RESUMEN
RATIONALE: Household air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown. OBJECTIVES: The Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determine the effect of early childhood HAP exposure on growth of lung function. METHODS: RESPIRE households with pregnant women or infant children were randomised to receive a chimney stove at the beginning or at the end of the 18-month trial. During CRECER, a subset of these children, as well as children from households with newly installed stoves, were followed with spirometry beginning at age 5. Biomass smoke exposure was measured using personal carbon monoxide tubes. Two-stage regression models were employed to analyse associations with lung function growth. MEASUREMENTS AND MAIN RESULTS: Longitudinal peak expiratory flow (PEF) and FEV1 data were available for 443 and 437 children, respectively, aged 5-8 (mean follow-up 1.3â years). Decreases in PEF growth of 173â mL/min/year (95% CI -341 to -7) and FEV1 of 44â mL/year (95% CI -91 to 4) were observed with stove installation at 18â months compared with stove installation at birth in analyses adjusted for multiple covariates. No statistically significant associations were observed between personal HAP exposure and lung function. CONCLUSIONS: A significant decrease in PEF growth and a large non-significant decrease in FEV1 growth were observed with later stove installation. Additional studies including longer follow-up and cleaner stoves or fuels are needed.
Asunto(s)
Contaminación del Aire Interior/efectos adversos , Monóxido de Carbono/efectos adversos , Culinaria , Flujo Espiratorio Forzado , Material Particulado/efectos adversos , Neumonía/inducido químicamente , Mujeres Embarazadas , Población Rural , Humo/efectos adversos , Madera/efectos adversos , Contaminación del Aire Interior/análisis , Niño , Preescolar , Guatemala/epidemiología , Humanos , Incidencia , Ápice del Flujo Espiratorio , Neumonía/mortalidad , Neumonía/prevención & control , Estudios Prospectivos , Población Rural/estadística & datos numéricos , Naciones UnidasRESUMEN
BACKGROUND: COPD is the third most frequent cause of death globally, with much of this burden attributable to household biomass smoke exposure in developing countries. As biomass smoke exposure is also associated with cardiovascular disease, lower respiratory infection, lung cancer, and cataracts, it presents an important target for public health intervention. METHODS: Lung function in Guatemalan women exposed to wood smoke from open fires was measured throughout the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) stove intervention trial and continued during the Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER) cohort study. In RESPIRE, early stove households received a chimney woodstove at the beginning of the 18-month trial, and delayed stove households received a stove at trial completion. Personal exposure to wood smoke was assessed with exhaled breath carbon monoxide (CO) and personal CO tubes. Change in lung function between intervention groups and as a function of wood smoke exposure was assessed using random effects models. RESULTS: Of 306 women participating in both studies, acceptable spirometry was collected in 129 early stove and 136 delayed stove households (n = 265), with a mean follow-up of 5.6 years. Despite reduced wood smoke exposures in early stove households, there were no significant differences in any of the measured spirometric variables during the study period (FEV1, FVC, FEV1/FVC ratio, and annual change) after adjustment for confounding. CONCLUSIONS: In these young Guatemalan women, there was no association between lung function and early randomization to a chimney stove or personal wood smoke exposure. Future stove intervention trials should incorporate cleaner stoves, longer follow-up, or potentially susceptible groups to identify meaningful differences in lung function.
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Contaminación del Aire Interior/efectos adversos , Monóxido de Carbono/análisis , Enfermedades Ambientales/epidemiología , Material Particulado/efectos adversos , Respiración/efectos de los fármacos , Población Rural , Madera , Adulto , Niño , Culinaria , Enfermedades Ambientales/fisiopatología , Femenino , Guatemala/epidemiología , Humanos , Incidencia , Humo , EspirometríaRESUMEN
BACKGROUND: With 40% of the world's population relying on solid fuel, household air pollution (HAP) represents a major preventable risk factor for COPD (chronic obstructive pulmonary disease). Meta-analyses have confirmed this relationship; however, constituent studies are observational, with virtually none measuring exposure directly. OBJECTIVES: We estimated associations between HAP exposure and respiratory symptoms and lung function in young, nonsmoking women in rural Guatemala, using measured carbon monoxide (CO) concentrations in exhaled breath and personal air to assess exposure. METHODS: The Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) Guatemala study was a trial comparing respiratory outcomes among 504 women using improved chimney stoves versus traditional cookstoves. The present analysis included 456 women with data from postintervention surveys including interviews at 6, 12, and 18 months (respiratory symptoms) and spirometry and CO (ppm) in exhaled breath measurements. Personal CO was measured using passive diffusion tubes at variable times during the study. Associations between CO concentrations and respiratory health were estimated using random intercept regression models. RESULTS: Respiratory symptoms (cough, phlegm, wheeze, or chest tightness) during the previous 6 months were positively associated with breath CO measured at the same time of symptom reporting and with average personal CO concentrations during the follow-up period. CO in exhaled breath at the same time as spirometry was associated with lower lung function [average reduction in FEV1 (forced expiratory volume in 1 sec) for a 10% increase in CO was 3.33 mL (95% CI: -0.86, -5.81)]. Lung function measures were not significantly associated with average postintervention personal CO concentrations. CONCLUSIONS: Our results provide further support for the effects of HAP exposures on airway inflammation. Further longitudinal research modeling continuous exposure to particulate matter against lung function will help us understand more fully the impact of HAP on COPD.
Asunto(s)
Contaminación del Aire Interior/efectos adversos , Incendios , Fenómenos Fisiológicos Respiratorios/efectos de los fármacos , Madera , Adulto , Contaminación del Aire Interior/prevención & control , Monóxido de Carbono/análisis , Culinaria , Femenino , Humanos , Material Particulado/análisis , Población Rural , Humo/efectos adversos , Adulto JovenRESUMEN
BACKGROUND: More than two-fifths of the world's population uses solid fuels, mostly biomass, for cooking. The resulting biomass smoke exposure is a major cause of chronic obstructive pulmonary disease (COPD) among women in developing countries. OBJECTIVE: To assess whether lower woodsmoke exposure from use of a stove with a chimney, compared to open fires, is associated with lower markers of airway inflammation in young women. DESIGN: We carried out a cross-sectional analysis on a sub-cohort of participants enrolled in a randomized controlled trial in rural Guatemala, RESPIRE. PARTICIPANTS: We recruited 45 indigenous women at the end of the 18-month trial; 19 women who had been using the chimney stove for 18-24 months and 26 women still using open fires. MEASUREMENTS: We obtained spirometry and induced sputum for cell counts, gene expression of IL-8, TNF-α, MMP-9 and 12, and protein concentrations of IL-8, myeloperoxidase and fibronectin. Exhaled carbon monoxide (CO) and 48-hr personal CO tubes were measured to assess smoke exposure. RESULTS: MMP-9 gene expression was significantly lower in women using chimney stoves. Higher exhaled CO concentrations were significantly associated with higher gene expression of IL-8, TNF-α, and MMP-9. Higher 48-hr personal CO concentrations were associated with higher gene expression of IL-8, TNF- α, MMP-9 and MMP-12; reaching statistical significance for MMP-9 and MMP-12. CONCLUSIONS: Compared to using an open wood fire for cooking, use of a chimney stove was associated with lower gene expression of MMP-9, a potential mediator of airway remodeling. Among all participants, indoor biomass smoke exposure was associated with higher gene expression of multiple mediators of airway inflammation and remodeling; these mechanisms may explain some of the observed association between prolonged biomass smoke exposure and COPD.
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Contaminantes Atmosféricos/efectos adversos , Inflamación/patología , Enfermedad Pulmonar Obstructiva Crónica/etiología , Población Rural , Humo/efectos adversos , Adulto , Monóxido de Carbono/química , Estudios de Cohortes , Estudios Transversales , Femenino , Fibronectinas/metabolismo , Guatemala , Humanos , Interleucina-8/metabolismo , Metaloproteinasa 12 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Peroxidasa/metabolismo , Espirometría , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
OBJECTIVES: We identified barriers to care seeking for pneumonia and diarrhea among rural Guatemalan children. METHODS: A population-based survey was conducted twice from 2008 to 2009 among 1605 households with children younger than 5 years. A 14-day calendar recorded episodes of carer-reported pneumonia (n = 364) and diarrhea (n = 481), and formal (health services, public, private) and informal (neighbors, traditional, local shops, pharmacies) care seeking. RESULTS: Formal care was sought for nearly half of severe pneumonias but only for 27% within 2 days of onset, with 31% and 18%, respectively, for severe diarrhea. In multivariable analysis, factors independently associated with formal care seeking were knowing the Community Emergency Plan, mother's perception of illness severity, recognition of World Health Organization danger signs, distance from the health center, and having someone to care for family in an emergency. CONCLUSIONS: Proximal factors associated with recognizing need for care were important in determining formal care, and were strongly linked to social determinants. In addition to specific action by the health system with an enhanced community health worker role, a systems approach can help ensure barriers are addressed among poorer and more remote homes.
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Diarrea/terapia , Aceptación de la Atención de Salud , Neumonía/terapia , Adulto , Preescolar , Recolección de Datos , Diarrea/epidemiología , Femenino , Guatemala/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Humanos , Lactante , Entrevistas como Asunto , Masculino , Aceptación de la Atención de Salud/estadística & datos numéricos , Neumonía/epidemiología , Población Rural/estadística & datos numéricos , Índice de Severidad de la Enfermedad , Factores SocioeconómicosRESUMEN
Household air pollution (HAP) due to solid fuel use is a major public health threat in low-income countries. Most health effects are thought to be related to exposure to the fine particulate matter (PM) component of HAP, but it is currently impractical to measure personal exposure to PM in large studies. Carbon monoxide (CO) has been shown in cross-sectional analyses to be a reliable surrogate for particles<2.5 µm in diameter (PM2.5) in kitchens where wood-burning cookfires are a dominant source, but it is unknown whether a similar PM2.5-CO relationship exists for personal exposures longitudinally. We repeatedly measured (216 measures, 116 women) 24-hour personal PM2.5 (median [IQR]â=â0.11 [0.05, 0.21] mg/m(3)) and CO (median [IQR]â=â1.18 [0.50, 2.37] mg/m(3)) among women cooking over open woodfires or chimney woodstoves in Guatemala. Pollution measures were natural-log transformed for analyses. In linear mixed effects models with random subject intercepts, we found that personal CO explained 78% of between-subject variance in personal PM2.5. We did not see a difference in slope by stove type. This work provides evidence that in settings where there is a dominant source of biomass combustion, repeated measures of personal CO can be used as a reliable surrogate for an individual's PM2.5 exposure. This finding has important implications for the feasibility of reliably estimating long-term (months to years) PM2.5 exposure in large-scale epidemiological and intervention studies of HAP.
Asunto(s)
Contaminación del Aire Interior , Monóxido de Carbono/análisis , Material Particulado/análisis , Vigilancia en Salud Pública , Adulto , Femenino , Guatemala , Humanos , Estudios Longitudinales , Peso Molecular , Tamaño de la PartículaRESUMEN
BACKGROUND: Pneumonia causes more child deaths than does any other disease. Observational studies have indicated that smoke from household solid fuel is a significant risk factor that affects about half the world's children. We investigated whether an intervention to lower indoor wood smoke emissions would reduce pneumonia in children. METHODS: We undertook a parallel randomised controlled trial in highland Guatemala, in a population using open indoor wood fires for cooking. We randomly assigned 534 households with a pregnant woman or young infant to receive a woodstove with chimney (n=269) or to remain as controls using open woodfires (n=265), by concealed permuted blocks of ten homes. Fieldworkers visited homes every week until children were aged 18 months to record the child's health status. Sick children with cough and fast breathing, or signs of severe illness were referred to study physicians, masked to intervention status, for clinical examination. The primary outcome was physician-diagnosed pneumonia, without use of a chest radiograph. Analysis was by intention to treat (ITT). Infant 48-h carbon monoxide measurements were used for exposure-response analysis after adjustment for covariates. This trial is registered, number ISRCTN29007941. FINDINGS: During 29,125 child-weeks of surveillance of 265 intervention and 253 control children, there were 124 physician-diagnosed pneumonia cases in intervention households and 139 in control households (rate ratio [RR] 0·84, 95% CI 0·63-1·13; p=0·257). After multiple imputation, there were 149 cases in intervention households and 180 in controls (0·78, 0·59-1·06, p=0·095; reduction 22%, 95% CI -6% to 41%). ITT analysis was undertaken for secondary outcomes: all and severe fieldworker-assessed pneumonia; severe (hypoxaemic) physician-diagnosed pneumonia; and radiologically confirmed, RSV-negative, and RSV-positive pneumonia, both total and severe. We recorded significant reductions in the intervention group for three severe outcomes-fieldworker-assessed, physician-diagnosed, and RSV-negative pneumonia--but not for others. We identified no adverse effects from the intervention. The chimney stove reduced exposure by 50% on average (from 2·2 to 1·1 ppm carbon monoxide), but exposure distributions for the two groups overlapped substantially. In exposure-response analysis, a 50% exposure reduction was significantly associated with physician-diagnosed pneumonia (RR 0·82, 0·70-0·98), the greater precision resulting from less exposure misclassification compared with use of stove type alone in ITT analysis. INTERPRETATION: In a population heavily exposed to wood smoke from cooking, a reduction in exposure achieved with chimney stoves did not significantly reduce physician-diagnosed pneumonia for children younger than 18 months. The significant reduction of a third in severe pneumonia, however, if confirmed, could have important implications for reduction of child mortality. The significant exposure-response associations contribute to causal inference and suggest that stove or fuel interventions producing lower average exposures than these chimney stoves might be needed to substantially reduce pneumonia in populations heavily exposed to biomass fuel air pollution. FUNDING: US National Institute of Environmental Health Sciences and WHO.
Asunto(s)
Contaminación del Aire Interior/efectos adversos , Culinaria , Incendios , Neumonía/prevención & control , Madera , Contaminación del Aire Interior/prevención & control , Monóxido de Carbono/análisis , Exposición a Riesgos Ambientales/efectos adversos , Guatemala/epidemiología , Humanos , Lactante , Neumonía/diagnóstico , Neumonía/epidemiología , Vigilancia de la Población , Infecciones por Virus Sincitial Respiratorio/epidemiología , Índice de Severidad de la Enfermedad , Humo/efectos adversosRESUMEN
BACKGROUND: A growing body of evidence indicates a relationship between household indoor air pollution from cooking fires and adverse neonatal outcomes, such as low birth weight (LBW), in resource-poor countries. OBJECTIVE: We examined the effect of reduced wood smoke exposure in pregnancy on LBW of Guatemalan infants in RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects). METHODS: Pregnant women (n = 266) either received a chimney stove (intervention) or continued to cook over an open fire (control). Between October 2002 and December 2004 we weighed 174 eligible infants (69 to mothers who used a chimney stove and 105 to mothers who used an open fire during pregnancy) within 48 hr of birth. Multivariate linear regression and adjusted odds ratios (ORs) were used to estimate differences in birth weight and LBW (< 2,500 g) associated with chimney-stove versus open-fire use during pregnancy. RESULTS: Pregnant women using chimney stoves had a 39% reduction in mean exposure to carbon monoxide compared with those using open fires. LBW prevalence was high at 22.4%. On average, infants born to mothers who used a stove weighed 89 g more [95% confidence interval (CI), -27 to 204 g] than infants whose mothers used open fires after adjusting for maternal height, diastolic blood pressure, gravidity, and season of birth. The adjusted OR for LBW was 0.74 (95% CI, 0.33-1.66) among infants of stove users compared with open-fire users. Average birth weight was 296 g higher (95% CI, 109-482 g) in infants born during the cold season (after harvest) than in other infants; this unanticipated finding may reflect the role of maternal nutrition on birth weight in an impoverished region. CONCLUSIONS: A chimney stove reduced wood smoke exposures and was associated with reduced LBW occurrence. Although not statistically significant, the estimated effect was consistent with previous studies.
Asunto(s)
Contaminación del Aire Interior , Peso al Nacer/efectos de los fármacos , Culinaria , Exposición Materna/efectos adversos , Humo/efectos adversos , Madera , Adolescente , Adulto , Contaminación del Aire Interior/efectos adversos , Monóxido de Carbono/toxicidad , Femenino , Guatemala , Humanos , Recién Nacido , Embarazo , Adulto JovenRESUMEN
During the first randomized intervention trial (RESPIRE: Randomized Exposure Study of Pollution Indoors and Respiratory Effects) in air pollution epidemiology, we pioneered application of passive carbon monoxide (CO) diffusion tubes to measure long-term personal exposures to woodsmoke. Here we report on the protocols and validations of the method, trends in personal exposure for mothers and their young children, and the efficacy of the introduced improved chimney stove in reducing personal exposures and kitchen concentrations. Passive diffusion tubes originally developed for industrial hygiene applications were deployed on a quarterly basis to measure 48-hour integrated personal carbon monoxide exposures among 515 children 0-18 months of age and 532 mothers aged 15-55 years and area samples in a subsample of 77 kitchens, in households randomized into control and intervention groups. Instrument comparisons among types of passive diffusion tubes and against a continuous electrochemical CO monitor indicated that tubes responded nonlinearly to CO, and regression calibration was used to reduce this bias. Before stove introduction, the baseline arithmetic (geometric) mean 48-h child (n=270), mother (n=529) and kitchen (n=65) levels were, respectively, 3.4 (2.8), 3.4 (2.8) and 10.2 (8.4) p.p.m. The between-group analysis of the 3355 post-baseline measurements found CO levels to be significantly lower among the intervention group during the trial period: kitchen levels: -90%; mothers: -61%; and children: -52% in geometric means. No significant deterioration in stove effect was observed over the 18 months of surveillance. The reliability of these findings is strengthened by the large sample size made feasible by these unobtrusive and inexpensive tubes, measurement error reduction through instrument calibration, and a randomized, longitudinal study design. These results from the first randomized trial of improved household energy technology in a developing country and demonstrate that a simple chimney stove can substantially reduce chronic exposures to harmful indoor air pollutants among women and infants.
Asunto(s)
Contaminación del Aire Interior/análisis , Monóxido de Carbono/análisis , Culinaria/instrumentación , Monitoreo del Ambiente/métodos , Exposición por Inhalación/análisis , Exposición Materna , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Guatemala , Humanos , Lactante , Persona de Mediana Edad , Embarazo , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Regresión , Humo/análisis , Madera , Adulto JovenRESUMEN
Exposure to household wood smoke from cooking is a risk factor for chronic obstructive lung disease among women in developing countries. The Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) is a randomized intervention trial evaluating the respiratory health effects of reducing indoor air pollution from open cooking fires. A total of 504 rural Mayan women in highland Guatemala aged 15-50 years, all using traditional indoor open fires, were randomized to either receive a chimney woodstove (plancha) or continue using the open fire. Assessments of chronic respiratory symptoms and lung function and individual measurements of carbon monoxide exposure were performed at baseline and every 6 months up to 18 months. Use of a plancha significantly reduced carbon monoxide exposure by 61.6%. For all respiratory symptoms, reductions in risk were observed in the plancha group during follow-up; the reduction was statistically significant for wheeze (relative risk = 0.42, 95% confidence interval: 0.25, 0.70). The number of respiratory symptoms reported by the women at each follow-up point was also significantly reduced by the plancha (odds ratio = 0.7, 95% confidence interval: 0.50, 0.97). However, no significant effects on lung function were found after 12-18 months. Reducing indoor air pollution from household biomass burning may relieve symptoms consistent with chronic respiratory tract irritation.
Asunto(s)
Contaminación del Aire Interior/prevención & control , Incendios , Lesión Pulmonar/etiología , Sistema Respiratorio/lesiones , Enfermedades Respiratorias/etiología , Humo/efectos adversos , Adolescente , Adulto , Contaminación del Aire Interior/efectos adversos , Monóxido de Carbono/toxicidad , Intervalos de Confianza , Culinaria/métodos , Utensilios de Comida y Culinaria , Países en Desarrollo , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Guatemala/epidemiología , Humanos , Estudios Longitudinales , Lesión Pulmonar/epidemiología , Lesión Pulmonar/fisiopatología , Oportunidad Relativa , Prevalencia , Pruebas de Función Respiratoria , Sistema Respiratorio/fisiopatología , Enfermedades Respiratorias/epidemiología , Enfermedades Respiratorias/fisiopatología , Factores de Riesgo , Madera/efectos adversos , Adulto JovenRESUMEN
BACKGROUND: Epidemiology frequently relies on surrogates of long-term exposures, often either individual-level short-term measurements or group-level based on long-term characteristics of subjects and their environment. Whereas individual-level measures are often imprecise due to within-subject variability, group-level measures tend to be inaccurate due to residual between-subject variability within groups. Rather than choose between these error-prone estimates, we borrow strength from each by use of mixed-model prediction and we compare the predictive validity. METHODS: We compared alternative measures of long-term exposure to carbon monoxide (CO) among children in the RESPIRE woodstove randomized control trial during years 2003 and 2004. The main study included 1932 repeated 48-hour-average personal CO measures among 509 children from 0-18 months of age. We used a validation study with additional CO measures among a random subsample of 70 of the children to compare the predictive validity of individual-level estimates (based on observed short-term exposures), group-level estimates (based on stove type and other residential characteristics), and mixed-model predictions that combine these 2 sources of information. RESULTS: The estimated error variance for mixed-model prediction was 63% lower than the individual-level measure based on the exposure data and 58% lower than the corresponding group-level measure. CONCLUSIONS: When both individual- and group-level estimates are available but imperfect, mixed-model prediction may provide substantially better measures of long-term exposure, potentially increasing the sensitivity of epidemiologic studies to underlying causal relations.
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Contaminación del Aire Interior/análisis , Monóxido de Carbono/análisis , Incineración/métodos , Adolescente , Adulto , Culinaria , Métodos Epidemiológicos , Femenino , Guatemala , Humanos , Lactante , Recién Nacido , Masculino , Modelos Teóricos , Estudios de Validación como Asunto , Adulto JovenRESUMEN
BACKGROUND: Indoor air pollution (IAP) from solid fuels is a serious health problem in low-income countries that can be alleviated using improved stoves. Although women are the principal users, few studies have investigated the self-assessed impact of the stoves on their health and lives. METHODS: This study was conducted in rural highland Guatemala, involving 89 intervention and 80 control Mayan Indian young women (mean 27.8 years, SD 7.2). Outcomes were assessed after approximately 18 months use of the new stove. Our objectives were to compare self-rated health and change in health among women participating in a randomised control trial comparing a chimney stove with an open fire, to describe impacts on women's daily lives and their perceptions of how reduced kitchen smoke affects their own and their children's health. RESULTS: On intention-to-treat analysis, 52.8% of intervention women reported improvement in health, compared to 23.8% of control women (p < 0.001). Among 84 intervention women who reported reduced kitchen smoke as an important change, 88% linked this to improvement in their own health, particularly for non-respiratory symptoms (for example eye discomfort, headache); 57% linked reduced smoke to improvement in their children's health, particularly sore eyes. CONCLUSION: Women's perception of their health was improved, but although smoke reduction was valued, this was linked mainly with alleviation of non-respiratory symptoms like eye discomfort and headache. More focus on such symptoms may help in promoting demand for improved stoves and cleaner fuels, but education about more severe consequences of IAP exposure is also required.
RESUMEN
OBJECTIVE: Trials of environmental risk factors and acute lower respiratory infections (ALRI) face a double challenge: implementing sufficiently sensitive and specific outcome assessments, and blinding. We evaluate methods used in the first randomized exposure study of pollution indoors and respiratory effects (RESPIRE): a controlled trial testing the impact of reduced indoor air pollution on ALRI, conducted among children
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Contaminantes Atmosféricos/toxicidad , Contaminación del Aire Interior/efectos adversos , Neumonía/epidemiología , Adulto , Antígenos Virales/sangre , Comorbilidad , Femenino , Incendios , Guatemala/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Oximetría , Neumonía/diagnóstico , Neumonía/etiología , Pobreza , Embarazo , Radiografía Torácica , Proyectos de Investigación , Virus Sincitial Respiratorio Humano/inmunología , Infecciones del Sistema Respiratorio/complicaciones , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Factores de RiesgoRESUMEN
Estimating the prevalence of asthma is an epidemiologic challenge, particularly in rural areas of lesser-developed countries characterized by low literacy and poor access to health care. To avoid under or over reporting of symptoms, questionnaires must use terminology familiar to participants and that accurately describes the triad of cough, wheeze and breathlessness characteristic of asthma. In preparation for a large longitudinal cohort study entitled Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER) that will examine the effects of variable early lifetime woodsmoke exposure on the respiratory health of Mam-speaking children residing in communities in the western highlands of Guatemala, we conducted individual interviews (n=18) and five focus groups (n=46) with indigenous women from 17 of these communities to elicit and define local Mam and Spanish terms for common respiratory symptoms used to describe their own and their children's respiratory symptoms. Focus group participants were also shown an International Study of Asthma and Allergies in Childhood (ISAAC) video of wheezing children and adults. We developed a conceptual framework that can be used as an efficient model for future studies investigating health and/or disease terminology in isolated communities, an integral step in the development of standardized questionnaires. Among this Mam-speaking population, wheeze was best described as nxwisen or ntzarrin, "breathing sounds that are heard in the neck but come from the chest." The variation in understanding of terms between women with and without children with a history of wheeze (such that for those without wheezing children some terms were virtually unrecognized), has important implications for large-scale population surveys within countries and comparative surveys such as ISAAC. It is important to use linguistically and culturally appropriate terminology to describe wheeze in prevalence studies of asthmatic symptoms among relatively isolated communities in lesser-developed countries.
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Asma/etnología , Actitud Frente a la Salud/etnología , Indígenas Sudamericanos/psicología , Madres/psicología , Ruidos Respiratorios/clasificación , Salud Rural/estadística & datos numéricos , Terminología como Asunto , Asma/clasificación , Asma/diagnóstico , Niño , Preescolar , Femenino , Grupos Focales , Guatemala/epidemiología , Humanos , Indígenas Sudamericanos/educación , Masculino , Madres/educación , Cuello/fisiopatología , Prevalencia , Encuestas y Cuestionarios , Tórax/fisiopatología , Traducción , Grabación en VideoRESUMEN
BACKGROUND: Indoor air pollution (IAP) from combustion of biomass fuels represents a global health problem, estimated to cause 1.6 million premature deaths annually. AIMS: RESPIRE (Randomised Exposure Study of Pollution Indoors and Respiratory Effects) Guatemala is the first randomised controlled trial ever performed on health effects from solid fuel use. Its goal is to assess the effect of improved stoves (planchas) on exposure and health outcomes in a rural population reliant on wood fuel. METHODS: Questions about symptoms were asked at baseline and periodically after the intervention, to an initial group of 504 women (259 randomly assigned to planchas (mean (standard deviation) age 27.4 (7.2) years) and 245 using traditional open fires (28.1 (7.1) years)). Levels of carbon monoxide (CO) in exhaled breath, a biomarker of recent exposure to air pollution from biomass combustion, were measured at each visit. In addition to reducing IAP levels, the plancha may also have a positive health effect by changing the working posture to an upright position. RESULTS: A high prevalence of eye discomfort, headache and backache was found. The odds of having sore eyes and headache were substantially reduced in the plancha group relative to the group using open fires for the follow-up period (odds ratio (OR) 0.18, 95% confidence interval (CI) 0.11 to 0.29 and (OR) 0.63, 95% CI 0.42 to 0.94, respectively). Median CO in breath among women in the intervention trial was significantly lower than controls. CONCLUSION: In addition to reducing discomfort for women, tangible improvements in symptoms experienced by a substantial proportion of women may help to gain acceptance and wider use of planchas.
Asunto(s)
Contaminación del Aire Interior/análisis , Dolor de Espalda/epidemiología , Monóxido de Carbono/análisis , Exposición a Riesgos Ambientales/análisis , Oftalmopatías/epidemiología , Cefalea/epidemiología , Adulto , Contaminación del Aire Interior/efectos adversos , Dolor de Espalda/inducido químicamente , Pruebas Respiratorias , Monóxido de Carbono/efectos adversos , Culinaria/instrumentación , Exposición a Riesgos Ambientales/efectos adversos , Oftalmopatías/inducido químicamente , Femenino , Guatemala/epidemiología , Cefalea/inducido químicamente , Artículos Domésticos/instrumentación , Humanos , Salud Rural , Ventilación , Madera/efectos adversosRESUMEN
The goal of this study was to assess the impact of improved stoves, house ventilation, and child location on levels of indoor air pollution and child exposure in a rural Guatemalan population reliant on wood fuel. The study was a random sample of 204 households with children less than 18 months in a rural village in the western highlands of Guatemala. Socio-economic and household information was obtained by interview and observation. Twenty-four hour carbon monoxide (CO) was used as the primary measure of kitchen pollution and child exposure in all homes, using Gastec diffusion tubes. Twenty-four hour kitchen PM(3.5) was measured in a random sub-sample (n=29) of kitchens with co-located CO tubes. Almost 50% of the homes still used open fires, around 30% used chimney stoves (planchas) mostly from a large donor-funded programme, and the remainder of homes used various combinations including bottled gas and open fires. The 24-h kitchen CO was lowest for homes with self-purchased planchas: mean (95% CI) CO of 3.09 ppm (1.87-4.30) vs. 12.4 ppm (10.2-14.5) for open fires. The same ranking was found for child CO exposure, but with proportionately smaller differentials (P<0.0001). The 24-h kitchen PM(3.5) in the sub-sample showed similar differences (n=24, P<0.05). The predicted child PM for all 203 children (based on a regression model from the sub-sample) was 375 microg/m(3) (270-480) for self-purchased planchas and 536 microg/m(3) (488-584) for open fires. Multivariate analysis showed that stove/fuel type was the most important determinant of kitchen CO, with some effect of kitchen volume and eaves. Stove/fuel type was also the key determinant of child CO, with some effect of child position during cooking. The improved stoves in this community have been effective in reducing indoor air pollution and child exposure, although both measures were still high by international standards. Large donor-funded stove programmes need to aim for wider acceptance and uptake by the local families. Better stove maintenance is also required.
Asunto(s)
Contaminación del Aire Interior/análisis , Contaminación del Aire Interior/prevención & control , Culinaria , Exposición a Riesgos Ambientales , Arquitectura y Construcción de Instituciones de Salud , Artículos Domésticos/normas , Vivienda , Monóxido de Carbono/análisis , Femenino , Guatemala , Encuestas Epidemiológicas , Humanos , Lactante , Recién Nacido , Masculino , Movimiento , Clase Social , VentilaciónRESUMEN
We estimated the prevalence and severity of asthma, and the association with cooking on open wood fires, as preparation for a large-scale randomized field trial on effects of indoor air pollution and child health. This is one of the first systematic studies of asthma and indoor wood-smoke pollution and to our knowledge the first asthma study in a purely indigeneous population in Latin America. The mothers of 1058 children aged 4-6 years were interviewed, using the standardized ISAAC (International Study of Asthma and Allergies in Childhood) procedures and questionnaire. The study population is a Mam-speaking (Maya), indigenous group living at relatively high altitude (2000 m) in Western Guatemalan Highlands. We found that asthma prevalence is low among indigenous children in Guatemala, compared to other populations in Latin America. Only 3.3% of the children reported wheezing symptoms in the last 12 months, and 72% wheezing symptoms ever. The majority of the current wheezers had at least one of the criteria for severe asthma. The prevalence of all the symptoms of asthma was higher in children from households that used open fires compared to improved stoves with chimneys. In a logistic regression model, use of open fire for cooking was a significant risk factor for a number of asthma symptoms, with odds ratios varying from 2.0 to 3.5. Among the different cooking technologies (1-improved stove with chimney, 2-mixture of gas and open fire, 3-open fire) trends of higher prevalence with more pollution was found for some of the symptoms. Hence use of open fire for cooking, may be an important risk factor for asthma symptoms and severity.
Asunto(s)
Contaminación del Aire Interior/efectos adversos , Asma/epidemiología , Asma/etiología , Culinaria , Países en Desarrollo , Humo/efectos adversos , Asma/patología , Biomasa , Niño , Preescolar , Estudios Epidemiológicos , Femenino , Guatemala , Humanos , Incineración , Masculino , Prevalencia , Población Rural , Índice de Severidad de la Enfermedad , MaderaRESUMEN
In this study, we aimed to establish whether domestic use of wood fuel is associated with reduced birth weight, independent of key maternal, social, and economic confounding factors. We studied 1,717 women and newborn children in rural and urban communities in rural Guatemala. We identified subjects through home births reported by traditional birth attendants in six rural districts (n = 572) and all public hospital births in Quetzaltenango city during the study period (n = 1,145). All were seen within 72 hr of delivery, and data were collected on the type of household fuel used, fire type, and socioeconomic and other confounding factors. Smoking among women in the study community was negligible. Children born to mothers habitually cooking on open fires (n = 861) had the lowest mean birth weight of 2,819 g [95% confidence interval (CI), 2,790-2,848]; those using a chimney stove (n = 490) had an intermediate mean of 2,863 g (95% CI, 2,824-2,902); and those using the cleanest fuels (electricity or gas, n = 365) had the highest mean of 2,948 g (95% CI, 2,898-2,998) (p< 0.0001). The percentage of low birth weights (< 500 g) in these three groups was 19.9% (open fire), 16.8% (chimney stove), and 16.0% (electricity/gas), (trend (p = 0.08). Confounding factors were strongly associated with fuel type, but after adjustment wood users still had a birth weight 63 g lower (p = 0.05; 95% CI, 0.4-126). This is the first report of an association between biofuel use and reduced birth weight in a human population. Although there is potential for residual confounding despite adjustment, the better-documented evidence on passive smoking and a feasible mechanism through carbon monoxide exposure suggest this association may be real. Because two-thirds of households in developing countries still rely on biofuels and women of childbearing age perform most cooking tasks, the attributable risk arising from this association, if confirmed, could be substantial.