Isocyanic acid and its possible link to smoke-related health effects

May 19, 2011 · 1 comment

Researchers have now pinpointed a compound common in disparate forms of smoke that might explain some of the frequent ills associated with it. The findings are described in a new paper published online May 16 in the Proceedings of the National Academy of Sciences.

“We found isocyanic acid in a number of places, from air in downtown Los Angeles and air downwind of a Colorado wildfire, to cigarette smoke,” Jim Roberts, a chemist at NOAA’s Earth System Research Laboratory and co-author of the new study, said in a prepared statement. Isocyanic acid—abbreviated as HNCO—is a substance known to act in the body along disease-related pathways through a process known as protein carbamylation.

Although the new study did not look specifically at how ambient HNCO might be affecting people’s health, the researchers note that it makes sense that it would have easy access into the human body’s innards. “It dissolves readily in water, which means that humans can be exposed directly if it gets into eyes or lungs,” Roberts said.

This is the first time that HNCO had been measured in ambient air, the researchers report. To get specific readings, the team used a negative-ion proton-transfer chemical ionization mass spectrometer.

In addition to these significant concerns for people living here in the U.S., the risks might be greater for the many people in the developing world who use open-fire stoves, or cook stoves. A lab test of burning biomass produced concentrations of 600 parts per billion when measured close to the flames. “There are literally billions of people in the world who burn biomass for cooking and heating,” Roberts said. “If these indoor fires release similar levels of isocyanic acid as the fires we studied in the laboratories, families could be exposed to high levels of the chemical.”

The team underscored the need for further research into how HNCO might be affecting human health—especially with the prevalence of biomass-based stoves and the prediction for more wild fires due to climate change. “We may be facing a future of higher amounts of HNCO in the atmosphere,” Roberts said. And although that might be bad news for human health, Roberts noted that at least “it is fortunate that now we can measure it.”

Source – Scientific American

Uganda Stoves Saving on Fuel to Save Forests

May 16, 2011 · 0 comments

KAMPALA, May 16, 2011 (IPS) – Carbon finance is putting new and efficient charcoal stoves into hundreds of thousands of kitchens in Uganda – reducing charcoal use and protecting forests as well as saving money for poor households.

The mouthwatering smell of stewing beef is drifting through the congested streets of Nkere, on the outskirts of Kampala. It’s coming from Susan Nanpiima’s newly-acquired stove.

“You can’t compare this stove to the ones I have used in the past. It uses so little charcoal,” says Nanpiima, seated on the veranda of her one-room home. “I had been getting through a [60 kilo] sack of charcoal every month, but the sack I bought this month is not even half empty.”

Nanpiima’s new and efficient stove comes from a factory right in the midst of this densely-populated part of the city. Ugastove – Uganda Stove Manufacturers Ltd – claims to have already reached over 300,000 families in Uganda’s major towns and plans to ramp up production to 20,000 stoves a year.

The stoves have a thick clay lining that holds in the heat of burning charcoal and cooks food more efficiently. According to Ugastove chief executive officer Mohamed Kawere, the stoves use only half as much fuel as conventional stoves, saving a family the equivalent of 80 dollars a year.

Burning up the future

More than 98 percent of Ugandans rely on charcoal or firewood as an energy source. Producing so much charcoal has taken a massive toll on the country’s forests. Uganda’s National Environment Authority says the country has lost two-thirds of its forests in the last 20 years and would lose it all by 2050 at present rates of destruction. The trees are cut down and then burned in inefficient kilns, releasing large amounts of methane, a greenhouse gas shown to be 20 times more potent than carbon dioxide in global warming terms.

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Burning issues: tackling indoor air pollution

May 16, 2011 · 1 comment

The Lancet, Volume 377, Issue 9777, Pages 1559 – 1560, 7 May 201

Burning issues: tackling indoor air pollution

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Talha Khan Burki

“The best vaccine for pneumonia is ensuring kids don’t breathe dirty air at home”, asserts Maria Neira, director of WHO’s Public Health and the Environment Department, referring to just one of the many health problems arising from indoor air pollution.

According to WHO, 2 million people die as a result of the smoke generated by open fires or crude stoves within their homes every year. Indoor air pollution has been definitively linked to lung cancer, chronic obstructive pulmonary disease, and pneumonia, the risk of which is doubled by exposure to indoor smoke. More than 900 000 people die from pneumonia caused by indoor air pollution every year. 500 million households worldwide—roughly 3 billion people—rely on solid fuels, such as wood, animal dung, or coal, for cooking and heating. These fuels are usually burned in a rudimentary stove, or in a traditional open fire. It need not be a problem, at least in terms of health. But only assuming the fuel is completely combusted—wood must be dry, and the stove must work efficiently—and there is plenty of ventilation, a spacious chimney, or a sizeable window. In those places where the use of solid fuels prevails, however, these conditions rarely apply, and the consequences can be severe.

Moreover, research into the subject began fairly recently, and is far from comprehensive. The pollutants carried by indoor smoke can fill households to levels well in excess of WHO guidelines for indoor air quality. Emerging evidence implicates indoor smoke in the development of tuberculosis, low birthweight and perinatal mortality, asthma, cataracts, and cardiovascular disease. Some of this might well be taken into account when WHO updates its global burden of disease data later this year. Even the numbers for lung cancer might be underestimated: the percentage refers only to those cases attributable to the burning of coal—predominantly in China—which doubles the risk of lung cancer, but when biomass fuels (wood, for instance) burn, they also emit carcinogens.

Additionally, when family members—usually women—are despatched to gather fuel, they risk snakebite, broken bones, and backache. It can take several hours to accumulate adequate material for a household’s needs, especially if the stove does not work very well, time which cannot be devoted to, say, education.

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Assessment of DNA damage of Indian women chronically exposed to biomass smoke

May 13, 2011 · 0 comments

Int J Hyg Environ Health. 2011 May 5.

Assessment of DNA damage by comet assay and fast halo assay in buccal epithelial cells of Indian women chronically exposed to biomass smoke.

Mondal NK, Bhattacharya P, Ray MR.

Department of Experimental Hematology, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata 700026, India.

Genotoxicity of indoor air pollution from biomass burning was evaluated in buccal epithelial cells (BECs) of 85 pre-menopausal Indian women who were engaged in cooking with biomass (wood, dung, crop residues) and 76 age-matched control women
who were cooking with cleaner fuel liquefied petroleum gas (LPG). DNA damage was evaluated by comet assay and fast halo assay (FHA). The concentrations of particulate matter with aerodynamic diameters of less than 10 and 2.5μm (PM(10) and PM(2.5), respectively) in indoor air were measured by real-time aerosol monitor. Generation of reactive oxygen species (ROS) was measured by flow cytometry and the level of superoxide dismutase (SOD) by spectrophotometry.

Compared with control, BEC of biomass users illustrated 2.6-times higher comet tail % DNA (32.2 vs. 12.4, p<0.001), 2.7-times greater comet tail length (37.8μm vs. 14.2μm, p<0.001) and 2.2-times more olive tail moment (7.1 vs. 3.2, p<0.001),
suggesting marked increase in DNA damage. FHA also showed 5-times more mean nuclear diffusion factor (9.2 vs. 1.8, p<0.0001) in BEC of biomass users, confirming sharp rise in DNA single strand breaks. Airway cells of biomass-using women showed 51% rise in ROS generation but 28% reduction in SOD, suggesting oxidative stress in the airways.

Indoor air of biomass-using households had 3-times more PM(10) and PM(2.5) than LPG-using families, and DNA damage showed
positive association with PM(10) and PM(2.5) levels controlling education, kitchen location and family income as potential confounders. In summary, chronic inhalation of biomass smoke elicits oxidative stress and extensive DNA damage in
BEC.

US Dept of Energy – Biomass cookstoves summary report, May 2011

May 10, 2011 · 0 comments

US Dept of Energy – Biomass cookstoves summary report, May 2011.

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The U.S. Department of Energy’s (DOE’s) offices of Policy and International Affairs (PI) and Energy Efficiency and Renewable Energy (EERE) held a meeting on January 11–12, 2011, to gather input on a proposed DOE research and development (R&D) program to address the technical barriers to cleaner and more fuel-efficient biomass cookstoves.

The nearly 80 participants at the meeting evaluated DOE’s proposed goals, identified the major research challenges, and defined pathways toward technology solutions.

Key recommendations from meeting participants include the following:

  • At least 90% emissions reductions and 50% fuel savings are appropriate initial targets. A limited number of improved stoves already meet these targets, but additional technical research and development can lower costs and make these successes more widespread for a range of laboratory and field conditions and for a variety of unprocessed and processed fuels. Measuring progress toward these targets will require clear definitions of baseline performance or absolute targets for emissions and efficiency based on health and climate impacts. Several participants suggested that these targets should be more aggressive to maximize health and climate benefits.
  • No single solution will adequately address the cookstove challenge. Multiple stove designs will be needed to accommodate a variety of cooking practices, fuels, and levels of affordability. DOE will need to balance efforts to improve existing stoves with research that could impact a range of stove types and regions. Participants presented a variety of views on how to balance near- and long-term gains.
  • Technical R&D should guide and be guided by field research and implementation programs.
  • Technical research should be informed by health studies on appropriate emissions levels and by social science and field research on cooking practices. At the same time, new technical insights can be used to stimulate new stove designs, improve existing stoves, and support dissemination and testing efforts. Design guides and tools can make these insights accessible and relevant for downstream efforts. At every stage, laboratory and field work should be integrated into an iterative cycle of feedback and improvement.
  • The cost and performance tradeoffs associated with the use of processed versus unprocessed fuels should be explored. While processed fuels can improve stove emissions and efficiency, the processing adds additional costs, and these fuels may require a fuel distribution system. Simultaneous efforts are needed to reduce the logistical barriers and costs of processed fuels and to improve stove performance with unprocessed fuels.

USAID – Emissions of Greenhouse Pollutants from Rocket and Traditional Biomass Cooking Stoves in Uganda

May 5, 2011 · 0 comments

In-Home Emissions of Greenhouse Pollutants from Rocket and Traditional Biomass Cooking Stoves in Uganda, April 2o11.

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USAID.

In July 2010, Berkeley Air Monitoring Group, in collaboration with Columbia University’s Earth Institute and the University of Illinois at Urbana-Champaign, collected cookstove emissions data in Ruhiira, Uganda, one of the Millennium Village project sites. This project was a highly collaborative effort made possible by funding from the United States Agency for International Development, with the goal of better understanding the relationship between climate change and improved stoves.

The resulting data provide the first field assessment in Africa of a stove intervention’s impact on greenhouse gas and health damaging pollutant emissions, which are defined as the quantity or rate of pollutants emitted directly from the stove as a result of combusting fuels. It is important to distinguish this type of field-based emissions study from health-focused assessments of household air pollution concentrations, which previously have been conducted in Africa, albeit not extensively.

A total of 35 cooking events were sampled in 10 homes. Each home was sampled when the cook was using a traditional openfire (hereafter referred to as a traditional stove) and again when she was using a StoveTec rocket stove to allow direct comparison of samples. Cooking events were uncontrolled, with the participants asked to cook their regular meals and use their normal fuelwood and fire tending practices. The StoveTec rocket stove is a well characterized, mass-manufactured stove that was disseminated in this Millennium Village 5-12 months prior to the emissions study.

The impact of asthma and COPD in sub-Saharan Africa

May 4, 2011 · 0 comments

Prim Care Respir J. 2011 Apr 20.

The impact of asthma and COPD in sub-Saharan Africa.

van Gemert F, van der Molen T, Jones R, Chavannes N. Department of General Practice, University Medical Center Groningen, Groningen, The Netherlands.

Many countries in sub-Saharan Africa have the highest risk of developing chronic diseases and are the least able to cope with them.

AIM: To assess the current knowledge of the prevalence and impact of asthma and chronic obstructive pulmonary disease (COPD) in sub- Saharan Africa.

METHODS:A literature search was conducted using Medline (1995-2010) and Google Scholar.

RESULTS: Eleven studies of the prevalence of asthma in sub-Saharan Africa were identified, all of which showed a consistent increase, particularly in urban regions. The data on asthma show a wide variation (5.7-20.3%), with the highest prevalence in ‘westernised’ urban areas. Only two studies of the prevalence of COPD in sub-Saharan Africa have been performed. Nevertheless, COPD has become an increasing health problem in sub-Saharan Africa due to tobacco smoking and exposure to biomass fuels. In most countries of sub-Saharan Africa, 90% of the rural households depend on biomass fuel for cooking and heating, affecting young children (acute lower respiratory infections) and women (COPD). This is the cause of significant mortality and morbidity in the region.

CONCLUSIONS: Asthma and COPD in sub-Saharan Africa are under-recognised, under-diagnosed, under-treated, and insufficiently prevented. A major priority is to increase the awareness of asthma and COPD and their risk factors, particularly the damage caused by biomass fuel. Surveys are needed to provide local healthcare workers with the possibility of controlling asthma and COPD.

Variation in indoor levels of PAHs from burning various biomass types

May 4, 2011 · 0 comments

Environ Pollut. 2011 Apr 16.

Variation in indoor levels of polycyclic aromatic hydrocarbons from burning various biomass types in the traditional grass-roofed households in Western Kenya.

Lisouza FA,, et al. Department of Chemistry, Maseno University, P.O. Box 333, Maseno 40105, Kenya.

Biomass burning as fuel in the traditional grass-roofed rural households of Western Province of Kenya in open fire places, in poorly ventilated conditions, lead to accumulation of soot under the roofs. This study characterized and quantified the polycyclic aromatic hydrocarbons (PAHs) in accumulated soot in these households and determined the variation in PAHs concentrations with fuel biomass type.

Soot samples collected from the households were extracted, cleaned and analysed by gas chromatography. The PAHs were identified using retention times, verified by gas chromatographic mass spectral analysis and quantified from peak area responses using the internal standard method. The PAHs levels significantly varied (P≤0.05) with biomass type in the order: dung≥indigenous trees≥exotic trees≥shrubs and crop residues. Use of dung and wood from indigenous trees as fuel should be discouraged since they are higher emitters (P≤0.05) of carcinogenic PAHs.

Rwanda: Minister Promotes Use of Energy-Efficient Stoves

May 4, 2011 · 0 comments

May 1, 2011 — In order to enhance sustainable use of forest resources for energy, local communities have been advised to adopt the use of efficient wood stoves.

The call was made, yesterday, by the State Minister in charge of Water and Energy, Eng. Coletha Ruhamya, in Nyarugati Cell, Nyamata Sector in Bugesera District.

The Minister and other officials from the Ministry of Infrastructure (MININFRA) were taking part in the monthly community work (Umuganda).

Later, Practical Action Consulting East Africa, a company hired by MININFRA to train local people how to make the stoves, demonstrated how they are used.

Ruhamya noted that the stoves were environmentally friendly.

“We should adopt these stoves that consume little firewood in order to sustain our environment,” she said.

The stoves that are nicknamed Canamuce (use less energy) and Zigama (save), are made from mud.

Only one piece of firewood is needed to cook food as it takes 45 minutes for the wood to be consumed.

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Emission of oxygenated polycyclic aromatic hydrocarbons

April 29, 2011 · 0 comments

Environ Sci Technol. 2011 Apr 15;45(8):3459-65. 

Emission of oxygenated polycyclic aromatic hydrocarbons from indoor solid fuel combustion.

Shen G, et al.

Indoor solid fuel combustion is a dominant source of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) and the latter are believed to be more toxic than the former. However, there is limited quantitative information on the emissions of OPAHs from solid fuel combustion. In this study, emission factors of OPAHs (EF(OPAH)) for nine commonly used crop residues and five coals burnt in typical residential stoves widely used in rural China were measured under simulated kitchen conditions.

The total EF(OPAH) ranged from 2.8 ± 0.2 to 8.1 ± 2.2 mg/kg for tested crop residues and from 0.043 to 71 mg/kg for various coals and 9-fluorenone was the most abundant species. The EF(OPAH) for indoor crop residue burning were 1-2 orders of magnitude higher than those from open burning, and they were affected by fuel properties and combustion conditions, like moisture and combustion efficiency. For both crop residues and coals, significantly positive correlations were found between EFs for the individual OPAHs and the parent PAHs. An oxygenation rate, R(o), was defined as the ratio of the EFs between the oxygenated and parent PAH species to describe the formation potential of OPAHs.

For the studied OPAH/PAH pairs, mean R(o) values were 0.16-0.89 for crop residues and 0.03-0.25 for coals. R(o) for crop residues burned in the cooking stove were much higher than those for open burning and much lower than those in ambient air, indicating the influence of secondary formation of OPAH and loss of PAHs. In comparison with parent PAHs, OPAHs showed a higher tendency to be associated with particulate matter (PM), especially fine PM, and the dominate size ranges were 0.7-2.1 μm for crop residues and high caking coals and <0.7 μm for the tested low caking briquettes.

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