Inefficient biomass combustion in traditional cookstoves generates high levels of household air pollution (HAP) that is associated with numerous adverse environmental and human health conditions. ...Many cookstoves have been evaluated using laboratory tests, but past studies revealed discrepancies between laboratory and field measurements. Fuel re-loading, a common operation in actual use but not required in the laboratory test, might be a contributing factor to this laboratory-field gap. In this study, we evaluated the pollutant emissions performance of a semi-gasifier cooking stove using both laboratory and field measurements. Emission factors and real-time properties of CO and PM
were separately measured during the following 4 phases of a typical cooking event: lighting, stable combustion, fuel re-loading and post fuel re-loading. We quantified the CO and PM
contributions to total cooking event emissions in each phase. We found over 70% lower PM
emissions and 60% lower CO emissions during 3 no re-loading laboratory tests compared with all 16 field tests. Lighting generated 83.8% ± 15.6% of the total PM
and 39.1% ± 7.8% of the total CO in laboratory tests without fuel re-loading, and 57.8% ± 33.5% and 37.9% ± 21.2% of the total PM
and CO in field tests, respectively. On average, fuel re-loading led to 29.1% ± 30.8% of PM
emissions and 24.9% ± 22.6% of CO emissions in 16 field tests, which also contributed to significant discrepancies between laboratory and field-based emissions. According to the ISO IWA tiered stove ratings for emissions, fuel re-loading led to at least one tier lower ranking in both laboratory and field cookstove tests. Fuel re-loading could be an important factor causing laboratory-field discrepancy of emissions, thus it could be considered in future cookstove selection and intervention projects.
Understanding linkages between household behavior and
Aedes aegypti
(L.) larval ecology is essential for community-based dengue mitigation. Here we associate water storage behaviors with the rate of
...A. aegypti
pupal production in three dengue-endemic Colombian cities with different mean temperatures. Qualitative, semi-structured interviews and pupal counts were conducted over a 7–15-day period in 235 households containing a water storage vessel infested with larvae. Emptying vessels more often than every 7 days strongly reduced pupal production in all three cities. Emptying every 7–15 days reduced production by a similar magnitude as emptying <7 days in Armenia (21.9°C), has a threefold smaller reduction as compared to <7 days in Bucaramanga (23.9°C), and did not reduce production in Barranquilla (29.0°C). Lidding vessels reduced mosquito production and was most feasible in Barranquilla because of container structure. Vessel emptying strongly correlated with usage in Barranquilla, where many households stored water in case of interruptions in piped service rather than for regular use. In the cooler cities, >90% of households regularly used stored water for washing clothes, generating a weaker correlation between emptying and usage. Emptying was less frequent in the households surveyed in the dry season in all three cities. These results show that
A. aegypti
production and human behaviors are coupled in a temperature-dependent manner. In addition to biological effects on aquatic stages, climate change may impact
A. aegypti
production through human behavioral adaptations. Vector control programs should account for geographic variation in temperature and water usage behaviors in designing targeted interventions.
Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred ...morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties.
We performed 40 semi-structured interviews in seven communities. We calculated Sutrop's salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA).
Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka' and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves.
The association between C. cujete bowls and traditional beverages in ritual and daily life situations has driven for centuries the selection of preferred fruit morphology in this tree. Selection of fruit roundness and volume has allowed for the differentiation between the wild variety and the three domesticated ones, counteracting gene flow among them. By choosing the best fruits from domesticated varieties propagated in homegardens, the Maya people model the domestication process of this important tree in their culture.
Household air pollution from cooking with biomass fuels negatively impacts maternal and child health and the environment, and contributes to the global burden of disease. In Uganda, nearly 20,000 ...young children die of household air pollution-related pneumonia every year. Qualitative research was used to identify behavioral determinants related to the acquisition and use of improved cookstoves in peri-urban Uganda. Results were used to design a behavior change strategy for the introduction of a locally-fabricated top-lit updraft gasifier (TLUD) stove in Wakiso district. A theoretical framework--opportunity, ability, and motivation--was used to guide the research and behavior change strategy development. Participants consistently cited financial considerations as the most influential factor related to improved cookstove acquisition and use. In contrast, participants did not prioritize the potential health benefits of improved cookstoves. The theoretical framework, research methodology, and behavior change strategy design process can be useful for program planners and researchers interested in identifying behavioral determinants and designing and evaluating improved cookstove interventions.
With the development of modern waste management systems in Western Europe, a remarkable increase in the distances for waste transportation has been observed. The question thus arises whether ...recycling with longer transport distances is ecologically advantageous or whether disposal without recycling is to be preferred. This situation was analysed using selected product and waste streams. This included refrigerators, paper, polyethylene films and expanded polystyrene. For each of these streams, a life cycle analysis was conducted with an emphasis on waste transport. The system boundaries were set in terms of the generation of waste to recycling or landfilling. The comparison included several scenarios with recycling and different transport distances. Landfilling was used as the reference scenario. The results obtained demonstrated how transport distances influence the ecological benefit of recycling. In the case of expanded polystyrene, the ecological boundaries are reached in practical situations, while with other materials these boundaries are far from being attained. In these cases, more complex and elaborate collection schemes, such as kerbside collection, which is economically convenient and shows the highest collection rates, can also be recommended.
The first European waste from electric and electronic equipment directive obliged the Member States to collect 4 kg of used devices per inhabitant and year. The target of the amended directive ...focuses on the ratio between the amount of waste from electric and electronic equipment collected and the mass of electric and electronic devices put on the market in the three foregoing years. The minimum collection target is 45% starting in 2016, being increased to 65% in 2019 or alternatively 85% of waste from electric and electronic equipment generated.
Being aware of the new target, the question arises how Member States with ‘best practice’ organise their collection systems and how they enforce the parties in this playing field. Therefore the waste from electric and electronic equipment schemes of Sweden, Denmark, Switzerland, Germany and the Flemish region of Belgium were investigated focusing on the categories IT and telecommunications equipment, consumer equipment like audio systems and discharge lamps containing hazardous substances, e.g. mercury. The systems for waste from electric and electronic equipment collection in these countries vary considerably.
Recycling yards turned out to be the backbone of waste from electric and electronic equipment collection in most countries studied. For discharge lamps, take-back by retailers seems to be more important. Sampling points like special containers in shopping centres, lidded waste bins and complementary return of used devices in all retail shops for electric equipment may serve as supplements. High transparency of collection and recycling efforts can encourage ambition among the concerned parties. Though the results from the study cannot be transferred in a simplistic manner, they serve as an indication for best practice methods for waste from electric and electronic equipment collection.
Hypersensitivity of the central nervous system is widely present in pain patients and recognized as one of the determinants of chronic pain and disability. Electronic pressure algometry is often used ...to explore aspects of central hypersensitivity. We hypothesized that a simple pain provocation test with a clothes peg provides information on pain sensitivity that compares meaningfully to that obtained by a well-established electronic pressure algometer. "Clinically meaningful" was defined as a medium (r = 0.3-0.5) or high (r > 0.5) correlation coefficient according to Cohen's conventions.
We tested 157 in-patients with different pain types. A calibrated clothes peg was applied for 10 seconds and patients rated the pain intensity on a 0 to 10 numerical rating scale. Pressure pain detection threshold (PPdt) and pressure pain tolerance threshold (PPtt) were measured with a standard electronic algometer. Both methods were performed on both middle fingers and ear lobes. In a subgroup of 47 patients repeatability (test-retest reliability) was calculated.
Clothes peg values correlated with PPdt values for finger testing with r = -0.54 and for earlobe testing with r = -0.55 (all p-values < 0.001). Clothes peg values also correlated with PPtt values for finger testing with r = -0.55 (p < 0.001). Test-retest reliability (repeatability) showed equally stable results for clothes peg algometry and the electronic algometer (all r-values > 0.89, all p-values < 0.001).
Information on pain sensitivity provided by a calibrated clothes peg and an established algometer correlate at a clinically meaningful level.
Poorly ventilated combustion stoves and pollutants emitted from combustion stoves increase the risk of acute lower respiratory illnesses (ALRI) in children living in developing countries but few ...studies have examined these issues in developed countries. Our objective is to investigate behaviors related to gas stove use, namely using them for heat and without ventilation, on the odds of pneumonia and cough in U.S. children.
The National Health and Nutrition Examination Survey (1988-1994) was used to identify children < 5 years who lived in homes with a gas stove and whose parents provided information on their behaviors when operating their gas stoves and data on pneumonia (N = 3,289) and cough (N = 3,127). Multivariate logistic regression models were used to examine the association between each respiratory outcome and using a gas stove for heat or without ventilation, as well as, the joint effect of both behaviors.
The adjusted odds of parental-reported pneumonia (adjusted odds ratio aOR = 2.08, 95% confidence interval CI: 1.08, 4.03) and cough (aOR = 1.66, 95% CI: 1.14, 2.43) were higher among children who lived in homes where gas stoves were used for heat compared to those who lived in homes where gas stoves were only used for cooking. The odds of pneumonia (aOR = 1.76, 95% CI: 1.04, 2.98), but not cough (aOR = 1.23, 95% CI: 0.87, 1.75), was higher among those children whose parents did not report using ventilation when operating gas stoves compared to those who did use ventilation. When considering the joint association of both stove operating conditions, only children whose parents reported using gas stoves for heat without ventilation had significantly higher odds of pneumonia (aOR = 3.06, 95% CI: 1.32, 7.09) and coughing (aOR = 2.07, 95% CI: 1.29, 3.30) after adjusting for other risk factors.
Using gas stoves for heat without ventilation was associated with higher odds of pneumonia and cough among U.S. children less than five years old who live in homes with a gas stove. More research is needed to determine if emissions from gas stoves ventilation infrastructure, or modifiable behaviors contribute to respiratory infections in children.
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