A cross-sectional study of determinants of indoor environmental exposures in households with and without chronic exposure to biomass fuel smoke

April 2, 2014 · 0 comments

A cross-sectional study of determinants of indoor environmental exposures in households with and without chronic exposure to biomass fuel smoke. Env Health, March 2014.

Authors: Suzanne L Pollard, et al.

Background – Burning biomass fuels indoors for cooking is associated with high concentrations of particulate matter (PM) and carbon monoxide (CO). More efficient biomass-burning stoves and chimneys for ventilation have been proposed as solutions to reduce indoor pollution. We sought to quantify indoor PM and CO exposures in urban and rural households and determine factors associated with higher exposures. A secondary objective was to identify chronic vs. acute changes in cardiopulmonary biomarkers associated with exposure to biomass smoke.

Methods – We conducted a census survey followed by a cross-sectional study of indoor environmental exposures and cardiopulmonary biomarkers in the main household cook in Puno, Peru. We measured 24-hour indoor PM and CO concentrations in 86 households. We also measured PM2.5 and PM10 concentrations gravimetrically for 24 hours in urban households and during cook times in rural households, and generated a calibration equation using PM2.5 measurements.

Results – In a census of 4903 households, 93% vs. 16% of rural vs. urban households used an open-fire stove; 22% of rural households had a homemade chimney; and <3% of rural households participated in a national program encouraging installation of a chimney. Median 24-hour indoor PM2.5 and CO concentrations were 130 vs. 22 µg/m3 and 5.8 vs. 0.4 ppm (all p<0.001) in rural vs. urban households. Having a chimney did not significantly reduce median concentrations in 24-hour indoor PM2.5 (119 vs. 137 µg/m3; p=0.40) or CO (4.6 vs. 7.2 ppm; p=0.23) among rural households with and without chimneys. Having a chimney did not significantly reduce median cook-time PM2.5 (360 vs. 298 µg/m3, p=0.45) or cook-time CO concentrations (15.2 vs. 9.4 ppm, p=0.23). Having a thatched roof (p=0.007) and hours spent cooking (p=0.02) were associated with higher 24-hour average PM concentrations. Rural participants had higher median exhaled CO (10 vs. 6 ppm; p=0.01) and exhaled carboxyhemoglobin (1.6% vs. 1.0%; p=0.04) than urban participants.

Conclusions Indoor air concentrations associated with biomass smoke were six-fold greater in rural vs. urban households. Having a homemade chimney did not reduce environmental exposures significantly. Measures of exhaled CO provide useful cardiopulmonary biomarkers for chronic exposure to biomass smoke.

An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine Particulate Matter Exposure

April 2, 2014 · 0 comments

An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine Particulate Matter Exposure. Environmental Health Perspectives, Feb 2014.

Authors: Richard T. Burnett, et al.

Background: Estimating the burden of disease attributable to long-term exposure to fine particulate matter (PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk function (RR). However, there is inadequate direct evidence to identify the shape of the mortality RR functions at high ambient concentrations observed in many places in the world.

Objective: Develop relative risk (RR) functions over entire global exposure range for causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). In addition, develop RR functions for the incidence of acute lower respiratory infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children less than 5 years old.

Methods: An Integrated Exposure-Response (IER) model was fit by integrating available RR information from studies of ambient air pollution (AAP), second hand tobacco smoke (SHS), household solid cooking fuel (HAP) and active smoking (AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass. Population attributable fractions (PAF) were derived for every country based on estimated world-wide ambient PM2.5 concentrations.

Results: The IER model was a superior predictor of RR compared to seven other forms previously used in burden assessments. The PAF (%) attributable to AAP exposure varied among countries from: 2-41 for IHD, 1-43 for stroke, < 1-21 for COPD, < 1-25 for LC, and < 1-38 for ALRI.

Conclusions: We developed a fine particulate mass-based RR model that covered the global range of exposure by integrating RR information from different combustion types that generate emissions of particulate matter. The model can be updated as new RR information becomes available.

Impact of neighborhood biomass cooking patterns on episodic high indoor particulate matter concentrations in clean fuel homes in Dhaka, Bangladesh

April 2, 2014 · 0 comments

Impact of neighborhood biomass cooking patterns on episodic high indoor particulate matter concentrations in clean fuel homes in Dhaka, Bangladesh. Indoor Air, April 2014.

Authors: H. Salje et al.

Exposure to particulate matter (PM2.5) from the burning of biomass is associated with increased risk of respiratory disease. In Dhaka, Bangladesh, households that do not burn biomass often still experience high concentrations of PM2.5, but the sources remain unexplained. We characterized the diurnal variation in the concentrations of PM2.5 in 257 households and compared the risk of experiencing high PM2.5 concentrations in biomass and non-biomass users. Indoor PM2.5 concentrations were estimated every minute over 24 h once a month from April 2009 through April 2010.

We found that households that used gas or electricity experienced PM2.5 concentrations exceeding 1000 μg/m3 for a mean of 35 min within a 24-h period compared with 66 min in biomass-burning households. In both households that used biomass and those that had no obvious source of particulate matter, the probability of PM2.5 exceeding 1000 μg/m3 were highest during distinct morning, afternoon, and evening periods. In such densely populated settings, indoor pollution in clean fuel households may be determined by biomass used by neighbors, with the highest risk of exposure occurring during cooking periods. Community interventions to reduce biomass use may reduce exposure to high concentrations of PM2.5 in both biomass and non-biomass using households.

Emissions and Climate-Relevant Optical Properties of Pollutants Emitted from a Three-Stone Fire and the Berkeley-Darfur Stove Tested under Laboratory Conditions

April 2, 2014 · 0 comments

Emissions and Climate-Relevant Optical Properties of Pollutants Emitted from a Three-Stone Fire and the Berkeley-Darfur Stove Tested under Laboratory Conditions. Environ Sci Technol. 2014 Mar 31.

Authors: Preble CV, Hadley OL, Gadgil A, Kirchstetter T.

Abstract – Cooking in the developing world generates pollutants that endanger the health of billions of people and contribute to climate change. This study quantified pollutants emitted when cooking with a three-stone fire (TSF) and the Berkeley-Darfur Stove (BDS), the latter of which encloses the fire to increase fuel efficiency. The stoves were operated at the Lawrence Berkeley National Laboratory testing facility with a narrow range of fuel feed rates to minimize performance variability. Fast (1 Hz) measurements of pollutants enabled discrimination between the stoves’ emission profiles and development of woodsmoke-specific calibrations for the aethalometer (black carbon, BC) and DustTrak (fine particles, PM2.5). The BDS used 65 ± 5% (average ± 95% confidence interval) of the wood consumed by the TSF and emitted 50 ± 5% of the carbon monoxide emitted by the TSF for an equivalent cooking task, indicating its higher thermal efficiency and a modest improvement in combustion efficiency. The BDS reduced total PM2.5 by 50% but achieved only a 30% reduction in BC emissions.

The BDS-emitted particles were, therefore, more sunlight-absorbing: the average single scattering albedo at 532 nm was 0.36 for the BDS and 0.47 for the TSF. Mass emissions of PM2.5 and BC varied more than emissions of CO and wood consumption over all tests, and emissions and wood consumption varied more among TSF than BDS tests. The international community and the Global Alliance for Clean Cookstoves have proposed performance targets for the highest tier of cookstoves that correspond to greater reductions in fuel consumption and PM2.5 emissions of approximately 65% and 95%, respectively, compared to baseline cooking with the TSF. Given the larger decrease in BC than carbon dioxide (CO2) emissions for stoves that achieve this stretch goal and BC’s extremely high global warming potential, the short term climate change mitigation from avoided BC emissions could exceed that from avoided CO2 emissions.

Socio-Economic Survey as a Support Tool during the Scaling Up of Improved Stoves in the Logone Valley

April 2, 2014 · 0 comments

Socio-Economic Survey as a Support Tool during the Scaling Up of Improved Stoves in the Logone Valley (Chad/Cameroon). Sustainability 2014, 6(3), 1427-1447; doi:10.3390/su6031427

Authors: Francesco Vitali and Mentore Vaccariemail

Abstract: Field assessment plays a key role in the evaluation of the energy access modalities and of the socio-economic features that may influence the beneficiaries’ choices and preferences in the adoption and use of an energy technology. This work presents the findings of a survey conducted during the implementation of a cooperation project in the Logone Valley (Chad/Cameroon). After an initial period of promotion of an improved cookstove (ICS), a survey was conducted that was aimed at identifying different beneficiary groups, matching their preferences and cooking habits to the technology proposed, in order to best tailor the scaling-up strategy.

In-depth analysis of the data gathered identified two household-user behaviors and the relative influencing features: in the urban area, the increased adoption rates confirmed the appropriateness of the technology proposed and its sustainability, whereas in the rural area, ICS use was not perceived by the final users as advantageous and lower adoption rates were observed. Thus, due to the outcome of the survey, the project action was re-oriented in order to achieve a higher impact on the territory and on the population.

WASHplus Weekly – Global Burden of Disease from Household Air Pollution

March 28, 2014 · 0 comments

Issue 139 | March 28, 2014 | Global Burden of Disease from Household Air Pollution

In new estimates released on March 25, the World Health Organization reports that in 2012 around 7 million people died—one in eight of total global deaths—as a result of air pollution exposure. This finding more than doubles previous estimates and confirms that air pollution is now the world’s largest single environmental health risk. Resources in this issue of the WASHplus Weekly include links to fact sheets, research, and reports related to the burden of disease from household air pollution (HAP).

We also invite you to join the Clean Cookstove Community on Linkedin which we hope will become a crowdsourcing community for sharing information and collaborating on household air pollution issues.

PRESS RELEASES

7 million Premature Deaths Annually Linked to Air Pollution, 2014. World Health Organization (WHO). (Link)
The WHO estimates that the joint effects of HAP and ambient air pollution were attributable to over 7 million deaths in 2012, representing one of eight total global deaths and confirming that air pollution is now the world’s largest single environmental health risk. The WHO also estimates that the South Asian and Southeast Asian and Western Pacific regions bear most of the burden with 1.69 and 1.62 million deaths, respectively. Almost 600,000 deaths occur in Africa, 200,000 in the Eastern Mediterranean region, 99,000 in Europe, and 81,000 in the Americas. The remaining 19,000 deaths occur in high income countries.

Senator Collins Introduces Clean Cookstoves Bill That Would Improve Environment, Public Health, March 10, 2014. (Link)
The “Clean Cookstoves Support Act,” co-sponsored by Senator Dick Durbin (D-IL), would reinforce the U.S. Government’s commitment to spur the adoption of clean cookstoves around the world. It would require the Secretary of State to work to advance the goals of the Global Alliance for Clean Cookstoves, which was formed through the leadership of Secretary of State Hillary Clinton and the United Nation’s Foundation to help create a thriving global market for clean and efficient household cooking solutions.

FACT SHEETS/BRIEFING NOTES

Household Air Pollution and Health. Fact Sheet, 2014. World Health Organization.(Link)
An update of WHO’s estimates on the health impacts of household air pollution as well as its impact on health equity, development, and climate change. The document also includes an overview of WHO’s response and how it connects to Millennium Development Goal targets.

Air Pollution Estimates: Burden of Disease from Household Air Pollution for 2012, Summary of Results. World Health Organization, March 2014. (Link)
A regional and demographic statistical breakdown of the health impacts of household air pollution.

The Burden of Disease from Household Air Pollution: How and Why Are the Estimates Changing? 2014. Global Alliance for Clean Cookstoves. (Link)
WHO just released its 2012 estimates of the global burden of disease from air pollution and reports that globally 4.3 million deaths were attributable to household air pollution in 2012, almost all in low and middle income countries. The new estimates make it clear that reducing air pollution could save millions of lives and further underscore the need for clean cooking technologies for the close to 3 billion people who continue to live in homes using solid fuels for cooking and heating.

PAPERS

Millions Dead: How Do We Know and What Does It Mean? Methods Used in the Comparative Risk Assessment of Household Air Pollution. Annual Review of Public Health, March 2014. K Smith. (Link with supplements)
In the comparative risk assessment (CRA) done as part of the Global Burden of Disease project (GBD-2010), the global and regional burdens of HAP due to the use of solid cook fuels were estimated along with more than 60 other risk factors. This article describes how the HAP CRA was framed; how global HAP exposures were modeled; how diseases were judged to have sufficient evidence for inclusion; and how meta-analyses and exposure-response modeling were done to estimate relative risks.

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WHO Fact Sheet – Household air pollution and health

March 25, 2014 · 0 comments

Fact Sheet: Household Air Pollution and Health: March 2014. World Health Organization.

Key facts

  • Around 3 billion people cook and heat their homes using open fires and simple stoves burning biomass (wood, animal dung and crop waste) and coal.
  • Over 4 million people die prematurely from illness attributable to the household air pollution from cooking with solid fuels.
  • More than 50% of premature deaths among children under 5 are due to pneumonia caused by particulate matter (soot) inhaled from household air pollution.
  • 3.8 million premature deaths annually from noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution.

Indoor air pollution and household energy: the forgotten 3 billion
Around 3 billion people still cook and heat their homes using solid fuels (i.e. wood, crop wastes, charcoal, coal and dung) in open fires and leaky stoves. Most are poor, and live in low- and middle-income countries.

Such inefficient cooking fuels and technologies produce high levels of household air pollution with a range of health-damaging pollutants, including small soot particles that penetrate deep into the lungs. In poorly ventilated dwellings, indoor smoke can be 100 times higher than acceptable levels for small particles. Exposure is particularly high among women and young children, who spend the most time near the domestic hearth.

Impacts on health
4.3 million people a year die prematurely from illness attributable to the household air pollution caused by the inefficient use of solid fuels (2012 data). Among these deaths:

  • 12% are due to pneumonia
  • 34% from stroke
  • 26% from ischaemic heart disease
  • 22% from chronic obstructive pulmonary disease (COPD), and
  • 6% from lung cancer.

Pneumonia – Exposure to household air pollution almost doubles the risk for childhood pneumonia. Over half of deaths among children less than 5 years old from acute lower respiratory infections (ALRI) are due to particulate matter inhaled from indoor air pollution from household solid fuels (WHO, 2014).

Stroke – Nearly one quarter of all premature deaths due to stroke (i.e. about 1.4 million deaths of which half are in women) can be attributed to the chronic exposure to household air pollution caused by cooking with solid fuels.

Ischaemic heart disease – Approximately 15% of all deaths due to ischaemic heart disease, accounting for over a million premature deaths annually, can be attributed to exposure to household air pollution.

Chronic obstructive pulmonary disease – Over one third of premature deaths from chronic obstructive pulmonary disease (COPD) in adults in low- and middle-income countries are due to exposure to household air pollution. Women exposed to high levels of indoor smoke are 2.3 times as likely to suffer from COPD than women who use cleaner fuels. Among men (who already have a heightened risk of COPD due to their higher rates of smoking), exposure to indoor smoke nearly doubles (i.e. 1.9) that risk.

Lung cancer – Approximately 17% of annual premature lung cancer deaths in adults are attributable to exposure to carcinogens from household air pollution caused by cooking with solid fuels like wood, charcoal or coal. The risk for women is higher, due to their role in food preparation.

Other health impacts and risks

More generally, small particulate matter and other pollutants in indoor smoke inflame the airways and lungs, impairing immune response and reducing the oxygen-carrying capacity of the blood.

There is also evidence of links between household air pollution and low birth weight, tuberculosis, cataract, nasopharyngeal and laryngeal cancers.

Mortality from ischaemic heart disease and stroke are also affected by risk factors such as high blood pressure, unhealthy diet, lack of physical activity and smoking. Some other risks for childhood pneumonia include suboptimal breastfeeding, underweight and second-hand smoke. For lung cancer and chronic obstructive pulmonary disease, active smoking and second-hand tobacco smoke are also main risk factors.

Impacts on health equity, development and climate change

Without a substantial change in policy, the total number of people relying on solid fuels will remain largely unchanged by 2030 (World Bank, 2010). The use of polluting fuels also poses a major burden on sustainable development.

  • Fuel gathering consumes considerable time for women and children, limiting other productive activities (e.g. income generation) and taking children away from school. In less secure environments, women and children are at risk of injury and violence during fuel gathering.
  • Black carbon (sooty particles) and methane emitted by inefficient stove combustion are powerful climate change pollutants.
  • The lack of access to electricity for at least 1.2 billion people (many of whom then use kerosene lamps for lighting) creates other health risks, e.g. burns, injuries and poisonings from fuel ingestion, as well as constraining other opportunities for health and development, e.g. studying or engaging in small crafts and trades, which require adequate lighting.

From Kirk Smith, UC Berkeley – Millions Dead

March 25, 2014 · 0 comments

Our new paper in the Annual Review of Public Health has an immense amount of additional information on how the comparative risk assessment for household air pollution from solid cookfuels (HAP) was done. Indeed,covering over 60 risk factors, the original Lim et al. Lancet article (Dec 2012) had less than 300 words on HAP itself, while ours has more than 30,000 words (with the supplement). >100x more. Of course, we do not attempt to produce the vast array of figures and tables comparing with other risk factors and by age, sex, region, etc.

We found some relatively minor glitches in how the calculations were done during the last hectic weeks before the Lancet article went to press and believe that the ARPH article is a more accurate representation of the estimates that can still be compared across the other risk factors. Unlike the Lancet article, it also incorporates the burden from HAP’s contribution to outdoor air pollution, corrected for overlap as explained. The resulting premature death total is 3.9 million globally for 2010, quite close to the 3.5 directly from HAP plus the implied 0.5 million due to an uncorrected addition of HAP’s contribution to outdoor pollution in the Lancet article.

We also of course could take direct advantage of the publication of some major pieces of the HAP analysis that occurred after the Lancet article.

We also are able to do some sensitivity analysis toward the end of our article that show, for example, that the results are not sensitive to uncertainties in the exposure assessment, but that the ranking of HAP against other risk factors in the poorest countries is quite sensitive to the choice of what risk factors were left out in the main GBD study.

The paper and supplement can be downloaded from my website below can the original Lancet article. Please note that Nigel Bruce and I are co-first authors/k

———————————————————-
Millions Dead: How Do We Know and What Does It Mean? Methods Used in the Comparative Risk Assessment of Household Air Pollution

Kirk R. Smith,1,. Nigel Bruce,2,. Kalpana Balakrishnan,3 Heather Adair-Rohani,1 John Balmes,1,4 ZoNe Chafe,1,5 Mukesh Dherani,2 H. Dean Hosgood,6 Sumi Mehta,7 Daniel Pope,2 Eva Rehfuess,8 and others in the HAP CRA Expert Group

Abstract – In the Comparative Risk Assessment (CRA) done as part of the Global Burden of Disease project (GBD-2010), the global and regional burdens of household air pollution (HAP) due to the use of solid cookfuels, were estimated along with 60+ other risk factors. This article describes how the HAP CRA was framed; how global HAP exposures were modeled; how diseases were judged to have sufficient evidence for inclusion; and how meta-analyses and exposure-response modeling were done to estimate relative risks. We explore relationships with the other air pollution risk factors: ambient air pollution, smoking, and secondhand smoke. We conclude with sensitivity analyses to illustrate some of the major uncertainties and recommendations for future work. We estimate that in 2010 HAP was responsible for 3.9 million premature deaths and ~4.8% of lost healthy life years (DALYs), ranking it highest among environmental risk factors examined and one of the major risk factors of any type globally.

Kirk R. Smith, MPH, PhD
(Professor of Global Environmental Health, University of California, Berkeley)
Fulbright-Nehru Distinguished Chair (Fall/Winter 2013/14)
Centre for Atmospheric Sciences
Indian Institute of Technology-Delhi
Delhi cell: (91) 96-5092-6030 [note new number]
http://ehs.sph.berkeley.edu/krsmith/

USAID – Cooking With Green Charcoal Helps to Reduce Deforestation in Haiti

March 19, 2014 · 0 comments

USAID – Cooking With Green Charcoal Helps to Reduce Deforestation in Haiti | Source/complete article: by Anna-Maija Mattila Litvak, USAID Impact Blog, March 13th 2014 |

Excerpts – An organization in northern Haiti is promoting a cooking fuel made from agricultural waste that can save trees, help farmers increase their yields and generate additional income.

“Our aim is to try to stop deforestation in Haiti by teaching people to switch from cooking with charcoal to using cooking briquettes, small discs made from charred agricultural waste,” said Anderson Pierre, the Supply Chain Manager forCarbon Roots International (CRI), a USAID-supported non-profit organization operating in Quartier Morin.

Despite the fact that only about 2 percent of Haiti’s forests remain, it is difficult to shift habits of cooking with wood charcoal to methods that are environmentally friendly.  According to Pierre, other alternative fuels are still not well-known – or accepted.

“We work little by little, changing perceptions and providing information on the benefits of using briquettes,” Pierre said.

CRI employs smallholder farmers and entrepreneurs to produce carbon-rich char from agricultural waste such as sugarcane bagasse, the fibrous matter that remains after sugarcane stalks are crushed to extract their juice. CRI uses this waste to create two innovative products: renewable charcoal cooking briquettes called “green charcoal,” and “biochar,” a potent natural soil additive that increases soil fertility and removes carbon from the atmosphere. CRI sells the briquettes as an alternative to traditional wood charcoal through a network of women retailers, and disburses biochar back to farmers to increase crop yields and further raise incomes.

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Switching to biogas: What effect could it have on indoor air quality and human health?

March 19, 2014 · 0 comments

Commentary: Switching to biogas – What effect could it have on indoor air quality and human health?

Authors: Sean Semple, Andrew Apsley, Adamu Wushishi, Jo Smith

Highlights
• Indoor air pollution from biomass fuels causes a health burden comparable to malaria.
• Data on improvements to household air quality from switching to biogas are lacking.
• Using comparable studies for LPG, reductions in PM2.5 and CO may be as much as 90%.
• Health benefits of such exposure reductions are likely to be considerable.
• Longitudinal biogas intervention studies need to assess exposure and health changes.

Indoor combustion of solid biomass fuels such as wood and charcoal is common in large parts of the world and has been demonstrated to lead to high levels of exposure to fine particulate matter and gases such as carbon monoxide. Such exposures have been shown to be linked to increased risk of respiratory and cardiovascular illness and may contribute to as many as 2 million early deaths globally per annum. There are a range of interventions currently being trialled including improved cookstoves and changes in fuel type. Small household biogas digesters are now available and are likely to have the capacity to significantly reduce household concentrations of respirable particulate matter and carbon monoxide. Although no direct evidence is available, comparison with households using Liquified Petroleum Gas (LPG) would suggest that improvements in indoor air quality may be of the order of 66–99%. Such improvements in households taking up this technology could bring respiratory and cardiovascular health benefits of the order of 20–25% reduction in risk of a wide range of diseases. There is a need for well-designed longitudinal studies to examine the impact of introducing biogas digesters to communities on both exposure to indoor air pollution and the health effects this may bring.

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