WorldStove/Italy

August 19, 2009 · 0 comments

WorldStove is committed to creating useful and innovative carbon negative products that increase quality of life for individuals and households around the globe.

We recognize that in order to make a difference we must think beyond building efficient stoves. It is necessary to have a strategy promoting:

• Adaptation of fuel efficient ways of cooking, heating and power generation;
• Creation of economic opportunities for participating households; and
• Development of individual and community capacity to continue to innovate on an environmentally friendly trajectory.

Currently all of our products are manufactured in Italy and in local communities in developing nations where the LuciaStove technology is being used. We do this to ensure that our method of production remains in keeping with our values. Often, a lower price indicates substandard working conditions, an unhealthy working environment and inferior craftsmanship. By working with local manufacturers in Italy and in the communities we directly serve, we are more certain that the means of production are not contributing to the growth of the complex system of poverty, but working in tandem with the technology of our stoves to change it.

WorldStove website – http://worldstove.com

Statements from Biochar Conference

August 19, 2009 · 0 comments

Interesting Statements from Biochar Conference, from Climate Today

– Minimal data available suggest biochar has 500-1000 year half life.

– Biochar has multiple benefits- it can mitigate climate change, be a powerful waste management tool, provide energy, and improve soils. All these are powerful, but sometimes multiple benefits confuse people about what biochar really is and who should claim it. Thus far, it tends to get lost in policy discussions. Biochar also can reduce the health-damaging effects of home cook stoves used in developing countries and reduce deforestation caused by using wood for cook stoves.

Biochar can be created through different methods and different feedstocks and thus can be adapted to provide benefits to different kinds of soils as tailored chars. One needs to do some research to determine what is best for particular soils. Even alkaline soils can benefit when done appropriately. Biochar can be treated once made to have specific qualities.

– A wide variety of projects are going on around the world- 20 tons a week in South Africa from macadamia shells, 14 tons a week in British Columbia, a new manufacturing plant in China making small stoves, simple cooking stoves from cookie tins designed for herdsmen in Manchuria, and a new plant in Dunlap, Tennessee which will have the capacity to create 8,000 lbs an hour.

– Ties are being built with international programs fighting desertification because biochar can help restore recently destroyed drylands. See http://www.unccd.int/

– The National Labs in Italy want to work on desertification and were offered 2 choices- a very big scale project or “10,000 stoves.” Recognizing the barriers to transporting biomass long distances to a big plant, they chose the stoves! Four African countries are now creating the Lucia stove, Lucia stove invented by entrepreneur Nat Mulcahy of WorldStove with local manufacturing.

Read More on Biochar Conference

A bibliography on mosquito coil smoke and indoor air pollution

August 19, 2009 · 0 comments

Below are citations and abstracts to 5 published studies on the health impacts of smoke from mosquito coils. Entries are arranged by publication date.

1: Inhal Toxicol. 2009 Aug;21(10):837-48.

Particles emitted from indoor combustion sources: size distribution measurement and chemical analysis.

Roy AA, Baxla SP, Gupta T, Bandyopadhyaya R, Tripathi SN.

Department of Civil Engineering, Environmental Engineering Programme, Indian Institute of Technology Kanpur, Kanpur, India.

This study is primarily focused toward measuring the particle size distribution and chemical analysis of particulate matter that originates from combustion sources typically found in Indian urban homes. Four such sources were selected: cigarette, incense stick, mosquito coil, and dhoop, the latter being actually a thick form of incense stick. Altogether, seven of the most popular brands available in the Indian market were tested. Particle size distribution in the smoke was measured using a scanning mobility particle sizer, using both long and nano forms of differential mobility analyzer (DMA), with readings averaged from four to six runs. The measurable particle size range of the nano DMA was 4.6 nm to 157.8 nm, whereas that of the long DMA was 15.7 nm to 637.8 nm. Therefore, readings obtained from the long and the nano DMA were compared for different brands as well as for different sources. An overlap was seen in the readings in the common range of measurement. The lowest value of peak concentration was seen for one brand of incense stick (0.9 x 10(6) cm(-3)), whereas the highest (7.1 x 10(6) cm(-3)) was seen for the dhoop. Generally, these sources showed a peak between 140 and 170 nm; however, 2 incense stick brands showed peaks at 79 nm and 89 nm. The dhoop showed results much different from the rest of the sources, with a mode at around 240 nm. Chemical analysis in terms of three heavy metals (cadmium, zinc, and lead) was performed using graphite tube atomizer and flame-atomic absorption spectrophotometer. Calculations were made to assess the expected cancer and noncancer risks, using published toxicity potentials for these three heavy metals. Our calculations revealed that all the sources showed lead concentrations much below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) level. One of the two mosquito coil brands (M(2)) showed cadmium concentrations two times higher than the California Environmental Protection Agency (Cal EPA) reference exposure level (REL). The latter also showed the highest carcinogenic risks of 350 people per million population. The amount of zinc obtained from the sources, however, was found to be quite below the standard limits, implying no risk in terms of zinc.

2: J Epidemiol. 2008;18(1):19-25.

Exposure to mosquito coil smoke may be a risk factor for lung cancer in Taiwan.

Chen SC, Wong RH, Shiu LJ, Chiou MC, Lee H.

Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.

BACKGROUND: About 50% of lung cancer deaths in Taiwan are not related to cigarette smoking. Environmental exposure may play a role in lung cancer risk. Taiwanese households frequently burn mosquito coil at home to repel mosquitoes. The aim of this hospital-based case-control study was to determine whether exposure to mosquito coil smoke is a risk for lung cancer.

METHODS: Questionnaires were administered to 147 primary lung cancer patients and 400 potential controls to ascertain demographic data, occupation, lifestyle data, indoor environmental exposures (including habits of cigarette smoking, cooking methods, incense burning at home, and exposure to mosquito coil smoke ), as well as family history of cancer and detailed medical history.

RESULTS: Mosquito coil smoke exposure was more frequent in lung cancer patients than controls (38.1% vs.17.8%; p<0.01). Risk of lung cancer was significantly higher in frequent burners of mosquito coils (more than 3 times [days] per week) than nonburners (adjusted odds ratio = 3.78; 95% confidence interval: 1.55-6.90). Those who seldom burned mosquito coils (less than 3 times per week) also had a significantly higher risk of lung cancer (adjusted odds ratio = 2.67; 95% confidence interval: 1.60-4.50).

CONCLUSION: Exposure to mosquito coil smoke may be a risk factor for development of lung cancer.

3: J Appl Toxicol. 2006 May-Jun;26(3):279-92.

Mosquito coil smoke inhalation toxicity. Part II: subchronic nose-only inhalation study in eats.

Pauluhn J, Mohr U.

Institute of Toxicology, Bayer HealthCare, Wuppertal, Germany. juergen.pauluhn@bayerhealthcare.com

This paper addresses the results of a subchronic inhalation study in rats exposed to the smoke of burning mosquito coils manufactured in Indonesia. The objective of the study was a comparative assessment of different mosquito coils, including a blank coil, utilizing the OECD No. 413 testing paradigm, however, with the
focus on hazard identification at a single maximum tolerated exposure concentration rather than concentration-response. Groups of rats were nose-only exposed 6 h a day, 5 days a week for 13 weeks to an average particulate concentration of 30 mg m(-3) from either blank coils or coils that contain the insecticidal ingredient transfluthrin. Nose-only air-exposed rats served as a control. A range of markers of exposure have been characterized to define the most critical exposure metrics with regard to total suspended particulate matter (TSP) and potentially noxious volatile products of combustion. During the course of the exposure period the smoke-exposed rats showed clinical signs suggestive of acute upper respiratory tract sensory irritation. Body weights were mildly affected in the male rats, but food and water consumption were indistinguishable amongst the groups. Carboxyhemoglobin concentrations were approximately 11% throughout the exposure period in smoke exposed rats. Hematology, clinical pathology and urinalysis as well as the analysis of organ weights and histopathology of extrapulmonary organs and the lung did not reveal any evidence of adverse systemic or local effects, whereas in the anterior region of the nasal passages, and to some extent also in the larynx, irritant-related changes typical for water-soluble upper respiratory irritants were found. Markers of pulmonary inflammation or increased phagocytosis and lysosomal activity in bronchoalveolar lavage were indistinguishable amongst the groups. gamma-Glutamyltranspeptidase was significantly increased in the smoke exposure groups, which is taken as
indirect evidence of an adaptive upregulation of the pulmonary antioxidant glutathione. In rats exposed to mosquito coil smoke containing transfluthrin, a somewhat increased frequency of alveolar macrophages with foamy appearance was identified through cytodifferentiation but not histopathology compared with the blank coil. From the specific staining of intracellular phospholipids, the notion is supported that this equivocal finding is probably related to an increased uptake of modified pulmonary surfactant rather than increased engulfment of insoluble particulate matter since pigmentation or clustering or intra-alveolar cells did not occur. The results of this subchronic inhalation study support the conclusion that smoke from burning mosquito coils in concentrations high enough to elicit acute upper respiratory tract irritation due to the presence of common wood-combustion products (such as aliphatic aldehydes) did not cause any adverse
effect in the lower respiratory tract or any other extrapulmonary organ. The most critical mode of action is related to acute and readily perceivable sensory irritation. The concentration tested was estimated to be well above that occurring under more realistic exposure conditions. Therefore, overnight exposure to the smoke from burning mosquito coils (manufactured in Indonesia) is unlikely to be associated with any unreasonable health risk.

4: J Appl Toxicol. 2006 May-Jun;26(3):269-78.

Mosquito coil smoke inhalation toxicity. Part I: validation of test approach and acute inhalation toxicity.

Pauluhn J.

Institute of Toxicology, Bayer HealthCare, Wuppertal, Germany. juergen.pauluhn@bayerhealthcare.com

Burning mosquito coils indoors to repel mosquitoes is a common practice in many households in tropical countries. The evaluation and assessment of the inhalation toxicity of smoke emitted from mosquito coils appear to be particularly challenging due to the complex nature of this type of exposure atmosphere. The potential health implications of the gases, volatile agents and particulate matter emitted from burning coils or incense have frequently been addressed; however, state-of-the-art inhalation toxicity studies are scarce. The focus of this paper was comparatively to evaluate and assess the appropriateness and practical constraints of the whole-body versus the nose-only mode of exposure for inhalation toxicity studies with burning mosquito coils. With regard to the controlled exposure of laboratory animals to complex smoke atmospheres the nose-only mode of exposure had distinct advantages over the whole-body exposure,
which included a rapid attainment of the inhalation chamber steady state, minimization of particle coagulation and uncontrolled adsorption of condensate onto the chamber surfaces. While in whole-body chambers a different kinetic behaviour of volatile and particulate constituents was found which caused
inhomogeneous, i.e. artificially enriched atmospheres with volatile components at the expense of aerosols, the nose-only mode of exposure provided maximum exposure intensities without losses of the particulate phase of the exposure atmosphere. Collectively, the results obtained support the conclusion that the dynamic
nose-only mode of exposure is experimentally superior to the quasistatic whole-body exposure mode which provides the least control over exposure atmospheres and the outcome highly contingent on selected experimental factors. Acute inhalation toxicity studies in rats suggest that the most critical metrics of exposure are apparently related to (semi)volatile upper respiratory tract sensory irritants, whilst the asphyxic component, carbon monoxide, plays a role only at overtly irritant exposure levels. However, this study was conducted at exposure concentrations much higher than encountered by people in residential settings and the effects observed under these conditions may not be relevant to hazards from exposures at common use levels. Neither an acute 8 h exposure of rats nor the 1 h sensory irritation study in mice and rats provided experimental evidence that irritant particle-related effects had occurred in the lower respiratory tract. In summary, the protocols devised evaluate and assess the acute inhalation toxicity of mosquito coil smoke demonstrating that the nose-only mode of exposure of rats to the smoke of mosquito coils is suitable to assess the toxic potency of different coils. The nose-only mode has clear advantages over the whole-body exposure mode. The inhalation studies conducted show unequivocally that acute toxic effects are difficult to produce with this type of product even under rigorous testing conditions.

5: Environ Health Perspect. 2003 Sep;111(12):1454-60.

Mosquito coil emissions and health implications.

Liu W, Zhang J, Hashim JH, Jalaludin J, Hashim Z, Goldstein BD.

Joint Graduate Program in Exposure Measurement and Assessment, University of Medicine and Dentistry of New Jersey (UMDNJ) and Rutgers University, 170 Frelinghuysen Road, Piscataway, NJ 08854, USA.

Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured
emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.

Malawi – Biomass Fuel Use and Indoor Air Pollution

August 17, 2009 · 0 comments

Occup Environ Med. 2009 Aug 10.

Biomass Fuel Use and Indoor Air Pollution in Homes in Malawi.

Fullerton DG, Semple S, Kalambo F, Malamba R, Suseno A, Henderson G, Ayres JG, Gordon SB.

Malawi-Liverpool-Wellcome Clinical Research Laboratories, Universities of Malawi and Liverpool, Malawi.

BACKGROUND: Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes.

METHODS: Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 hour period. Four different devices were used (one gravimetric device, two photometric devices (Sidepak and University of California Berkley), and a carbon monoxide (HOBO) monitor). Gravimetric samples were
analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socio-economic status were collected by questionnaire.

RESULTS: Respirable dust levels in both the urban and rural environment were high with the mean 24h average levels being 226microg/m3 (SD 206microg/m3). Data from real-time instruments indicated respirable dust concentrations were >250microg/m3 for over 1 hour per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared to rural homes (6.14ppm vs 1.87ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes.

CONCLUSIONS: Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.

WHO, Aug 2009 Pneumonia Fact Sheet

August 12, 2009 · 0 comments

Fact sheet N°331, August 2009

Pneumonia

Key facts

Pneumonia is the leading cause of death in children worldwide.
Pneumonia kills an estimated 1.8 million children every year – more than AIDS, malaria and measles combined.
Pneumonia can be caused by viruses, bacteria or fungi.
Pneumonia can be prevented by immunization, adequate nutrition and by addressing environmental factors.
Pneumonia can be treated with antibiotics, but less than 20% of children with pneumonia receive the antibiotics they need.

Pneumonia is a form of acute respiratory infection that affects the lungs. The lungs are made up of small sacs called alveoli, which fill with air when a healthy person breathes. When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake.

Pneumonia is the single largest cause of death in children worldwide. Every year, it kills an estimated 1.8 million children under the age of five years, accounting for 20% of all deaths of children under five years old worldwide. There are some 155 million cases of childhood pneumonia every year in the world. Pneumonia affects children and families everywhere, but is most prevalent in South Asia and sub-Saharan Africa. It can be prevented with simple interventions, and treated with low-cost, low-tech medication and care.

Causes

Pneumonia is caused by a number of infectious agents, including viruses, bacteria and fungi. The most common are:

– Streptococcus pneumonia – the most common cause of bacterial pneumonia in children;
– Haemophilus influenzae type b (Hib) – the second most common cause of bacterial pneumonia;
– Pneumocystis jiroveci (PJP) – a fungus and major cause of pneumonia in children under six months of age with HIV/AIDS, responsible for at least one quarter of all deaths in HIV-positive infants.

Transmission

Pneumonia can be spread in a number of ways. The viruses and bacteria that are commonly found in a child’s nose or throat, can infect the lungs if they are inhaled. They may also spread via air-borne droplets from a cough or sneeze. In addition, pneumonia may spread through blood, especially during and shortly after birth. More research needs to be done on the different pathogens causing pneumonia and the ways they are transmitted, as this has critical importance for treatment and prevention.

Symptoms

The symptoms of viral and bacterial pneumonia are similar. However, the symptoms of viral pneumonia may be more numerous than the symptoms of bacterial pneumonia.

The symptoms of pneumonia include:

– rapid or difficult breathing
– cough
– fever
– chills
– loss of appetite
– wheezing (more common in viral infections).

When pneumonia becomes severe, children may experience lower chest wall indrawing, where their chests move in or retract during inhalation (in a healthy person, the chest expands during inhalation). Infants may be unable to feed or drink and may also experience unconsciousness, hypothermia and convulsions.

Risk factors

While most healthy children can fight the infection with their natural defences, children whose immune systems are compromised are at higher risk of developing pneumonia. A child’s immune system may be weakened by malnutrition or undernourishment, especially in infants who are not exclusively breastfed.

Pre-existing illnesses, such as symptomatic HIV infections and measles, also increase a child’s risk of contracting pneumonia.

The following environmental factors also increase a child’s susceptibility to pneumonia:

– living in crowded homes
– indoor air pollution caused by cooking and heating with biomass fuels (such as wood or dung)
– parental smoking.

Treatment

Pneumonia can be treated with antibiotics. These are usually prescribed at a health centre or hospital, but the vast majority of cases of childhood pneumonia can be administered effectively within the home. Hospitalization is recommended in infants aged two months and younger, and also in very severe cases.

Prevention

Preventing pneumonia in children is an essential component of a strategy to reduce child mortality. Immunization against Hib, pneumococcus, measles and whooping cough (pertussis) is the most effective way to prevent pneumonia.

Adequate nutrition is key to improving children’s natural defences, starting with exclusive breastfeeding for the first six months of life. This is also effective in preventing pneumonia and reducing the length of the illness.

Addressing environmental factors such as indoor air pollution (by providing affordable clean indoor stoves, for example) and encouraging good hygiene in crowded homes also reduces the number of children who fall ill with pneumonia.

In children infected with HIV, the antibiotic cotrimoxazole is given daily to decrease the risk of contracting pneumonia.

Economic costs

Research has shown that prevention and proper treatment of pneumonia could avert one million deaths in children every year. With proper treatment alone, 600 000 deaths could be avoided.

Globally, the cost of treating every child with pneumonia is estimated at around US$ 600 million. Treating pneumonia in South Asia and sub-Saharan Africa – which account for 85% of deaths – would cost a third of this total, at around US$ 200 million. The price includes the antibiotics themselves, as well as the cost of training health workers, which strengthens the health systems as a whole.

WHO response – Read More

Indoor charcoal smoke and acute respiratory infections in young children in the Dominican Republic.

August 11, 2009 · 0 comments

Am J Epidemiol. 2009 Mar 1;169(5):572-80.

Indoor charcoal smoke and acute respiratory infections in young children in the Dominican Republic.

Bautista LE, Correa A, Baumgartner J, Breysse P, Matanoski GM.

Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA. lebautista@wisc.edu

The authors investigated the effect of charcoal smoke exposure on risks of acute upper and lower respiratory infection (AURI and ALRI) among children under age 18 months in Santo Domingo, Dominican Republic (1991-1992). Children living in households using charcoal for cooking (exposed, n = 201) were age-matched to children living in households using propane gas (nonexposed, n = 214) and were followed for 1 year or until 2 years of age. Fuel use and new episodes of AURI and ALRI were ascertained biweekly through interviews and medical examinations. Household indoor-air concentration of respirable particulate matter (RPM) was measured in a sample of follow-up visits. Incidences of AURI and ALRI were 4.4 and 1.4 episodes/child-year, respectively. After adjustment for other risk factors, exposed children had no significant increase in risk of AURI but were 1.56 times (95% confidence interval: 1.23, 1.97) more likely to develop ALRI. RPM concentrations were higher in charcoal-using households (27.9 microg/m(3) vs. 17.6 microg/m(3)), and ALRI risk increased with RPM exposure (10-microg/m(3) increment: odds ratio = 1.17, 95% confidence interval: 1.02, 1.34). Exposure to charcoal smoke increases the risk of ALRI in young children, an effect that is probably mediated by RPM. Reducing charcoal smoke exposure may lower the burden of ALRI among children in this population.

Solid fuel use and cooking practices as a major risk factor for ALRI mortality among African children.

August 11, 2009 · 0 comments

J Epidemiol Community Health. 2009 May 28.

Solid fuel use and cooking practices as a major risk factor for ALRI mortality among African children.

Rehfuess EA, Tzala L, Best N, Briggs DJ, Joffe M.

BACKGROUND: Almost half of global child deaths due to acute lower respiratory infections (ALRI) occur in sub-Saharan Africa, where three quarters of the population cook with solid fuels. This study aims to quantify the impact of fuel type and cooking practices on childhood ALRI mortality in Africa, and to explore implications for public health interventions.

METHODS: Early-release World Health Survey data for the year 2003 were pooled for sixteen African countries. Among 32,620 children born during the last ten years, 1,455 (4.46%) were reported to have died prior to their fifth birthday. Survival analysis was used to examine the impact of different cooking-related parameters on ALRI mortality, defined as cough accompanied by rapid breathing or chest indrawing based on maternal recall of symptoms prior to death.

RESULTS: Solid fuel use increases the risk of ALRI mortality with an adjusted hazard ratio of 2.35 (1.22; 4.52); this association grows stronger with increasing outcome specificity. Differences between households burning solid fuels on a well-ventilated stove and households relying on cleaner fuels are limited. In contrast, cooking with solid fuels in the absence of a chimney or hood is associated with an adjusted hazard ratio of 2.68 (1.38; 5.23). Outdoor cooking is less harmful than indoor cooking but, overall, stove ventilation emerges as a more significant determinant of ALRI mortality.

CONCLUSIONS: This study shows substantial differences in ALRI mortality risk among African children in relation to cooking practices, and suggests that stove ventilation may be an important means of reducing indoor air pollution.

Indoor air pollution from solid biomass fuels combustion in Tibet

August 11, 2009 · 1 comment

Indoor Air. 2009 Jun;19(3):198-205.

Indoor air pollution from solid biomass fuels combustion in rural agricultural area of Tibet, China.

Gao X, Yu Q, Gu Q, Chen Y, Ding K, Zhu J, Chen L.

Department of Environmental Science and Engineering, Fudan University, Shanghai, China.

In this study, we are trying to investigate the indoor air pollution and to estimate the residents’ pollution exposure reduction of energy altering in rural Tibet. Daily PM(2.5) monitoring was conducted in indoor microenvironments like kitchen, living-room, bedroom, and yard in rural Tibet from December 2006 to
March 2007. For kitchen air pollution, impact of two fuel types, methane and solid biomass fuels (SBFs), were compared. Questionnaire survey on the domestic energy pattern and residents’ daily activity pattern was performed in Zha-nang County. Daily average PM(2.5) concentrations in kitchen, living-room, bedroom, and yard were 134.91 microg/m(3) (mean, n = 45, 95%CI 84.02, 185.80), 103.61 microg/m(3) (mean, n = 21, 95%CI 85.77, 121.45), 76.13 microg/m(3) (mean, n = 18, 95%CI 57.22, 95.04), and 78.33 microg/m(3) (mean, n = 34, 95%CI 60.00, 96.65) respectively. Using SBFs in kitchen resulted in higher indoor pollution than
using methane. PM(2.5) concentrations in kitchen with dung cake, fuel wood and methane use were 117.41 microg/m(3) (mean, n = 18, 95%CI 71.03, 163.79), 271.11 microg/m(3) (mean, n = 12, 95%CI 104.74, 437.48), and 46.96 microg/m(3) (mean, n = 15, 95%CI 28.10, 65.82) respectively. Family income has significant influence on cooking energy choice, while the lack of commercial energy supply affects the
energy choice for heating more. The effects of two countermeasures to improve indoor air quality were estimated in this research. One is to replace SBFs by clean energy like methane, the other is to separate the cooking place from other rooms and by applying these countermeasures, residents’ exposure to particulate
matters would reduce by 25-50% (methane) or 20-30% (separation) compared to the present situation.

PRACTICAL IMPLICATIONS: Indoor air pollution caused by solid biomass fuels is one of the most important burdens of disease in the developing countries, which attracts the attention of environment and public health
researchers, as well as policy makers. This paper gives a pilot research on the indoor air pollution and estimated the effects of some intervention policies in Tibet of China, where the living habits of the residents are quite different from other parts of the world. This work would be an important supply to the indoor air pollution studies, and would be helpful in policy making.

China to monitor endemic arsenic, fluoride poisoning

August 10, 2009 · 0 comments

BEIJING, Aug. 10 (Xinhua) — China will start to monitor the endemic poisoning of coal-burning arsenic and fluoride as environmentally-related illnesses continue to plague coal-rich central and western regions, the Ministry of Health said Monday.

Information to be monitored includes the management of arsenic and fluorine-rich coal mines, the progress of old furnace replacements and local people’s environmentally-related illnesses, according to a statement released Monday on the ministry’s website.

Fluorosis often results in yellow teeth, twisted spines, aching joints and deformed leg bones while long-term consumption of arsenic can lead to skin cancer and even death.

The coal-burning poisoning results mainly from cooking ranges as many rural households use arsenic and fluorine-rich coal as their major cooking fuel.

Since most clay stoves in central and western regions don’t have chimneys, there’s no way for the poisonous contents to vent. It’s concentrated in the smoke from cooking, so people breathe it. It also contaminates what is being cooked on the stove.

According to a statement, every year a total of 31 counties and cities in Jiangxi, Hubei, Hunan, Chongqing, Sichuan, Guizhou, Yunnan and Shaanxi will be randomly selected for the monitoring between September and next February.

The monitoring will be carried out by disease control and prevention centers at county level and the results will be reported through the ministry to the State Council.

China has been fighting the illnesses mainly by replacing traditional stoves and promoting people’s awareness.

In June, the Health Ministry launched a project to curb fluorosis in six provinces, including Yunnan and Guizhou. This year, it will upgrade the stoves of 870,000 households, with each getting 400 yuan (58.5 U.S. dollars) in compensation.

The new stoves pipe the smoke out of the room.

Source – China View

Three-in-one oven could ease energy needs in developing world

August 10, 2009 · 0 comments

score-ovenA combined combustion oven and refrigerator that can also harness electricity from its vibrations is now undergoing field trials in the UK and Nepal. The versatile appliance has been developed over the past two years through a UK research collaboration led by the University of Nottingham. With its cheap production costs and variety of functions, the new generator could become an affordable and sustainable energy technology for communities in the developing world, say the project leaders.

Underpinning the electricity generator is a two-step energy conversion from heat to sound to electricity, which takes place inside a gas-filled pipe. A fire at one end of the pipe creates a temperature gradient, which triggers acoustic waves as gas moves from hot to cold regions – much like a singing kettle as the water reaches boiling point. These sound waves can then be harnessed by a linear alternator, which converts mechanical energy into electrical electricity in the reverse process to an electric motor.

What’s more, some of the pipe’s vibrations can also be passed into another thermoacoustic engine, which works in reverse to generate a cooling effect. Finally, the heat from the burning wood or other available biomass can also be used for cooking. The real innovation is that these three functions can be run simultaneously to provide the users with a combined stove, refrigerator and electricity generator.

Three-in-one
The SCORE (Stove for Cooking, Refrigeration and Electricity supply) project was launched two years ago with the aim of developing an affordable, versatile domestic appliance to address the energy needs of rural communities in Africa and Asia, where access to power is extremely limited. One advantage of the new generator is its efficiency, which is higher than that in thermocouples – another device that converts heat into electrical energy. “The best [thermocouples] I have seen are less than 5-7% efficient. Compare this with 15 – 20% for a thermoacoustic engine,” said project director Paul Riley.

Technical development of the appliance has been split between different institutions in the UK. Researchers at the University of Nottingham have been working to maximize the efficiency of the linear accelerator. “The current design is very exciting for me as it solves many of the problems we had with using loudspeakers as alternators,” said Chitta Saha, a member of the Nottingham team.

Researchers at City University London have been developing the stove design and working with the University of Manchester to hone the thermoacoustic engine. In addition, researchers at Queen Mary University of London are working on the heat transfer aspects of the device.

Putting it into action
Paul Riley told physicsworld.com that his team has already generated 8W of electrical power by using a propane burner instead of biomass. “We have built the stove top unit using local materials and tested it in Nepal. The results look very encouraging – the science is progressing well and we have developed mathematical models that are being tested,” he said.

The SCORE team are aiming to create a generator weighing between 10 and 20kg, at a cost of £20 per household, based on the production of a million units. The target is to generate an hour’s use per kilogram of fuel — which could be wood, dung or any other locally-available biomass material. SCORE are now looking for sponsorship to fund further testing and Riley believes that the Indian sub-continent (particularly Nepal), Sub-Saharan Africa and South America are regions that could benefit particularly from the new innovation.

Riley also told physicsworld.com that his team will also begin to explore other applications once they have proven the technology. “Examples could include waster heat recovery, CHP for domestic boilers and low cost solar power,” he said.

Source – PhysicsWorld

← Previous Entries

Next Entries →