More deaths are caused every year by indoor air pollution than malaria, HIV/AIDS and tuberculosis combined. Cooking with traditional fuels such as charcoal and fuelwood with poor ventilation causes the single most important environmental health risk factor worldwide. It also contributes to environmental issues such as deforestation as traditional biomass fuels and cooking stoves are inefficient and requires large quantities of wood. This is especially critical in Africa where the largest regional population growth in the world is expected to occur. A solution to these issues was realized through fuel pellets and modern cooking stoves by Emerging Cooking Solutions, a company started by two Swedes and based in Zambia. The production of fuel pellets in Zambia is dependent on pine sawdust from small sawmills and is a declining source of raw material. However, other sources of biomass are available in Zambia such as pigeon pea stalk, an agricultural waste product, and sicklebush, an invasive tree species. If these species are viable for pelletization, the production of pellets can increase while reducing issues with sicklebush and promoting cultivation of pigeon pea. The aim of this work is to evaluate if pigeon pea stalk and sicklebush are viable to pelletize in Zambia and how the press is affected by the different raw materials. A pilot study is done at Karlstad University with a single unit press, hardness tester and soxhlet extractor to evaluate how the material constituents correlate to friction in the press channel and hardness of the pellets. The results of the pilot study provide support for full scale tests done in a pellet plant in Zambia. The normal production of pellets from pine sawdust is used as quality and production reference for the tests with pigeon pea stalk, sicklebush, and different mixes of the raw materials. The properties used to evaluate the quality of the pellets are hardness, durability, moisture content, bulk density, and fines. The press configuration is evaluated by logging the electricity consumption by the press motor, calculating the power and specific energy consumption from the logs, and observations during the tests. The results show that sicklebush, and mixes of sicklebush with pigeon pea stalk can produce pellets with better quality than the reference pine pellets. An interesting composition is a mix of 80% pigeon pea and 20% sicklebush that produces pellets with the best quality of all the tests. However, pellets produced from sicklebush and pigeon pea show a larger variation in hardness as compared to the reference pellets from pine sawdust. Mixing pigeon pea with pine reduces these variations but reduces the hardness of the pellets below the reference. The press struggles to process sicklebush and pigeon pea stalk with fluctuating power consumption that causes the motor to trip. The inhomogeneity of the materials in sicklebush and pigeon pea are identified to cause the issues in the press. Production improvements are discussed to facilitate the production of pigeon pea stalk and sicklebush pellets.

The high incidence of upper respiratory diseases, contamination of waterways due to pathogens and nutrients from human and animal wastes, unsustainable deforestation, gender disparities in burden of disease due to unequal exposure to indoor air pollutants, and carbon black emissions from the burning of solid fuels are interrelated problems in many developing countries. Small scale anaerobic digestion provides a means of alleviating these problems by treating livestock waste onsite to produce biogas (methane and carbon dioxide) in rural areas in developing countries. Fuel can then be used for cooking, lighting, and heating. Methane fuel is an alternative to traditional three-stone fires, improved cook stoves, and liquid petroleum gas. However, there is a lack of information available on design methods for these systems. The goal of this research was to develop a design tool that could be used for anaerobic digester sizing based on livestock waste availability. An Excel spreadsheet model was developed for sizing the bioreactor and the gas container based upon recommended values from a literature review. Needed monitoring parameters for operation of an anaerobic digester in the field were identified and standard methods of analysis were recommended. Sample preservation techniques were detailed. Guidelines for pathogen reduction in thermophilic anaerobic digestion were identified. Further study of pathogen reduction in low temperature reactors currently in use in developing countries was recommended. Three digester designs included in the Excel spreadsheet model were: the polyethylene tubular digester, the floating drum digester, and the fixed dome digester. The design tool may be requested from Dr. Sarina Ergas, sergas(at)usf.edu. An organic loading rate of 1.0 kg VS/(m3*d) was chosen for use in the design tool based upon a review of the literature. A semi-empirical kinetic model was developed for defining the SRT based on the temperature inputted by the user. Three case studies, based upon livestock waste availability in a rural community in the Dominican Republic, were analyzed using the sizing design tool. The case studies were conducted on three scales: one household, six households, and a village of 48 households. The specific biogas production rates were, for Case Studies one through three, respectively, 0.0076, 0.0069, and 0.010 m3 biogas/kg Volatile Solids reduced. Additional future work included: characterization of human feces and guinea pig manure, laboratory and field testing of the Excel spreadsheet design tool, and promotion of anaerobic digesters by development workers, non-governmental organizations, and governments.

Background Birth defects are a significant cause of neonatal mortality and morbidity globally. Environmental and genetic factors may be the risk factors for birth defects. Thus, this study aims to evaluate the association between the type of household cooking fuel and birth defects in Nepal, as well as investigate whether air ventilation usage had a modifying effect on the possible association. Methods This cross-sectional study used secondary data from Nepal Perinatal Quality Improvement Projectfrom 2017 to 2018. The study sample was 66,713 women with a newborn, whose information was available in hospital records and exit interviews. The association between cooking fuel type usage and birth defects was investigated with adjusted multivariable logistic regression. To investigate the air ventilation usage, a stratified multivariable logistic regression analysis was performed. Results This study found a significant association between cooking fuel type usage and birth defects. Mothers using polluted fuels had higher odds (aOR 1.48 [95% CI 1.15-1.90]) of having a child with a birth defect compared to mothers using clean fuels. Women not using air ventilation while cooking had even higher odds of having a child with birth defects (aOR 1.56 [95% CI 1.20-2.03]), whereas the association was not significant among women using air ventilation. Conclusion The usage of polluted cooking fuels is an important factor related to birth defects. Air ventilation in turn may be important in decreasing its effects. Hence, future studies and interventions are needed to reduce neonatal mortality and life-long morbidity.

Abstract Air pollution is a major concern in urban areas of developing countries as a result of industrial expansion and increased vehicular ownership, and in most households due to solid fuel use and garbage burning at home. Urban poverty is also widespread in developing countries, and besides perpetuating household air pollution (HAP), it has also meant hazardous occupational choices such as street vending by the urban poor. The epidemiologic evidence linking HAP exposure with adverse pregnancy outcomes is very limited. Research on the health effects of street vending is also scarce with its relationship with fetal growth still unexplored in spite of women dominating this venture. This project assessed the effects of HAP practices and ambient air pollution exposure on fetal growth and gestational duration, and elaborated the role of environmental exposures in the influence of socioeconomic deprivation on pregnancy endpoints. The project comprised an epidemiologic study, and a qualitative and quantitative synthesis of evidence. A cross-sectional study of 1,151 mothers-infant pairs accessing postnatal services at the Korle Bu Teaching Hospital in Accra (n = 592), and the four main health facilities in Cape Coast (n = 559) was conducted. Information on socioeconomic characteristics and activity patterns of mothers, and characteristics of the indoor and outdoor environment were collected in a structured questionnaire. Birth weight and gestational age was retrieved from hospital records. PUBMED, Ovid MEDLINE, SCOPUS and CINAHL databases were searched for studies investigating HAP exposure and pregnancy outcomes for the review. Multivariate modeling adjusting for confounders resulted in a 243g (95% CI: 496, 11) reduction in birth weight and 41% (risk ratio [RR] = 1.41; 95% CI: 0.62, 3.23) increased risk of low birth weight (LBW) for use of charcoal. Garbage burning was associated with a 195% (RR = 2.95; 95% CI: 1.10, 7.92) increased risk of LBW. The meta-analysis indicated an 86.43g (95% CI: 55.49, 117.37) reduction in birth weight and a 35% (summary-effect estimate [EE] = 1.35; 95% CI: 1.23, 1.48) increased risk of LBW for solid fuel use. Increased risk of other pregnancy endpoints with use of solid fuels was also noted in the meta-analysis. Moderate street vending activity and high traffic density in the vending area jointly resulted in 84% (RR = 1.84; 95% CI: 1.05, 3.24) and 29% (RR = 1.29; 95% CI: 0.68, 2.46) increased risk of LBW and preterm birth, respectively. Evidence of the effects of maternal socioeconomic disadvantage on pregnancy outcomes was noted, with HAP especially substantially mediating the observed effects. Interventions for mitigating the effects of solid fuel use on health call for eliminating barriers to the adoption of cleaner fuels and educating women about behavioral changes required to minimize exposure. Government should also extend their social safety net programs to pregnant women engaged in hazardous occupations to enable them give up or minimize the number of hours in the work. / Tiivistelmä Ilmansaasteet ovat merkittävä huolenaihe kehitysmaiden urbaaneilla alueilla teollisuuden ja ajoneuvoliikenteen lisäännyttyä sekä useimmissa kodeissa biomassan, hiilen ja jätteiden polttamisen takia. Urbaani köyhyys on kehitysmaissa laajamittaista, ja sisäilman saasteongelmien pahentamisen lisäksi se johtaa vaarallisiin ammatinvalintoihin, kuten kadulla tapahtuvaan myyntityöhön. sisäilman saasteiden ja sikiön kehityshäiriöiden välisistä yhteyksistä on kuitenkin vain vähän epidemiologisia todisteita. Katumyynnin terveysvaikutuksia on tutkittu hyvin vähän, eikä sen yhteyttä sikiön kasvuun ole tutkittu, vaikka naiset ovat vahvasti edustettuna kyseisellä alalla. Tässä väitöskirjassa tarkasteltiin sisäilman saasteiden ja ympäristön ilmansaasteiden vaikutuksia sikiön kasvuun ja raskauden kestoon sekä tutkittiin ympäristöaltisteiden roolia sosioekonomisen vähäosaisuuden vaikutuksessa sikiön kehityshäiriöihin. Väitöskirja koostuu epidemiologisesta tutkimuksesta sekä määrällisestä ja laadullisesta aineiston yhdistelemisestä. Poikittaistutkimukseen osallistui 1151 äiti-vauvaparia, jotka olivat käyneet synnytyksen jälkeen neuvolassa Korle Bu -opetussairaalassa Accrassa (n=592) tai jossain Cape Coastin neljästä pääsairaalasta (n=559). Kyselyllä kerättiin tietoa äitien sosioekonomisesta asemasta ja liikkuvuudesta sekä sisä- ja ulkoympäristön ominaisuuksista. Vauvojen syntymäpainot ja syntymähetken raskausviikot selvitettiin sairaaloiden rekistereistä. Sisäilman saasteille altistumista ja sikiön kehityshäiriöitä tarkastelevia tutkimuksia etsittiin katsausta varten PUBMED-, Ovid MEDLINE-, SCOPUS- ja CINAHL-tietokannoista. Monimuuttujamallissa, jossa sekoittavat tekijät oli huomioitu, puuhiilen käyttö pienensi syntymäpainoa 243 grammaa (95 % luottamusväli: 496-11) ja lisäsi alhaisen syntymäpainon riskiä 41 % (riskisuhde [RR]=1.41; 95 % luottamusväli: 0.62-3.23). Roskien polttoon liittyi 195 % (RR=2.95; 95 % CI: 1.10-7.92) suurentunut alhaisen syntymäpainon riski. Meta-analyysissä biomassan ja hiilen poltto alensi syntymäpainoa 86.43 grammaa (95 % luottamusväli: 55.49-117.37) ja lisäsi alhaisen syntymäpainon riskiä 35 % (meta-analyysin riskisuhde =1.35; 95 % luottamusväli: 1.23-1.48). Meta-analyysissä havaittiin myös muita biomassan ja hiilen polttoon liittyviä kohonneita kehityshäiriöiden riskejä. Kohtalainen katumyyntiaktiivisuus ja korkea liikennetiheys myyntialueella yhdessä lisäsivät matalan syntymäpainon riskiä 84 % (RR=1.84; 95 % luottamusväli: 1.05-3.24) ja ennenaikaisen syntymän riskiä 29 % (RR=1.29; 95 % luottamusväli 0.68-2.46). Tutkimuksessa todettiin äidin matalan sosioekonomisen aseman vaikutus sikiön terveyteen ja havaittiin, että sisäilman saasteiden rooli havaittujen vaikutusten välittäjänä on merkittävä. Biomassan ja hiilen polttamisesta aiheutuvien terveysuhkien ehkäisemiseksi puhtaampien polttoaineiden käyttöä tulisi edistää ja naisia tulisi valistaa siitä, kuinka ilmansaasteille altistumista voi vähentää. Hallituksen tulisi sosiaalitukien avulla mahdollistaa vaarallisissa ammateissa työskentelevien, raskaana olevien naisten työajan minimointi.

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