Air pollution and daily mortality in Inchon, Korea.

The association between total daily mortality and air pollution was investigated for a 1-year period (January 1995 to December 1995) in Inchon, Korea. The purpose of this study was to evaluate the relative importance of particulate and gaseous air pollution as predictors of daily mortality. Concentration of total suspended particulates (TSP), inhalable particles (PM10), and gaseous pollutants, such as sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, were measured daily during the study period. A generalized additive model was used to regress daily death counts on each air pollutant, controlling for time trend and meteorologic influences such as temperature or relative humidity. Total mortality was found to increase 1.2% (95% CI: 0.2 to 2.2%) for each 10 microg/m3 increase in 6-day moving average of TSP, and 1.2% (95% CI 0.2 to 2.1%) for each 10 microg/m3 increase in 5-day moving average of PM10. The association is similar in magnitude to associations between particulate air pollution and mortality found in several other communities in America and Europe. Associations with gaseous pollutants were all statistically insignificant in the generalized additive model. The relative risk of death increased at particulate levels that were well below the current Korean Ambient Air Quality Standard.     

The association between emergency clinic visits for asthmatic attacks and fluctuating environmental factors]

The number of nocturnal visits of asthmatic attack patients to the emergency room of Yokohama Medical Association's Clinic from January 1990 to December 1991 was compared to daily levels of air pollution (NO, NO2, SO2 and SPM) and weather (temperature and relative humidity) variables measured in Yokohama City. Trend-cycle components (Trend) that control for the weekly effects, other irregular variance for asthmatic attack incidence and environmental parameter measurements were estimated from the original data series using the method of Akaike and Ishiguro (1980). The rate of increase for each environmental parameter was then calculated from its trend-cycle components. We classified the data into four stages on the basis of rising and falling temperature and humidity. For each stage of temperature and humidity, fluctuation we estimated correlations between the number of asthmatic attack visits and original data series measurements, estimated trend-cycle components, and calculated rates of increase for each of the air pollutants. The daily number of asthmatic attack visits was negatively correlated to the daily mean values of all air pollutants, but positively correlated to the daily mean temperature and relative humidity. The trend-cycle components of the air pollutants were also negatively correlated to the frequencies of asthmatic attacks (p < 0.01 for all pollutants except NO2). In contrast, the number of asthmatic attack visits were in general positively correlated with increasing levels of pollutants. Furthermore, when both temperature and relative humidity decreased, significant correlations (r > 0.31, p < 0.001) between the number of asthmatic attacks and increased rates of all air pollutants were observed (r: NO2 > NO > SO2 > SPM).     

Temporal relationship between air pollution and hospital admissions for asthmatic children in Hong Kong

BACKGROUND: Many epidemiological studies have shown positive association between respiratory health and current levels of outdoor air pollution in Europe and America. OBJECTIVE: The aim of this study was to investigate the association between air pollution and the number of childhood admissions for asthma in Hong Kong. METHODS: Daily counts of childhood admission for asthma to a large teaching Hospital were obtained from the computerized database for the period 1993-1994. A Poisson regression allowing for seasonal patterns and meteorological conditions was used to assess the associations between the number of Hospital admissions and the three pollutants: nitrogen dioxide, sulphur dioxide and inhalable particles (measured as PM10, particles < 10 microm in aerodynamic diameter). RESULTS: A total of 1217 children under 15 years of age were admitted for asthma during the study period. The calculated annual hospitalization rates were 283 and 178 per 100 000 for boys and girls, respectively. The mean PM10, NO2 and SO2 levels were 44.1 microg/m3, 43.3 microg/m3, and 12.2 microg/m3, respectively. Daily admission for asthma increased significantly with increasing ambient level of nitrogen dioxide (relative risk (RR) = 1.08 per 10 microg/m3 increase), sulphur dioxide (RR = 1.06) and inhalable particles (RR = 1.03). No association was found between hospital admission and humidity, temperature or atmospheric pressure. CONCLUSION: This is the first daily time series study of childhood admissions for asthma and air pollution in Hong Kong. The results support that current levels of air pollution contribute to the respiratory morbidity in asthmatic children in Hong Kong.     

Effects of air pollution on asthma hospitalization rates in different age groups in Hong Kong

AIMS: To assess the relationship between levels of ambient air pollutants and hospitalization rates for asthma in Hong Kong (HK). METHODS: This is a retrospective ecological study. Data of daily emergency hospital admissions to 15 major hospitals in HK for asthma and indices of air pollutants [sulphur dioxide (SO(2)), nitrogen dioxide (NO(2)), ozone (O(3)), particulates with an aerodynamic diameter of <10 microm particulate matter (PM(10)) and 2.5 microm (PM(2.5))] and meteorological variables from January 2000 to December 2005 were obtained from several government departments. Analysis was performed by the generalized additive models with Poisson distribution. The effects of time trend, season, other cyclical factors, temperature and humidity were adjusted. Autocorrelation and overdispersion were corrected. RESULTS: Altogether, 69 716 admissions were assessed. Significant associations were found between hospital admissions for asthma and levels of NO(2), O(3), PM(10) and PM(2.5). The relative risks (RR) for hospitalization for every 10 microg/m(3) increase in NO(2), O(3), PM(10) and PM(2.5) were 1.028, 1.034, 1.019 and 1.021, respectively, at a lag day that ranged from cumulative lag 0-4 to 0-5. In a multi-pollutant model, O(3) was significantly associated with increased admissions for asthma. The younger age group (0-14 years) tended to have a higher RR for each 10 microg/m(3) increase in pollutants than those aged 15-65 years. The elderly (aged >/=65 years) had a shorter 'best' lag time to develop asthma exacerbation following exposure to pollutants than those aged <65 years. CONCLUSION: Adverse effects of ambient concentrations of air pollutants on hospitalization rates for asthma are evident. Measures to improve air quality in HK are urgently needed.     

Gaseous air pollution and atopy

BACKGROUND: Photochemical air pollutants are commonly thought to be implicated in the gradual increase in the prevalence of atopy. However, no epidemiological data are available. METHODS: To clarify this issue, we performed a cross-sectional epidemiological survey in 2604 primary school children, 10 and 11 years old, living in seven communities among which some have the highest photochemical exposure in France. The mean levels of the main gaseous air pollutants (SO2, NO2 and O3) were measured during a 2-month period in 1993. The protocol included a standardized questionnaire, skin prick tests to common aeroallergens and in the atopic children, collection of a sample of mattress dust to measure group 1 mite allergens. Atopy was only defined on the basis of the skin prick tests. RESULTS: Percentage of positive skin tests and the number of positive skin tests were similar in the different communities looked at. The distribution of dust samples with a group 1 allergen level greater than 2 microg/g dust, was also similar. Logistic regression analysis including potential confounding factors, as well as the mean level of air pollutants, did not demonstrate any association between atopy and mean SO2, NO2 and O3 levels. CONCLUSION: The increase in photochemical air pollutants is unlikely to be a major determinant for the recent increase in the prevalence of atopy.     

Effects of wintertime ambient air pollutants on asthma exacerbations in urban minority children with moderate to severe disease

BACKGROUND: Urban minority children with asthma are at higher risk for severe exacerbations leading to hospitalizations and deaths. Because multiple studies have reported associations between air pollution and asthma worsening, elevated levels of air pollution are cited as a possible trigger for increased asthma morbidity in urban areas. Few studies have prospectively followed panels of urban children with asthma to determine whether air pollution levels are associated with clinically relevant outcomes such as asthma exacerbations. OBJECTIVE: To determine the association between levels of ambient air pollutants and asthma exacerbations in urban poor children with moderate to severe asthma. METHODS: A school-based panel of children with difficult-to-control disease was followed over a period of 3 consecutive winters in Denver, Colo. The panel consisted of predominantly urban African American children with moderate to severe asthma. Levels of Environmental Protection Agency criteria air pollutants were measured on a daily basis with concurrent monitoring of lung function, bronchodilator use, symptoms, and asthma exacerbations. RESULTS: After controlling for time-varying factors such as upper respiratory infections and meteorologic factors, a weak association was found between ambient carbon monoxide levels and bronchodilator use. Ozone levels were associated with daytime symptoms only. No association was observed between daily air pollution concentrations and daily levels of FEV 1 , peak flow, nighttime symptom scores, or asthma exacerbations over the 3-year period. CONCLUSION: Ambient levels of Environmental Protection Agency criteria air pollutants in Denver do not lead to clinically significant asthma worsening in urban children with moderate to severe asthma during winter months when children are primarily indoors.     

Long-term exposure to background air pollution related to respiratory and allergic health in schoolchildren

BACKGROUND: The impact of air pollution on asthma and allergies still remains a debate. OBJECTIVE: Our cross-sectional study was intended to analyse the associations between long-term exposure to background air pollution and atopic and respiratory outcomes in a large population-based sample of schoolchildren. METHODS: Six thousand six hundred and seventy-two children aged 9-11 years recruited from 108 randomly schools in six French cities underwent a clinical examination including a skin prick test (SPT) to common allergens, exercise-induced bronchial reactivity (EIB) and skin examination for flexural dermatitis. The prevalence of asthma, allergic rhinitis (AR) and atopic dermatitis was assessed by a standardized health questionnaire completed by the parents. Three-year-averaged concentrations of air pollutants (NO2, SO2, PM10 and O3) were calculated at children' schools using measurements of background monitoring stations. RESULTS: After adjusting for confounders, EIB, lifetime asthma and lifetime AR were found to be positively related to an increase in the exposure to SO2, PM10 and O3. The adjusted odds ratios (aOR) per increase of 5 microg/m3 of SO2 was 1.39 (95% confidence interval (CI)=1.15-1.66) for EIB and 1.19 (1.00-1.41) for lifetime asthma. The aOR for lifetime AR per increase of 10 microg/m3 of PM10 was 1.32 (CI=1.04-1.68). Moreover, SPT positivity was associated with O3 (aOR=1.34; CI=1.24-1.46). Associations with past year symptoms were consistent, even if not always statistically significant. Results persisted in long-term resident (current address for at least 8 years) children. However, no consistent positive association was found with NO2. CONCLUSIONS: A moderate increase in long-term exposure to background ambient air pollution was associated with an increased prevalence of respiratory and atopic indicators in children.     

Association of asthma symptoms and severity with indoor bioaerosols

BACKGROUND: In this study, repeated measurements were made of levels of mold spores, bacteria, and dust-mite allergens over a 7-month period in the homes of asthmatics, and relationships with measures of asthma severity were evaluated. METHODS: A sample of 57 asthmatic individuals, living in 44 homes in East Moline, Illinois, and nearby communities, participated in a panel study. The homes were visited up to nine times during the study to collect air and dust samples. Asthma severity indicators were derived from questionnaire data and from the daily health records from the panel study. Associations between indoor levels of mold spores, bacteria, and dust-mite allergens were tested with several asthma severity indicators. RESULTS: There was evidence of associations between all asthma severity measures and levels of total and gram-negative bacteria, but mold-spore abundance was associated only with emergency room (ER) visits for asthma. No significant associations were found with house-dust-mite allergen and any of the asthma severity indicators, but the levels of dust-mite allergen were low, with median concentrations of 0.18 microg/g dust Der f 1 and 0.19 microg/g dust Der p 1. CONCLUSIONS: Some evidence was found for associations of increased concentrations of gram-negative bacteria and mold spores with asthma severity, particularly with ER visits. No association was found between house-dust-mite allergen and asthma severity indicators; however, the mite-allergen levels in the study homes were generally well below the proposed threshold level of 2 microg/g dust.     

Non-linear short-term effects of airborne pollen levels with allergenic capacity on asthma emergency room admissions in Madrid, Spain

BACKGROUND: Several time-series studies have shown positive associations between pollen levels and asthma morbidity. However, few studies have included air pollution as a potential confounder when examining this relationship, and they have only done so on a linear basis. OBJECTIVE: To investigate the potential non-linear short-term effects of the types of pollen with allergenic capacity across the whole range of exposure on the daily number of asthma-related hospital emergencies in Madrid for the period 1995-1998. METHODS: Data were collected on the daily number of asthma emergency room admissions and daily average levels of major types of pollen with allergenic capacity: Olea, Plantago, Poaceae and Urticaceae. We used Poisson regression with generalized additive models, controlling for trend and seasonality, meteorological variables, acute respiratory infections and air pollutants. To study the non-linear effect of pollen levels on asthma emergency room admissions, pollens were categorized into five groups defined on the basis of their respective distributions. RESULTS: The strongest associations were registered in respect of a lag of 1 day for Urticaceae, a lag of 2 days for Plantago, and a day lag of 3 days for Poaceae. Adjustment for the different types of pollen failed to result in major changes. Non-linearities were evident for pollen levels. The greatest increase in risk vs. the reference category (minimum value - 50th percentile) was observed for the categories between the 95th and 99th percentiles, with increases of 32.0% for Plantago, 32.2% for Poaceae and 24.6% for Urticaceae, and between the 99th percentile and the maximum value, with increases of 31.3%, 78.7% and 49.8%, respectively. Olea was not related with asthma emergency room admissions. CONCLUSIONS: Pollens with allergenic capacity in Madrid are positively associated with asthma-related hospital emergencies. These associations remain stable when simultaneous adjustment is made for the four types of pollen and for air pollutants and meteorological variables. In terms of non-linear effects, Poaceae register the strongest association with asthma emergency room admissions.     

Fine particulate air pollution and mortality in 20 U.S. cities, 1987-1994

BACKGROUND: Air pollution in cities has been linked to increased rates of mortality and morbidity in developed and developing countries. Although these findings have helped lead to a tightening of air-quality standards, their validity with respect to public health has been questioned. METHODS: We assessed the effects of five major outdoor-air pollutants on daily mortality rates in 20 of the largest cities and metropolitan areas in the United States from 1987 to 1994. The pollutants were particulate matter that is less than 10 microm in aerodynamic diameter (PM10), ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. We used a two-stage analytic approach that pooled data from multiple locations. RESULTS: After taking into account potential confounding by other pollutants, we found consistent evidence that the level of PM10 is associated with the rate of death from all causes and from cardiovascular and respiratory illnesses. The estimated increase in the relative rate of death from all causes was 0.51 percent (95 percent posterior interval, 0.07 to 0.93 percent) for each increase in the PM10 level of 10 microg per cubic meter. The estimated increase in the relative rate of death from cardiovascular and respiratory causes was 0.68 percent (95 percent posterior interval, 0.20 to 1.16 percent) for each increase in the PM10 level of 10 microg per cubic meter. There was weaker evidence that increases in ozone levels increased the relative rates of death during the summer, when ozone levels are highest, but not during the winter. Levels of the other pollutants were not significantly related to the mortality rate. CONCLUSIONS: There is consistent evidence that the levels of fine particulate matter in the air are associated with the risk of death from all causes and from cardiovascular and respiratory illnesses. These findings strengthen the rationale for controlling the levels of respirable particles in outdoor air.     

Relationship of outdoor air quality to pediatric asthma exacerbations.

BACKGROUND: Although exposure to outdoor air pollutants has been shown to be associated with exacerbations of asthma, there are relatively few admissions for asthma to Cincinnati Children's Hospital, Cincinnati, OH during the summer months when air quality tends to be worst. OBJECTIVE: The objective of this study was to determine the relationship of outdoor air quality parameters to asthma exacerbations in children. METHODS: The number of emergency room visits and hospitalizations for asthma were determined by review of emergency department logs and the hospital computer database. Outdoor air concentrations of ozone, particulates of < 10 microm diameter (PM-10), pollens, and fungal spores were obtained from the Hamilton County Department of Environmental Services. Multiple regression analysis was performed, looking for relationships between the daily number of asthma visits and the air quality data for the same day and for 1 through 5 days before the visits. RESULTS: A significant association was found between the number of asthma visits and the daily pollen count (P = 0.014, SE = 0.001). The effect was stronger for visits 1, 2, and 3 days after the pollen count (P < 0.001 for pollen count lagged 3 days). High PM-10 counts were synergistic with the pollen count as a predictor of asthma visits. There was no association between asthma visits and the ozone concentration or fungal spore count. CONCLUSIONS: Exacerbations of asthma severe enough to require visits to the hospital were associated with elevated concentrations of airborne pollens and particulates, with a significant delayed effect. Ozone, in the concentrations measured here, was not a risk factor for severe asthma exacerbations in children.     

Low level atmospheric sulfur dioxide pollution and childhood asthma

Quarterly analysis (1983-1987) of childhood asthma in Hong Kong from 13,620 hospitalization episodes in relation to levels of pollutants (SO2, NO2, NO, O3, TSP, and RSP) revealed a seasonal pattern of attack rates that correlates inversely with exposure to sulfur dioxide (r = -.52, P less than .05). The same cannot be found with other pollutants. Many factors may contribute to the seasonal variation of asthma attacks. We speculate that prolonged exposure (in terms of months) to low level SO2 is one factor that might induce airway inflammation and bronchial hyperreactivity and predispose to episodes of asthma.     

Air pollution and seasonal asthma during the pollen season. A cohort study in Puertollano and Ciudad Real (Spain)

BACKGROUND: Many studies have demonstrated a positive association between air pollutants and emergency visits for asthma. However, few studies have included pollen when analysing this relationship in mild-moderate asthmatic patients. OBJECTIVE: To determine the importance of the pollutants such as ozone (O(3)), particles (PM(10)), nitrogen dioxide (NO(2)) and sulphur dioxide (SO(2)) in the clinical course of mild-moderate pollen-allergic asthmatic patients from two Spanish towns in La Mancha: Puertollano (high pollution levels) and Ciudad Real (low pollution levels). METHODS: We used a Poisson regression model to study a cohort of 137 patients from Puertollano and Ciudad Real during two pollen seasons (2000-2001) and analysed the relationship between air pollutant and pollen levels and daily symptoms, the medication used and peak-flow measurements. RESULTS: The number of asthma symptoms and the mean values of the PM(10), SO(2) and NO(2) levels were higher in Puertollano than in Ciudad Real. In Puertollano, the risk of asthma increased by 6% with a 3-day lag for PM(10), by 8% with a 3-day lag for O(3), by 4% with a 1-day lag for SO(2) and by 15% with a 3-day lag for O(3) when its values exceeded the health threshold (P < 0.05). CONCLUSIONS: The air pollution levels in Puertollano were associated with an increased risk of asthma symptoms in pollen-allergic asthmatic patients com pared with a similar group from Ciudad Real.     

Circulating neutrophil CD14 expression and the inverse association of ambient particulate matter on lung function in asthmatic children.

BACKGROUND: Identifying baseline inflammatory biomarkers that predict susceptibility to size-specific particulate matter (PM) independent of gaseous pollutants could help us better identify asthmatic subpopulations at increased risk for the adverse health effects of PM. OBJECTIVE: To evaluate whether the association between lung function and exposure to ambient levels of PM less than 2.5 microm in diameter (PM2.5) (fine) and 10 to 2.5 microm in diameter (PM(10-2.5)) (coarse) in children with persistent asthma differed across baseline measures of inflammation and innate immune activation. METHODS: We performed a panel study on a local population of 16 children with persistent asthma and evaluated daily pulmonary function (percentage of predicted peak expiratory flow and forced expiratory volume in 1 second) while concurrently measuring daily PM2.5 and PM(10-2.5) exposure from a central site in Chapel Hill, North Carolina. The children underwent a baseline medical evaluation that included assessment of several immunoinflammatory biomarkers in peripheral blood. RESULTS: Children without measurable CD14 expression on circulating neutrophils had significantly reduced pulmonary function (forced expiratory volume in 1 second and peak expiratory flow) with each interquartile range (IQR) increase in PM2.5 (IQR = 8.5 microg/m3) and PM(10-2.5) (IQR = 4.1 microg/m3) concentration, unlike children with measurable CD14 expression (P < .001 for interaction). CONCLUSIONS: Asthmatic children with muted surface expression of CD14 on circulating neutrophils may have a decreased capacity to respond to bacterial components of PM.     

Particulate air pollution and hospitalization for asthma.

Age-specific quarterly asthmatic hospital discharge rates in Hong Kong during 1983 to 1989 were examined in relation to mean levels of six pollutants: sulfur dioxide (SO2), ozone (O3), total suspended particles (TSP), respiratory suspended particles (RSP), nitrogen dioxide (NO2), and nitrogen oxides (NOX). Discharges from the hospital of children under 14 years of age represented 56% of 33,952 discharges recorded in all age groups. Trends of adult hospitalization rates over time remained stable during the study period. In children, however, there was an increase in these rates, particularly marked in the age group of 1 to 4 years. Univariate analysis revealed a strong correlation between quarterly mean TSP and hospital discharge rate for the 1 to 4-year-old children (r = .62, P less than .001). In the 5 to 14-year-old age group, there was an inverse relationship between hospital discharge rate and sulfur dioxide level (r = -.38, P less than .05). Stepwise multiple regression analysis, controlling for confounding variables (seasonal and annual trends of asthma hospitalizations) confirmed these relationships. A highly significant linear regression equation was derived between hospitalization rate for ages 1 to 4 years and total suspended particles (P less than .001). The highly significant correlation between pollution and asthmatic hospitalization rate for the 1 to 4-year-old group suggests that young children are vulnerable to the adverse environmental effects of pollution. Auditing these relationships offers a logical basis for approaching control.     

Association between air pollution and asthma admission among children in Hong Kong

OBJECTIVE: To examine the association of air pollutants with hospital admission for childhood asthma in Hong Kong. METHODS: Data on hospital admissions for asthma, influenza and total hospital admissions in children aged < or =18 years at all Hospital Authority hospitals during 1997-2002 were obtained. Data on daily mean concentrations of particles with aerodynamic diameter <10 microm (i. e. PM10) and <2.5 microm (i. e. PM2.5), nitrogen dioxide (NO2), sulphur dioxide (SO2), and ozone (O3) and data on meteorological variables were associated with asthma hospital admissions using Poisson's regression with generalized additive models for correction of yearly trend, temperature, humidity, day-of-week effect, holiday, influenza admissions and total hospital admission. The possibility of a lag effect of each pollutant and the interaction of different pollutants were also examined. RESULTS: The association between asthma admission with change of NO2, PM10, PM2.5 and O3 levels remained significant after adjustment for multi-pollutants effect and confounding variables, with increase in asthma admission rate of 5.64% (3.21-8.14) at lag 3 for NO2, 3.67% (1.52-5.86) at lag 4 for PM10, 3.24% (0.93-5.60) at lag 4 for PM2.5 and 2.63% (0.64-4.67) at lag 2 for O3. Effect of SO2 was lost after adjustment. CONCLUSION: Ambient levels of PM10, PM2.5) NO2 and O3 are associated with childhood asthma hospital admission in Hong Kong.     

Low-dose inhaled budesonide once or twice daily for 27 months in children with mild asthma

This study is an extended follow-up for 24 months of a 12-week trial to study the long-term clinical efficacy of low-dose inhaled budesonide (BUD) once or twice daily in children with mild asthma. A total of 122 children (mean age 9.7 years, girls/boys; 42/80) with mild asthma (FEV1 103.7% of predicted, reversibility in FEV1 3.5%, and fall in FEV1 after exercise 12.2%), not previously treated with inhaled steroids, were included in a double-blind, randomized, parallel-group study. The children were treated with inhaled BUD 100 or 200 microg administered via Turbuhaler once daily in the morning, 100 microg twice daily, or placebo for 27 months. Exercise and methacholine challenges were performed at 3-month intervals the first year and at 6-month intervals the second year, in a total of seven visits. A significant dose-response effect favoring BUD 200 microg daily (vs 100 microg daily) was found when comparing changes in FEV1, FEF25%, and FEV50%; the fall in FEV1 after an exercise test; and the effect on blood eosinophils. Bronchial hyperreactivity to methacholine decreased significantly on three visits in patients treated with BUD 200 microg daily compared to placebo. Growth rate was not significantly affected except in children aged 7-11 years at baseline after 12 months of treatment. In conclusion, 100 or 200 microg daily of inhaled BUD for 27 months is safe and effective in protecting against exercise-induced asthma and achieving nearly normal lung function. Baseline lung function was not significantly affected in this group of children with mild asthma.     

Effects of ambient air pollution on symptom severity and medication use in children with asthma.

BACKGROUND: Exposure to air pollutants has been investigated as a possible cause of asthma attacks in children. OBJECTIVE: To investigate the short-term effects of air pollutants on a panel of 133 children with asthma who enrolled in the Childhood Asthma Management Program. METHODS: During screening, the children completed daily diary cards for an average of 58 days to indicate their medication use and asthma severity. We used ordinal logistic regression to compare the odds of a more serious relative to a less serious asthma attack, and we used a Poisson model to analyze medication use. In both analyses we accommodate dependence in the data and different periods of observation for study subjects. RESULTS: Our results indicate that a 10-microg/m3 increase in particulate matter less than or equal to 2.5 microm (PM2.5) lagged 1 day was associated with a 1.20 times increased odds of having a more serious asthma attack [95% confidence interval (CI), 1.05 to 1.37] and a 1.08-fold increase in medication use (95% CI, 1.01 to 1.15). A 10-microg/m3 increase in particulate matter less than or equal to 10 microm (PM10) increased the odds of a more serious asthma attack (odds ratio = 1.12; 95% CI, 1.04 to 1.22) and also increased medication use (relative risk = 1.05; 95% CI, 1.00 to 1.09). CONCLUSIONS: Increases in PM2.5 and PM10 are significantly associated with an increased risk of more severe asthma attacks and medication use in Seattle area children with asthma. We also found associations with carbon monoxide, but we believe that carbon monoxide is a marker for exposure to combustion byproducts.     

Lack of relationship between eosinophil cationic protein and eosinophil protein X in nasal lavage and urine and the severity of childhood asthma in a 6-month follow-up study.

BACKGROUND: Recent studies suggest that eosinophil cationic protein (ECP) and eosinophil protein X (EPX) may be valuable markers of airway inflammation in various body fluids of asthmatic children. Most of these studies have relied on a single measure of inflammatory markers. OBJECTIVE: We measured ECP and EPX in nasal lavage fluids (NALF) and urine samples in children with asthma over a 6-month period to study the relationship between inflammatory markers and clinical severity. METHODS: Fourteen children with mild persisting asthma (mean age 11.7 years, SD 2.2) were recruited. All patients were on therapy including inhaled steroids. For a 6-month period asthma severity was monitored by at least monthly physical examination and pulmonary function tests. Daily morning and evening PEF, asthma symptoms and medication were recorded in diaries for the whole study period. Telephone interviews were performed between visits and additional visits were done in case of an increase in asthmatic symptoms or drop of PEF values under 80% of best value. An exacerbation was defined by a fall of FEV1 > 10% and an increase in asthma symptoms and additional need of beta2-agonist. NALF and urine samples were obtained at each visit and analysed for ECP (NALF only) and EPX. RESULTS: Mean observation time was 186.4 days (SD 19.8). Thirteen patients completed the study. During the study period 11 exacerbations were observed in six patients. No significant associations between PEF, PEF variability (amplitude % of mean), daily symptoms, additional beta2-agonist, FEV1 and MEF50 and nasal ECP, nasal EPX and urinary EPX were found. However, at exacerbations an average increase of nasal ECP (9.3 vs 50.3 microg/L) and EPX (nasal EPX 36.4 vs 141.7 microg/L, urinary EPX 46.4 vs 74.1 microg/mmol creatinine) was observed. CONCLUSION: Serial measurements of ECP and EPX in NALF and urine samples do not provide additional information for the practical management in monitoring childhood asthma.     

Safety of nasal budesonide in the long-term treatment of children with perennial rhinitis

BACKGROUND: Intranasal budesonide is an efficacious treatment for perennial allergic rhinitis. Long-term effects on safety, particularly in children, need further investigation. OBJECTIVE: To investigate the long-term safety of intranasal budesonide in children. METHODS: In an open trial, 78 children (5-15 years) with perennial rhinitis were treated with intranasal budesonide pressurized metered dose inhaler 200 microg twice daily (delivered daily dose 256 microg) for 12 months; 43 children stayed in the study for 12 additional months and were switched to aqueous suspension (400 microg delivered daily dose) for 6 months. Statural growth, bone age, ophthalmologic and rhinoscopic status, cortisol and biochemical analyses in blood and urine were monitored during the first and second years, and adverse events (AEs) were continuously recorded. RESULTS: No significant effects on statural growth and bone age, compared with reference values, were observed. Morning plasma cortisol and 24-h urinary cortisol were not changed during treatment. Patients reported 195 AEs, most commonly nasal dryness (30%), blood-tinged secretions (21%) and, among non-nasal AEs, headache (13%). Rhinoscopy revealed no signs of mucosal atrophy, ulceration, or candidiasis but some nasal dryness. No treatment-related ophthalmological or biochemical aberrations were found. Reduction of blood eosinophils and nasal symptom scores, compared with pre-treatment values, indicated the efficacy of budesonide treatment. CONCLUSION: Long-term treatment for 1-2 years with intranasal budesonide 256-400 microg daily in children with perennial rhinitis revealed no negative effects on growth or endogenous cortisol production. Local side-effects were mild and patient symptoms decreased.