Persistent Phlegm Research Articles

Long-term ambient ozone exposure and childhood asthma, rhinitis, eczema, and conjunctivitis: A multi-city study in China

Evidence on the link of long-term exposure to ozone (O3) with childhood asthma, rhinitis, conjunctivitis and eczema is inconclusive. We did a population-based cross-sectional survey, including 177,888 children from 173 primary and middle schools in 14 Chinese cities. A satellite-based spatiotemporal model was employed to assess four-year average O3 exposure at both residential and school locations. Information on asthma, allergic rhinitis, eczema and conjunctivitis was collected by a standard questionnaire developed by the American Thoracic Society. We used generalized non-linear and linear mixed models to test the associations. We observed linear exposure-response associations between O3 and all outcomes. The odds ratios of doctor-diagnosed asthma, rhinitis, eczema, and conjunctivitis associated with per interquartile increment in home-school O3 concentration were 1.31 (95 % confidence interval [CI]: 1.28, 1.34), 1.25 (95 %CI: 1.23, 1.28), 1.19 (95 %CI: 1.16, 1.21), and 1.28 (95 %CI: 1.21, 1.34), respectively. Similar associations were observed for asthma-related outcomes including current asthma, wheeze, current wheeze, persistent phlegm, and persistent cough. Moreover, stronger associations were observed among children who were aged > 12 years, physically inactive, and exposed to higher temperature. In conclusion, long-term O3 exposure was associated with higher risks of asthma, allergic rhinitis, conjunctivitis and eczema in children.

Sometimes Things Look Worse Than They Are: Case Report of Esophagitis Dissecans Superficialis

Esophagitis dissecans superficialis is a rare and benign disorder of the esophagus that can appear severe and frightening at first glance. It is characterized by the extensive desquamation of the mucosal epithelium and the formation of tubular casts. This case report presents a 66-year-old female patient complaining of persistent phlegm and acid reflux, who was diagnosed with esophagitis dissecans superficialis on endoscopy.

Relationships between Long-Term Ozone Exposure and Allergic Rhinitis and Bronchitic Symptoms in Chinese Children.

Numerous studies have demonstrated that exposure to ambient ozone (O3) could have adverse effects on children’s respiratory health. However, previous studies mainly focused on asthma and wheezing. Evidence for allergic rhinitis and bronchitic symptoms (e.g., persistent cough and phlegm) associated with O3 is limited, and results from existing studies are inconsistent. This study included a total of 59,754 children from the seven northeastern cities study (SNEC), who were aged 2 to 17 years and from 94 kindergarten, elementary and middle schools. Information on doctor-diagnosed allergic rhinitis (AR), persistent cough, and persistent phlegm was collected during 2012–2013 using a standardized questionnaire developed by the American Thoracic Society (ATS). Information for potential confounders was also collected via questionnaire. Individuals’ exposure to ambient ozone (O3) during the four years before the investigation was estimated using a satellite-based random forest model. A higher level of O3 was significantly associated with increased risk of AR and bronchitic symptoms. After controlling for potential confounders, the OR (95% CI) were 1.13 (1.07–1.18), 1.10 (1.06–1.16), and 1.12 (1.05–1.20) for AR, persistent cough, and persistent phlegm, respectively, associated with each interquartile range (IQR) rise in O3 concentration. Interaction analyses showed stronger adverse effects of O3 on AR in children aged 7–17 years than those aged 2–6 years, while the adverse association of O3 with cough was more prominent in females and children aged 7–12 years than in males and children aged 2–6 and 13–17 years. This study showed that long-term exposure to ambient O3 was significantly associated with higher risk of AR and bronchitic symptoms in children, and the association varies across age and gender. Our findings contribute additional evidence for the importance of controlling O3 pollution and protecting children from O3 exposure.

Association of mild cognitive impairment and characteristic of COPD and overall health status in a cohort study

ABSTRACT Introduction: We evaluated risk factors and demographic characteristics of associated with mild cognitive impairment (MCI) in patients with COPD. Methods: 220 individuals with COPD enrolled in a cohort study designed to evaluate anxiety conducted at 16 clinical centers. Cognitive impairment was assessed with the Montreal Cognitive Assessment (MoCA), a cutoff score of <26 defined as MCI. Data were collected including spirometry, 6-minute walk test, symptom burden by COPD Assessment Test and dyspnea by Modified Medical Research Council, anxiety measured by Anxiety Inventory of Respiratory Disease, Generalized Anxiety Disorder-7 and Hospital Anxiety Depression Scale, depression by Patient Health Questionnaire-9 and health status by Patient Reported Outcomes Measurement Information System and sleep quality by the Pittsburg Sleep Quality Index. Results: The median age was 65 years and 54% of participants were male. 119(54%) of participants had MCI as classified by MoCA. In multivariable logistic regression, higher odds ratios (OR) (95% confidence interval) for MCI (MoCA) <26 were associated with increased years of age, 1.06 (1.02 -1-09, p<0.003); African-American race, 3.68(1.67-8.11, p<0.001); persistent phlegm, 2 (1.12-3.57, p<0.01) and sleep disturbance, 1.04(1.01-1.08, p<0.01). Conclusions: COPD patients commonly screen positive for MCI. Characteristics associated with MCI included age, African-American race, sleep disturbance and persistent phlegm.

Association of pet-keeping in home with self-reported asthma and asthma-related symptoms in 11611 school children from China

Objective We conducted a cross-sectional study to investigate the associations between domestic pets and respiratory health in children. Methods We randomly recruited 11,611 school children from Zhongshan, a southern city in China. Information about the respiratory symptoms and disease history of the recruited children, the status of domestic pets, and other related risk factors were collected from March to July 2016. Results We identified cat-keeping at home increases the risk of persistent cough (OR, 1.77; 95%CI, 1.03–3.05); poultry-keeping at home increases the risk of current asthma (OR, 3.87; 95%CI, 1.08–13.92) and allergic rhinitis (OR, 1.84; 95%CI, 1.01–3.37); sleeping with pets increases the risk of persistent phlegm (OR, 5.04; 95%CI, 1.05–24.28), doctor-diagnosed asthma (OR, 3.35; 95%CI, 1.31–8.57) and current asthma (OR, 4.94; 95%CI, 1.05–23.31) in children. Conclusions Cat-keeping and molds on the wall of the house had the multiplicative and additive interaction in doctor-diagnosed asthma. In conclusion, pet-keeping increased the risk of respiratory symptoms in children.

Cross-sectional associations between ambient air pollution and respiratory signs and symptoms among young children in Tehran

Exposure to ambient air pollutants may significantly affect the incidence of respiratory symptoms and lung function in children. The present study examined the associations between exposure to ambient air pollutants and respiratory symptoms in children. In this cross-sectional study, 1070 children under the age of seven years were recruited from 61 day-care centers of Tehran in 2015. Initially, day-care centers were selected at a radius of 2 km from the air pollution monitoring stations, and subsequently all the children attending these day-care centers were interviewed. The data on the respiratory complaints of children were obtained by using the ATS questionnaire (ATS-DLD-78-C). Moreover, the annual average concentration of pollutants was calculated based on the time children spent at home and at the day-care center using the air pollution monitoring stations. Crude and adjusted logistic regression analysis was conducted. The findings indicated that ambient air SO2 and NO2 concentrations near home were associated with current asthma for 1 part per billion (ppb) increase with an OR of 1.20 (1.00–1.45) and 1.08 (1.01–1.15), respectively. The odds of developing persistent phlegm for each unit (ppm) of raise in the average annual concentration of CO in ambient air near home (OR 1.40; 1.09 to 1.81) increased as well. The daily mean concentration of PM2.5, PM10, and SO2 was higher than the limits provided in the World Health Organization (WHO) air quality guidelines (AQGS). Moreover, the prevalence of severe wheezing, asthma history, and bronchitis was higher in boys. Therefore, long-term exposure to ambient air pollutants such as SO2, NO2, and CO may be associated with an increase in current asthma and persistent phlegm in children.

Benefits of influenza vaccination on the associations between ambient air pollution and allergic respiratory diseases in children and adolescents: New insights from the Seven Northeastern Cities study in China

BackgroundLittle information exists on interaction effects between air pollution and influenza vaccination on allergic respiratory diseases. We conducted a large population-based study to evaluate the interaction effects between influenza vaccination and long-term exposure to ambient air pollution on allergic respiratory diseases in children and adolescents. MethodsA cross-sectional study was investigated during 2012–2013 in 94 schools from Seven Northeastern Cities (SNEC) in China. Questionnaires surveys were obtained from 56 137 children and adolescents aged 2–17 years. Influenza vaccination was defined as receipt of the influenza vaccine. We estimated air pollutants exposure [nitrogen dioxide (NO2) and particulate matter with aerodynamic diameters ≤1 μm (PM1), ≤2.5 μm (PM2.5) and ≤10 μm (PM10)] using machine learning methods. We employed two-level generalized linear mix effects model to examine interactive effects between influenza vaccination and air pollution exposure on allergic respiratory diseases (asthma, asthma-related symptoms and allergic rhinitis), after controlling for important covariates. ResultsWe found statistically significant interactions between influenza vaccination and air pollutants on allergic respiratory diseases and related symptoms (doctor-diagnosed asthma, current wheeze, wheeze, persistent phlegm and allergic rhinitis). The adjusted ORs for doctor-diagnosed asthma, current wheeze and allergic rhinitis among the unvaccinated group per interquartile range (IQR) increase in PM1 and PM2.5 were significantly higher than the corresponding ORs among the vaccinated group [For PM1, doctor-diagnosed asthma: OR: 1.89 (95%CI: 1.57–2.27) vs 1.65 (95%CI: 1.36–2.00); current wheeze: OR: 1.50 (95%CI: 1.22–1.85) vs 1.10 (95%CI: 0.89–1.37); allergic rhinitis: OR: 1.38 (95%CI: 1.15–1.66) vs 1.21 (95%CI: 1.00–1.46). For PM2.5, doctor-diagnosed asthma: OR: 1.81 (95%CI: 1.52–2.14) vs 1.57 (95%CI: 1.32–1.88); current wheeze: OR: 1.46 (95%CI: 1.21–1.76) vs 1.11 (95%CI: 0.91–1.35); allergic rhinitis: OR: 1.35 (95%CI: 1.14–1.60) vs 1.19 (95%CI: 1.00–1.42)]. The similar patterns were observed for wheeze and persistent phlegm. The corresponding p values for interactions were less than 0.05, respectively. We assessed the risks of PM1-related and PM2.5-related current wheeze were decreased by 26.67% (95%CI: 1.04%–45.66%) and 23.97% (95%CI: 0.21%–42.08%) respectively, which was attributable to influenza vaccination (both p for efficiency <0.05). ConclusionsInfluenza vaccination may play an important role in mitigating the detrimental effects of long-term exposure to ambient air pollution on childhood allergic respiratory diseases. Policy targeted at increasing influenza vaccination may yield co-benefits in terms of reduced allergic respiratory diseases.

Cross-sectional Study of Children’s Respiratory Health and Ambient Air Exposure in two communities in Lanzhou

TPS 682: Long-term health effects of air pollutants 2, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Objective: The objective of this study was to investigate the potential association between air pollutants and respiratory diseases (RDs) as well as risk factors of children’s respiratory symptoms or morbidity. Methods: With informed consent and written responses, the questionnaire survey concerning children’s personal information, household condition, parents’ behavior, as well as parents’ health history, was conducted in Lanzhou by field investigation. Totally, 2000 local subjects distributing in urban (Chengguan) and suburban (Xigu) communities of Lanzhou were enrolled to participate into the survey. Data on risk factors and on respiratory disease were collected on the basis of double entry and validation of questionnaire. To analyze the effects of various risk factors to children’s respiratory disease, a two-stage regression approach was used in analysis; in the first-stage, the researcher obtained regression logits of community-specific prevalence of asthma, bronchitis, hospitalization, persistent cough and persistent phlegm for respiratory diseases, adjusted for covariates representing personal, family and household variables. Results: Some of the covariates showed to be risk factors of school children’s respiratory disease. However, there were community differences. The results showed that there were associations between community-specific adjusted prevalence rates and ambient air pollutant, also the positive association between morbidity prevalence and outdoor levels of PM2.5. Conclusions: It was found that Children’s grade (2nd grade), exclusive breastfeeding, pet (cat) ownership, parent’s smoking behavior, educational level and medical history of bronchitis and average number of cooking days were found to be risk factors of children’s’ respiratory morbidity. Also, it was found out that at Xigu, asthma was more associated with persistent cough while at Chenggang’s allergic/allergic rhinitis appeared to be more strongly associated.

Is smaller worse? New insights about associations of PM1 and respiratory health in children and adolescents

Background and objectivesLittle is known about PM1 effects on respiratory health, relative to larger size fractions (PM2.5). To address this literature gap, we assessed associations between PM1 exposure and asthmatic symptoms in Chinese children and adolescents, compared with PM2.5. MethodsA total of 59,754 children, aged 2–17 years, were recruited from 94 kindergartens, elementary and middle schools in the Seven Northeast Cities (SNEC) study, during 2012–2013. We obtained information on asthma and asthma-related symptoms including wheeze, persistent phlegm, and persistent cough using a standardized questionnaire developed by the American Thoracic Society. PM1 and PM2.5 concentrations were estimated using a spatial statistical model matched to the children's geocoded home addresses. To examine the associations, mixed models with school/kindergarten as random intercept were used, controlling for covariates. ResultsOdds ratios (ORs) of doctor-diagnosed asthma associated with a 10-μg/m3 increase for PM1 and PM2.5 were 1.56 (95% CI: 1.46–1.66) and 1.50 (1.41–1.59), respectively, and similar pattern were observed for other outcomes. Interaction analyses indicated that boys and the individuals with an allergic predisposition may be vulnerable subgroups. For example, among children with allergic predisposition, the ORs for doctor diagnosed asthma per 10 μg/m3 increase in PM1 was 1.71 (95% CI: 1.60–1.83), which was stronger than in their counterparts (1.46; 1.37–1.56) (pfor interaction < 0.05). ConclusionsThis study indicated that long-term exposure to PM1 may increase the risk of asthma and asthma-related symptoms, especially among boys and those with allergic predisposition. Furthermore, these positive associations for PM1 were very similar to those for PM2.5.

Association of particulate matter pm with respiratory symptoms among children in selected primary schools in pahang

Particulate matter (PM) is one of the primary pollutants found in the indoor environment. It can cause deterioration of the indoor air quality (IAQ) and is often linked with adverse health effects especially towards susceptible subgroup of the population like children. School children are exposed to PM inside the classroom, as this indoor PM may originate from both indoor and outdoor sources. Furthermore, ambient surrounding could be one of the major factors that contribute to its high concentration, specifically for school environment like government-subsidized schools in Malaysia whereby the schools are using natural ventilation systems to control the thermal comfort inside the classrooms. Hence the infiltration of outdoor PM into the indoor is probably high and significant. The high concentration of PM may affect the children’s health and learning performances. Due to this reason, it is important to study the effects of PM towards children. Thus, this study aims to assess the concentrations of PM and selected IAQ parameters in the school indoor environment with distinct background characteristics including residential, industrial, and rural areas. PM and IAQ parameters (temperature, relative humidity (RH), carbon monoxide (CO) and carbon dioxide (CO2)) were assessed for 8-hours duration via DustMate Environmental Dust Detector (Turnkey Instruments, USA) and VelociCalc® Multi-Function Ventilation Meter 9565 (TSI®, USA) respectively, during occupied and non-occupied time in the classrooms. Second, considering the children’s prolonged and repetitive exposure towards PM in school indoor environment and their body sensitivity, this study also screened for the prevalence of non-specific respiratory disease (NSRD) and persistent cough and phlegm (PCP) among children via structured questionnaire developed by American Thoracic Society’s Division of Lung Diseases (ATS-DLD-78-C). Higher concentrations of PM and prevalence of respiratory symptoms in the school from the industrial area were expected, due to the high concentration of PM originated from nearby industrial activities and anthropogenic sources. Hopefully, better understanding and insights on the issue were obtained through this study.

Biomass Cooking Fuels and Health Outcomes for Women in Malawi.

In sub-Saharan Africa, biomass fuels account for approximately 90% of household energy consumption. Limited evidence exists on the association between different biomass fuels and health outcomes. We report results from a cross-sectional sample of 655 households in Malawi. We calculated odds ratios between hypothesized determinants of household air pollution (HAP) exposure (fuel, stove type, and cooking location) and five categories of health outcomes (cardiopulmonary, respiratory, neurologic, eye health, and burns). Reliance on high- or low-quality firewood or crop residue (vs. charcoal) was associated with significantly higher odds of shortness of breath, difficulty breathing, chest pains, night phlegm, forgetfulness, dizziness, and dry irritated eyes. Use of high-quality firewood was associated with significantly lower odds of persistent phlegm. Cooks in rural areas (vs. urban areas) had significantly higher odds of experiencing shortness of breath, persistent cough, and phlegm, but significantly lower odds of phlegm, forgetfulness, and burns. With deforestation and population pressures increasing reliance on low-quality biomass fuels, prevalence of HAP-related cardiopulmonary and neurologic symptoms will likely increase among cooks. Short- to medium-term strategies are needed to secure access to high-quality biomass fuels given limited potential for scalable transitions to modern energy.

Respiratory symptoms and cross-shift lung function in relation to cotton dust and endotoxin exposure in textile workers in Nepal: a cross-sectional study

ObjectivesInhalation of a cotton-based particulates has previously been associated with respiratory symptoms and impaired lung function. This study investigates the respiratory health of Nepalese textile workers in relation to dust...

Interactive effects of obesity and breastfeeding on asthma and asthma-like symptoms among children

Objective To investigate the interactive effects of obesity and breast feeding on asthma and asthma related symptoms among children. Methods Using a cluster random sampling method, 1 elemen-tary school and 2 kindergartens were randomly selected from each district of Shenyang. A total of 5 elementary schools and 10 kindergartens were included. The information about obesity and the type of breastfeeding, living environment and respiratory diseases were collected by an international standard questionnaire from American Thoracic Society while measuring physical system of children. Results A total of 9335 questionnaires were distributed to all the students enrolled in the selected schools, and 8371 completed questionnaires which collect-ed with a response rate of 89. 7%. Finally, 8212 questionnaires were used for further analysis with a qualified rate of 98. 1%. The percentage of overweight and obesity among children are 12. 7% and 15. 5% respectively. The percentage of breastfeeding was 78. 9%. The prevalence of obesity children with asthma （8. 5%） is nota-bly higher than normal children （5. 8%） with a significant difference （χ2 =13. 48, P=0. 0012）, while the prevalence of breastfeeding children with asthma （ 6. 05%） is notably lower than non-breastfeeding children （7. 38%） with a significant difference （χ2 =4. 05; P=0. 04）. Multivariate factor analysis showed that com-pared with normal weight children, obesity of breastfeeding children increased asthma risk by 38% （ OR =1. 38, 95%CI=1. 05 -1. 82）; while in non-breastfeeding children, obesity increased the risk of asthma by 56% （OR=1. 56, 95%CI=0. 99 -2. 44）. Further analysis showed obesity and breastfeeding for persistent phlegm and current wheeze in children. Conclusion Breastfeeding can significantly reduce the overweight obesity of children with asthma and asthma-like symptoms, and there is a significant impact on interaction. Key words: Obesity; Breastfeeding; Asthma; Children

Interaction effects of breastfeeding and passive smoking on asthma and asthma related symptoms among children

To evaluate the interaction effects of breastfeeding and passive smoking on asthma and asthma related symptoms among children. Using a cluster random sampling method, 2 elementary schools and 1 kindergarten were randomly selected from 7 cities of Liaoning province. The resulting 25 elementary schools and 50 kindergartens were included, and 31 049 children from the selected schools living up to 2 years were recruited in this survey. The information about the children's type of feeding up, living environment, passive smoking exposure, respiratory diseases and symptoms were collected. The interaction effects of breastfeeding and passive smoking on asthma and asthma related symptoms (persistent cough,persistent phlegm, current wheeze and allergic rhinitis) were evaluated with Glimmix procedure. There were 31 049 children involved in this investigation. The age was (8.32 ± 2.75) years old. There were 23 987 (77.26%) children with breastfeeding and 11 820 (38.07%) children with passive smoking. The prevalence of asthma and allergic rhinitis were 6.22%(1491/23 987), 4.67%(1120/23 987) in children with breastfeeding, and were 7.70%(544/7062), 5.48%(387/7062) in children without breastfeeding,compared to the children without breastfeeding, the children with breastfeeding had lower risk of asthma(OR = 0.79, 95%CI:0.72-0.88) and allergic rhinitis(OR = 0.85, 95%CI:0.75-0.95); The prevalence of current wheeze was 7.89%(929/11 770) in children with father smoking, and was 5.37%(1036/19 279) in children without father smoking, compared to the children without father smoking, the children with father smoking increased the risk of current wheeze(OR = 1.51, 95%CI:1.38-1.65). The prevalence of persistent cough was 18.96%(51/269) in children with mother smoking, and was 9.51%(2926/30 780) in children without mother smoking,compared to the children without mother smoking, the children with mother smoking increased the risk of persistent cough(OR = 2.23, 95%CI:1.64-3.03). The prevalence of persistent phlegm was 5.69%(871/5316) in children with anyone smoking, and was 3.50%(550/15 733) in children without anyone smoking, compared to the children without anyone smoking, the children with anyone smoking increased the risk of persistent phlegm(OR = 1.67, 95%CI:1.49-1.86).Glimmix procedure analysis showed there was a significant interaction effects between breastfeeding and passive smoking. The estimated OR for father smoking among breastfeeding children were consistently lower than those among non-breastfeeding children for asthma. The estimated OR for mother smoking among breastfeeding children were consistently lower than those among non-breastfeeding children for allergic rhinitis. The estimated OR for anyone smoking among breastfeeding children were consistently lower than those among non-breastfeeding children for asthma and allergic rhinitis(all P values < 0.05). Breastfeeding decreases the detrimental effects of passive smoking on asthma and asthma related symptoms in children.

Interactive effects of environmental tobacco smoke and pets ownership on respiratory diseases and symptoms in children

Over the past few decades, secondhand smoke exposure among children become more serious and with China's implementation of the national policy of family planning and the family structure change, domestic pet has gradually become popular. This survey aimed to investigate the interactive effects of pet ownership and environmental tobacco smoke (ETS) on children's respiratory diseases and symptoms. Using a cluster random sampling method, 5 elementary schools and 10 kindergartens were randomly selected from each district of Shenyang, and all children from the selected schools were recruited in this survey. The information about the children's respiratory diseases, conditions of pets ownership and ETS exposure were collected by an international standard questionnaire from American Thoracic Society. A total of 9679 questionnaires were distributed to all the students enrolled in the selected schools, and 8798 completed questionnaires were collected with a response rate of 90.9%. Finally, 8733 questionnaires were used for further analysis. The results showed that the number of the patients and the prevalence of persistent cough, persistent phlegm, doctor-diagnosed asthma, current asthma, wheeze, and allergic rhinitis in children were 835 (9.57%), 366 (4.42%), 559 (6.40%), 215 (2.46%), 229 (2.62%), 397 (4.55%), respectively. After controlling for the effects of age, gender and other confounding factors, the results from the multivariate unconditional logistic regression analysis showed that either pet ownership or the ETS exposure significantly increased the risk of prevalence of respiratory diseases and symptoms in children. Compared with control group children, only the prenatal exposure to passive smoking or domestic pets made the risk of children with allergic rhinitis increased respectively 34% (OR = 1.34, 95%CI = 0.99 - 1.80) and 106% (OR = 2.06, 95%CI = 1.28 - 3.31), while the exposure of these two factors made the risk of children with allergic rhinitis increased 376% (OR = 4.76, 95%CI = 2.65 - 8.85), compared with the separate effect, the range of increase was 2.5 times.There was a significant interaction between pet ownership and ETS exposure on persistent cough, persistent phlegm, and allergic rhinitis in children, whereas, the combined effects of these two factors on doctor-diagnosed asthma, current asthma, and wheeze was approximately as expected on the basis of their independent effects on an additive scale. This study provides evidence that pet ownership and ETS exposure increases the risk of respiratory diseases and symptoms in children, and there was a significant interaction effects between these two factors on some respiratory diseases and symptoms.

Effects of indoor air pollution on asthma and asthma-related symptoms among children in Shenyang city

To study the effects of indoor air pollution and individual susceptible factors on prevalence of children's asthma and asthma-related symptoms in Shenyang city. On April, 2007, 8733 Han children who were under age of 12 and lived for more than 2 years in Shenyang city, were selected from five administrative areas (one primary school and two kindergartens for each area) through cluster random sampling method. Information on children's general condition, asthma and related symptoms (including stridor, stridor symptoms, persistent cough, persistent phlegm), indoor air pollution, and susceptibility history were obtained by a standard questionnaire from the American Thoracic Society. The effects of indoor air pollution on asthma and asthma-related symptoms was analyzed through χ(2) test. Logistic regression was used to research the effects of risk factors on the prevalence of asthma and asthma-related symptoms of both susceptible and non-susceptible children. Among the 8733 subjects, 4420 (50.6%) were boy and 4313 (49.4%) were girl, with the age of (8.08 ± 2.88) years old. The prevalence of asthma, current asthma, cough, persistent phlegm, stridor and stridor symptom were 6.4% (559 cases), 2.5% (215 cases), 9.6% (836 cases), 4.4% (386 cases), 17.5% (1524 cases) and 2.6% (229 cases) respectively. The prevalence of asthma the boys and girls were among 7.1% (313 cases) and 5.7% (246 cases) (χ(2) = 6.916, P < 0.05); and stridor symptom for them were 19.2% (850 cases), 15.6% (674 cases) (χ(2) = 19.678, P < 0.05), respectively. Passive smoking before two years old, house decoration and pet were related to asthma of children, and there was significant difference between the two groups. The prevalence of asthma of exposed children were 7.7% (312 cases), 9.5% (159 cases), 8.0% (270 cases), 9.0% (114 cases), respectively. Compared with the non-exposed children who had asthma, the prevalence of asthma were 5.7% (400 cases), 5.4% (289 cases), 6.0% (445 cases), the value of χ(2) were 33.646, 23.944 and 16.527 respectively (all P values < 0.05). Children who had family history of asthma, family history of allergy and allergy history were also related with asthma, the prevalence of asthma were 17.3% (106 cases), 13.1% (85 cases), 22.0% (147 cases), compared with the non-exposed children who had asthma, the prevalence of asthma were 5.5% (453), 5.9% (474), 5.1% (412), and there was significant difference between the two groups, the value of χ(2) were 130.522, 59.929 and 293.997, respectively (all P values < 0.05). Logistic regression analysis showed that passive smoking (OR = 1.7, 95%CI: 1.2 - 2.4), house decoration (OR = 1.5, 95%CI: 1.1 - 1.9) and pet (OR = 1.6, 95%CI: 1.1 - 2.3) were statistically significant to asthma in non-susceptible children. While passive smoking (OR = 1.3, 95%CI: 1.0 - 1.7) and house decoration (OR = 1.4, 95%CI: 1.1 - 1.7) were increased the risk of asthma. Indoor air pollution is a risk factor of children' s asthma. Family history of asthma and physical susceptible children are high risk to asthma, and susceptible children are easily influenced by other risk factors.

Effects of Outdoor and Indoor Air Pollution on Respiratory Health of Chinese Children from 50 Kindergartens

BackgroundConcentrations of ambient air pollution and pollutants in China have changed considerably during the last decade. However, few studies have evaluated the effects of current ambient air pollution on the health of kindergarten children.MethodsWe studied 6730 Chinese children (age, 3–7 years) from 50 kindergartens in 7 cities of Northeast China in 2009. Parents or guardians completed questionnaires that asked about the children’s histories of respiratory symptoms and risk factors. Three-year concentrations of particles with an aerodynamic diameter ≤10 µm (PM10), sulfur dioxide (SO2), and nitrogen dioxides (NO2) were calculated at monitoring stations in 25 study districts. A 2-stage regression approach was used in data analyses.ResultsThe prevalence of respiratory symptoms was higher among children living near a busy road, those living near chimneys or a factory, those having a coal-burning device, those living with smokers, and those living in a home that had been recently renovated. Among girls, PM10 was associated with persistent cough (odds ratio [OR]PM10 = 1.44; 95% CI, 1.18–1.77), persistent phlegm (ORPM10 = 1.36; 95% CI, 1.02–1.81), and wheezing (ORPM10 = 1.31; 95% CI, 1.04–1.65). NO2 concentration was associated with increased prevalence of allergic rhinitis (OR = 1.96; 95% CI, 1.27–3.02) among girls. In contrast, associations of respiratory symptoms with concentrations of PM10, SO2, and NO2 were not statistically significant among boys.ConclusionsAir pollution is particularly important in the development of respiratory morbidity among children. Girls may be more susceptible than boys to air pollution.

Comparison of total suspended particulate concentration–response relationships for respiratory symptoms between Chinese children with a different susceptibility status

Few studies have explored concentration–response (C–R) relationships between levels of particulate matter (PM) and respiratory morbidity in terms of the susceptibility of children to respiratory diseases. We sought to determine whether the shapes of C–R curves for comparing total suspended particle (TSP) concentration versus the adjusted prevalence of bronchitis (persistent cough or phlegm) and asthma (current wheeze or asthma) symptoms between children with a different susceptibility status. We used the restricted cubic spline (RCS) function to characterize the C–R relationships between TSP and the adjusted prevalence rates of four respiratory symptoms, after controlling for possible confounding by SO2 and NO2 levels, in 11,860 children selected from 18 districts of six cities in Liaoning province. Susceptible children exhibited a 2- to 3-fold elevation in the prevalence of all four respiratory symptoms across the entire TSP range (188–689μg/m3). Significant differences in the shapes of C–R curves were evident in children with symptoms of bronchitis (ballistic “S”-shaped curves) and asthma (flattened “U”-shaped curves), as well as between the low and high TSP ranges of such curves, when children were grouped by susceptibility status. A significant linear association between TSP levels and current asthma prevalence was found only among susceptible children exposed to high levels of TSP. The shapes and properties of the TSP-morbidity C–R curves differed significantly by type of respiratory symptom, susceptibility status, and TSP range. More work is required to characterize CR relationships in terms of susceptibility status in countries with different PM levels.

Fetal and Infant Growth and Asthma Symptoms in Preschool Children

Low birth weight is associated with an increased risk of wheezing in childhood. We examined the associations of longitudinally measured fetal and infant growth patterns with the risks of asthma symptoms in preschool children. This study was embedded in a population-based prospective cohort study among 5,125 children. Second- and third-trimester fetal growth characteristics (head circumference, femur length, abdominal circumference, and weight) were estimated by repeated ultrasounds. Infant growth (head circumference, length, and weight) was measured at birth and at the ages of 3, 6, and 12 months. Parental report of asthma symptoms until the age of 4 years was yearly obtained by questionnaires. Both fetal restricted and accelerated growth, defined as a negative or positive change of more than 0.67 standard deviation score, were not associated with asthma symptoms until the age of 4 years. Accelerated weight gain from birth to 3 months following normal fetal growth was associated with increased risks of asthma symptoms (overall odds ratio for wheezing: 1.44 [95% confidence interval: 1.22, 1.70]; shortness of breath: 1.32 [1.12, 1.56]; dry cough: 1.16 [1.01, 1.34]; persistent phlegm: 1.30 [1.07, 1.58]), but not with eczema (0.95 [0.80, 1.14]). These associations were independent of other fetal growth patterns and tended to be stronger for children of atopic mothers than for children of nonatopic mothers. Weight-gain acceleration in early infancy was associated with increased risks of asthma symptoms in preschool children, independent of fetal growth. Early infancy might be a critical period for the development of asthma.

Roles of pollution in the prevalence and exacerbations of allergic diseases in Asia

The prevalence of asthma and allergic diseases has been found to be increasingly rapidly, especially in developing countries. Environmental factors have been found to be important contributors to the manifestations of allergic diseases. Air pollution has been extensively studied in different regions of the world. The levels of ambient air pollutants in many Asian countries are very high when compared with those in developed Western countries. However, the prevalence of asthma was relatively low across many Asian countries. Many studies have clearly documented that environmental air pollution is an important factor resulting in exacerbations of asthma. In particular, levels of traffic-related pollutants are increasing rapidly across many Asian countries in parallel with the level of urbanization and economic development. The loss of protective factors associated with a rural environment will further contribute to the adverse effect on patients with allergic diseases such as asthma. In this review the roles of air pollution were examined in relation to the inception and exacerbations of allergic diseases in Asia.