Revisión rápida: monitoreo de la presencia e infectividad del virus SARS-CoV-2 y otros coronavirus en aguas residuales / Quick review: monitoring the presence and infectivity of SARS-CoV-2 and other coronaviruses in wastewater

Resumen: Objetivo: Describir la evidencia sobre la presencia e infectividad de SARS-CoV-2 y otros coronavirus en aguas residuales y su potencial uso como herramienta de vigilancia epidemiológica. Material y métodos: Búsqueda de publicaciones en PubMed y medRxiv desde enero 2003 hasta el 8 de junio de 2020 de acuerdo con la guía de revisiones rápidas de Cochrane. Resultados: Se incluyeron 29 publicaciones. El ARN de SARS-CoV-2 no infectivo se encontró en agua residual hospitalaria, agua residual cruda, tratada y lodos de plantas de tratamiento. Los niveles cuantitativos de ARN viral en agua residual presentan relación con el número de casos de Covid-19. SARS-CoV-1 y otros coronavirus permanecieron infectivos en agua residual cruda hasta por dos días. Conclusiones: Hasta esta revisión no existe evidencia sobre la presencia de virus infectivos de SARS-CoV-2 en agua residual cruda o tratada. La cuantificación de ARN de SARS-CoV-2 en agua residual es útil para la vigilancia epidemiológica.

Abstract: Objective: To describe the current evidence on the presence and infectivity of SARS-CoV-2 and other coronaviruses in wastewater; and its potential use as an epidemiological surveillance tool. Materials and methods: A search was performed in PubMed and medRxiv databases from January 2003 to June 8, 2020 according to the Cochrane Rapid Review Guide. Results: Twenty-nine publications were included. Non-infective RNA of SARS-CoV-2 has been detected in hospital sewage; raw and treated wastewater, and primary sludges from sewage treatment plants. Quantitative levels of viral RNA in wastewater are related with the number of Covid-19 cases. SARS-CoV-1 and other coronaviruses remained infective in wastewater up to two days. Conclusions: Currently, there is no evidence of the presence of infective SARS-CoV-2 in wastewater and its inactivation through treatment/disinfection has been proven. Quantification of SARS-CoV-2 RNA in wastewater can be a useful epidemiological surveillance tool.

Prenatal exposure to VOCs and NOx and lung function in preschoolers.

BACKGROUND: Several studies have shown that exposure to air pollutants affects lung growth and development and can result in poor respiratory health in early life. METHODS: We included a subsample of 772 Mexican preschoolers whose mothers participated in a Prenatal Omega-3 fatty acid Supplements, GRowth, And Development birth cohort study with the aim to evaluate the impact of prenatal exposure to volatile organic compounds and nitrogen oxides on lung function measured by oscillation tests. The preschoolers were followed until 5 years of age. Anthropometric measurements and forced oscillation tests were performed at 36, 48, and 60 months of age. Information on sociodemographic and health characteristics was obtained during follow up. Prenatal exposure to volatile organic compounds and nitrogen oxides was evaluated using a land use regression models and the association between them was tested using a lineal regression and longitudinal linear mixed effect models adjusting for potential confounders. RESULTS: Overall, the mean (standard deviation) of the measurements of respiratory system resistance and respiratory system reactance at 6, 8, and 10 Hz during the follow-up period was 11.3 (2.4), 11.1 (2.4), 10.3 (2.2) and -5.2 (1.6), -4.8 (1.7), and -4.6 hPa s L-1 (1.6), respectively. We found a significantly positive association between respiratory resistance (ßRrs6 = 0.011; 95%CI: 0.001, 0.023) (P < .05) and prenatal exposure to nitrogen dioxide and a marginally negatively association between respiratory reactance (ßXrs6 = -11.40 95%CI: -25.26, 1.17 and ßXrs8 = -11.91 95%CI: -26.51, 1.43) (P = .07) and prenatal exposure to xylene. CONCLUSION: Prenatal exposure to air pollutants was significantly associated with the alteration of lung function measured by oscillation tests in these preschool children.

Revisión rápida: monitoreo de la presencia e infectividad del virus SARS-CoV-2 y otros coronavirus en aguas residuales.

Objetivo. Describir la evidencia sobre la presencia e infectividad de SARS-CoV-2 y otros coronavirus en aguas residuales y su potencial uso como herramienta de vigilancia epidemiológica. Material y métodos. Búsqueda de publicaciones en PubMed y medRxiv desde enero 2003 hasta el 8 de junio de 2020 de acuerdo con la guía de revisiones rápidas de Cochrane. Resultados. Se incluyeron 29 publicaciones. El ARN de SARS-CoV-2 no infectivo se encontró en agua residual hospitalaria, agua residual cruda, tratada y lodos de plantas de tratamiento. Los niveles cuantitativos de ARN viral en agua residual presentan relación con el número de casos de Covid-19. SARS-CoV-1 y otros coronavirus permanecieron infectivos en agua residual cruda hasta por dos días. Conclusiones. Hasta esta revisión no existe evidencia sobre la presencia de virus infectivos de SARS-CoV-2 en agua residual cruda o tratada. La cuantificación de ARN de SARS-CoV-2 en agua residual es útil para la vigilancia epidemiológica.

Women exposure to household air pollution after an improved cookstove program in rural San Luis Potosi, Mexico.

The state government of San Luis Potosí (SLP), Mexico implemented an improved cookstove (ICS) program in rural areas. As part of the comprehensive program evaluation, we compared fine particulate material (PM2.5) concentrations in kitchens and patios in treated (TH), and non-treated households (NTH), and analyzed pollutant levels according to patterns of fuels and devices use reported by the women. A panel study was conducted in 728 households (357 TH and 371 NTH) in three regions of SLP including two sampling rounds in 2015-16. Data on exposure determinants, ICS conditions and cooking practices were collected. Daily PM2.5 in kitchen and patio was measured in a subsample. The average treatment effect was estimated using the double difference method. We constructed a mixed linear model to estimate PM2.5 levels for the entire study sample and obtained personal exposure according to time-activity logs. NTH had lower socioeconomic status compared to TH. The average daily PM2.5 concentrations in NTH compared to TH were 155.2 and 92.6 µg/m3 for kitchen and 35.4 and 39.8 µg/m3 for patio, respectively. PM2.5 levels showed significant regional differences but no significant treatment effect. In many cases, the ICS was added to previous open fire and LPG use (stacking). The household size, kitchen ventilation, relative humidity, temperature and the ratio of indoor/outdoor PM2.5 concentration were significant predictors of kitchen PM2.5 levels. The daily PM2.5 personal exposure was significantly reduced using ICS in good conditions or LPG (57 µg/m3) compared to the traditional open fire (86 µg/m3). This study strengthens the evidence on the potential daily PM2.5 exposure reduction for women using an ICS in good conditions or LPG, displacing the polluting open fire. Comprehensive strategies tailored to the sociocultural context of the communities are needed to implement clean energy programs that achieve adoption and sustained use of ICS or LPG.

Air Pollution and Suicide in Mexico City: A Time Series Analysis, 2000-2016.

The association between air pollution and suicide has recently been under examination, and the findings continue to be contradictory. In order to contribute evidence to this still unresolved question, the objective of the present study was to evaluate the association between air quality and daily suicides registered in Mexico City (MC) between 2000 and 2016. Air quality was measured based on exposure to particulate matter under 2.5 and 10 micrometers (µm) (PM2.5 and PM10, respectively), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), adjusting for weather variables (air temperature and relative humidity), and holidays. To this end, an ecologic time series analysis was performed using a Poisson regression model conditioned by time and stratified by gender and age groups. Models were also generated to explore the lagged and accumulative effects of air pollutants, adjusted by weather variables. The effects of the pollutants were very close to the null value in the majority of the models, and no accumulative effects were identified. We believe these results, in this case, no evidence of a statistical association, contribute to the current debate about whether the association between air pollution and suicide reported in the scientific literature reflects an actual effect or an uncontrolled confounding effect.

A follow-up study after an improved cookstove intervention in rural Mexico: Estimation of household energy use and chronic PM2.5 exposure.

The benefits of improved biomass cookstoves (ICS) depends on their adoption and sustained use. Few studies have documented if and how they are used more than five years after being introduced. We conducted a 9-year prospective cohort study among young rural women in the highlands of Michoacan, Mexico. Participants had received a Patsari ICS during a community trial either in 2005 or 2006. With retrospective information collected in 2012-13, we studied the households' energy use, ICS survival, and cooking practices during the follow-up period. Using an exposure model constructed with personal PM2.5 measurements in a subsample of homes at the time of the initial trial in 2005, we estimated the exposure associated with different energy use patterns during the follow-up period. The ICS had a mean lifespan of 4 years, after which more than half of the stoves were not in use; therefore, the use of open fire increased, particularly among the indigenous communities. ICS use peak was achieved two years after the initial trial, either exclusively or combined with open fire. Yearly household energy use and other variables were used to estimate chronic air pollution exposure. Mean PM2.5 exposure during the follow-up period ranged from 51 to 319 µg/m3; the median was 102 and 146 µg/m3 for mainly ICS and mainly open fire use, respectively. The ICS has a useful period after which it needs maintenance, repair, or replacement. Unfortunately, many programs have not afforded a follow-up component. Exposure to biomass smoke air pollutants can be reduced by using an ICS instead of the traditional open fire. Household energy strategies should ensure equitable access to clean energy options adapted to local needs and preferences with culturally appropriate technology implemented on a sustainable perspective.

Environmental Health Promotion of a Contaminated Site in Mexico.

Entangled in complex ecological, sociocultural, and economic systems, current environmental health problems require integrated participatory approaches. Alpuyeca, a semi-urban, highly marginalized community in South-Central Mexico burdened by lead and polychlorinated biphenyl (PCB) contamination, dengue fever, and intestinal diseases, illustrates this. Its residents are distinctive, however, for their concerted actions in the face of environmental problems and the presence of defenders of a prehispanic worldview based on the protection of nature. This article addresses the health impacts of an integrated environmental health promotion strategy implemented through a participatory action research intervention based on qualitative and quantitative methods. Different actors, sectors, dimensions, and knowledge types were harmonized in a collaborative space created specifically for our interdisciplinary research team, community residents and local authorities. Reflections, plans and actions were developed collectively in this space with the view of finding solutions anchored in the local culture. Results included sharp reductions in blood-lead concentrations among children, in entomological indices, and in PCB contamination, as well as capacity strengthening. Medium-level community participation was achieved. This work contributes evidence that participatory environmental health research can be effective in analyzing and reducing problems in communities with multiple environmental health concerns. It complements ecohealth and environmental health literacy approaches.

Evaluation of the effect of an environmental management program on exposure to manganese in a mining zone in Mexico.

BACKGROUND: In the state of Hidalgo, Mexico, is found the largest second deposit of Manganese (Mn) in Latin America. Various studies on the sources of emission, exposure, and the effects on the health of children and adults have been conducted utilizing an ecosystem approach. Given the findings of Mn levels in air and the neurocognitive effects, an Environmental Management Program (EMP) was designed and implemented with the purpose of reducing exposure to Mn of the population, including various actions for reducing Mn emissions into the atmosphere. OBJECTIVE: To evaluate the impact of the EMP on the concentrations of Mn in air, as well as the modification of exposure to Mn in the blood and hair of adult residents of the communities intervened. METHODS: A quasi-experimental study was conducted in five rural communities, in which Mn concentrations were evaluated in air and in blood in the years 2002 and 2007, pre-intervention, and in 2013, postintervention. In 2003, the concentration of hair Mn among the communities was evaluated. Measurements were carried out of Particulate Matter (PM) of >10 and 2.5µm (PM10 and PM2.5), and Mn in PM10 and PM2.5 were measured using proton-induced X-ray emissions (PIXE). The method of Difference in Differences (DID) was applied to estimate the impact of EMP on Mn concentrations in particulate matter via linear regression through multilevel models. To evaluate the effect of Mn concentrations in air over Mn concentrations in blood in both study periods in the mining communities per year (2002 and 2013), a linear regression model for each year was employed. RESULTS: We estimated that the EMP contributed to reducing the average daily concentrations of Mn in PM10 and PM2.5 by 92 and 85%, respectively. The adjusted model did not show an effect of Mn concentrations in air over Mn concentrations in blood in both study periods. CONCLUSIONS: The results suggest that the measures implemented to reduce Mn emissions in air exerted a significant impact on the reduction of inhaled exposure in adult population.

State of Children Environmental Health Research in Latin America.

BACKGROUND: Promotion of biomedical research along with the development of evidence-based prevention policies have been suggested as an effective way to reduce environmental risks for children's health in Latin America. However, there is little information on the current state of childhood environmental health research, which might help identify its strengths and limitations, as well as to design a strategy to improve the future of child environmental health research in the region. OBJECTIVE: To describe the current state of environmental health research on children exposed to environmental pollutants in Latin America. METHODOLOGY: We performed a comprehensive search of published peer-reviewed environmental health articles (1994-2014), dealing with the exposure of Latin American children to chemical compounds. We described the type of studies and their research topics, and identified networks of co-authors. We also analyzed the relationship between research funding sources and the impact factor (IF) of the journal where research was published. RESULTS: The average number of publications was about 20 per year. Mexico and Brazil produced almost 70% of the 409 identified papers. The most studied contaminant was lead, but research on this element has declined since 2005. Retrospective studies were the most frequent, and also showed a decreasing trend. Most studies did not assess health effects. Four groups of leading investigators and two collaboration models for scientific production were identified. Except for Mexico, there was very little collaboration with North American and European countries. Compared to articles that did not report financial support, those that received international funding had on average an IF around 7, and those with national funding reached a mean IF near 3. CONCLUSION: There is a limited number of publications and insufficient collaboration between Latin-American scientists. It is necessary to identify strategies to stimulate South-South-North alliances and strengthen the scarce research on the environmental health of children in the region.

Prenatal Exposure to Nitrogen Oxides and its Association with Birth Weight in a Cohort of Mexican Newborns from Morelos, Mexico.

BACKGROUND: The Child-Mother binomial is potentially susceptible to the toxic effects of pollutants because some chemicals interfere with placental transfer of nutrients, thus affecting fetal development, and create an increased the risk of low birth weight, prematurity and intrauterine growth restriction. OBJECTIVE: To evaluate the impact of prenatal exposure to nitrogen oxides (NOx) on birth weight in a cohort of Mexican newborns. METHODOLOGY: We included 745 mother-child pair participants of the POSGRAD cohort study. Information on socio-demographic characteristics, obstetric history, health history and environmental exposure during pregnancy were readily available and the newborns' anthropometric measurements were obtained at delivery. Prenatal NOx exposure assessment was evaluated using a Land-Use Regression predictive models considering local monitoring from 60 sites on the State of Morelos. The association between prenatal exposure to NOx and birth weight was estimated using a multivariate linear regression models. RESULTS: The average birth weight was 3217 ± 439 g and the mean of NOx concentration was 21 ppb (Interquartile range, IQR = 6.95 ppb). After adjusting for maternal age and other confounders, a significant birthweight reduction was observed for each IQR of NOx increase (ß = -39.61 g, 95% CI: -77.00; -2.21; p = 0.04). CONCLUSIONS: Our results provides evidence that prenatal NOx exposure has a negative effect on birth weight, which may influence the growth and future development of the newborn.

Modeling and estimating manganese concentrations in rural households in the mining district of Molango, Mexico.

Airborne manganese (Mn) is considered the most hazardous route of exposure since Mn particles can enter into the body through the lung and may access the brain directly through olfactory uptake, thereby bypassing homeostatic excretory mechanisms. Environmental indoor and outdoor manganese concentrations in PM2.5 were monitored in ten rural households from two communities of Hidalgo, Mexico, from 2006 to 2007. Indoor and outdoor air samples of PM2.5 were collected using MiniVol samplers, and Mn concentrations in the filters were measured using proton-induced X-ray emission (PIXE). An adjusted generalized linear mixed model was applied and then used for estimating indoor concentrations in non-monitored households. Our monitoring results showed a higher daily average concentration of indoor PM2.5 vs. outdoor PM2.5 (46.4 vs. 36.2 µg/m(3), respectively); however, manganese concentration in PM2.5 indoor and outdoor was 0.09 µg/m(3) in both sceneries. Predictor variables of indoor Mn concentration were outdoor Mn concentration (64.5% increase per 0.1 µg/m(3) change in Mn) and keeping the windows open (4.2% increase). Using these predictors, the average estimated indoor Mn concentration in PM2.5 was 0.07 µg/m(3) (SD = 0.05). Our results confirm the direct effect of outdoor Mn levels, opening house windows, and the distance to the mining chimney in indoor Mn levels in houses.

Population health diagnosis with an ecohealth approach.

OBJECTIVE: To analyze the characteristics of health diagnosis according to the ecohealth approach in rural and urban communities in Mexico. METHODS: Health diagnosis were conducted in La Nopalera, from December 2007 to October 2008, and in Atlihuayan, from December 2010 to October 2011. The research was based on three principles of the ecohealth approach: transdisciplinarity, community participation, gender and equity. To collect information, a joint methodology and several techniques were used to stimulate the participation of inhabitants. The diagnostic exercise was carried out in five phases that went from collecting information to prioritization of problems. RESULTS: The constitution of the transdisciplinary team, as well as the participation of the population and the principle of gender/equity were differentials between the communities. In the rural community, the active participation of inhabitants and authorities was achieved and the principles of transdisciplinarity and gender/equity were incorporated. CONCLUSIONS: With all the difficulties that entails the boost in participation, the incorporation of gender/equity and transdisciplinarity in health diagnosis allowed a holistic public health approach closer to the needs of the population.

Effect of Personal Exposure to PM2.5 on Respiratory Health in a Mexican Panel of Patients with COPD.

BACKGROUND: Air pollution is a problem, especially in developing countries. We examined the association between personal exposure to particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5) on respiratory health in a group of adults with chronic obstructive pulmonary disease (COPD). METHODS: All participants resided in Mexico City and during follow-up, personal exposure to PM2.5, respiratory symptoms, medications, and daily activity were registered daily. Peak expiratory flow (PEF) was measured twice daily, from February through December, 2000, in 29 adults with moderate, severe, and very severe COPD. PEF changes were estimated for each 10 µg/m³ increment of PM2.5, adjustment for severity of COPD, minimum temperature, and day of the sampling. RESULTS: For a 10-µg/m³ increase in the daily average of a two-day personal exposure to PM2.5, there was a significant 33% increase in cough (95% CI, range, 5-69%), and 23% in phlegm (95% CI, range, 2-54%), a reduction of the PEF average in the morning of -1.4 L/min. (95% CI , range, -2.8 to -0.04), and at night of -3.0 L/min (95% CI, range, -5.7 to -0.3), respectively. CONCLUSIONS: Exposure to PM2.5 was associated with reductions in PEF and increased respiratory symptoms in adults with COPD. The PEF reduction was observed both at morning and at night.

Population health diagnosis with an ecohealth approach / Diagnóstico de salud poblacional con enfoque de ecosalud

OBJECTIVE To analyze the characteristics of health diagnosis according to the ecohealth approach in rural and urban communities in Mexico.METHODS Health diagnosis were conducted in La Nopalera, from December 2007 to October 2008, and in Atlihuayan, from December 2010 to October 2011. The research was based on three principles of the ecohealth approach: transdisciplinarity, community participation, gender and equity. To collect information, a joint methodology and several techniques were used to stimulate the participation of inhabitants. The diagnostic exercise was carried out in five phases that went from collecting information to prioritization of problems.RESULTS The constitution of the transdisciplinary team, as well as the participation of the population and the principle of gender/equity were differentials between the communities. In the rural community, the active participation of inhabitants and authorities was achieved and the principles of transdisciplinarity and gender/equity were incorporated.CONCLUSIONS With all the difficulties that entails the boost in participation, the incorporation of gender/equity and transdisciplinarity in health diagnosis allowed a holistic public health approach closer to the needs of the population.

OBJETIVO Analizar las características del diagnóstico de salud según el enfoque de ecosalud en comunidades rural y urbana en México.MÉTODOS Los diagnósticos de salud se efectuaron en La Nopalera, de diciembre 2007 a octubre 2008 y en Atlihuayan de diciembre 2010 a octubre de 2011. Se basó en tres principios del enfoque de ecosalud: transdiciplina, participación comunitaria, género y equidad. Para colectar la información se utilizó una metodología mixta y diversas técnicas para estimular la participación de los habitantes. El ejercicio de diagnóstico se efectuó en cinco fases que oscilaron desde la recolección de información hasta la priorización de problemas.RESULTADOS La constitución del equipo transdisciplinario, así como la participación de la población y el principio de género/equidad fue diferencial entre las comunidades. En la comunidad rural, se logró la participación activa de los pobladores y autoridades y se incorporaron los principios de transdisciplina y género/equidad.CONCLUSIONES Con todas las dificultades que acarrea el impulso de la participación, la incorporación del género/equidad y la transdisciplina en el diagnóstico de salud, permitió un abordaje holístico de salud pública más cercano a las necesidades de la población.

Association between light absorption measurements of PM2.5 and distance from heavy traffic roads in the Mexico City metropolitan area.

OBJECTIVE: To study the relationship between light absorption measurements of PM2.5 at various distances from heavy traffic roads and diesel vehicle counts in Mexico City. MATERIALS AND METHODS: PM2.5 samples were obtained from June 2003-June 2005 in three MCMA regions. Light absorption (b abs) in a subset of PM2.5 samples was determined. We evaluated the effect of distance and diesel vehicle counts to heavy traffic roads on PM2.5 b abs using generalized estimating equation models. RESULTS: Median PM2.5 b abs measurements significantly decrease as distance from heavy traffic roads increases (p<0.002); levels decreased by 7% (CI95% 0.9-14) for each 100 additional meters from heavy traffic roads. Our model predicts that PM2.5 b abs measurements would increase by 20% (CI95% 3-38) as the hourly heavy diesel vehicle count increases by 150 per hour. CONCLUSION: PM2.5 b abs measurements are significantly associated with distance from motorways and traffic density and therefore can be used to assess human exposure to traffic-related emissions.

Association between light absorption measurements of PM2.5 and distance from heavy traffic roads in the Mexico City metropolitan area / Asociación entre las mediciones de PM2.5 por absorbancia y la distancia a vías de alto tráfico en la zona metropolitana de la Ciudad de México

OBJECTIVE: To study the relationship between light absorption measurements of PM2.5 at various distances from heavy traffic roads and diesel vehicle counts in Mexico City. MATERIALS AND METHODS: PM2.5 samples were obtained from June 2003-June 2005 in three MCMA regions. Light absorption (b abs) in a subset of PM2.5 samples was determined. We evaluated the effect of distance and diesel vehicle counts to heavy traffic roads on PM2.5 b abs using generalized estimating equation models. RESULTS: Median PM2.5 b abs measurements significantly decrease as distance from heavy traffic roads increases (p<0.002); levels decreased by 7% (CI95% 0.9-14) for each 100 additional meters from heavy traffic roads. Our model predicts that PM2.5 b abs measurements would increase by 20% (CI95% 3-38) as the hourly heavy diesel vehicle count increases by 150 per hour. CONCLUSION: PM2.5 b abs measurements are significantly associated with distance from motorways and traffic density and therefore can be used to assess human exposure to traffic-related emissions.

OBJETIVO: Evaluar la relación entre las mediciones de absorción de luz de las PM2.5 a diferentes distancias de vías de tráfico y el aforo vehicular de diesel en la Ciudad de México. MATERIAL Y MÉTODOS: Se realizaron mediciones de PM2.5 y su análisis de b abs en tres zonas de la Ciudad de México. Se usaron modelos GEE para evaluar el efecto de la distancia y el aforo vehicular de tráfico pesado sobre PM2.5 b abs. RESULTADOS: Se observó una tendencia decreciente en la mediana de PM2.5 b abs conforme se incrementó la distancia a las avenidas de alto tráfico (p<0.002); los niveles decrecen en 7% (CI95% 0.9-14) por cada 100 metros de incremento. Las mediciones de PM2.5 b abs se incrementan en 20% (CI95% 3-38) cuando el aforo vehicular a diesel es mayor de 150 en una hora. CONCLUSIONES: Las mediciones de PM2.5 b abs están significativamente asociadas con la distancia de avenidas con alto tránsito vehicular y con vehículos de diesel.

[Validation of reported location of solid waste using Procrustes analysis in the context of a participatory community initiative]. / Validación del auto-reporte de la localización de residuos sólidos con análisis de Procusto en el contexto de una iniciativa comunitaria participativa.

This study is part of a community initiative for integrated solid waste management based on "popular epidemiology" and participatory action research. The study proposes a method for validation of spatial data (X and Y data) on solid waste reported by community members. Location of sites was conducted by 76 residents of the La Nopalera community (Yautepec, Morelos, Mexico) and compared with reports by three environmental health experts. Agreement was explored using Procrustes analysis. Experts identified 23 sites with abundant solid waste, while community members only identified 22 sites. There were minimal differences in location, scale, and positioning of reported waste. Procrustes statistics showed 95% agreement between community and expert reports. The findings suggest that community knowledge can be a valid source of information in epidemiological studies, and that measurement error can be quantified. The simple methodology described here can be used in further "popular epidemiology" studies or similar approaches.

Validación del auto-reporte de la localización de residuos sólidos con análisis de Procusto en el contexto de una iniciativa comunitaria participativa / Validation of reported location of solid waste using Procrustes analysis in the context of a participatory community initiative / Validação do auto-relatório na localização de resíduos sólidos com análise de Procusto no contexto de uma iniciativa comunitária participativa

Este estudio forma parte de una iniciativa comunitaria de manejo integral de residuos, basada en "epidemiología popular" y la investigación acción participativa. En este estudio se propone un método de validación de datos espaciales (ordenadas y abscisas) de residuos sólidos auto-reportados por la comunidad. La ubicación de los sitios fue realizada por 76 residentes de la localidad La Nopalera (Yautepec, Morelos, México), y comparada con los reportados por tres expertos en salud ambiental. La concordancia fue explorada con análisis de Procusto. Los expertos identificaron 23 sitios de concentración de residuos sólidos, mientras que la comunidad ubicó solo 22 sitios. Hubo mínimas diferencias en la localización, escala y orientación. El estadístico de Procusto mostró 95% de concordancia entre legos y expertos. Los hallazgos sugieren que el saber popular es una fuente de información válida en estudios epidemiológicos, y que su error de medición puede ser cuantificado. La sencilla metodología descrita podrá ser usada en futuros estudios de "epidemiología popular" o aproximaciones similares.

This study is part of a community initiative for integrated solid waste management based on "popular epidemiology" and participatory action research. The study proposes a method for validation of spatial data (X and Y data) on solid waste reported by community members. Location of sites was conducted by 76 residents of the La Nopalera community (Yautepec, Morelos, Mexico) and compared with reports by three environmental health experts. Agreement was explored using Procrustes analysis. Experts identified 23 sites with abundant solid waste, while community members only identified 22 sites. There were minimal differences in location, scale, and positioning of reported waste. Procrustes statistics showed 95% agreement between community and expert reports. The findings suggest that community knowledge can be a valid source of information in epidemiological studies, and that measurement error can be quantified. The simple methodology described here can be used in further "popular epidemiology" studies or similar approaches.

O estudo é parte de uma iniciativa comunitária de gerenciamento integral de resíduos sólidos, baseada na "epidemiologia popular" e em uma pesquisa de ação participativa. Aqui está sendo proposto um método de validação de dados espaciais (ordenadas e abscissas) de resíduos sólidos auto-relatados pela comunidade. A localização dos pontos foi realizada por 76 moradores da localidade de La Nopalera (Yautepec, Morelos, México), e comparada com os relatórios de três especialistas em saúde ambiental. A concordância foi explorada com análise de Procusto. Os especialistas identificaram 23 pontos de concentração de resíduos sólidos, ao passo que a comunidade localizou apenas 22. Foram verificadas diferenças mínimas na localização, escala e orientação. A estatística de Procusto mostrou 95% de concordância entre leigos e especialistas. Os resultados sugerem que o conhecimento popular constitui uma fonte de informação válida em estudos epidemiológicos, e que seus erros de medição podem ser quantificados. A metodologia simples descrita poderá ser usada em futuros estudos de "epidemiologia popular" ou aproximações similares.

Traffic-related air pollution and respiratory symptoms among asthmatic children, resident in Mexico City: the EVA cohort study.

BACKGROUND: Taffic-related air pollution has been related to adverse respiratory outcomes; however, there is still uncertainty concerning the type of vehicle emission causing most deleterious effects. METHODS: A panel study was conducted among 147 asthmatic and 50 healthy children, who were followed up for an average of 22 weeks. Incidence density of coughing, wheezing and breathing difficulty was assessed by referring to daily records of symptoms and child's medication. The association between exposure to pollutants and occurrence of symptoms was evaluated using mixed-effect models with binary response and poisson regression. RESULTS: Wheezing was found to relate significantly to air pollutants: an increase of 17.4 microg/m3 (IQR) of PM2.5 (24-h average) was associated with an 8.8% increase (95% CI: 2.4% to 15.5%); an increase of 34 ppb (IQR) of NO2 (1-h maximum) was associated with an 9.1% increase (95% CI: 2.3% to 16.4%) and an increase of 48 ppb (IQR) in O3 levels (1 hr maximum) to an increase of 10% (95% CI: 3.2% to 17.3%). Diesel-fueled motor vehicles were significantly associated with wheezing and bronchodilator use (IRR = 1.29; 95% CI: 1.03 to 1.62, and IRR = 1.32; 95% CI: 0.99 to 1.77, respectively, for an increase of 130 vehicles hourly, above the 24-hour average). CONCLUSION: Respiratory symptoms in asthmatic children were significantly associated with exposure to traffic exhaust, especially from natural gas and diesel-fueled vehicles.