RESUMEN
Residential biomass burning is an important source of black carbon (BC) exposure among rural communities in low- and middle-income countries. We collected 7165 personal BC samples and individual/household level information from 3103 pregnant women enrolled in the Household Air Pollution Intervention Network trial. Women in the intervention arm received free liquefied petroleum gas stoves and fuel throughout pregnancy; women in the control arm continued the use of biomass stoves. Median (IQR) postintervention BC exposures were 9.6 µg/m3 (5.2-14.0) for controls and 2.8 µg/m3 (1.6-4.8) for the intervention group. Using mixed models, we characterized predictors of BC exposure and assessed how exposure contrasts differed between arms by select predictors. Primary stove type was the strongest predictor (R2 = 0.42); the models including kerosene use, kitchen location, education, occupation, or stove use hours also provided additional explanatory power from the base model adjusted only for the study site. Our full, trial-wide, model explained 48% of the variation in BC exposures. We found evidence that the BC exposure contrast between arms differed by study site, adherence to the assigned study stove, and whether the participant cooked. Our findings highlight factors that may be addressed before and during studies to implement more impactful cookstove intervention trials.
Asunto(s)
Culinaria , Humanos , Femenino , Embarazo , Adulto , Contaminación del Aire Interior , Hollín , Carbono , Contaminantes Atmosféricos , Exposición a Riesgos AmbientalesRESUMEN
Waste collection services are uncommon in rural areas of low-resource countries, causing waste accumulation and subsequent dumping and burning of garbage. Air pollution from household garbage burning, including plastics, has been observed in Jalapa, Guatemala in addition to household air pollution (HAP) from cooking. Adolescent girls often help with these cooking and household tasks, but little is known about their exposures. We characterized 24-h exposures to HAP and household garbage burning in adolescent girls by measuring fine particulate matter (PM2.5), black carbon (BC), urinary biomarkers of polycyclic aromatic hydrocarbons (PAHs), bisphenol A (BPA), and phthalates. We recruited 60 girls between 13 and 17 years of age who helped with cooking activities and lived with participants of the Household Air Pollution Intervention Network (HAPIN) trial. We recruited n = 30 girls each from the control (wood-burning stove) and intervention (liquefied petroleum gas stove) arms. We also measured real-time kitchen concentrations of BC in 20 homes (33%). PM2.5 and BC were measured in n = 21 control and n = 20 intervention participants. Median concentrations of personal PM2.5 and BC and kitchen BC were lower (p < 0.05) in the intervention arm by 87%, 80%, and 85%, respectively. PAH metabolite concentrations were lower (p < 0.001) for all nine metabolites in intervention (n = 26) compared to control participants (n = 29). Urinary BPA concentrations were 66% higher in participants who reported using cosmetics (p = 0.02), and phthalate concentrations were 63% higher in participants who had reported using hair products during the sample period (p = 0.05). Our results suggest that gas stoves can reduce HAP exposures among adolescents who are not primary cooks at home. Biomarkers of plastic exposure were not associated with intervention status, but some were elevated compared to age- and sex-matched participants of the National Health and Nutrition Examination Survey (NHANES).
Asunto(s)
Contaminación del Aire Interior , Contaminación del Aire , Femenino , Humanos , Adolescente , Encuestas Nutricionales , Contaminación del Aire Interior/análisis , Guatemala , Contaminación del Aire/análisis , Material Particulado/análisis , Hollín , Culinaria , Biomarcadores , Población RuralRESUMEN
Exposure to household air pollution is a leading cause of ill-health globally. The Household Air Pollution Intervention Network (HAPIN) randomized controlled trial evaluated the impact of a free liquefied petroleum gas stove and fuel intervention on birth outcomes and maternal and child health. As part of HAPIN, an extensive exposure assessment was conducted. Here, we report on PM 2.5 and CO exposures of young children (≤ 15 months old) reconstructed using a Bluetooth-beacon based time-activity monitoring system coupled with microenvironmental pollutant monitors. Median (IQR) exposures to PM 2.5 were 65.1 (33 - 128.2) µg/m 3 in the control group and 22.9 (17.2 - 35.3) µg/m3 in the intervention group; for CO, median (IQR) exposures were 1.1 (0.3 - 2.9) ppm and 0.2 (0 - 0.7) ppm for control and intervention group, respectively. Exposure reductions were stable over time and consistent with previous findings for the children's mothers. In the intervention group, 75% of children's reconstructed exposures were below the WHO interim target guideline value of 35 µg/m 3 , while 26% were below the standard in the control group. Our findings suggest that an LPG fuel and stove intervention can substantially reduce children's exposure to household air pollution.
RESUMEN
BACKGROUND: Household air pollution (HAP) from solid fuel use is associated with adverse birth outcomes, but data for exposure-response relationships are scarce. We examined associations between HAP exposures and birthweight in rural Guatemala, India, Peru, and Rwanda during the Household Air Pollution Intervention Network (HAPIN) trial. METHODS: The HAPIN trial recruited pregnant women (9-<20 weeks of gestation) in rural Guatemala, India, Peru, and Rwanda and randomly allocated them to receive a liquefied petroleum gas stove or not (ie, and continue to use biomass fuel). The primary outcomes were birthweight, length-for-age, severe pneumonia, and maternal systolic blood pressure. In this exposure-response subanalysis, we measured 24-h personal exposures to PM2·5, carbon monoxide, and black carbon once pre-intervention (baseline) and twice post-intervention (at 24-28 weeks and 32-36 weeks of gestation), as well as birthweight within 24 h of birth. We examined the relationship between the average prenatal exposure and birthweight or weight-for-gestational age Z scores using multivariate-regression models, controlling for the mother's age, nulliparity, diet diversity, food insecurity, BMI, the mother's education, neonate sex, haemoglobin, second-hand smoke, and geographical indicator for randomisation strata. FINDINGS: Between March, 2018, and February, 2020, 3200 pregnant women were recruited. An interquartile increase in the average prenatal exposure to PM2·5 (74·5 µg/m3) was associated with a reduction in birthweight and gestational age Z scores (birthweight: -14·8 g [95% CI -28·7 to -0·8]; gestational age Z scores: -0·03 [-0·06 to 0·00]), as was an interquartile increase in black carbon (7·3 µg/m3; -21·9 g [-37·7 to -6·1]; -0·05 [-0·08 to -0·01]). Carbon monoxide exposure was not associated with these outcomes (1·7; -3·1 [-12·1 to 5·8]; -0·003 [-0·023 to 0·017]). INTERPRETATION: Continuing efforts are needed to reduce HAP exposure alongside other drivers of low birthweight in low-income and middle-income countries. FUNDING: US National Institutes of Health (1UM1HL134590) and the Bill & Melinda Gates Foundation (OPP1131279).
Asunto(s)
Contaminación del Aire Interior , Contaminación del Aire , Efectos Tardíos de la Exposición Prenatal , Estados Unidos , Recién Nacido , Femenino , Humanos , Embarazo , Monóxido de Carbono/efectos adversos , Monóxido de Carbono/análisis , Material Particulado/efectos adversos , Material Particulado/análisis , Peso al Nacer , Contaminación del Aire Interior/efectos adversos , Contaminación del Aire Interior/prevención & control , Contaminación del Aire Interior/análisis , Culinaria , Contaminación del Aire/efectos adversos , Contaminación del Aire/prevención & control , HollínRESUMEN
BACKGROUND: Conflicting evidence exists on the impact of the COVID-19 pandemic restrictions on preterm birth (PTB) and stillbirth rates. We aimed to evaluate changes in PTB and stillbirth rates before and during the pandemic period and assess the potential effect modification of socioeconomic status (SES). METHODS: Using the linked administrative health databases from Manitoba, Canada, we conducted a cross-sectional study among all pregnant women, comparing 3.5 years pre-pandemic (1 October 2016 to 29 February 2020) to the first year of the pandemic (1 March 2020 to 31 March 2021). We used generalised linear models to assess the quarterly rates of PTB (<37 weeks) and stillbirths. We calculated the predicted trends based on pre-pandemic period data. Finally, we evaluated the PTB and stillbirth rates among lower and higher SES pregnant women (average annual household income) using subgroup analysis and interaction models. RESULTS: We examined 70 931 pregnancies in Manitoba during the study period. The risk of PTB increased by 7.7% (95%CI 1.01 to 1.13) and stillbirths by 33% (95% CI 1.08 to 1.64) during the pandemic period. Following COVID-19 restrictions implemented in March 2020, there were increases in the quarterly rates of both PTB (immediate increase (ß2)=1.37; p=0.0247) and stillbirths (immediate increase (ß2)=0.12; p=0.4434). Among the lower income groups, the pandemic restrictions resulted in an immediate relative increase in PTB and stillbirth rates by 20.12% (immediate increase (ß2)=3.17; p=0.0057) and 27.19% (immediate increase (ß2)=0.48; p=0.0852). However, over the pandemic, the overall PTB rate significantly decreased as a rebound effect by 0.85% per quarter (p=0.0004), whereas the overall stillbirth rate did not decrease significantly (slope decrease (ß3) =-0.01; p=0.8296) compared with the pre-pandemic period. The quarterly rates during the pandemic among the higher income group decreased by 0.39% (p=0.1296) for PTB and increased by 0.07% (p=0.1565) for stillbirth. We observed an effect modification by SES for PTB rates (p=0.047). CONCLUSION: While the onset of COVID-19 pandemic restrictions was not associated with significant effects on stillbirth rates, we observed an immediate and rebound effect on PTB rates. The impact of COVID-19 on preterm birth was dependent on SES, with higher influence on families with lower SES. Further studies are needed to detect future trend changes during pandemic waves after 2021 and assess potential underlying mechanisms.
Asunto(s)
COVID-19 , Nacimiento Prematuro , Recién Nacido , Embarazo , Humanos , Femenino , COVID-19/epidemiología , Disparidades Socioeconómicas en Salud , Estudios Transversales , Pandemias , Nacimiento Prematuro/epidemiología , Mortinato/epidemiologíaRESUMEN
BACKGROUND: Exposure to PM2.5 arising from solid fuel combustion is estimated to result in â¼2.3 million premature deaths and 91 million lost disability-adjusted life years annually. Interventions attempting to mitigate this burden have had limited success in reducing exposures to levels thought to provide substantive health benefits. OBJECTIVES: This paper reports exposure reductions achieved by a liquified petroleum gas (LPG) stove and fuel intervention for pregnant mothers in the Household Air Pollution Intervention Network (HAPIN) randomized controlled trial. METHODS: The HAPIN trial included 3,195 households primarily using biomass for cooking in Guatemala, India, Peru, and Rwanda. Twenty-four-hour exposures to PM2.5, carbon monoxide (CO), and black carbon (BC) were measured for pregnant women once before randomization into control (n=1,605) and LPG (n=1,590) arms and twice thereafter (aligned with trimester). Changes in exposure were estimated by directly comparing exposures between intervention and control arms and by using linear mixed-effect models to estimate the impact of the intervention on exposure levels. RESULTS: Median postrandomization exposures of particulate matter (PM) with aerodynamic diameter ≤2.5µm (PM2.5) in the intervention arm were lower by 66% at the first (71.5 vs. 24.1 µg/m3), and second follow-up visits (69.5 vs. 23.7 µg/m3) compared to controls. BC exposures were lower in the intervention arm by 72% (9.7 vs. 2.7 µg/m3) and 70% (9.6 vs. 2.8 µg/m3) at the first and second follow-up visits, respectively, and carbon monoxide exposure was 82% lower at both visits (1.1 vs. 0.2 ppm) in comparison with controls. Exposure reductions were consistent over time and were similar across research locations. DISCUSSION: Postintervention PM2.5 exposures in the intervention arm were at the lower end of what has been reported for LPG and other clean fuel interventions, with 69% of PM2.5 samples falling below the World Health Organization Annual Interim Target 1 of 35 µg/m3. This study indicates that an LPG intervention can reduce PM2.5 exposures to levels at or below WHO targets. https://doi.org/10.1289/EHP10295.
Asunto(s)
Contaminación del Aire , Petróleo , Monóxido de Carbono , Femenino , Humanos , Material Particulado , Embarazo , Mujeres Embarazadas , HollínRESUMEN
The Household Air Pollution Intervention Network trial is a multi-country study on the effects of a liquefied petroleum gas (LPG) stove and fuel distribution intervention on women's and children's health. There is limited data on exposure reductions achieved by switching from solid to clean cooking fuels in rural settings across multiple countries. As formative research in 2017, we recruited pregnant women and characterized the impact of the intervention on personal exposures and kitchen levels of fine particulate matter (PM2.5) in Guatemala, India, and Rwanda. Forty pregnant women were enrolled in each site. We measured cooking area concentrations of and personal exposures to PM2.5 for 24 or 48 h using gravimetric-based PM2.5 samplers at baseline and two follow-ups over two months after delivery of an LPG cookstove and free fuel supply. Mixed models were used to estimate PM2.5 reductions. Median kitchen PM2.5 concentrations were 296 µg/m3 at baseline (interquartile range, IQR: 158-507), 24 µg/m3 at first follow-up (IQR: 18-37), and 23 µg/m3 at second follow-up (IQR: 14-37). Median personal exposures to PM2.5 were 134 µg/m3 at baseline (IQR: 71-224), 35 µg/m3 at first follow-up (IQR: 23-51), and 32 µg/m3 at second follow-up (IQR: 23-47). Overall, the LPG intervention was associated with a 92% (95% confidence interval (CI): 90-94%) reduction in kitchen PM2.5 concentrations and a 74% (95% CI: 70-79%) reduction in personal PM2.5 exposures. Results were similar for each site. CONCLUSIONS: The intervention was associated with substantial reductions in kitchen and personal PM2.5 overall and in all sites. Results suggest LPG interventions in these rural settings may lower exposures to the WHO annual interim target-1 of 35 µg/m3. The range of exposure contrasts falls on steep sections of estimated exposure-response curves for birthweight, blood pressure, and acute lower respiratory infections, implying potentially important health benefits when transitioning from solid fuels to LPG.
Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminación del Aire , Petróleo , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Niño , Salud Infantil , Culinaria , Femenino , Humanos , Material Particulado/análisis , Embarazo , Mujeres Embarazadas , Población Rural , Salud de la MujerRESUMEN
BACKGROUND: High quality personal exposure data is fundamental to understanding the health implications of household energy interventions, interpreting analyses across assigned study arms, and characterizing exposure-response relationships for household air pollution. This paper describes the exposure data collection for the Household Air Pollution Intervention Network (HAPIN), a multicountry randomized controlled trial of liquefied petroleum gas stoves and fuel among 3,200 households in India, Rwanda, Guatemala, and Peru. OBJECTIVES: The primary objectives of the exposure assessment are to estimate the exposure contrast achieved following a clean fuel intervention and to provide data for analyses of exposure-response relationships across a range of personal exposures. METHODS: Exposure measurements are being conducted over the 3-y time frame of the field study. We are measuring fine particulate matter [PM < 2.5µm in aerodynamic diameter (PM2.5)] with the Enhanced Children's MicroPEM™ (RTI International), carbon monoxide (CO) with the USB-EL-CO (Lascar Electronics), and black carbon with the OT21 transmissometer (Magee Scientific) in pregnant women, adult women, and children <1 year of age, primarily via multiple 24-h personal assessments (three, six, and three measurements, respectively) over the course of the 18-month follow-up period using lightweight monitors. For children we are using an indirect measurement approach, combining data from area monitors and locator devices worn by the child. For a subsample (up to 10%) of the study population, we are doubling the frequency of measurements in order to estimate the accuracy of subject-specific typical exposure estimates. In addition, we are conducting ambient air monitoring to help characterize potential contributions of PM2.5 exposure from background concentration. Stove use monitors (Geocene) are being used to assess compliance with the intervention, given that stove stacking (use of traditional stoves in addition to the intervention gas stove) may occur. CONCLUSIONS: The tools and approaches being used for HAPIN to estimate personal exposures build on previous efforts and take advantage of new technologies. In addition to providing key personal exposure data for this study, we hope the application and learnings from our exposure assessment will help inform future efforts to characterize exposure to household air pollution and for other contexts. https://doi.org/10.1289/EHP6422.
Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Culinaria/instrumentación , Exposición Materna , Gas Natural/efectos adversos , Material Particulado/análisis , Ensayos Clínicos Controlados Aleatorios como Asunto , Adulto , Anciano , Monóxido de Carbono/análisis , Femenino , Guatemala , Humanos , India , Lactante , Recién Nacido , Persona de Mediana Edad , Perú , Embarazo , Rwanda , Hollín/análisis , Adulto JovenRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
Household air pollution (HAP) generated from solid fuel combustion is a major health risk. Direct measurement of exposure to HAP is burdensome and challenging, particularly for children. In a pilot study of the Household Air Pollution Intervention Network (HAPIN) trial in rural Guatemala, we evaluated an indirect exposure assessment method that employs fixed continuous PM2.5 monitors, Bluetooth signal receivers in multiple microenvironments (kitchen, sleeping area and outdoor patio), and a wearable signal emitter to track an individual's time within those microenvironments. Over a four-month period, we measured microenvironmental locations and reconstructed indirect PM2.5 exposures for women and children during two 24-h periods before and two periods after a liquefied petroleum gas (LPG) stove and fuel intervention delivered to 20 households cooking with woodstoves. Women wore personal PM2.5 monitors to compare direct with indirect exposure measurements. Indirect exposure measurements had high correlation with direct measurements (n = 62, Spearman ρ = 0.83, PM2.5 concentration range: 5-528 µg/m3). Indirect exposure had better agreement with direct exposure measurements (bias: -17 µg/m3) than did kitchen area measurements (bias: -89 µg/m3). Our findings demonstrate that indirect exposure reconstruction is a feasible approach to estimate personal exposure when direct assessment is not possible.
Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire Interior/análisis , Niño , Culinaria , Monitoreo del Ambiente , Femenino , Humanos , Material Particulado/análisis , Proyectos Piloto , Población RuralRESUMEN
s play the pivotal role of selling an article to a prospective reader, and for students, the ability to communicate science in concise written form may foster scientific thinking. However, students struggle with abstract composition, and we lack evidence-based educational innovations to help them develop this skill. We designed, implemented, and assessed an intervention for abstract composition with elements of scaffolding and transparency to ask whether deliberate practice improves concise scientific writing in early career undergraduate biology majors. We evaluated student performance by analyzing abstracts written before and after the intervention and by assessing pre- and posttest student concept maps. We found that scaffolded learning improved student abstract writing, with the greatest gains in students' ability to describe the motivation for their work. Using a set of tested tools to teach scientific writing has important implications for strengthening students' capacity to reinforce and synthesize content in the future, whether that is in laboratory course exercises, in independent research, or as a transferable skill to general critical thinking.
RESUMEN
One goal of postsecondary education is to assist students in developing expert-level understanding. Previous attempts to encourage expert-level understanding of phylogenetic analysis in college science classrooms have largely focused on isolated, or "one-shot," in-class activities. Using a deliberate practice instructional approach, we designed a set of five assignments for a 300-level plant systematics course that incrementally introduces the concepts and skills used in phylogenetic analysis. In our assignments, students learned the process of constructing phylogenetic trees through a series of increasingly difficult tasks; thus, skill development served as a framework for building content knowledge. We present results from 5 yr of final exam scores, pre- and postconcept assessments, and student surveys to assess the impact of our new pedagogical materials on student performance related to constructing and interpreting phylogenetic trees. Students improved in their ability to interpret relationships within trees and improved in several aspects related to between-tree comparisons and tree construction skills. Student feedback indicated that most students believed our approach prepared them to engage in tree construction and gave them confidence in their abilities. Overall, our data confirm that instructional approaches implementing deliberate practice address student misconceptions, improve student experiences, and foster deeper understanding of difficult scientific concepts.
Asunto(s)
Biología/educación , Filogenia , Enseñanza/métodos , Evaluación Educacional , Retroalimentación , Humanos , Estudiantes , PensamientoRESUMEN
Graduate students and postdoctoral fellows currently encounter requests for a statement of teaching philosophy in at least half of academic job announcements in the United States. A systematic process for the development of a teaching statement is required that integrates multiple sources of support, informs writers of the document's purpose and audience, helps writers produce thoughtful statements, and encourages meaningful reflection on teaching and learning. This article for faculty mentors and instructional consultants synthesizes practices for mentoring graduate students, postdoctoral fellows, and junior faculty members as they prepare statements of teaching philosophy. We review background information on purposes and audiences, provide writing resources, and synthesize empirical research on the use of teaching statements in academic job searches. In addition, we integrate these resources into mentoring processes that have helped graduate students in a Health Sciences Pedagogy course to collaboratively and critically examine and write about their teaching. This summary is intended for faculty mentors and instructional consultants who want to refine current resources or establish new mentoring programs. This guide also may be useful to graduate students, postdoctoral fellows, and junior faculty members, especially those who lack mentoring or who seek additional resources, as they consider the many facets of effective teaching.
Asunto(s)
Comunicación , Educación de Postgrado/métodos , Mentores , Filosofía , Enseñanza/métodos , Escritura , Conducta Cooperativa , Docentes , Retroalimentación , Humanos , Internet , Aprendizaje , Modelos Educacionales , Grupo ParitarioRESUMEN
The implementation of virtual microscopy in the teaching of pathology at the Bloomington, Indiana extension of the Indiana University School of Medicine permitted the assessment of student attitudes, use and academic performance with respect to this new technology. A gradual and integrated approach allowed the parallel assessment with respect to both the virtual and optical microscopes. Student survey data indicated that the virtual imaging technology was enthusiastically received, and aggregate grade comparisons with the previous classes showed no decrease in content mastery. Survey questions assessing a variety of parameters reveal improved time and resource utilization, as well as increased student collaboration. Even so, 50% of the respondents indicated having both optical and virtual microscopes available was preferable.