, November 14th, 2012
Hike in parking rates to curb pollution.

NDTV, November 14th, 2012
With China and India ravenous for energy, coal's future seems assured.

Times of India, November 14th, 2012
Delhi smog lifts somewhat, but pollution stays.

Huffingtons Post, November 14th, 2012
Climate Disruption: New Delhi's Trees Need A Helping Hand.

New York Times, November 14th, 2012
Delhi’s Disappearing Night Sky.

The Economic Times, November 14th, 2012
Big cities are gasping for fresh air; air pollution worsens in metros.

China Daily, November 14th, 2012
Quarry workers get new jobs in clean-city push.

China Daily, November 13th, 2012
Environment the biggest challenge.

The Hindu, November 13th, 2012
Slew of measures mooted to curb air pollution in Delhi.

South China Morning Post, November 11th, 2012
China's birth defects blamed on pollution, unhealthy living.

The Hindu, November 11th, 2012
Smog, pollution multiply health risks.

The Indian Express, November 11th, 2012
Burning of paddy straw will be illegal.

Indian Express, November 11th, 2012
Coming up at key locations: Air quality info, smog alerts.

Times of India, November 10th, 2012
Lax pollution control norms exposed: Indian Foundation of Transport Research and Training.

NDTV, November 10th, 2012
Will Delhi have a smog-filled Diwali? High-level meeting today to discuss situation.

Times of India, November 10th, 2012
Govt to act against air pollution soon.

Hindustan Times, November 10th, 2012
Pollution likely to get worse after Diwali in Delhi.

Wall Street Journal, November 9th, 2012
Delhi Journal: Five Ways to Avoid the Pollution.

UB Post, November 9th, 2012
Another Winter Looms and So Does the Smog.

UB Post, November 9th, 2012
National Committee for Reducing Air Pollution Convenes.

Hindustan Times, November 9th, 2012
Officials meet EPCA to devise ways to control smog levels.

Today Online, November 9th, 2012
Delhi smog blamed on farmers burning straw.

NDTV, November 8th, 2012
Haze due to farm fires in Punjab, Haryana and Uttar Pradesh: Sheila Dikshit.

First Post, November 8th, 2012
Dear Mrs Dikshit, don’t blame farmers but Delhi cars for smog.

IBN Live, November 8th, 2012
SC expresses concern as smog situation worsens; Delhi govt blames UP, Haryana.

PTI News, November 8th, 2012
Delhi govt to crack down burning of leaves, garbage.

Wall Street Journal, November 8th, 2012
Delhi’s Air Pollution Worse Than Ever.

Science Network, November 8th, 2012
Air pollution study must factor in bushfire smoke.

BBC, November 8th, 2012
Delhi smog blamed on burning straw.

The Guardian, November 7th, 2012
Barack Obama stokes expectations of climate change action in second term.

Fort Worth Weekly, November 7th, 2012
Notice How Much Cleaner the Air Is?

Science Daily, November 7th, 2012
Climate Science: Trends in Use of Words in Scientific Studies May Impact Public Perceptions.

The Economist, November 6th, 2012
Air pollution in India - A Delhi Particular.

Deccan Chronicle, November 6th, 2012
Smog to lift over Delhi by Friday November 9th, 2012.

NDTV, November 6th, 2012
Delhi smog worrying, we'll take up matter: Chief Justice of India.

The National, November 6th, 2012
New Delhi haze sets in, prompting warnings city 'will choke by 2021'.

The New York Times, November 5th, 2012
Delhiites: Why Don’t You Use Public Transportation?

IBN Live, November 5th, 2012
Delhi smog sets alarm bells ringing, haze to continue for three days.

Times of India, November 5th, 2012
Smog screen thickens, to stay.

NDTV, November 5th, 2012
Winds back, Delhi smog shows signs of let-up after five days.

Science Daily, November 5th, 2012
Indian Monsoon Failure More Frequent With Global Warming.

Money Life, November 3rd, 2012
Protecting your Parisar in Pune.

Down to Earth, November 3rd, 2012
Diwali is far, but smog is here.

Science Daily, November 1st, 2012
Air Pollution, Gone With the Wind: Proposed New Building Guidelines to Clean Up the Air We Breath.

The Hindu, October 28th, 2012
Will walkers unite?

The Express Tribune, October 17th, 2012
Check Manufacturers to Cut Emissions in Lahore.

The Nation, October 16th, 2012
Absence of mass transit system ups traffic woes in Karachi.

The Express Tribune, October 5th, 2012
More women than men in Pakistan get lung disease in Pakistan.

Wednesday, November 28, 2012

An Emissions Inventory for Delhi - PM2.5, PM10, SO2, NOx, CO, and VOCs

This was published in Atmospheric Environment in November, 2012


In Delhi, between 2008 and 2011, at seven monitoring stations, the daily average of particulates with diameter < 2.5 micron meter was 123 ± 87 μg m3 and particulates with diameter < 10 micron meter was 208 ± 137 μg m3. The bulk of the pollution is due to motorization, power generation, and construction activities. In this paper, we present a multi-pollutant emissions inventory for the National Capital Territory of Delhi, covering the main district and its satellite cities – Gurgaon, Noida, Faridabad, and Ghaziabad. For the base year 2010, we estimate emissions (to the nearest 000's) of 63,000 tons of PM2.5, 114,000 tons of PM10, 37,000 tons of sulfur dioxide, 376,000 tons of nitrogen oxides, 1.42 million tons of carbon monoxide, and 261,000 tons of volatile organic compounds. The inventory is further spatially disaggregated into 80 × 80 grids at 0.01° resolution for each of the contributing sectors, which include vehicle exhaust, road dust re-suspension, domestic cooking and heating, power plants, industries (including brick kilns), diesel generator sets and waste burning. The GIS based spatial inventory coupled with temporal resolution of 1 h, was utilized for chemical transport modeling using the ATMoS dispersion model. The modeled annual average PM2.5 concentrations were 122 ± 10 μg m3 for South Delhi; 90 ± 20 μg m3 for Gurgaon and Dwarka; 93 ± 26 μg m3 for North-West Delhi; 93 ± 23 μg m3 for North-East Delhi; 42 ± 10 μg m3 for Greater Noida; 77 ± 11 μg m3 for Faridabad industrial area. The results have been compared to measured ambient PM pollution to validate the emissions inventory.

Two figures from the paper are presented below.

Location of power plants and brick kilns in Delhi
Gridded emissions inventory for Delhi

Swing at a Bus Stop in Moscow (Playful Spaces)

Saturday, November 10, 2012

Air Pollution in Hong Kong - November, 2012

Air Pollution in Delhi - Winter Time Highs and Blame Games

The smog and pollution in Delhi this year is particularly bad given that it is so early in the winter season. Usually the health and economic impacts of the smog become front news headlines later in the winter season when travel is disrupted and there is a permanent haze over the city due to several factors including burning of biomass to keep warm. Read more @ what's polluting Delhi's air

In response to the call for action to reduce air pollution in the city, the minister in charge of environment, Sheila Dikshit declared that the source of the pollution in the city is agricultural waste burning from farms in Punjab and Haryana and none of the pollution is from sources within the city. Commentary on air pollution in Delhi, published in EPW - June, 2012  

Delhi's Air Pollution - Emissions vs. Meteorology

As the capital of India with a population of about 20 million – Delhi does have a well-recognized air pollution problem and over the years the government has taken some steps to reduce air pollution (e.g conversion of buses to run on Compressed Natural Gas - CNG). However these measures are not enough, in the wake of the increasing activity within the city and the peculiar meteorological conditions of the city.

Pollution from particulate matter (PM) has been growing steadily in Delhi. As the graph below shows, there were some gains post-implementation of the CNG program, but those have been by far overtaken with time. The benefits of leapfrogging to alternative fuels like CNG is outdone by the increasing number of passenger vehicles on the road, lack of enough public transport buses, the in- crease in freight movement and construction material and debris by trucks passing through the city, the lack of maintenance of trucks and buses, growing demand for electricity leading to the use of in- situ generator sets, and industrial growth.

The above graph is the data presented by the Minister of State, Ms. Jayanti Natarajan, in the Rajya Sabha, in March 2012. The increase in annual averages between 2001-10 is not due to seasonal agricultural burning that happens for a few weeks.

An emissions inventory for Delhi @ 1kmx1km resolution

A source apportionment study of PM2.5 Hydrocarbon analysis of measured samples from 2002 highlights the main contributions to pollution in Delhi. As we see in the graphs, the profiles differ for summer and winter. Additionally, pollution is 2 to 4 times as high in winter as in summer. With summer concentrations approximately 40-80 micro-gm/m3 daily average and winter concentrations 90-320 micro-gm/m3 daily average. The biomass burning which forms a large part of the pollution in winter, includes emissions from both outside, as well as from within the city (waste, cooking, warmth). 

What is source apportionment?

Sources within the city, such as coal burning, vehicle emissions, resuspension of road dust and garbage burning are significant contributors to pollution in Delhi. In winter, in addition to garbage burning, biomass burning for cooking and for keeping warm is a major threat to air quality. To avoid freezing, people without access to electric and gas heaters resort to burning not just wood, but also plastic, rubber, cloth, etc. These are even more hazardous than wood and agricultural wate burning as they release significant toxins and heavy metals in the air.

Meteorology of Delhi

Delhi experiences extremes in climate – very hot summers and cold winters. It is a landlocked city, and hence cannot rely on breeze from the sea to carry away pollutants. A characteristic of these extremes is that the inversion layer is high in summer, but significantly lower in winter. What this means is that, emissions in winter are more concentrated because they cannot get distributed high into the atmosphere. As the graph below shows, on average mixing layer heights are almost twice as high in summer months as compared to winter. Winds are also much lower strength in winter, and hence any pollution that is created tends to stay for longer.

Role of meteorology in the seasonality of air pollution in Delhi

Air pollution emissions tend to be higher in the winters because of increased burning of bio-mass across sectors. Watchmen, pavement dwellers, slum dwellers do not have a choice but to burn wood or any item to keep warm or for cooking, this is the peak season for brick kiln operations on the outskirts of the city, and agricultural waste burning. Black dots in the map below shows the location of brick kilns around Delhi. There are 1,000 large units mapped in graph and there are more in the outskirts. All these emissions are thus concentrated in a small space and stay around for long – thus causing a lot of pollution.

The night time pollution levels in Delhi are worse compared to the daytime. This is primarily due to all the trucks passing through the city at night (as well as meteorological conditions, explained above). And even when the trucks stop operating after 6 AM, it takes time for the pollution dissipate.

Air pollution in the city is extremely high compared to international, and our own ambient, standards. Data on pollution levels over the past years shows that the situation has deteriorated. This has happened despite a fairly successful CNG conversion programme in the early 2000s. Part of the reason for this is because transport accounts for only a fifth of air pollution in the city.

We know the areas that need action. These include emissions from power plants and industrial units, waste burning, re-suspension of road dust and dust from construction activities, etc. But at the end of the day, pollution is an externality (a public bad) that cannot be addressed without concerted action from the city and national authorities. This goes beyond just setting emission and ambient standards, monitoring emissions and pollution but also enforcing these for vehicles, industry, waste management and power plants. Pollution in Delhi is a result of multiple sectors and focusing on one alone or blaming on neighbors will not have an impact on the air we breathe.

Health impacts of air pollution in Delhi

A video on On-road exposure on Delhi roads by Joshua Apte.

Friday, November 09, 2012

Particulate Pollution in Hyderabad, India

An article published in EMAS, November, 2012


Air quality in Hyderabad, India, often exceeds the national ambient air quality standards, especially for particulate matter (PM), which, in 2010, averaged 82.2 ± 24.6, 96.2 ± 12.1, and 64.3 ± 21.2 μg/m3 of PM10, at commercial, industrial, and residential monitoring stations, respectively, exceeding the national ambient standard of 60 μg/m3. In 2005, following an ordinance passed by the Supreme Court of India, a source apportionment study was conducted to quantify source contributions to PM pollution in Hyderabad, using the chemical mass balance (version 8.2) receptor model for 180 ambient samples collected at three stations for PM10 and PM2.5 size fractions for three seasons. The receptor modeling results indicated that the PM10 pollution is dominated by the direct vehicular exhaust and road dust (more than 60 %). PM2.5 with higher propensity to enter the human respiratory tracks, has mixed sources of vehicle exhaust, industrial coal combustion, garbage burning, and secondary PM. In order to improve the air quality in the city, these findings demonstrate the need to control emissions from all known sources and particularly focus on the low-hanging fruits like road dust and waste burning, while the technological and institutional advancements in the transport and industrial sectors are bound to enhance efficiencies. Andhra Pradesh Pollution Control Board utilized these results to prepare an air pollution control action plan for the city.

Tuesday, November 06, 2012

Air Pollution in Delhi (The Economist)

The Economist, November 6th, 2012

MID-AFTERNOON in Delhi, and a red blob looms in the haze. The sun barely illuminates the city. A yellow-green smog hangs low. Even indoors, fuzzy halos of dust and smoke surround lamps. Those foolish enough to be out jogging, or compelled to stand at junctions directing traffic, complain of shortness of breath, migraines, clogged lungs. Newspapers are crammed with articles about asthma, wheezing children at clinics, an epidemic of grumpiness and gloom, the frail and elderly falling victim to an annual—and worsening—scourge: Delhi’s winter pea-soupers.

Top 100 cities with the worst air quality in the World (WHO, 2011).  

By one estimate the Delhi smog kills 10,500 people a year: smog can trigger heart or asthma attacks, particulate matter causes cancer. Like just about every big Asian city that has grown fast, with only a passing concern for environmental standards, its air is wretched. Official data prove it so. India’s minister for the environment, Jayanthi Natarajan, said so explicitly before parliament in March, explaining that India sets national standards for various nasty pollutants, and monitors for them in 216 towns and cities.

For Delhi, between 2001 and 2010, there was one bright light. The annual average level of sulphur dioxide fell from 14 micrograms per cubic meter to just five. For that Dilliwallahs should thank improvements in transport: a court order roughly a decade ago compelled some 100,000 buses, taxis and auto-rickshaws to switch from running on diesel to compressed natural gas; a successful metro network has been rolled out; a ban on lorries from Delhi’s roads is reasonably well enforced, between 6am and 9pm.

On other scores, matters are much worse. Levels of nitrogen oxide almost doubled over the same period, from 29 micrograms to 55, on average. A measure of particulate matter known as PM10 (any dust with a diameter less than 10 micrometres) has also more than doubled, from 120 to 261, way above the prescribed limit of 100. Keep in mind, too, that pollution is relatively low in the blazing summer months, and during the monsoon. In the winter, by contrast, truly terrifying levels lift the annual average. A glance at the website of a Delhi government agency on November 5th, for example, showed the PM10 level at 749, more than seven times over the safe limit. And for more dangerous tiny particles, known as PM2.5, the agreed safe limit is 60, whereas the official Delhi site reported a level of 489, over eight times too high.

Such statistics are not really needed. Rub your skin after a short walk outside and your fingers are left coated with black smudges. As the worst of the smog appears,it becomes riskier than ever to drive or walk on chaotic roads as visibility falls to just a few metres. Come the new year, Delhi’s airport is battered by delays as fog and smog, usually in the morning, slow the departure and arrival of aircraft. The huge annual festival of Diwali—to be celebrated on November 13th this year—sees a series of immense, deafening and beautiful firework displays, which leave sulphur and gunpowder smoke choking the air for days.

Add to that the impact of the huge bonfires of waste, post-harvest. A striking picture just released by NASA shows thousands of orange dots, blazes that give off the smoke and smog that gathers across much of north India and then sits unmoving as temperatures drop and air pressure—an “inversion”—holds everything still. It is as if a greenhouse is erected above Delhi, to catch and contain the swirling brown exhaust from cars, smoke from oily fires, along with dust and industrial fumes. Right now, too, meteorologists say a distant cyclone, off the east coast of India, has left extra moisture over the northern plains, which has helped to make the smog even denser.

By some measures, Delhi’s rotten air, at least at the worst time of year, competes with the most gasp-inducing of all. One ranking (by UN Habitat) of carbon-dioxide levels, indoor pollution and PM10, suggests its air is worse even than that in Beijing, China’s capital. Residents there may beg to differ, saying their own smogs are worse yet. Even if, on average around the year, some other cities are arguably even worse—Karachi in Pakistan and Dhaka in Bangladesh look particularly dire—it is a miserable competition to join.

What could be done? Getting away from the city makes good sense: Kashmir is rather nice at this time of year. Individuals are told they may protect themselves a bit, for example by hiding indoors, keeping doors and windows closed and using air filters. General advice against exercising outdoors at least gives couch potatoes an excuse to put off keep-fit regimes for another few months.

For Delhi, a series of other measures make sense. Perhaps a fifth of all the pollution in the city is still caused by traffic, notably from diesel cars. Scrapping subsidies on diesel might help, for example by pushing more people on to public transport or at least into more efficient vehicles. The metro is now some 180km long, and is rather good, but it could be expanded further. Lots more buses, and bus lanes, would be useful too.

Beyond vehicle emissions, there are other causes of woe aplenty, as well described by Sarath Guttikunda of the Indian Institute of Technology, Delhi in a recent study (subscription required). He notes for example that some 1,000 brick kilns surround Delhi, serving its construction boom, baking bricks by burning coal, wood and other organic smoky stuff. Such kilns are traditional, inefficient and dirty. Converting these to something cleaner—or moving them farther away—would surely help.

Similarly coal- and oil-fired power stations near Delhi have, over the years, been converted to gas or moved away. Six power plants remain near the city, but as the general power grid fails repeatedly, wealthy residents, hospitals and businesses turn increasingly to diesel-generators in the city centre, points out Mr Guttikunda. Making the grid more reliable, therefore, would cut the use of such stinky and noisy machines. Paving more roads would lessen the amount of dust (a big portion of PM10) thrown up into the air, while a ban on burning rubbish would cut the oily particles, and so on.

The lesson from the court-ordered transport switch is that official intervention, and proper monitoring, can bring direct and most welcome improvements. It helps, too, that the rich, aside from fleeing, can hardly breathe different air from the poor; thus almost everyone should have a strong interest in doing something to improve matters. Delhi, after all, is gasping for a change.

Saturday, November 03, 2012

Particulate pollution from brick kiln clusters in the Greater Dhaka region, Bangladesh

Published in Air Quality, Atmosphere, and Health


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Brick manufacturing is the fastest-growing industrial sector in Bangladesh and among the top three sectors, along with vehicle exhaust and resuspended road dust, contributing to the air pollution and health problems in Dhaka. The brick manufacturing in the Greater Dhaka region, from ~1,000 brick kilns spread across six districts, is confined to the winter season (October to March) as current technologies do not allow production during the monsoon. The total emissions are estimated at 23,300 t of PM2.5; 15,500 t of sulfur dioxide (SO2), 302,000 t of carbon monoxide (CO), 6,000 t of black carbon, and 1.8 million tons of CO2 emissions from these clusters, to produce 3.5 billion bricks per year, using energy-inefficient fixed chimney bull trench kiln technology and predominantly using coal and agricultural waste as fuel. The associated health impacts largely fall on the densely populated districts of Dhaka Metropolitan Area (DMA), Gazipur, and Narayanganj. Using the Atmospheric Transport Modeling System dispersion model, the impact of brick kiln emissions was estimated over DMA—ranging from 7 to 99 μg/m3 (5th and 95th percentile concentration per model grid) at an average of 38 μg/m3;

and spatial contributions from the surrounding clusters—with 27 % originating from Narayanganj (to the south with the highest kiln density), 30 % from Gazipur (to the north with equally large cluster spread along the river and canals), and 23 % from Savar. The modeling results are validated using evidence from receptor modeling studies conducted in DMA.

An introduction of emerging vertical shaft combustion technology can provide faster benefits for public health in DMA and reduce climate precursor emissions by selecting the most influential clusters discussed in this paper.

Thursday, November 01, 2012

Air Pollution News & Alerts - November 1st, 2012

Hindustan Times, November 1st, 2012
Winter spurts air pollution in Delhi.

Scientific American, November 1st, 2012
People in Poor Neighborhoods Breathe More Hazardous Particles.

Bangkok Post, October 31st, 2012
Judge backs bus pollution guilty verdict in Bangkok.

The Nation, October 31st, 2012
BMTA told to maintain clean buses.

All Africa, October 29th, 2012
South Africa: Govt Needs to Be Tough on Air Polluters.

UB Post, October 29th, 2012
Prime Minister Challenges on Recent Air Pollution Initiatives.

Environment News Service, October 29th, 2012
Atlas Aims to Ease Extreme Weather Impacts on Public Health.

Transport Extra, October 26th, 2012
A manifesto to make UK urban transport amongst the best in Europe.

China Daily, October 25th, 2012
Better use of air quality reports urged.

CNN, October 25th, 2012
Report: More Chinese cities need to come clean on air pollution.

CNN, October 25th, 2012
Report: More Chinese cities need to come clean on air pollution.

China Daily, October 25th, 2012
China's energy policy 2012.

Khaleej Times, October 25th, 2012
People power in China.
Hindustan Times, October 24th, 2012
Delhi: Ten points where the city chokes.

Bloomberg, October 24th, 2012
China Electric Vehicle Sales to Fall Short of Target.

NASA, October 24th, 2012
Haze over Eastern China.

The Huffington Post, October 24th, 2012
Fighting Climate Change and Air Pollution With One Swat.

The Telegraph, October 24th, 2012
Linfen: how China's Chernobyl turned the corner.

Phys.Org, October 23rd, 2012
Making transport a driver for development in Africa.

Renewables Biz, October 23rd, 2012
Environment so Far Taking a Back Seat.

China.Org, October 22nd, 2012
Air quality drops in Shanghai as PM2.5 spikes in fog.

The Washington Post, October 22nd, 2012
Obama’s record: Environmental agenda pushes sweeping attack on air pollution.

The Economist, October 20th, 2012
Climate change needs better regulation, not more political will.

City InfoOnline, October 20th, 2012
EPA Sued Over Vehicle Fees for Ozone Pollution.

Healthline, October 20th, 2012
Pollution from Megacities Decreases Air Quality in the U.S.

MIT News, October 19th, 2012
Researchers examine health impacts of more U.K. runways.

Environmental Health News, October 19th, 2012
Clean air regulations reduce hospital admissions in New York.

Phys.Org, October 19th, 2012
Hong Kong to tighten power plant emission limits.

Nature, October 18th, 2012
Technology: Clean stoves benefit climate and health.

The Breakthrough, October 18th, 2012
Cheap Gas — Not EPA Regs — Driving Coal’s Decline.

The National, October 17th, 2012
India green tax would be breath of fresh air: World Bank.

The Atlantic, October 17th, 2012
A Visual Guide to Chinese Air Pollution.

Bloomberg, October 17th, 2012
Is Obama Really Waging a War on Coal?

Xinhua Net, October 17th, 2012
China's power consumption slows further.

Hindustan Times, October 16th, 2012
Now, China to fly kites to keep pollution in check.

China Dialogue, October 15th, 2012
Official air pollution data in Beijing still failing the public.

Wednesday, October 17, 2012

Application of SIM-air Family of Tools for Air Quality Analysis in Six Indian Cities

Published in Atmospheric Environment


A prerequisite to an air quality management plan for a city is some idea of the main sources of pollution and their contributions for a city. This paper presents the results of an application of the SIM-air modeling tool in six Indian cities – Pune, Chennai, Indore, Ahmedabad, Surat, and Rajkot. Using existing and publicly available data, we put together a baseline of multi-pollutant emissions for each of the cities and then calculate concentrations, health impacts, and model alternative scenarios for 2020. The measured annual PM10 (particulate matter with aerodynamic diameter less than 10 micron meter) concentrations in μg/m3 averaged 94.7 ± 45.4 in Pune, 73.1 ± 33.7 in Chennai, 118.8 ± 44.3 in Indore, 94.0 ± 20.4 in Ahmedabad, 89.4 ± 12.1 in Surat, and 105.0 ± 25.6 in Rajkot, all exceeding the annual standard of 60 μg/m3. The PM10 inventory in tons/year for the year 2010 of 38,400 in Pune, 50,200 in Chennai, 18,600 in Indore, 31,900 in Ahmedabad, 20,000 in Surat, and 14,000 in Rajkot, is further spatially segregated into 1 km grids and includes all known sources such as transport, road dust, residential, power plants, industries (including the brick kilns), waste burning, and diesel generator sets. We use the ATMoS chemical transport model to validate the emissions inventory and estimate an annual premature mortality due to particulate pollution of 15,200 for the year 2010 for the six cities. Of the estimated 21,400 premature deaths in the six cities in 2020, we estimate that implementation of the six interventions in the transport and brick kiln sectors, can potentially save 5870 lives (27%) annually and result in an annual reduction of 16.8 million tons of carbon dioxide emissions in the six cities.