Atmospheric pollution and the prevalence of asthma: study among schoolchildren of 2 areas in Rio de Janeiro, Brazil

A Systematic Review of Children's Environmental Health in Brazil

In the region of the Americas, approximately 100,000 children under the age of 5 years die each year due to environmental hazards. Brazil, due to its large size and wide range of environmental challenges, presents numerous hazards to children's health. The aim of this study was to systematically review the scientific literature that describes children's exposures to environmental pollutants in Brazil and their effects on Brazilian children's health. A systematic review of the scientific literature was performed without language restrictions and time of publication (years). The literature search was conducted in the following key resources: PubMed (MEDLINE), Scopus and Web of Science with the MeSH Terms: Environmental exposure AND Brazil (filters: Human, Child [birth to 18 years] and Affiliation Author). The Virtual Health Library was also employed to access the databases Scielo and Lilacs. The search strategy was [DeCS Terms]: Child OR adolescent AND Environmental exposure AND Brazil. Health effects in children associated with exposure to environmental pollutants in Brazil were reported in 74 studies, during the period between 1995 and 2015. The most frequently cited effect was hospital admission for respiratory causes including wheezing, asthma, and pneumonia among children living in areas with high concentrations of air pollutants. A broad spectrum of other health effects possibly linked to pollutants also was found such as prematurity, low birth weight, congenital abnormality (cryptorchidism, hypospadia, micropenis), poor performance in tests of psychomotor and mental development, and behavioral problems. Exposure to pesticides in utero and postnatally was associated with a high risk for leukemia in children <2 years old. These results show that there is a need in Brazil for stricter monitoring of pollutant emissions and for health surveillance programs especially among vulnerable populations such as pregnant women and young children.

Association of outdoor air pollution with the prevalence of asthma in children of Latin America and the Caribbean: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the association between asthma prevalence and outdoor air pollution in children in Latin America and the Caribbean.

DATA SOURCES

We searched studies in global and regional databases: PubMed, Scopus, LILACS and SciELO.

STUDY SELECTION

Articles following a cross-sectional design, studying children from 0 to 18 years old, and comparing the prevalence of asthma in two or more areas of LAC countries with different air pollution levels were included. The exclusion criteria comprised air pollution not related to human activities.

RESULTS

Database searches retrieved 384 records, while 20 studies were retained for qualitative and 16 for quantitative analysis, representing 48 442 children. We found a positive association, i.e. a higher prevalence of asthma in children living in a polluted environment, with pooled odds ratio (OR) of 1.34 (95% CI: 1.17-1.54). Heterogeneity between studies was moderate (I²: 68.39%), while the risk of bias was intermediate or high in 14 studies. In all the subgroup and sensitivity analyses, the pooled ORs were significant and higher than those found in the general analysis Conclusions: Our results showed that living in a polluted environment is significantly associated with children having asthma in LAC. Limitations of this study include the low number of studies performed in LAC countries, differences in methodologies and the risk of bias in individual studies.

Asthma in children and adolescents in Brazil: contribution of the International Study of Asthma and Allergies in Childhood (ISAAC)

Objective:

To assess asthma among Brazilian pediatric population applying the International Study of Asthma and Allergies in Childhood (ISAAC), an internationally standardized and validated protocol.

Data sources:

ISAAC was conceived to maximize the value of epidemiologic studies on asthma and allergic diseases, establishing a standardized method (self-applicable written questionnaire and/or video questionnaire) capable to facilitate the international collaboration. Designed to be carried out in three successive and dependent phases, the ISAAC gathered a casuistic hitherto unimaginable in the world and in Brazil. This review included data gathered from ISAAC official Brazilian centers and others who used this method.

Data synthesis:

At the end of the first phase, it has been documented that the prevalence of asthma among Brazilian schoolchildren was the eighth among all centers participating all over the world. Few centers participated in the second phase and investigated possible etiological factors, especially those suggested by the first phase, and brought forth many conjectures. The third phase, repeated seven years later, assessed the evolutionary trend of asthma and allergic diseases prevalence in centers that participated simultaneously in phases I and III and in other centers not involved in phase I.

Conclusions:

In Brazil, the ISAAC study showed that asthma is a disease of high prevalence and impact in children and adolescents and should be seen as a Public Health problem. Important regional variations, not well understood yet, and several risk factors were found, which makes us wonder: is there only one or many asthmas in Brazil?

Geospatial relationships of air pollution and acute asthma events across the Detroit-Windsor international border: study design and preliminary results

The Geospatial Determinants of Health Outcomes Consortium (GeoDHOC) study investigated ambient air quality across the international border between Detroit, Michigan, USA and Windsor, Ontario, Canada and its association with acute asthma events in 5- to 89-year-old residents of these cities. NO2, SO2, and volatile organic compounds (VOCs) were measured at 100 sites, and particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) at 50 sites during two 2-week sampling periods in 2008 and 2009. Acute asthma event rates across neighborhoods in each city were calculated using emergency room visits and hospitalizations and standardized to the overall age and gender distribution of the population in the two cities combined. Results demonstrate that intra-urban air quality variations are related to adverse respiratory events in both cities. Annual 2008 asthma rates exhibited statistically significant positive correlations with total VOCs and total benzene, toluene, ethylbenzene and xylene (BTEX) at 5-digit zip code scale spatial resolution in Detroit. In Windsor, NO2, VOCs, and PM10 concentrations correlated positively with 2008 asthma rates at a similar 3-digit postal forward sortation area scale. The study is limited by its coarse temporal resolution (comparing relatively short term air quality measurements to annual asthma health data) and interpretation of findings is complicated by contrasts in population demographics and health-care delivery systems in Detroit and Windsor.

Asthma and the socio-economic reality in Brazil

BACKGROUND

Asthma is a prevalent disease that is considered a health problem worldwide. The aim of this study was to analyze the clinical and socioeconomic characteristics of a cohort of asthmatics receiving specialized outpatient treatment in a tertiary/teaching public hospital in Brazil.

METHODS

Persistent asthmatics older than 5 years old were consecutively included. They received clinical treatment at 3- to 4-month intervals and were interviewed 2 times at 6-month intervals over a 12-month observation period. The data were collected directly from the patients or their parents by 2 researchers who did not participate in their clinical care. The primary variables were age, gender, education level, monthly family income, place of residence, number of lost days of school or work, BMI, the severity and control level of asthma, the number of scheduled and non-scheduled visits and hospitalization days and the best peak-flow measurement.

RESULTS

Of the 117 participants, 108 completed the study. Of the participants, 73.8% were women, and 25.0% lived outside the county. Of those who lived within the county, 60.1% lived in areas far from the health care unit. The majority (83.3%) had associated rhinitis, and more than 50.0% were overweight or obese, in whom the prevalence of severe asthma was greater (p = 0.001). The median monthly income was US$ 536.58 and was greater among the patients with controlled asthma (p = 0.005 and p = 0.01 at the start and the end of the study, respectively). In the initial evaluation, 16 participants had severe asthma, and in the final evaluation, 8 out of 21 patients with uncontrolled asthma had improved. Three-quarters of the students and half of the workers had missed days of school or work, respectively. The asthmatic population in this study had medium to low socioeconomic status in Brazil and socioeconomic status was associated with overweigth/obesity and with poor control of asthma.

CONCLUSION

Asthma has a great impact on absenteeism in Brazil. Lower monthly family income and body weight above the ideal level were associated with greater severity and worse control of asthma.

Early-life air pollution and asthma risk in minority children. The GALA II and SAGE II studies

RATIONALE

Air pollution is a known asthma trigger and has been associated with short-term asthma symptoms, airway inflammation, decreased lung function, and reduced response to asthma rescue medications.

OBJECTIVES

To assess a causal relationship between air pollution and childhood asthma using data that address temporality by estimating air pollution exposures before the development of asthma and to establish the generalizability of the association by studying diverse racial/ethnic populations in different geographic regions.

METHODS

This study included Latino (n = 3,343) and African American (n = 977) participants with and without asthma from five urban regions in the mainland United States and Puerto Rico. Residential history and data from local ambient air monitoring stations were used to estimate average annual exposure to five air pollutants: ozone, nitrogen dioxide (NO₂), sulfur dioxide, particulate matter not greater than 10 μm in diameter, and particulate matter not greater than 2.5 μm in diameter. Within each region, we performed logistic regression to determine the relationship between early-life exposure to air pollutants and subsequent asthma diagnosis. A random-effects model was used to combine the region-specific effects and generate summary odds ratios for each pollutant.

MEASUREMENTS AND MAIN RESULTS

After adjustment for confounders, a 5-ppb increase in average NO₂ during the first year of life was associated with an odds ratio of 1.17 for physician-diagnosed asthma (95% confidence interval, 1.04-1.31).

CONCLUSIONS

Early-life NO₂ exposure is associated with childhood asthma in Latinos and African Americans. These results add to a growing body of evidence that traffic-related pollutants may be causally related to childhood asthma.

Short-term effects of air pollution on respiratory morbidity at Rio de Janeiro--PART I: Air pollution assessment

Exposure to air pollution has been related with the most varied adverse health outcomes. This study aims to assess the impact of air pollution on the emergency hospitalization for respiratory disease in Rio de Janeiro, Brazil. The study was divided in two parts: Part I specifically addressing the air pollution assessment and Part II addressing the health assessment. Accordingly, this Part I aims to: i) evaluate the concentrations of PM(10), SO(2) and CO at two sites in Rio de Janeiro and compare them; ii) analyse the concentrations observed according to the national and international standards; and iii) analyse the air pollutants behaviour, namely, annually, seasonally, daily and considering weekdays/weekends variations. The pollutant concentrations were measured at two different sites in Rio de Janeiro and the analysis was performed for the period between September 2000 and December 2005. Results showed that PM(10) concentrations in Rio de Janeiro exceeded the daily and annual standards imposed by the European Union, the Brazilian legislation and WHO guidelines. Regarding SO(2) and CO, concentrations were, generally, below both European and Brazilian standards. Nevertheless, considering WHO guidelines, SO(2) threshold for daily concentrations (20 μg m(-3)) was exceeded around 150 times. Behaviour assessment showed that the influence of traffic is a major factor affecting the air pollution in Rio de Janeiro. Considering the results achieved and the proven health effects of air pollution, strategies should be defined for its reduction, particularly concerning particulate matter, and consequently contribute to the protection of public health.

Short-term effects of air pollution on respiratory morbidity at Rio de Janeiro--Part II: health assessment

The effects of air pollution on health have been studied worldwide. Given that air pollution triggers oxidative stress and inflammation, it is plausible that high levels of air pollutants cause higher number of hospitalisations. This study aimed to assess the impact of air pollution on the emergency hospitalisation for respiratory disease in Rio de Janeiro, Brazil. The study was divided in two parts: Part I specifically addressing the air pollution assessment and Part II addressing the health assessment. Accordingly, this Part II aimed to estimate the association between the concentrations of PM₁₀, SO₂ and CO observed in Rio de Janeiro and the number of emergency hospitalisations at a central hospital due to respiratory diseases. The pollutant concentrations were measured at two different sites in Rio de Janeiro, but the excess relative risks were calculated based on the concentrations observed at one of the sites, where limits were generally exceeded more frequently, between September 2000 and December 2005. A time series analysis was performed using the number of hospitalisations, divided in three categories (children until 1 year old, children aged between 1 and 5 years old and elderly with 65 years old or more) as independent variable, the concentrations of pollutants as dependent variables and temperature, relative humidity, long term trend, and seasonality as confounders. Data were analysed using generalised additive models with smoothing for some of the dependent variables. Results showed an excess risk of hospitalisation for respiratory disease higher than 2% per 10 μg m⁻³ increase in PM₁₀ concentrations for children under 5 years old, of 2% per 10 μg m⁻³ increase in SO₂ for elderly above 65 years old and around 0.1% per 10 μg m⁻³ increase in CO for children under 1 year and elderly. Other studies have found associations that are in agreement with the results achieved in this study. The study suggests that the ambient levels of air pollutants experienced in Rio de Janeiro between 2000 and 2005 were linked to the number of hospitalisations for respiratory diseases among children and elderly.

Is the asthma epidemic still ascending?

Asthma is a phenotypically heterogeneous disorder of multifactorial origins that affects 300 million people suffering from asthma and more than 250,000 asthma-related deaths each year. Although treatment for asthma has improved, its prevalence continues to increase, particularly in low and middle income countries, or in some ethnic groups in which prevalence was previously low. Observed spatio-temporal variations in the increased prevalence of asthma depend on exposure to environmental factors. Recently, several arguments are also in favor of the involvement of host susceptibility and stress in the observed increase of asthma prevalence. Further investigations are warranted to better understand mechanisms underlying asthma increase or stagnation.

A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil

The aim of this study was to carry out a review of scientific literature published in Brazil between 2000 and 2009 on the characteristics of air pollutants from different emission sources, especially particulate matter (PM) and its effects on respiratory health. Using electronic databases, a systematic literature review was performed of all research related to air pollutant emissions. Publications were analyzed to identify the physical and chemical characteristics of pollutants from different emission sources and their related effects on the respiratory system. The PM2.5 is composed predominantly of organic compounds with 20% of inorganic elements. Higher concentrations of metals were detected in metropolitan areas than in biomass burning regions. The relative risk of hospital admissions due to respiratory diseases in children was higher than in the elderly population. The results of studies of health effects of air pollution are specific to the region where the emissions occurred and should not be used to depict the situation in other areas with different emission sources.

Sugar cane burning pollution and respiratory symptoms in schoolchildren in Monte Aprazível, Southeastern Brazil

OBJECTIVE

To estimate the prevalence of respiratory symptoms and to analyze associated factors as well as peak expiratory flow measurements in schoolchildren.

METHODS

This is a descriptive cross-sectional study with schoolchildren aged 10-14 from the city of Monte Aprazível (Southeastern Brazil). Questionnaires containing the asthma and rhinitis components of the International Study of Asthma and Allergies in Childhood were administered. The questionnaires also approached sociodemographic characteristics, predisposing factors, and family and personal medical history. Repeated measures of peak expiratory flow in the children, and of black carbon and particulate matter (PM2,5) concentration levels were carried out.

RESULTS

The prevalence of asthma and rhinitis symptoms was 11% and 33.2%, respectively. Among asthmatic children, 10.6% presented four or more wheezing attacks in the past 12 months. Past family history of bronchitis and rhinitis was associated with presence of asthma (p=0.002 and p <0.001) and rhinitis (p <0.001 and p<0.001, respectively). Regarding rhinitis, there was association with presence of mold or cracks on the house (p=0.009). Rhinitis was most frequent from June to October, a period that matches the sugarcane harvest season. Daily prevalence of peak expiratory flow below 20% of the median of each child's measurements was higher in days with greater PM2,5 concentration.

CONCLUSIONS

The prevalence of asthma symptoms is below and that of rhinitis is above the national average. Although within acceptable levels, pollution in the cane trash burn season may contribute to the exacerbation of asthma and rhinitis episodes.

A review of low-level air pollution and adverse effects on human health: implications for epidemiological studies and public policy

The aim of this study was to review original scientific articles describing the relationship between atmospheric pollution and damage to human health. We also aimed to determine which of these studies mentioned public policy issues. Original articles relating to atmospheric pollution and human health published between 1995 and 2009 were retrieved from the PubMed database and analyzed. This study included only articles dealing with atmospheric pollutants resulting primarily from vehicle emissions. Three researchers were involved in the final selection of the studies, and the chosen articles were approved by at least two of the three researchers. Of the 84 non-Brazilian studies analyzed, 80 showed an association between atmospheric pollution and adverse effects on human health. Moreover, 66 showed evidence of adverse effects on human health, even at levels below the permitted emission standards. Three studies mentioned public policies aimed at changing emission standards. Similarly, the 29 selected Brazilian studies reported adverse associations with human health, and 27 showed evidence of adverse effects even at levels below the legally permitted emission standards. Of these studies, 16 mentioned public policies aimed at changing emission standards. Based on the Brazilian and non-Brazilian scientific studies that have been conducted, it can be concluded that, even under conditions that are compliant with Brazilian air quality standards, the concentration of atmospheric pollutants in Brazil can negatively affect human health. However, as little discussion of this topic has been generated, this finding demonstrates the need to incorporate epidemiological evidence into decisions regarding legal regulations and to discuss the public policy implications in epidemiological studies.

Environmental and occupational allergies

Airborne allergens are the major cause of allergic rhinitis and asthma. Daily exposure comes from indoor sources, chiefly at home but occasionally at schools or offices. Seasonal exposure to outdoor allergens, pollens, and molds is another important source. Exposure to unusual substances at work causes occupational asthma, accounting for about 5% of asthma in adults. Indoor and outdoor air pollutants trigger airway inflammation and increase the severity of asthma. Diesel exhaust particles increase the production of IgE antibodies. Identification and reduction of exposure to allergens is a very important part of the management of respiratory allergic diseases. The first section of this chapter discusses domestic allergens, arthropods (mites and cockroaches), molds, and mammals (pets and mice). Indoor humidity and water damage are important factors in the production of mite and mold allergens, and discarded human food items are important sources of proliferation of cockroaches and mice. Means of identifying and reducing exposure are presented. The second section discusses outdoor allergens: pollens and molds. The particular plants or molds and the amount of exposure to these allergens is determined by the local climate, and local pollen and mold counts are available to determine the time and amount of exposure. Climate change is already having an important effect on the distribution and amount of outdoor allergens. The third section discusses indoor and outdoor air pollution and methods that individuals can take to reduce indoor pollution in addition to eliminating cigarette smoking. The fourth section discusses the diagnosis and management of occupational asthma.

Effect of air pollution on lung function in schoolchildren in Rio de Janeiro, Brazil

OBJECTIVE

To assess the association between daily exposure to air pollution and lung function in school children.

METHODS

Panel study with a random sample of 118 students (between 6 and 15 years of age), enrolled in a public school of the city of Rio de Janeiro, state of Rio de Janeiro, and living within 2 km of the study site. Data on students' characteristics were obtained with a questionnaire, including the International Study of Asthma and Allergies in Childhood - ISAAC. Daily peak expiratory flow measurements were taken to measure lung function. Daily data on PM10, SO2, O3, NO2 and CO levels, temperature and humidity were provided by a portable monitor. Repeated measurements of lung function were associated with pollutant levels with a multilevel model adjusted for time trend, temperature, air humidity, exposure to smoking at home, presence of asthma, height, sex, weight and age of children.

RESULTS

Mean peak expiratory flow was 243.5 l/m (sd=58.9). The lowest mean peak expiratory flow was 124 l/m, and the highest, 450 l/m. For the 10 microg/m(3) increase in PM10, there was a 0.34 l/min decrease in mean peak flow on the third day. For the 10 microg/m(3) increase in NO2, there was a decrease between 0.23 l/min and 0.28 l/min in mean peak flow after exposure. CO and SO2 effects on students' peak flow were not statistically significant. O3 showed a protective result: an increase in 10 microg/m(3) of O3 would be associated, after a day of exposure, with a 0.2 l/min increase in mean lung function.

CONCLUSIONS

Even within acceptable levels most of the time, air pollution, especially PM10 and NO2, was associated with a decrease in lung function in children living in the city of Rio de Janeiro.

Home indoor pollutant exposures among inner-city children with and without asthma

BACKGROUND

Evidence for environmental causes of asthma is limited, especially among African Americans. To look for systematic differences in early life domestic exposures between inner-city preschool children with and without asthma, we performed a study of home indoor air pollutants and allergens.

METHODS

Children 2-6 years of age were enrolled in a cohort study in East Baltimore, Maryland. From the child's bedroom, air was monitored for 3 days for particulate matter <or= 2.5 and <or= 10 microm in aerodynamic diameter (PM(2.5), PM(10)), nitrogen dioxide, and ozone. Median baseline values were compared for children with (n = 150) and without (n = 150) asthma. Housing characteristics related to indoor air pollution were assessed by caregiver report and home inspection. In addition, indoor allergen levels were measured in settled dust.

RESULTS

Children were 58% male, 91% African American, and 88% with public health insurance. Housing characteristics related to pollutant exposure and bedroom air pollutant concentrations did not differ significantly between asthmatic and control subjects [median: PM(2.5), 28.7 vs. 28.5 microg/m(3); PM(10), 43.6 vs. 41.4 microg/m(3); NO(2), 21.6 vs. 20.9 ppb; O(3), 1.4 vs. 1.8 ppb; all p > 0.05]. Settled dust allergen levels (cat, dust mite, cockroach, dog, and mouse) were also similar in bedrooms of asthmatic and control children.

CONCLUSIONS

Exposures to common home indoor pollutants and allergens are similar for inner-city preschool children with and without asthma. Although these exposures may exacerbate existing asthma, this study does not support a causative role of these factors for risk of developing childhood asthma.

Ecological study of socio-economic indicators and prevalence of asthma in schoolchildren in urban Brazil

BACKGROUND

There is evidence of higher prevalence of asthma in populations of lower socio-economic status in affluent societies, and the prevalence of asthma is also very high in some Latin American countries, where societies are characterized by a marked inequality in wealth. This study aimed to examine the relationship between estimates of asthma prevalence based on surveys conducted in children in Brazilian cities and health and socioeconomic indicators measured at the population level in the same cities.

METHODS

We searched the literature in the medical databases and in the annals of scientific meeting, retrieving population-based surveys of asthma that were conducted in Brazil using the methodology defined by the International Study of Asthma and Allergies in Childhood. We performed separate analyses for the age groups 6-7 years and 13-14 years. We examined the association between asthma prevalence rates and eleven health and socio-economic indicators by visual inspection and using linear regression models weighed by the inverse of the variance of each survey.

RESULTS

Six health and socioeconomic variables showed a clear pattern of association with asthma. The prevalence of asthma increased with poorer sanitation and with higher infant mortality at birth and at survey year, GINI index and external mortality. In contrast, asthma prevalence decreased with higher illiteracy rates.

CONCLUSION

The prevalence of asthma in urban areas of Brazil, a middle income country, appears to be higher in cities with more marked poverty or inequality.

Asma em escolares de 13 e 14 anos do Município de Nova Iguaçu, Rio de Janeiro, Brasil: estimativas de prevalência, gravidade e diferenças de gênero

O objetivo deste estudo foi descrever a prevalência, a gravidade e os sintomas associados à asma e sua relação com o gênero em escolares de 13 e 14 anos do Município de Nova Iguaçu, Rio de Janeiro, Brasil. Trata-se de estudo transversal, no qual se utilizou o questionário escrito auto-aplicável para asma do International Study of Asthma and Allergies in Childhood (ISAAC). Participaram 3.033 escolares de 37 escolas públicas e privadas selecionadas aleatoriamente. A prevalência de sibilância alguma vez na vida foi de 26% e nos últimos 12 meses (asma atual) de 11,7%, sendo essas taxas maiores entre as meninas (razão de prevalência - RP = 1,46; IC95%: 1,31-1,62 e RP =1,72; IC95%: 1,35-2,21, respectivamente). Sintomas associados à gravidade da doença, como distúrbio do sono e limitação da fala por sibilos, também se associaram positivamente com o gênero feminino (RP = 2,57; IC95%:1,77-3,73 e RP = 2,07; IC95%:1,25-3,43). A prevalência da asma mostrou-se menor quando comparada com as de outras cidades brasileiras, porém ainda é alta entre adolescentes de Nova Iguaçu, sendo mais freqüente e mais grave no gênero feminino. Outros estudos são necessários para explicar tais diferenças.

Environmental and socio-demographic factors associated to asthma in adolescents in Rio de Janeiro, Brazil

Although asthma is of frequent occurrence, little is known about the factors associated with this disease in Brazil. We studied the association between asthma, environmental and socio-demographic factors in adolescents in Nova lguacu, Rio de Janeiro State. Cross-sectional study using the questionnaires about asthma and environmental factors from the International Study of Asthma and Allergies in Childhood (ISAAC). We performed bivariate analyses between asthma and the factors studied using prevalence ratio (PR), confidence intervals of 95% (95% Cl) and Chi-squared test. Factors associated to asthma in a bivariate analysis were studied using logistic regression and odds ratio (OR). We included 3,033 students, aged 13-14 yrs, selected from 37 schools. The prevalence of asthma was 13.1%. Being female (OR = 1.40; 95%Cl:1.11-1.77), the presence of a mother who smokes (OR = 1.32; 95%Cl:1.04-1.66), a cat in the domicile (OR = 1.32; 95%Cl:1.04-1.69), being the firstborn (OR = 1.34; 95%Cl:1.07-1.68), frequent use of paracetamol (OR = 1.45; 95%Cl: 1.15-1.84), the presence of rhinitis (OR = 5.15; 95%:3.89-6.82) and eczema (OR = 2.35; 95%Cl:1.73-3.19) were independently associated to asthma. Environmental and socio-demographic factors were associated to asthma in adolescents in Rio de Janeiro, irrespective of the presence of others allergic diseases. Interventions acting on these factors may decrease the occurrence of asthma in this population.

Is the global rise of asthma an early impact of anthropogenic climate change?

The increase in asthma incidence, prevalence, and morbidity over recent decades presents a significant challenge to public health. Pollen is an important trigger of some types of asthma, and both pollen quantity and season depend on climatic and meteorological variables. Over the same period as the global rise in asthma, there have been considerable increases in atmospheric carbon dioxide concentration and global average surface temperature. We hypothesize anthropogenic climate change as a plausible contributor to the rise in asthma. Greater concentrations of carbon dioxide and higher temperatures may increase pollen quantity and induce longer pollen seasons. Pollen allergenicity can also increase as a result of these changes in climate. Exposure in early life to a more allergenic environment may also provoke the development of other atopic conditions, such as eczema and allergic rhinitis. Although the etiology of asthma is complex, the recent global rise in asthma could be an early health effect of anthropogenic climate change.

Is the global rise of asthma an early impact of anthropogenic climate change?

The increase in asthma incidence, prevalence, and morbidity over recent decades presents a significant challenge to public health. Pollen is an important trigger of some types of asthma, and both pollen quantity and season depend on climatic and meteorologic variables. Over the same period as the global rise in asthma, there have been considerable increases in atmospheric carbon dioxide concentration and global average surface temperature. We hypothesize anthropogenic climate change as a plausible contributor to the rise in asthma. Greater concentrations of carbon dioxide and higher temperatures may increase pollen quantity and induce longer pollen seasons. Pollen allergenicity can also increase as a result of these changes in climate. Exposure in early life to a more allergenic environment may also provoke the development of other atopic conditions, such as eczema and allergic rhinitis. Although the etiology of asthma is complex, the recent global rise in asthma could be an early health effect of anthropogenic climate change.

Prevalência e gravidade de sintomas relacionados à asma em escolares e adolescentes no município de Duque de Caxias, Rio de Janeiro

INTRODUÇÃO: A asma é considerada a doença crônica mais comum na infância. Entretanto, há poucos estudos sobre sua prevalência em nosso meio. OBJETIVO: Avaliar prevalência e gravidade de sintomas de asma em escolares e adolescentes de Duque de Caxias (RJ). MÉTODO: Estudo transversal utilizando o questionário do International Study of Asthma and Allergies in Childhood. A amostra foi composta por alunos de 6, 7, 13 e 14 anos. RESULTADOS: Foram avaliados 4.040 alunos de 13 e 14 anos e 2.334 de 6 e 7 anos. A freqüência de sibilos nos últimos doze meses foi de 27,7% entre os mais jovens e de 19% entre os adolescentes (p < 0,0001). No primeiro grupo houve predomínio do sexo masculino (29,9% vs 25,6%, p = 0,01) e no segundo do feminino (21,9% vs 15,8%, p < 0,0001). Não existiram diferenças entre as faixas etárias relacionadas ao diagnóstico prévio de asma (cerca de 10%). Sibilância aos exercícios físicos foi mais prevalente entre os adolescentes (21,4% vs 7,8%, p < 0,0001). A gravidade dos sintomas foi maior entre as adolescentes (asma grave: 6,6% vs 4,4%, p = 0,001), não havendo diferenças entre gêneros aos 6 e 7 anos. CONCLUSÃO: A prevalência de asma em Duque de Caxias é alta, comparável à de outros municípios brasileiros e latino-americanos. Os valores são superiores aos 6 e 7 anos, quando os sintomas predominam no sexo masculino. Entre os adolescentes, a prevalência e a gravidade dos sintomas são maiores no gênero feminino, fato de observação recente e que parece representar novo comportamento epidemiológico da asma.