Indoor Particulate Matter Concentration, Water Boiling Time, and Fuel Use of Selected Alternative Cookstoves in a Home-Like Setting in Rural Nepal

Does Use of Solid Cooking Fuels Increase Family Medical Expenses in China?

China has tried to replace solid fuels with cleaner energy in households. The benefits of fuel switching need to be identified. This article shows that households using solid cooking fuels suffer heavier medical expenses than those using non-solid cooking fuels. After accounting for family characteristics, using solid fuels is associated with 1.4–1.9% increases in medical care. Through the analysis of the impact mechanism, we found that solid cooking fuels harm the health conditions of family members and increase the probability of illness, thereby increasing medical expenses, while the ratio of fuel fees does not change significantly if switching cooking fuels. Furthermore, we explored heterogeneity to better understand the underlying relationship. For urban and higher-educated families with house ownership, the impact of solid fuels on medical expenses was weaker compared to rural and lower-educated households without owned houses. Therefore, considering the costs and benefits, we recommend continuing the conversion from solid fuels to non-solid fuels. In the fuel transition process, it is beneficial to raise residents’ awareness and improve behavior to avoid indoor air pollution.

Interrelationship of Indoor Particulate Matter and Respiratory Dust Depositions of Women in the Residence of Dhanbad City, India

Women spend relatively more time in indoor environments in developing countries. Exposure to various indoor air pollutants leads them to higher health risks according to household air quality in which they reside. Particulate matter (PM) exposure with their exposure duration inside the household plays a significant role in women's respiratory problems. This study measured size-segregated particulate matter concentrations in 63 residences at different locations. Respiratory dust depositions (RDDs) for 118 women in their different respiratory regions like head airway (HD), tracheobronchial (TB), and alveolar (AL) regions for the three PM size fractions (PM₁₀, PM_2.5, and PM₁) were investigated. For different positions like light exercise and the sitting condition, RDDs values found for AL region were 0.091 μgmin^-1 (SD: 0.067, 0.012-0.408) and 0.028 μgmin^-1 (SD: 0.021, 0.003-0.126) for PM₁₀, 0.325 μgmin^-1 (SD: 0.254, 0.053-1.521) and 0.183 μgmin^-1 (SD: 0.143, 0.031-0.857) for PM_2.5, 0.257 μgmin^-1 (SD: 0.197, 0.043-1.04) and 0.057 μgmin^-1 (SD: 0.044, 0.009-0.233) respectively for PM₁ to females. RDDs values in the AL region significantly increase as PM₁₀ (11%), PM_2.5 (68%), and PM₁ (21%), confirming that for women, the AL region is the most prominent affected zone by fine particles (PM_2.5).

Rat model of smoke inhalation-induced acute lung injury

BACKGROUND

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a lethal disease with limited therapeutic options and an unacceptably high mortality rate. Understanding the complex pathophysiological processes involved in the development of ALI/ARDS is critical for developing novel therapeutic strategies. Smoke inhalation (SI) injury is the leading cause of morbidity and mortality in patients with burn-associated ALI/ARDS; however, to our knowledge few reliable, reproducible models are available for pure SI animal model to investigate therapeutic options for ALI/ARDS without the confounding variables introduced by cutaneous burn or other pathology.

OBJECTIVE

To develop a small animal model of pure SI-induced ALI and to use this model for eventual testing of novel therapeutics for ALI.

METHODS

Rats were exposed to smoke using a custom-made smoke generator. Peripheral oxygen saturation (SpO₂), heart rate, arterial blood gas, and chest X-ray (CXR) were measured before and after SI. Wet/dry weight (W/D) ratio, lung injury score and immunohistochemical staining of cleaved caspase 3 were performed on harvested lung tissues of healthy and SI animals.

RESULTS

The current study demonstrates the induction of ALI in rats after SI as reflected by a significant, sustained decrease in SpO₂ and the development of diffuse bilateral pulmonary infiltrates on CXR. Lung tissue of animals exposed to SI showed increased inflammation, oedema and apoptosis as reflected by the increase in W/D ratio, injury score and cleaved caspase 3 level of the harvested tissues compared with healthy animals.

CONCLUSION

We have successfully developed a small animal model of pure SI-induced ALI. This model is offered to the scientific community as a reliable model of isolated pulmonary SI-induced injury without the confounding variables of cutaneous injury or other systemic pathology to be used for study of novel therapeutics or other investigation.

Household air pollution related to biomass cook stove emissions and its interaction with improved cookstoves

Introduction

Household air pollution (HAP) is associated with significant global morbidity and mortality. Newer initiatives including improved cookstove (IC) and cleaner fuels are being implemented to improve HAP effects.

Methods

A literature review was conducted for household air pollution related to biomass cookstoves in resource limited countries. In January 2018, we electronically searched the PubMed database for the term cookstoves with no date restrictions. We included cohort, case-control, cross-sectional studies, conference abstracts, editorials, and reviews; studies that assessed the emissions related to cookstove and factors affecting HAP emissions.

Results

Twenty-three articles met the objectives of the review. Fine particulate matter with aerodynamic diameter <2.5 µm (PM_2.5), carbon monoxide (CO) and polycyclic aromatic hydrocarbons (PAH) are the major HAP emissions. Emission factors are based on the stove and fuel used while the activity is based on cooking practices. Changes in composition and sources of PM_2.5 causes modification to its resulting toxicity. Many PAHs and their metabolites released by HAP have carcinogenic, teratogenic and mutagenic potential. Improving ventilation decreases concentrations of PM_2.5 and CO in the household air. Few standard tools are available to measure ventilation and continued IC efficacy in long term.

Conclusion

Unavailability of tools to measure ventilation and continued IC efficacy in long term affect uniformity and comparability of IC study results. Community education about the health effects of HAP and importance of ventilation in decreasing HAP is an important aspect of public health policy to prevent HAP effects.

Health effects of household air pollution related to biomass cook stoves in resource limited countries and its mitigation by improved cookstoves

BACKGROUND

Household air pollution (HAP) related to cooking is associated with significant global morbidity and mortality. An estimated three billion people worldwide are exposed to cooking related HAP caused by solid fuel combustion. This exposure is highest for the vulnerable population of women and children resulting in significant cumulative health effects.

METHODS

A literature review was conducted for health effects of household air pollution related to biomass cookstoves in resource limited countries and to evaluate the effect of improved cookstoves on these health effects. We searched PubMed, Embase and Cochrane Library. We conducted searches in January 2018 with a repeat in February 2020. We included only studies conducted in resource limited countries, published in English, irrespective of publication year and studies that examined the health effects of HAP and/or studied the effects of improved cookstove (IC). Two authors independently screened journal article titles, abstracts and full-text articles to identify those that included the following search term: biomass cookstoves and health risks. We also assessed the limitations of IC with barriers to their uptake.

RESULTS

Health effects associated with HAP mostly include increased blood pressure (BP), dyspnea, childhood pneumonia, lung cancer, low birthweight and cardiovascular diseases. Being a global problem with divergent environmental factors including wide variety of fuel used, housing condition, foods prepared, climatic condition and social factors; most solutions though efficient seems inadequate. Improved cookstove (IC) mitigates emissions and improves short term health, though few randomized long-term studies could substantiate its long-standing continuance and health benefits.

CONCLUSION

There is ample data about the health effects of HAP, with some benefit with IC intervention for elevated blood pressure, dyspnea symptoms, mutagenicity and cardiovascular diseases. IC does not have any benefit in pregnancy outcomes or children health.

Proinflammatory Effects in Ex Vivo Human Lung Tissue of Respirable Smoke Extracts from Indoor Cooking in Nepal

Rationale: Exposure to biomass smoke is believed to increase the risk of developing chronic obstructive pulmonary disease. However, little is known about the mechanisms underlying responses to biomass smoke in human lungs.Objectives: This study had two objectives: first, to quantify "real-life" exposures to particulate matter <2 μm in diameter (PM2.5) and carbon monoxide (CO) measured during cooking on stoves in rural areas of Nepal in different geographical settings; and second, to assess the effect of biomass smoke extracts on inflammatory responses in ex vivo human lung tissue.Methods: Personal exposures to PM2.5 and indoor near-stove CO concentrations were measured during cooking on a range of stoves in 103 households in 4 different Nepalese villages situated at altitudes between ∼100 and 4,000 m above sea level. Inflammatory profiles to smoke extracts collected in the field were assessed by incubating extracts with human lung tissue fragments and subsequent Luminex analysis.Results: In households using traditional cooking stoves, the overall mean personal exposure to PM2.5 during cooking was 276.1 μg/m3 (standard deviation [SD], 265 μg/m3), and indoor CO concentration was 16.3 ppm (SD, 19.65 ppm). The overall mean PM2.5 exposure was reduced by 51% (P = 0.04) in households using biomass fuel in improved cook stoves, and 80% (P < 0.0001) in households using liquefied petroleum gas. Similarly, the indoor CO concentration was reduced by 72% (P < 0.001) and 86% (P < 0.0001) in households using improved cook stoves and liquefied petroleum gas, respectively. Significant increases occurred in 7 of the 17 analytes measured after biomass smoke extract stimulation of human lung tissue (IL-8 [interleukin-8], IL-6, TNF-α [tumor necrosis factor-α], IL-1β, CCL2, CCL3, and CCL13).Conclusions: High levels of real-life exposures to PM2.5 and CO occur during cooking events in rural Nepal. These exposures induce lung inflammation ex vivo, which may partially explain the increased risk of chronic obstructive pulmonary disease in these communities.

Laboratory Testing of the Innovative Low-Cost Mewar Angithi Insert for Improving Energy Efficiency of Cooking Tasks on Three-Stone Fires in Critical Contexts

Currently, about 2.7 billion people across the world still lack access to clean cooking means. Humanitarian emergencies and post-emergencies are among the most critical situations: the utilization of traditional devices such as three-stone fires have a huge negative impact not only on food security but also on the socio-economic status of people, their health and the surrounding environment. Advanced Cooking Stoves may constitute better systems compared to actual ones, however, financial, logistic and time constraints have strongly limited the interventions in critical contexts until now. The innovative, low-cost Mewar Angithi insert for improving energy efficiency of three-stone fires may play a role in the transition to better cooking systems in such contexts. In this paper, we rely on the Water Boiling Test 4.2.3 to assess the performances of the Mewar Angithi insert respect to a traditional three-stone fire and we analyse the results through a robust statistical procedure. The potentiality and suitability of this novel solution is discussed for its use in critical contexts.

Characterizing Particulate Matter Exfiltration Estimates for Alternative Cookstoves in a Village-Like Household in Rural Nepal

Alternative stoves are an intervention option to reduce household air pollution. The amount of air pollution exiting homes when alternative stoves are utilized is not known. In this paper, particulate matter exfiltration estimates are presented for four types of alternative stoves within a village-like home, which was built to reflect the use of local materials and common size, in rural Nepal. Four alternative stoves with chimneys were examined, which included an alternative mud brick stove, original Envirofit G3355 model, manufacture altered Envirofit G3355, and locally altered Envirofit G3355. Multiple linear regression was utilized to determine estimates of PM2.5 exfiltration. Overall exfiltration fraction average (converted to a percent) for the four stoves were: alternative mud brick stove with chimney 56%, original Envirofit G3355 model with chimney 87%, manufacture altered Envirofit G3355 model with chimney 69%, and locally altered Envirofit G3355 model with chimney 69%. Alternative cookstoves resulted in higher overall average exfiltration due to direct and indirect ventilation relative to traditional, mud-based stoves. This contrast emphasizes the need for an improved understanding of the climate and health implications that are believed to come from implementing alternative stoves on a large scale and the resultant shift of exposure burden from indoors to outdoors.

Assessment of traditional and improved stove use on household air pollution and personal exposures in rural western Kenya

BACKGROUND

Over 40% of the world's population relies on solid fuels for heating and cooking. Use of improved biomass cookstoves (ICS) has the potential to reduce household air pollution (HAP).

OBJECTIVES

As part of an evaluation to identify ICS for use in Kenya, we collected indoor air and personal air samples to assess differences between traditional cookstoves (TCS) and ICS.

METHODS

We conducted a cross-over study in 2012 in two Kenyan villages; up to six different ICS were installed in 45 households during six two-week periods. Forty-eight hour kitchen measurements of fine particulate matter (PM2.5) and carbon monoxide (CO) were collected for the TCS and ICS. Concurrent personal CO measurements were conducted on the mother and one child in each household. We performed descriptive analysis and compared paired measurements between baseline (TCS only) and each ICS.

RESULTS

The geometric mean of 48-hour baseline PM2.5 and CO concentrations in the kitchen was 586μg/m3 (95% CI: 460, 747) and 4.9ppm (95% CI: 4.3, 5.5), respectively. For each ICS, the geometric mean kitchen air pollutant concentration was lower than the TCS: median reductions were 38.8% (95% CI: 29.5, 45.2) for PM2.5 and 27.1% (95% CI: 17.4, 40.3) for CO, with statistically significant relationships for four ICS. We also observed a reduction in personal exposures to CO with ICS use.

CONCLUSIONS

We observed a reduction in mean 48-hour PM2.5 and CO concentrations compared to the TCS; however, concentrations for both pollutants were still consistently higher than WHO air quality guidelines. Our findings illustrate that ICS tested in real-world settings can reduce exposures to HAP, but implementation of cleaner fuels and related stove technologies may also be necessary to optimize public health benefits.