Human urinary mutagenicity after wood smoke exposure during traditional temazcal use.

In Central America, the traditional temazcales or wood-fired steam baths, commonly used by many Native American populations, are often heated by wood fires with little ventilation, and this use results in high wood smoke exposure. Urinary mutagenicity has been previously employed as a non-invasive biomarker of human exposure to combustion emissions. This study examined the urinary mutagenicity in 19 indigenous Mayan families from the highlands of Guatemala who regularly use temazcales (N = 32), as well as control (unexposed) individuals from the same population (N = 9). Urine samples collected before and after temazcal exposure were enzymatically deconjugated and extracted using solid-phase extraction. The creatinine-adjusted mutagenic potency of urine extracts was assessed using the plate-incorporation version of the Salmonella mutagenicity assay with strain YG1041 in the presence of exogenous metabolic activation. The post-exposure mutagenic potency of urine extracts were, on average, 1.7-fold higher than pre-exposure samples (P < 0.005) and also significantly more mutagenic than the control samples (P < 0.05). Exhaled carbon monoxide (CO) was ~10 times higher following temazcal use (P < 0.0001), and both CO level and time spent in temazcal were positively associated with urinary mutagenic potency (i.e. P < 0.0001 and P = 0.01, respectively). Thus, the wood smoke exposure associated with temazcal use contributes to increased excretion of conjugated mutagenic metabolites. Moreover, urinary mutagenic potency is correlated with other metrics of exposure (i.e. exhaled CO, duration of exposure). Since urinary mutagenicity is a biomarker associated with genetic damage, temazcal use may therefore be expected to contribute to an increased risk of DNA damage and mutation, effects associated with the initiation of cancer

Bringing technology into social-ecological systems research-Motivations for a socio-technical-ecological systems approach

The purpose of this synthesis paper is to present the motivations and conceptual basis for research on socio-technical-ecological systems (STES), addressing the need for interdisciplinary studies targeting the technological mediation of human-environment relationships. The background is the very limited number of collaborations between scholars of social-ecological systems and sociotechnical systems (SES), despite repeated calls for bridging work. The synthesis builds on an in-depth review of previous literature, interdisciplinary exchanges, and empirical examples. The result is arguments for why a sociotechnical understanding of \u27technology\u27 is of central importance for SES studies, related to how technology: (1) mediates human-environment relationships; (2) brings ambivalence to these relationships; (3) enhances and transforms human agency and provides a source of constitutive power; (4) changes scalar relationships, enabling our interaction with and impact on the natural world across time and space. Furthermore, we present an STES analytical approach which starts from symmetrical attention to technology, society, and environment, specifically targeting interfaces and relationships of critical relevance for SES scholars, and address counterarguments that we have encountered. We conclude that a shift to STES research will enhance our knowledge of system interfaces that are often overlooked, opening further avenues for research and real-world interventions

Bringing technology into social-ecological systems research-Motivations for a socio-technical-ecological systems approach

The purpose of this synthesis paper is to present the motivations and conceptual basis for research on socio-technical-ecological systems (STES), addressing the need for interdisciplinary studies targeting the technological mediation of human-environment relationships. The background is the very limited number of collaborations between scholars of social-ecological systems and sociotechnical systems (SES), despite repeated calls for bridging work. The synthesis builds on an in-depth review of previous literature, interdisciplinary exchanges, and empirical examples. The result is arguments for why a sociotechnical understanding of \u27technology\u27 is of central importance for SES studies, related to how technology: (1) mediates human-environment relationships; (2) brings ambivalence to these relationships; (3) enhances and transforms human agency and provides a source of constitutive power; (4) changes scalar relationships, enabling our interaction with and impact on the natural world across time and space. Furthermore, we present an STES analytical approach which starts from symmetrical attention to technology, society, and environment, specifically targeting interfaces and relationships of critical relevance for SES scholars, and address counterarguments that we have encountered. We conclude that a shift to STES research will enhance our knowledge of system interfaces that are often overlooked, opening further avenues for research and real-world interventions

Implementation Science to Accelerate Clean Cooking for Public Health

Clean cooking has emerged as a major concern for global health and development because of the enormous burden of disease caused by traditional cookstoves and fires. The World Health Organization has developed new indoor air quality guidelines that few homes will be able to achieve without replacing traditional methods with modern clean cooking technologies, including fuels and stoves. However, decades of experience with improved stove programs indicate that the challenge of modernizing cooking in impoverished communities includes a complex, multi-sectoral set of problems that require implementation research. The National Institutes of Health, in partnership with several government agencies and the Global Alliance for Clean Cookstoves, has launched the Clean Cooking Implementation Science Network that aims to address this issue. In this article, our focus is on building a knowledge base to accelerate scale-up and sustained use of the cleanest technologies in low- and middle-income countries. Implementation science provides a variety of analytical and planning tools to enhance effectiveness of clinical and public health interventions. These tools are being integrated with a growing body of knowledge and new research projects to yield new methods, consensus tools, and an evidence base to accelerate improvements in health promised by the renewed agenda of clean cooking.Fil: Rosenthal, Joshua. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Balakrishnan, Kalpana. Sri Ramachandra University; IndiaFil: Bruce, Nigel. University of Liverpool; Reino UnidoFil: Chambers, David. National Institutes of Health. National Cancer Institute; Estados UnidosFil: Graham, Jay. The George Washington University; Estados UnidosFil: Jack, Darby. Columbia University; Estados UnidosFil: Kline, Lydia. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Masera, Omar Raul. Universidad Nacional Autónoma de México; MéxicoFil: Mehta, Sumi. Global Alliance for Clean Cookstoves; Estados UnidosFil: Mercado, Ilse Ruiz. Universidad Nacional Autónoma de México; MéxicoFil: Neta, Gila. National Institutes of Health. National Cancer Institute; Estados UnidosFil: Pattanayak, Subhrendu. University of Duke; Estados UnidosFil: Puzzolo, Elisa. Global LPG Partnership; Estados UnidosFil: Petach, Helen. U.S. Agency for International Development; Estados UnidosFil: Punturieri, Antonello. National Heart, Lung, and Blood Institute; Estados UnidosFil: Rubinstein, Adolfo Luis. Instituto de Efectividad Clínica y Sanitaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sage, Michael. Centers for Disease Control and Prevention; Estados UnidosFil: Sturke, Rachel. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Shankar, Anita. University Johns Hopkins; Estados UnidosFil: Sherr, Kenny. University of Washington; Estados UnidosFil: Smith, Kirk. University of California at Berkeley; Estados UnidosFil: Yadama, Gautam. Washington University in St. Louis; Estados Unido

The Stove Adoption Process: Quantification Using Stove Use Monitors (SUMs) in Households Cooking with Fuelwood

The exposure to the toxic products of the incomplete combustion of wood, charcoal, crop residues and dung used as cooking and heating fuels kills 1.6 million people every year. This leading environmental health risk also accounts for about one-third of the global human-caused black carbon emissions. Stove technologies that vent smoke to the outside of a house and have verified improved combustion efficiencies have been identified as a solution to the household air pollution problem. However, a persistent barrier to success has been the lack of systematic and proven ways to ensure that households continue using the stoves in the long-term and reduce their open fire practices.Over thirty-five years of experience with cookstove dissemination have demonstrated that providing access to the stoves is necessary but not sufficient: people need to accept bringing the stoves into the home (initial acceptance), use them on a the long-term basis (sustained use), incorporate them into their cooking practices, reduce their open-fire use, and importantly, the devices must maintain their performance through time. These seemingly obvious requirements imply that objective metrics need to be developed for these system parameters and ways found to optimize them. The optimization requires better understanding of the cooking technology-behavior interface and an integrative systems perspective to analyze the socio-cultural, economic, ecological and infrastructural factors that regulate the performance of cookstove programs.This dissertation presents a framework of analysis to characterize stove adoption and it introduces the field methods, signal analysis, metrics and visualization tools to quantify the adoption process using low-cost temperature dataloggers as Stove Use Monitors (SUMs). The SUMs enable the parameterization of stove usage behavior as a critical stove performance parameter that can be objectively measured, unobtrusively monitored and systematically evaluated together with the reductions in air pollution exposures, fuel consumption and greenhouse gas emissions. Data from two biomass chimney-stove case studies are presented: the Guatemala CRECER-RESPIRE stove trial and the Mexico Patsari Stove Project. In the first two chapters I review the main approaches to study the stove adoption process. I propose a new framework that redefines the emphasis previously placed solely on the stove technology, extending it to include the whole cooking system, thereby including the dynamic complex interactions between stoves, fuels and household behavior with the greater socioeconomic and ecological contexts. I argue that at the household level the innovation being introduced is not only the stove technology, but a set of modified or new cooking practices. When a new stove is brought into the home, the interactions between the user and the previous cooking fuels and devices are redefined. Each fuel-device combination creates its own niche and is used for the cooking tasks where it best fits the needs of the user ("the adoption niche"). This adoption process commonly leads to the combined use (or "stacking") of new and traditional stoves and fuels and to the redistribution of the cooking tasks that are performed with each device. Drawing from field data and well-documented experiences at the two study sites I find that at the population level the adoption process has three stages: initial adoption, sustained use, and disadoption. Further, I find that the process can be characterized by the following critical parameters: level of acceptance, level of initial use, level of sustained use, time for stabilization, and magnitude of the seasonal fluctuations.In the third chapter I introduce the concept of Stove Use Monitors (SUMs), devices that objectively quantify stove use through direct measurements of physical or chemical parameters on stoves, cookware or food. Using Thermochron iButton temperature dataloggers as SUMs I recorded the initial adoption and sustained use by 82 households in the Guatemala CRECER stove trial. During the 32 months of the study, I recorded stove temperature signals from a total of 31,112 stove-days, with a 10% data loss rate. I present the protocols for sensor placement, data collection and data management specific to these sensors. I implemented a peak detection algorithm based on the instantaneous derivatives and the statistical long-term behavior of the stove and the ambient temperature signals to count the number of daily meals and determine daily usage. The fraction of days in use from all stoves and days monitored in a period (the "percent stove-days") and other key quantitative metrics are defined and their population-averaged behavior and statistical variability are modeled. Using robust Poisson regression models I detected small (3-12%) but statistically significant seasonal variations in the population level of use, while the age of the stove and household size at baseline did not produce statistically significant variations. Usage was highest during the warm-dry period from February to April, with 92% stove-days (95% CI: 87%, 97%) and 2.56 daily meals (95% CI: 2.40, 2.74); and it was lower during the warm-rainy season of May to November and the cold-dry season of November to February. The high levels of sustained use found reflect optimal conditions for stove adoption in the CRECER trial. The narrow confidence intervals highlight the precision and accuracy of the SUMs to detect the small seasonal fluctuations. Modeling the variability with a random effects model I find an intraclass correlation coefficient of 76%, confirming the stability of daily use behavior within households, whereas the main sources of variance are found between homes. In the fourth chapter I study the critical role of behavior in the adoption process and in the delivery of benefits from cookstoves. I focus on the patterns of stove stacking found in the RESPIRE and CRECER studies. Using graphic representations for hierarchical clustering analysis ("heat maps"), I identify groups of households that had similar combined stove-fire use behavioral patterns ("stove stacking clusters"). Despite the high levels of stove use measured with the SUMs, fifty-percent of the households reported continued use of an open fire. The preparation of animal feed was the task most commonly performed with the fire (46% of the households) followed by the boiling of corn kernels to prepare tortillas (nixtamal, 25%), space heating (13%), boiling water (11%) and preparing food for the family (11%). The stratification of the SUMs-measured stove use was strongly driven by the preferences of the households for using the stove or the fire for specific tasks. Clusters that performed a larger number of tasks with the fire had lower stove usage. This explains why the between-household differences in the SUMs-measured stove use in the regression models could not be accounted for by the fixed characteristics of the households. Chapter five presents an integrated discussion and the concluding remarks of the dissertation. I conclude that when the energy end-uses of the open fires extend beyond cooking, cookstoves become imperfect substitutes for all fire tasks. Therefore, in addition to monitoring cookstove use it is crucial to include the residual use of traditional fires in the assessment of the impacts brought by the sustained use of new a cookstove. I describe current research efforts in the development of monitoring tools for stove adoption and discuss the need for open source platforms to scale up stove use monitoring and to merge fuel consumption, air pollution and emissions data with stove use parameters. The Stove Use Monitors can herald a new era of research to elucidate the behavioral determinants of stove usage and cookfire prevalence, which had not been possible previously at larger scales due to a lack of objective measurements. It is equally critical to develop analytical frameworks and quantitative monitoring tools to identify the distinct behaviors affecting each of the stages of the stove adoption process and to understand the role of other behaviors that influence the exposure to household air pollutants, such as the time-activity and time-location patterns of the household members, kitchen ventilation, fuel preparation, stove operation and stove maintenance practices

The Stove Adoption Process: Quantification Using Stove Use Monitors (SUMs) in Households Cooking with Fuelwood

The exposure to the toxic products of the incomplete combustion of wood, charcoal, crop residues and dung used as cooking and heating fuels kills 1.6 million people every year. This leading environmental health risk also accounts for about one-third of the global human-caused black carbon emissions. Stove technologies that vent smoke to the outside of a house and have verified improved combustion efficiencies have been identified as a solution to the household air pollution problem. However, a persistent barrier to success has been the lack of systematic and proven ways to ensure that households continue using the stoves in the long-term and reduce their open fire practices.Over thirty-five years of experience with cookstove dissemination have demonstrated that providing access to the stoves is necessary but not sufficient: people need to accept bringing the stoves into the home (initial acceptance), use them on a the long-term basis (sustained use), incorporate them into their cooking practices, reduce their open-fire use, and importantly, the devices must maintain their performance through time. These seemingly obvious requirements imply that objective metrics need to be developed for these system parameters and ways found to optimize them. The optimization requires better understanding of the cooking technology-behavior interface and an integrative systems perspective to analyze the socio-cultural, economic, ecological and infrastructural factors that regulate the performance of cookstove programs.This dissertation presents a framework of analysis to characterize stove adoption and it introduces the field methods, signal analysis, metrics and visualization tools to quantify the adoption process using low-cost temperature dataloggers as Stove Use Monitors (SUMs). The SUMs enable the parameterization of stove usage behavior as a critical stove performance parameter that can be objectively measured, unobtrusively monitored and systematically evaluated together with the reductions in air pollution exposures, fuel consumption and greenhouse gas emissions. Data from two biomass chimney-stove case studies are presented: the Guatemala CRECER-RESPIRE stove trial and the Mexico Patsari Stove Project. In the first two chapters I review the main approaches to study the stove adoption process. I propose a new framework that redefines the emphasis previously placed solely on the stove technology, extending it to include the whole cooking system, thereby including the dynamic complex interactions between stoves, fuels and household behavior with the greater socioeconomic and ecological contexts. I argue that at the household level the innovation being introduced is not only the stove technology, but a set of modified or new cooking practices. When a new stove is brought into the home, the interactions between the user and the previous cooking fuels and devices are redefined. Each fuel-device combination creates its own niche and is used for the cooking tasks where it best fits the needs of the user ("the adoption niche"). This adoption process commonly leads to the combined use (or "stacking") of new and traditional stoves and fuels and to the redistribution of the cooking tasks that are performed with each device. Drawing from field data and well-documented experiences at the two study sites I find that at the population level the adoption process has three stages: initial adoption, sustained use, and disadoption. Further, I find that the process can be characterized by the following critical parameters: level of acceptance, level of initial use, level of sustained use, time for stabilization, and magnitude of the seasonal fluctuations.In the third chapter I introduce the concept of Stove Use Monitors (SUMs), devices that objectively quantify stove use through direct measurements of physical or chemical parameters on stoves, cookware or food. Using Thermochron iButton temperature dataloggers as SUMs I recorded the initial adoption and sustained use by 82 households in the Guatemala CRECER stove trial. During the 32 months of the study, I recorded stove temperature signals from a total of 31,112 stove-days, with a 10% data loss rate. I present the protocols for sensor placement, data collection and data management specific to these sensors. I implemented a peak detection algorithm based on the instantaneous derivatives and the statistical long-term behavior of the stove and the ambient temperature signals to count the number of daily meals and determine daily usage. The fraction of days in use from all stoves and days monitored in a period (the "percent stove-days") and other key quantitative metrics are defined and their population-averaged behavior and statistical variability are modeled. Using robust Poisson regression models I detected small (3-12%) but statistically significant seasonal variations in the population level of use, while the age of the stove and household size at baseline did not produce statistically significant variations. Usage was highest during the warm-dry period from February to April, with 92% stove-days (95% CI: 87%, 97%) and 2.56 daily meals (95% CI: 2.40, 2.74); and it was lower during the warm-rainy season of May to November and the cold-dry season of November to February. The high levels of sustained use found reflect optimal conditions for stove adoption in the CRECER trial. The narrow confidence intervals highlight the precision and accuracy of the SUMs to detect the small seasonal fluctuations. Modeling the variability with a random effects model I find an intraclass correlation coefficient of 76%, confirming the stability of daily use behavior within households, whereas the main sources of variance are found between homes. In the fourth chapter I study the critical role of behavior in the adoption process and in the delivery of benefits from cookstoves. I focus on the patterns of stove stacking found in the RESPIRE and CRECER studies. Using graphic representations for hierarchical clustering analysis ("heat maps"), I identify groups of households that had similar combined stove-fire use behavioral patterns ("stove stacking clusters"). Despite the high levels of stove use measured with the SUMs, fifty-percent of the households reported continued use of an open fire. The preparation of animal feed was the task most commonly performed with the fire (46% of the households) followed by the boiling of corn kernels to prepare tortillas (nixtamal, 25%), space heating (13%), boiling water (11%) and preparing food for the family (11%). The stratification of the SUMs-measured stove use was strongly driven by the preferences of the households for using the stove or the fire for specific tasks. Clusters that performed a larger number of tasks with the fire had lower stove usage. This explains why the between-household differences in the SUMs-measured stove use in the regression models could not be accounted for by the fixed characteristics of the households. Chapter five presents an integrated discussion and the concluding remarks of the dissertation. I conclude that when the energy end-uses of the open fires extend beyond cooking, cookstoves become imperfect substitutes for all fire tasks. Therefore, in addition to monitoring cookstove use it is crucial to include the residual use of traditional fires in the assessment of the impacts brought by the sustained use of new a cookstove. I describe current research efforts in the development of monitoring tools for stove adoption and discuss the need for open source platforms to scale up stove use monitoring and to merge fuel consumption, air pollution and emissions data with stove use parameters. The Stove Use Monitors can herald a new era of research to elucidate the behavioral determinants of stove usage and cookfire prevalence, which had not been possible previously at larger scales due to a lack of objective measurements. It is equally critical to develop analytical frameworks and quantitative monitoring tools to identify the distinct behaviors affecting each of the stages of the stove adoption process and to understand the role of other behaviors that influence the exposure to household air pollutants, such as the time-activity and time-location patterns of the household members, kitchen ventilation, fuel preparation, stove operation and stove maintenance practices

Ecology and sociotechnical systems research – motivations for theoretical and methodological integration across fields

Currently, we are witnessing a number of global trends that do not promise well for the future. Accelerating climate change, loss of biodiversity, chemical pollution, disappearance of natural forest and degradation of fishing grounds and agricultural lands are just a few of the serious environmental problems that threaten the functional and structural integrity of ecosystems, to an extent that also human societies risk collapse. The scale of human impact is now such that scholars suggest that we live in the Anthropocene. The trends are driven by several linked factors, which are not easily disentangled into manageable specific problems to be solved by specific policies. More than ever, interdisciplinary and transdisciplinary collaborations are needed in order to address these urgent challenges. The objective of this paper is to argue for the importance of research on socio-technical-ecological systems (STES) rather than social-ecological (SES) and sociotechnical systems (STS) separately. Hence, we address researchers in both the social-ecological and sociotechnical fields. We organize the argument around six reasons why “technology” should be integrated into SES studies. We call these reasons: (1) the interface and mediation aspect, (2) ambivalence, (3) the agency aspect, (4) the question of scale, (5) the question of governance and politics, and (6) the question of epistemology and framing. We also highlight potential conceptual conflicts and mistranslations. Our discussion is primarily a theoretical argument, exemplified with empirical examples.Among the conceptual challenges, we note that SES scholars, if they consider technology in their analyses, generally treat it as an exogenous factor or as a passive background element. Similarly, STS scholars tend to neglect ecological dynamics and refer to the ecological domain mainly in terms of inputs and outputs, e.g. natural resources, environmental and health problems caused by human activities. In light of the discussion, we conclude that the importance of collaborating across the two fields goes beyond each field adding pieces together. We argue that integration and translation across these domains will lead to qualitative change in the theoretical and methodological approaches of both fields; and that technology, society and ecology should be given symmetric analytical attention

Quantitative metrics of stove adoption using Stove Use Monitors (SUMs)

The sustained use of cookstoves that are introduced to reduce fuel use or air pollution needs to be objectively monitored to verify the sustainability of these benefits. Quantifying stove adoption requires affordable tools, scalable methods and validated metrics of usage. We quantified the longitudinal patterns of chimney-stove use of 80 households in rural Guatemala, monitored with Stove Use Monitors (SUMs) during 32 months. We counted daily meals and days in use at each monitoring period and defined metrics like the percent stove-days in use (the fraction of days in use from all stoves and days monitored). Using robust Poisson regressions we detected small seasonal variations in stove usage, with peaks in the warm-dry season at 92% stove-days (95%CI: 87%,97%) and 2.56 average daily meals (95%CI: 2.40,2.74). With respect to these values, the percent stove-days in use decreased by 3% and 4% during the warm-rainy and cold-dry periods respectively, and the daily meals by 5% and 12% respectively. Cookstove age and household size at baseline did not affect usage. Qualitative indicators of use from recall questionnaires were consistent with SUMs measurements, indicating stable sustained use and questionnaire accuracy. These results reflect optimum conditions for cookstove adoption and for monitoring in this project, which may not occur in disseminations undertaken elsewhere. The SUMs measurements suggests that 90% stove-days is a more realistic best-case for sustained use than the 100% often assumed. Half of sample reported continued use of open-cookfires, highlighting the critical need to verify reduction of open-fire practices in stove disseminations