Phenomenological and Thermodynamic Model of Gas Exchanges in the Placenta during Pregnancy: A Case Study of Intoxication of Carbon Monoxide.

The present work simulates the transport of oxygen, carbon dioxide, and carbon monoxide between a fetus's circulatory system and the mother's. The organ responsible for this exchange is the placenta. Carbon monoxide is a common air pollutant, and it impacts the physiological conditions even in low concentration. The impacts of carbon monoxide are especially dangerous for pregnant women, fetuses, and newborn babies. A model of carbon monoxide transport, from the literature, is modified to simulate a pregnant woman (original model was a male), therefore changing some parameters to express the adjusted respiratory system. It was considered the gas exchange in the placenta, to evaluate the concentration of these different gases in the fetus arterial and venous blood. Three methods of the exergy analysis are implemented for both mother and fetus respiratory systems, aiming at the comparison with the respiratory system of a male adult. The destroyed exergy of the literature did not have the same trend as the models proposed in this article, taking into consideration the hemoglobin reactions. In contrast, the entropy generation associated only with the diffusion transport phenomena was one order of magnitude lower than the other methods. The placenta destroyed exergy rate is significantly higher compared to the irreversibilities of the mother's respiratory system. One possible explanation is the fact that the placenta has other physiological functions than gas transportation.

Biocides Used as Additives to Biodiesels and Their Risks to the Environment and Public Health: A Review.

One of the advantages of using biodiesel and its blends with diesel oil is the lower levels of emissions of particulate matter, sulfur dioxide, carbon monoxide, among others, making it less harmful to the environment and to humans. However, this biofuel is susceptible to microbial contamination and biodeterioration. In this sense, studies on the use of effective low toxicity biocides are being carried out, and this work aims to present the latest information (2008⁻2018) available in the scientific databases, on the use of biocides in biodiesel, mainly concerning their toxicity to the environment and public health. The results showed that in relation to the control of microbial contamination, the current scenario is limited, with seven publications, in which the most studied additives were isothiazolinones, oxazolidines, thiocyanates, morpholines, oxaborinanes, thiocarbamates and phenolic antioxidants. Studies regarding direct experiments with humans have not been found, showing the need for more studies in this area, since the potential growth of biodiesel production and consumption in the world is evident. Thus, there are need for more studies on antimicrobial products for use in biodiesel, with good broad-spectrum activity (bactericidal and fungicidal), and further toxicological tests to ensure no or little impact on the environment.

Salud ambiental, vigilancia y monitoreo de la calidad de aire: Contaminante atmosférico: Monóxido de carbono / Environmental health and air quality monitoring: Air pollutant: Carbon monoxide

El monóxido de carbono es un gas tóxico, inodoro e incoloro que se forma por la combustión incompleta de hidrocarburos como gas o kerosene. Las fuentes pueden ser estufas, calefones, braseros, calderas y hornos en malas condiciones de mantenimiento, así como los escapes de automóviles. Las viviendas o escuelas cercanas a calles de alto tránsito pueden estar también expuestas. Es importante señalar que es además uno de los componentes del humo del tabaco. La exposición al monóxido de carbono en el interior de los hogares produce una intoxicación de características graves e incluso con altos niveles de mortalidad. Respecto de la exposición en el aire exterior, las concentraciones más altas normalmente se miden cerca de las vías de transito principales, dado que los vehículos son la principal fuente de CO. se presentan una serie de gráficos que permiten observar los valores de monóxido de carbono registrados en la Ciudad de Buenos Aires. Dichos registros son obtenidos en las tres estaciones de Monitoreo de Calidad del Aire que posee la Ciudad (Estación La Boca, Parque Centenario y Córdoba), las cuales registran las concentraciones de éste contaminante en forma continua (24 horas diarias, los 365 días del año) mediante métodos homologados internacionalmente. (AU)

Situación epidemiológica de intoxicación por monóxido de carbono (CO) / Epidemiological situation of carbon monoxide intoxication (CO)

El monóxido de carbono es un gas tóxico, incoloro, inodoro e insípido que se produce durante la quema de combustible. Las intoxicaciones por monóxido de carbono (CO) constituyen causa de enfermedad y muerte. Además del evento agudo, los cuadros de intoxicación graves pueden dejar secuelas cognitivas. La exposición crónica también es importante dado que puede producir sintomatología neurológica y cognitiva. Se presentan diferentes análisis de la serie histórica que va desde 2005 a la Semana Epidemiológica 38 de 2016, de las intoxicaciones por Monóxido de Carbono asistidas en la Ciudad de Buenos Aires. Los datos para la construcción de indicadores del presente informe provienen del registro de casos individuales de intoxicación por CO, en el módulo C2 de Vigilancia Clínica del Sistema Nacional de Vigilancia de la Salud (SNVS)

Association between NOx exposure and deaths caused by respiratory diseases in a medium-sized Brazilian city

Exposure to nitrogen oxides (NOx) emitted by burning fossil fuels has been associated with respiratory diseases. We aimed to estimate the effects of NOx exposure on mortality owing to respiratory diseases in residents of Taubaté, São Paulo, Brazil, of all ages and both sexes. This time-series ecological study from August 1, 2011 to July 31, 2012 used information on deaths caused by respiratory diseases obtained from the Health Department of Taubaté. Estimated daily levels of pollutants (NOx, particulate matter, ozone, carbon monoxide) were obtained from the Centro de Previsão de Tempo e Estudos Climáticos Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System. These environmental variables were used to adjust the multipollutant model for apparent temperature. To estimate association between hospitalizations owing to asthma and air pollutants, generalized additive Poisson regression models were developed, with lags as much as 5 days. There were 385 deaths with a daily mean (±SD) of 1.05±1.03 (range: 0-5). Exposure to NOx was significantly associated with mortality owing to respiratory diseases: relative risk (RR)=1.035 (95% confidence interval [CI]: 1.008-1.063) for lag 2, RR=1.064 (95%CI: 1.017-1.112) lag 3, RR=1.055 (95%CI: 1.025-1.085) lag 4, and RR=1.042 (95%CI: 1.010-1.076) lag 5. A 3 µg/m3 reduction in NOx concentration resulted in a decrease of 10-18 percentage points in risk of death caused by respiratory diseases. Even at NOx concentrations below the acceptable standard, there is association with deaths caused by respiratory diseases.

Association between NOx exposure and deaths caused by respiratory diseases in a medium-sized Brazilian city.

Exposure to nitrogen oxides (NOx) emitted by burning fossil fuels has been associated with respiratory diseases. We aimed to estimate the effects of NOx exposure on mortality owing to respiratory diseases in residents of Taubaté, São Paulo, Brazil, of all ages and both sexes. This time-series ecological study from August 1, 2011 to July 31, 2012 used information on deaths caused by respiratory diseases obtained from the Health Department of Taubaté. Estimated daily levels of pollutants (NOx, particulate matter, ozone, carbon monoxide) were obtained from the Centro de Previsão de Tempo e Estudos Climáticos Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System. These environmental variables were used to adjust the multipollutant model for apparent temperature. To estimate association between hospitalizations owing to asthma and air pollutants, generalized additive Poisson regression models were developed, with lags as much as 5 days. There were 385 deaths with a daily mean (±SD) of 1.05±1.03 (range: 0-5). Exposure to NOx was significantly associated with mortality owing to respiratory diseases: relative risk (RR)=1.035 (95% confidence interval [CI]: 1.008-1.063) for lag 2, RR=1.064 (95%CI: 1.017-1.112) lag 3, RR=1.055 (95%CI: 1.025-1.085) lag 4, and RR=1.042 (95%CI: 1.010-1.076) lag 5. A 3 µg/m3 reduction in NOx concentration resulted in a decrease of 10-18 percentage points in risk of death caused by respiratory diseases. Even at NOx concentrations below the acceptable standard, there is association with deaths caused by respiratory diseases.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface.

PURPOSE: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). METHODS: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. RESULTS: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. CONCLUSIONS: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode.

Low birth weight at term and the presence of fine particulate matter and carbon monoxide in the Brazilian Amazon: a population-based retrospective cohort study.

BACKGROUND: Although studies have shown an association between air pollutants from anthropogenic sources and pregnancy outcomes, little is known regarding the association between low birth weight (LBW) and exposure to emissions of biomass burning. METHODS: This population-based retrospective cohort study assessed the effect of exposure to particulate matter and carbon monoxide (CO) from biomass burning in the Amazon and cerrado (Brazilian savanna) biomes on term LBW (<2500 g) in cities of Mato Grosso, Brazil. Data on births were obtained from the Information System on Live Births of the Ministry of Health. The exclusion criteria were a twin pregnancy, gestational age of less than 37 weeks, and congenital malformation diagnosed at birth. For exposure variables, we used a historical series of daily average concentrations of particulate matter with a diameter less than 2.5 µm (PM2.5) and CO provided by Coupled Aerosol and Trace Gases Transport Model for the Brazilian Development of the Regional Atmospheric Modeling System developed at the National Institute for Space National Center for Weather Forecasts and Climate Studies, National Institute for Space Research. Maternal exposure was estimated by the average amount of pollutants for each trimester and for the entire period of gestation. The association between air pollutants and LBW was analyzed by multiple logistic regression, adjusting for the newborn's sex, mother's age and education, and prenatal care. RESULTS: A total of 6147 full-term singleton live births were included in the study and 193 (3.1%) were LBW. In adjusted analysis, the number of prenatal visits and maternal education with 8 years or more were associated with LBW. The association between exposure to air pollutants and the risk of LBW was significant for the 4th quartile of PM2.5 concentrations in the 2nd trimester (OR = 1.51, 95% CI = 1.04 to 2.17) and in the 3rd trimester, and for the 4th quartile of CO concentrations in the 2nd trimester only, in adjusted analysis. CONCLUSIONS: This study provides further evidence of the effect of smoke from biomass burning on the occurrence of LBW in cities of the Brazilian Amazon.

Maternal exposure to biomass smoke and carbon monoxide in relation to adverse pregnancy outcome in two high altitude cities of Peru.

BACKGROUND: Exposure to pollution from biomass fuel has been associated with low birthweight in some studies. Few studies have included exposure-response analyses. METHOD: We conducted a case-control study of biomass fuel use and reproductive outcome at high altitude in Peru. Cases (n=101) were full term births who were SGA (birth weight <10th percentile for gestational age). Controls (n=101) had a birthweight ≥10th percentile, and were matched to cases on birth week and residence. Biomass fuel use during pregnancy was determined by questionnaire. Carbon monoxide (CO) in the kitchen was measured in a subgroup (n=72). Logistic regression was used to estimate the effects of biofuel and CO on the risk of SGA, controlling for maternal education and parity. RESULTS: Among cases, 30%, 27% and 44% used gas, gas+biomass, and biomass, respectively, while the figures for controls were 39%, 33%, and 29%. The adjusted odds ratio (OR) for biomass fuel alone compared with gas alone was 4.5 (95% CI: 1.3, 15.5, p=0.02), while the OR for biomass+gas vs. gas alone was 2.1 (0.80-5.5) (p=0.13). Among the subgroup with measured CO, the mean 48-h kitchen CO levels were 4.8, 2.2 and 0.4ppm for biofuel only, biofuel+gas, and gas respectively. ORs by increasing tertile of CO level were 1.0, 1.16, and 3.53 (test for trend, p=0.02). The exposure-response trend corresponds well with one other study with analogous data. CONCLUSION: Despite limited sample size, our data suggest that maternal exposure to biomass smoke and CO, at high altitude, is associated with SGA among term births.

Avaliação da concentração de monóxido de carbono em estudantes universitários da área da saúde / Evaluation of the carbon monoxide concentration in university students of health area

Objetivo - Avaliar o nível de monóxido de carbono exalado em estudantes universitários da área da saúde fumantes, não fumantes, fumantes passivos e ex-fumantes. Método - Participaram do estudo estudantes universitários da área da saúde, maiores de 18 anos, de ambos os sexos, fumantes, não fumantes, fumantes passivos e ex-fumantes. Foram excluídos do estudo estudantes em processo de cessação de tabagismo. Foram coletadas medidas de monóxido de carbono no ar exalado (COex) e nível de dependência de tabagismo através do teste de Fagerstrõm. Resultados - Foram estudados 100 universitários, sendo 65% não fumantes, 11% fumantes, 16% fumantes passivos e 8% ex-fumantes.Houve predomínio do sexo feminino para os estudantes não fumantes (55,48%) e para os fumantes passivos (68,75%). Os fumantes apresentaram grau de dependência do tabagismo de leve a moderada. A média de COex em não fumantes foi de 8,4±7,6 ppm, nos fumantes foi de 32,1±20,1 ppm, nos fumantes passivos de 14,6±8,3 ppm e nos ex-fumantes de 14,4±6,6 ppm. Os cursos que tiveram menos fumantes foram Fisioterapia (9,09%) e Enfermagem (9,09%) e o curso com mais fumante foi o de Medicina (36,36%). Conclusão - Há um percentual considerável de indivíduos fumantes entre os cursos da área da saúde e os níveis de monóxido de carbono no ar exalado destes estudantes fumantes, ex-fumantes, fumantes passivos e não fumantes foram altos.

Objective - To evaluate the level of exhaled carbon monoxide in university students in the health area smokers, nonsmokers, passive smokers and former smokers. Method - Participants were college students in the health area, over 18 years, of both sexes, smokers, nonsmokers, passive smokers and former smokers. The study excluded students in the process of smoking cessation. We collected measurements of carbon monoxide in exhaled air and level of dependence on smoking by the Fagerstrõm test. Results - There were 100 students, 65% nonsmokers,11% smokers, passive smokers 16% and 8% former smokers. There were more female students to nonsmokers (55.48%) and passive smokers (68.75%). Smokers had the degree of tobacco dependence treatment of mild to moderate. The mean expired CO in nonsmokers was 8.4 ±7.6 ppm, in smokers was 32.1 ± 20.1 ppm, in passive smokers, and 14.6 ± 8.3 ppm and in former smokers, 14.4 ± 6.6 ppm. The courses had fewer smokers were physiotherapy (9.09%) and nurses (9.09%) and the course was more smoking medicine (36.36%). Conclusion - There is a considerable percentage of smokers among the courses in the area of health and levels of carbon monoxide in exhaled air of student smokers, former smokers, passive smokers and nonsmokers were high.

Ambient levels of air pollution induce clinical worsening of blepharitis.

BACKGROUND: Even though air pollutants exposure is associated with changes in the ocular surface and tear film, its relationship to the clinical course of blepharitis, a common eyelid disease, had not yet been investigated. Our objective was to investigate the correlation between air pollution and acute manifestations of blepharitis. METHOD: We recorded all cases of changes in the eyelids and ocular surface, and rated clinical findings on a scale from zero (normal) to two (severe alterations). Daily values of carbon monoxide, particulate matter smaller than 10 µm in diameter and nitrogen dioxide concentrations and meteorological variables (temperature and relative humidity) in the vicinity of the medical service were obtained. Specific linear regression models for each outcome were constructed including pollutants as independent variables (single pollutant models). Temperature and humidity were included as confounding variables. RESULTS: increases of 28.8 µg/m(3) in the concentration of particulate matter and 1.1 ppm in the concentration of CO were associated with increases in cases of blepharitis on the day of exposure (5 cases, 95% CI: 1-10 and 6 cases, 95% CI: 1-12, respectively). CONCLUSION: Exposure to usual air pollutants concentrations present in large cities affects, in a consistent manner, the eyes of residents contributing to the increasing incidence of diseases of the eyelid margin.

Neurodevelopmental performance among school age children in rural Guatemala is associated with prenatal and postnatal exposure to carbon monoxide, a marker for exposure to woodsmoke.

We investigated whether early life chronic exposure to woodsmoke, using personal passive 48-h carbon monoxide (CO) as an indicator, is associated with children's neurodevelopmental and behavioral performance. CO measures were collected every 3 months from 2002 to 2005 among mother-child dyads during the Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) stove intervention trial in San Marcos, Guatemala. From March to June, 2010, study children of age 6-7 years, performed a follow-up non-verbal, culturally adapted neurodevelopmental assessment. We found inverse associations between CO exposure of pregnant mothers during their 3rd trimesters (m=3.8ppm ± 3.0ppm; range: 0.6-12.5 ppm) and child neuropsychological performance. Scores on 4 out of 11 neuropsychological tests were significantly associated with mothers' 3rd trimester CO exposures, including visuo-spatial integration (p<0.05), short-term memory recall (p<0.05), long-term memory recall (p<0.05), and fine motor performance (p<0.01) measured using the Bender Gestalt-II's Copy, Immediate Recall, and an adapted version of a Delayed Recall Figures drawing, and the Reitan-Indiana's Finger Tapping Tests, respectively. These 4 significant finding persisted with adjustment for child sex, age, visual acuity, and household assets (socio-economic status). Summary performance scores were also significantly associated with maternal 3rd trimester CO when adjusted for these covariates. Other variables accounting for variance but were excluded in our final multiple regression models included the following: HOME environment stimulation score, child examiner, WHO height-for-age percentile, and age that the infant stopped breastfeeding. This seems to be the first study on woodsmoke exposure and neurodevelopment, and the first longitudinal birth cohort study on chronic early life CO exposures, determined by high quality measures of mothers' and infants' personal CO exposures, and using well-established, reliable child neuropsychological tests. Further research is needed to replicate our results and inform future interventions and air quality standards for woodsmoke and CO.

Impact of reduced maternal exposures to wood smoke from an introduced chimney stove on newborn birth weight in rural Guatemala.

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.

Effects of atmospheric pollutants on the Nrf2 survival pathway.

BACKGROUND, AIM, AND SCOPE: Atmospheric pollution is a worldwide problem. Exposure to atmospheric pollutants causes toxic cellular effects. One of the mechanisms of toxicity by these pollutants is the promotion of oxidative stress. Several signaling pathways control cellular redox homeostasis. In this respect, nuclear factor erythroid 2-related factor 2 (Nrf2) is a crucial transcription factor in the cell's response to oxidative stress. MAIN FEATURES: In cellular animal models, exposure to atmospheric pollutants activates Nrf2, attenuating its toxic and even its carcinogenic effects. Therefore, we have reviewed the scientific literature in order to indicate that air pollutants, such as particulate matter, polycyclic aromatic hydrocarbons, and gaseous matter, are Nrf2 pathway inductors, triggering self-defense through the establishment of proinflammatory and antioxidant responses. RESULTS AND DISCUSSION: Exposure to reactive molecules as atmospheric pollutants causes the activation of Nrf2 and the subsequent regulation of the expression of cytoprotective and detoxifying enzymes, as well as antioxidants. Moreover, induction of Nrf2 prior to exposure reduces the harmful effects of pollutants. The present article discusses the protective role of the Nrf2 pathway against different atmospheric pollutant insults. CONCLUSIONS: Nrf2 regulates the expression of numerous cytoprotective genes that function to detoxify reactive species produced during atmospheric pollutant metabolic reactions. From the papers highlighted in this review, we conclude that Nrf2 has an important role in the defense against atmospheric pollutant-induced toxicity. PERSPECTIVES: Further studies are needed to understand the signaling events that turn on the system in response to atmospheric pollutant stress. This could allow for the possibility of targeting the pathway for prevention benefits in the near future.

Health risk estimation due to carbon monoxide pollution at different spatial levels in Santiago, Chile.

The Metropolitan Region of Santiago has been declared as nonattainment area for carbon monoxide (CO). The data was based on seven air monitoring stations that do not necessarily represent the real population exposure. Usually, a series of coefficients that relates the concentration of pollutants with health effects (betas of the concentration-response equations) are used. For the calculation of these betas, normally, a city average air pollution concentration is used; nevertheless, these betas do not necessarily represent the real risk of exposure that the inhabitants are experimented. For this reason, this study estimates two aspects that are unknown and that are necessary to policymakers in public health decisions. First, estimate the exposure at a lower spatial resolution level and, second, estimate a concentration-response curve that differs spatially and depends on the proportion of susceptible groups. We followed the Air Pollution and Health, European Approach/Spanish Multicenter Study on the Relationship Between Air Pollution and the Mortality methodology for the determination of the short-term health effect due to CO population exposure at the three spatial levels (city, zone, and county). We found that there are different risks in cardiorespiratory mortality in the group over 64 years old associated to an unequal exposure to CO in Santiago city. The higher risks are in counties located to the south-east of the city. These finding confirm the necessity to face, in a different way, the approach when evaluating control strategies and policy decision to control air pollution in Santiago.

Impact of improved cookstoves on indoor air pollution and adverse health effects among Honduran women.

Elevated indoor air pollution levels due to the burning of biomass in developing countries are well established. Few studies have quantitatively assessed air pollution levels of improved cookstoves and examined these measures in relation to health effects. We conducted a cross-sectional survey among 79 Honduran women cooking with traditional or improved cookstoves. Carbon monoxide and fine particulate matter (PM(2.5)) levels were assessed via indoor and personal monitoring. Pulmonary function and respiratory symptoms were ascertained. Finger-stick blood spot samples were collected to measure C-reactive protein (CRP) concentrations. The use of improved stoves was associated with 63% lower levels of personal PM(2.5), 73% lower levels of indoor PM(2.5), and 87% lower levels of indoor carbon monoxide as compared to traditional stoves. Women using traditional stoves reported symptoms more frequently than those using improved stoves. There was no evidence of associations between cookstove type or air quality measures with lung function or CRP.

Urban air pollution and chronic obstructive pulmonary disease-related emergency department visits.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) can have recurrent disease exacerbations triggered by several factors, including air pollution. Visits to the emergency respiratory department can be a direct result of short-term exposure to air pollution. The aim of this study was to investigate the relationship between the daily number of COPD emergency department visits and the daily environmental air concentrations of PM(10), SO(2), NO(2), CO and O(3) in the City of São Paulo, Brazil. METHODS: The sample data were collected between 2001 and 2003 and are categorised by gender and age. Generalised linear Poisson regression models were adopted to control for both short- and long-term seasonal changes as well as for temperature and relative humidity. The non-linear dependencies were controlled using a natural cubic spline function. Third-degree polynomial distributed lag models were adopted to estimate both lag structures and the cumulative effects of air pollutants. RESULTS: PM(10) and SO(2) readings showed both acute and lagged effects on COPD emergency department visits. Interquartile range increases in their concentration (28.3 microg/m(3) and 7.8 microg/m(3), respectively) were associated with a cumulative 6-day increase of 19% and 16% in COPD admissions, respectively. An effect on women was observed at lag 0, and among the elderly the lag period was noted to be longer. Increases in CO concentration showed impacts in the female and elderly groups. NO(2) and O(3) presented mild effects on the elderly and in women, respectively. CONCLUSION: These results indicate that air pollution affects health in a gender- and age-specific manner and should be considered a relevant risk factor that exacerbates COPD in urban environments.

Effect of reducing indoor air pollution on women's respiratory symptoms and lung function: the RESPIRE Randomized Trial, Guatemala.

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.

Prevalence of symptoms of asthma, rhinitis, and atopic eczema in Brazilian adolescents related to exposure to gaseous air pollutants and socioeconomic status.

OBJECTIVES: To evaluate the relationship between exposure to gaseous air pollutants (ozone [O3], carbon monoxide [CO], nitrogen dioxide [NO2], and sulfur dioxide [SO2]) socioeconomic status and the prevalence of symptoms of asthma, rhinitis and atopic eczema in adolescents. SUBJECTS AND METHODS: A sample of 16 209 adolescents from São Paulo West (SPW), São Paulo South (SPS), Santo André (SA), Curitiba (CR), and Porto Alegre (PoA) were enrolled. Data on air pollutants and socioeconomic status were compared to prevalence of symptoms with the Spearman correlation coefficient. RESULTS: Socioeconomic status was quite similar in all cities. The levels of O3 in SPW, SPS, and SA, and of CO in SA were higher than the acceptable ones. In relation to O3 and CO exposures, adolescents from SPW and SA had a significant risk of current wheezing, whereas living in SPW was associated with a high risk of rhinoconjunctivitis, eczema, and flexural eczema and living in CR to rhinitis. Exposure to NO2 was associated with a high risk of current wheezing in SPW and SA, and of severe asthma in SPW and PoA. Exposure to SO2 was associated with a high risk of current wheezing in SPW and SA, severe asthma in SPW and PoA, and nighttime cough, eczema, flexural eczema and severe eczema in SPW. Living in SPW, CR, or PoA was associated with a high risk of rhinitis, rhinoconjunctivitis, and severe rhinitis. CONCLUSIONS: Although we did not detect a characteristic pattern for all symptoms evaluated or a specific air pollutant, our data suggest a relationship between higher exposure to photochemical pollutants and high prevalence or risk of symptoms of asthma, rhinitis, and atopic eczema.

Chronic exposure to urban air pollution induces structural alterations in murine pulmonary and coronary arteries.

Epidemiological studies have shown that air pollution increases cardiovascular morbidity and mortality. Objective markers of cardiovascular risk have also been associated with increases in ambient pollution. This study was designed to assess whether prolonged exposure to ambient levels of air pollution may induce structural alterations of pulmonary and cardiac vessels. Mice were chronically exposed to ambient levels of air pollution in downtown São Paulo, Brazil. The animals were maintained in exposure chambers, 24 h/day, 7 days/wk, during 4 mo. One group was exposed to ambient air, and the control group was exposed to filtered air. Morphometric measurements of the ratio between the lumen and wall (L/W) areas were performed on transverse sections of renal, pulmonary, and coronary arteries. As expected, lumen/wall ratios increased with arterial caliber (p < .001). A significant decrease of L/W with exposure to air pollution was detected in pulmonary (p = .03) and coronary (p = .021) arteries, whereas no effects of air pollution were observed in renal vessels. Our results indicate that animals chronically exposed to ambient air pollution develop a significant thickening of the arterial wall in the coronary and pulmonary circulation.