At present, the main cooking fuels inChinaare natural gas, coal gas, liquefied petroleum gas (LPG), coal, biogas, wood and straw. This paper reviews the characteristics, advantages, disadvantages and the current application status of these different cooking fuels. Moreover, a questionnaire survey is presented, dealing with different cooking fuels in Chinese households and the occupants’ perceived health, ventilation behaviors and general knowledge in potential health hazards. About 56% of the respondents of the questionnaire survey stated that symptoms like itching eyes, dry or irritated throat, irritated nose, running or blocked nose and headache were worse when they were cooking in their kitchens. This suggests that cooking fuel combustion has a significant influence on human health. The most evident health effect was that wood and straw as cooking fuel caused eye irritation. The present common house planning in Chinese countryside, where the kitchens are separated from the rest of the house via a courtyard, is very likely to reduce the stove contaminant exposure of all occupants.   In general, the main cooking fuels of the cities tend to be better than the cooking fuels of the countryside. Natural gas appears to be the cleanest cooking fuel among all urban cooking fuels except electricity. For the rural residents, biogas or LPG is a better choice than wood, straw and coal as cooking fuel.

Household air pollution (HAP) has been recognized as one of the lethal causes of millions of premature deaths every year, victimizing mainly children and women. Literature suggests that transition to modern cooking fuels such as electricity, biogas from the conventional ones, for instance, fuelwood, coal, can reduce HAP, thus minimize the likelihood of respiratory health problems among household members. This study explores whether cooking fuels has an impact on children's respiratory health in the context of Nigeria, and in particular, whether modern cooking fuels can be a solution to this problem. By using the children recode of the survey data collected by the Demographic and Health Survey (DHS) for the year 2018, this study finds support to the claim that modern cooking fuels can reduce the probability of Acute Respiratory Infections (ARI) symptoms among children aged below 5 years in Nigeria. This probability is also found contingent on the age, gender, and education of the household heads. However, with regards to individual fuel types, the result seems inconclusive in some instances, mostly due to a lack of observations. The policy implication is that to reduce ARI among children, households should be encouraged to adopt modern cooking fuels, and this should follow with increasing education and empowerment opportunities for women in the household.

Anaerobic digestion is the process by which organic carbon is converted into biogas in the form of carbon dioxide (CO2) and methane (CH4). Both of these products are greenhouse gases that contribute to global warming. Therefore if anaerobic reactors are improperly maintained and biogas is leaked or intentionally released into the atmosphere because biogas production exceeds household demand, these reactors may become generators of greenhouse gas emissions instead of sustainable energy producers. The objective of this research was to develop a framework to assess if the demand for biogas by a rural adopter of an anaerobic digester matched with the associated local gas production. A literature review of the energy required to prepare commonly consumed food of rice and beans was conducted to establish required household biogas volumes. This review determined that 0.06 m3 of methane was required to prepare a half a kg of rice (on a dry weight basis) and 0.06 m3 of methane was required to prepare a half a kg of beans (on a dry weight basis). Furthermore an analysis of occupants of a rural Panamanian town was performed along with a design model for rural anaerobic reactor gas production to determine if an overproduction of biogas would occur if anaerobic reactors were built for families who owned swine. It was determined using this approach that all of the fifteen household would experience an overproduction of biogas based on household demand of methane and therefore would risk the release of greenhouse gases. Household size ranged from one to seven occupants and swine ownership ranged from one to fifteen per household. The differences of biogas supply with respect to demand from these fifteen situations ranged from 0.09 to 0.35 m3 of a biogas with 40% methane and 0.27 to 6.17 m3 of excess biogas with a methane content of 70% per household per day. An average of 0.45 m3 of a biogas with 40% methane per household per day was calculated and 0.87m3 for 70% methane for all fifteen households, excluding one outlier. However, because this research uses a model based on plug flow reactor mechanics, results may produce varied results from other studies concerning small scale anaerobic digestion.

Child mortality in sub-Saharan Africa is reducing but the levels remain high with subnational within-country variations. Birth weight is a key predictor of child survival and monitoring birth weight outcomes, in particular, prevalence of low birth weights, is important for resource allocation to improve child survival outcomes. Past research in sub-Saharan Africa has found that different individual-level factors are associated with birth weight including BMI of mother, sex of baby, educational level of mother, and wealth index of household. Some environmental factors are found to be associated with birth outcomes. However, past findings regarding the association of birth weight with household air pollution (HAP) resulting from cooking fuels are non-conclusive. In this study, we analyze variability in birth weights subnationally for Ghana and assess its association with household air pollution resulting from cooking fuels, accounting for variation due to other factors including maternal and household predictors, as well as geographical location. The analysis was based on birth weights for 1310 births, obtained from data collected in 2014 in the Demographic and Health Survey (DHS). We use Bayesian spatial regression models to estimate associations and capture spatial variation. Spatial variation was captured with a conditional autoregressive (CAR) model. Based on various models, we do not find evidence to suggest that cooking fuel is associated with birth weight. After accounting for covariates, the average birth weights per district ranged from 2823g (95% CI: 2613g, 3171g) in Ketu district to 3243g (95% CI: 3083g, 3358g) in Ashanti Akim North district. Across Ghana, difference in birth weight attributable to district spatial effects range from -33g in Lawra district in Upper West region of Ghana to 11g in Ho in the Volta region.