Effects of winter air pollution on pulmonary function of school children in Shenyang, China

The Effects of Short-Term PM2.5 Exposure on Pulmonary Function among Children with Asthma-A Panel Study in Shanghai, China

Fine particulate matter (PM_2.5) has been reported to be an important risk factor for asthma. This study was designed to evaluate the relationship between PM_2.5 and lung function among children with asthma in Shanghai, China. From 2016 to 2019, a total of 70 Chinese children aged 4 to 14 in Shanghai were recruited for this panel study. The questionnaire was used to collect baseline information, and the lung function covering forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were carried out for each child more than twice during follow-up. Meanwhile, the simultaneous daily air atmospheric pollutants and meteorological data were collected. The linear mixed effect (LME) model was used to assess the relationship between air pollutants and lung function. A significantly negative association was found between PM_2.5 and lung function in children with asthma. In the single-pollutant model, the largest effects of PM_2.5 on lung function were found for lag 0-2, with FVC and FEV1 decreasing by 0.91% [95% confidence interval (CI): -1.75, -0.07] and 1.05% (95% CI: -2.09, 0.00), respectively, for each 10 μg/m³ increase in PM_2.5. In the multi-pollution model (adjusted PM_2.5 + SO₂ + O₃), the maximum effects of PM_2.5 on FVC and FEV1 also appeared for lag 0-2, with FVC and FEV1 decreasing by 1.57% (95% CI: -2.69, -0.44) and 1.67% (95% CI: -3.05, -0.26), respectively, for each 10 μg/m³ increase in PM_2.5. In the subgroup analysis, boys, preschoolers (<6 years old) and hot seasons (May to September) were more sensitive to changes. Our findings may contribute to a better understanding of the short-term exposure effects of PM_2.5 on lung function in children with asthma.

Association Between Air Pollutants and Pediatric Respiratory Outpatient Visits in Zhoushan, China

Objective

This study aimed to explore the time-series relationship between air pollutants and the number of children's respiratory outpatient visits in coastal cities.

Methods

We used time series analysis to investigate the association between air pollution levels and pediatric respiratory outpatient visits in Zhoushan city, China. The population was selected from children aged 0–18 who had been in pediatric respiratory clinics for eight consecutive years from 2014 to 2020. After describing the population and weather characteristics, a lag model was used to explore the relationship between outpatient visits and air pollution.

Results

We recorded annual outpatient visits for different respiratory diseases in children. The best synergy lag model found a 10 μg/m³ increase in PM_2.5 for every 4–10% increase in the number of pediatric respiratory outpatient visits (P < 0.05). The cumulative effect of an increase in the number of daily pediatric respiratory clinics with a lag of 1–7 days was the best model.

Conclusions

PM_2.5 is significantly related to the number of respiratory outpatient visits of children, which can aid in formulating policies for health resource allocation and health risk assessment strategies.

Relationship between inter-city air pollution levels and physical fitness parameters among sixth-grade Mongolian primary school boys, China, 2013–2016

Objectives

Adverse health effects due to air pollution have recently been recognized as a serious social problem in China. In this study, we investigated inter-city relationships between air pollution and physical fitness levels among Mongolian elementary school boys in five cities of the Inner Mongolia Autonomous Region (IMAR), China.

Study design

Retrospective cross-sectional cohort study.

Methods

Physical fitness measurements of 1443 male Mongolian sixth-grade children were obtained from an existing dataset from the year 2013–2016, and correlations were calculated between these measurements and the percentage of good air quality days for five different cities: Hohhot, Baotou, Chifeng, Bayannur, and Xilinhot.

Results

Significant differences in the percentage of good air quality days from 2013 to 2016 were observed among the five cities studied. Statistical analysis showed a significantly positive correlation between good days and students’ vital capacity, and a significantly negative correlation between good days and 50 ​m ​× ​8 shuttle run time for the students included in this study. Differences in the extent of air pollution among the study cities might account for differences in lung function and cardiovascular endurance levels in these Mongolian children.

Conclusions

There is an urgent need for policy intervention to reduce air pollution levels in the IMAR. It is necessary to improve school physical education classes and physical training considering the current air pollution situation. Future research needs to replicate school year survey results from other cities, include longitudinal studies, and clarify the relationship between air pollution, physical exercise, and overall health.

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Inter-city relationship between air pollution and physical fitness.

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Policy intervention to reduce air pollution in the Inner Mongolia Autonomous Region.

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Need to improve school physical education training due to current air pollution.

Acute effects of ambient PM2.5 on lung function among schoolchildren

Previous studies have found that fine particulate matter (PM_2.5) air pollution is associated with decreased lung function. However, most current research focuses on children with asthma, leading to small sample sizes and limited generalization of results. The current study aimed to measure the short-term and lag effects of PM_2.5 among school-aged children using repeated measurements of lung function.This prospective panel study included 848 schoolchildren in Zhejiang Province, China. Each year from 2014–2017, two lung function tests were conducted from November 15^th to December 31^st. Daily air pollution data were derived from the monitoring stations nearest to the schools. A mixed-effects regression model was used to investigate the relationship between PM_2.5 and lung function. The effect of PM_2.5 on lung function reached its greatest at 1-day moving average PM_2.5 exposure. For every 10 μg/m³ increase in the 1-day moving average PM_2.5 concentration, Forced Vital Capacity (FVC) of children decreased by 33.74 mL (95% CI: 22.52, 44.96), 1-s Forced Expiratory Volume (FEV₁) decreased by 32.56 mL (95% CI: 21.41, 43.70), and Peak Expiratory Flow (PEF) decreased by 67.45 mL/s (95% CI: 45.64, 89.25). Stronger associations were found in children living in homes with smokers. Short-term exposure to PM_2.5 was associated with reductions in schoolchildren’s lung function. This finding indicates that short-term exposure to PM_2.5 is harmful to children’s respiratory health, and appropriate protective measures should be taken to reduce the adverse effects of air pollution on children’s health.

Acute effects of PM2.5 on lung function parameters in schoolchildren in Nanjing, China: a panel study

The association between exposure to ambient particulate matter (PM) and reduced lung function parameters has been reported in many works. However, few studies have been conducted in developing countries with high levels of air pollution like China, and little attention has been paid to the acute effects of short-term exposure to air pollution on lung function. The study design consisted of a panel comprising 86 children from the same school in Nanjing, China. Four measurements of lung function were performed. A mixed-effects regression model with study participant as a random effect was used to investigate the relationship between PM_2.5 and lung function. An increase in the current day, 1-day and 2-day moving average PM_2.5 concentration was associated with decreases in lung function indicators. The greatest effect of PM_2.5 on lung function was detected at 1-day moving average PM_2.5 exposure. An increase of 10 μg/m³ in the 1-day moving average PM_2.5 concentration was associated with a 23.22 mL decrease (95% CI: 13.19, 33.25) in Forced Vital Capacity (FVC), a 18.93 mL decrease (95% CI: 9.34, 28.52) in 1-s Forced Expiratory Volume (FEV₁), a 29.38 mL/s decrease (95% CI: -0.40, 59.15) in Peak Expiratory Flow (PEF), and a 27.21 mL/s decrease (95% CI: 8.38, 46.04) in forced expiratory flow 25-75% (FEF_25-75%). The effects of PM_2.5 on lung function had significant lag effects. After an air pollution event, the health effects last for several days and we still need to pay attention to health protection.

Air Pollution and Children's Health in Chinese

Children can be considered as a high-risk population to environmental stress since some of the organ systems including the immune system and respiratory system are still in development during childhood. During childhood, the impact of environmental pollutants exposure may program child growth and development that have long-term consequences on later health and disease risk. Considering the rapid economic growth in recent decades in China, the impact of ambient air pollution on children health causes concerns. Therefore, we aimed to review the current epidemiological evidence on the effects of air pollution exposure on adverse health outcome, including respiratory diseases, lung function, high blood pressure, cognitive disorder, and obesity in childhood in China. We believe that the findings summarized in our review demonstrate an unequivocal relationship between air pollutants exposure and Chinese children health and these results have large public health influences.

Health benefits from improved outdoor air quality and intervention in China

China is at its most critical stage of outdoor air quality management. In order to prevent further deterioration of air quality and to protect human health, the Chinese government has made a series of attempts to reduce ambient air pollution. Unlike previous literature reviews on the widespread hazards of air pollution on health, this review article firstly summarized the existing evidence of human health benefits from intermittently improved outdoor air quality and intervention in China. Contents of this paper provide concrete and direct clue that improvement in outdoor air quality generates various health benefits in China, and confirm from a new perspective that it is worthwhile for China to shift its development strategy from economic growth to environmental economic sustainability. Greater emphasis on sustainable environment design, consistently strict regulatory enforcement, and specific monitoring actions should be regarded in China to decrease the health risks and to avoid long-term environmental threats.

Peak expiratory flow, breath rate and blood pressure in adults with changes in particulate matter air pollution during the Beijing Olympics: a panel study

OBJECTIVES

This study aims to examine whether changes in short-term exposures to particulate matter are associated with changes in lung function, breath rate, and blood pressure among healthy adults and whether smoking status modifies the association.

METHODS

We took advantage of the artificially controlled changes in air pollution levels that occurred during the 2008 Olympic Games in Beijing, China and conducted a panel study of 201 Beijing residents. Data were collected before, during, and after the Olympics, respectively. Linear mixed-effect models and generalized estimating equation models were used to compare measurements of peak expiratory flow, breath rate and blood pressure across three time points.

RESULTS

The mean values of peak expiratory flow were 346.0 L/min, 399.3 L/min, and 364.1L/min over the three study periods. Peak expiratory flow levels increased in 78% of the participants when comparing the during- with pre- Olympics time points, while peak expiratory flow levels decreased in 80% of participants for the post- and during-Olympic periods comparison. In subgroup analyses comparing the during-Olympic to pre-Olympic time points, we found a larger percentage change in peak expiratory flow (+17%) among female, younger and non-smoking participants than among male, elderly and smoking participants (+12%). The percentage of participants with a fast breath rate (>20/min) changed from 9.7% to 4.9% to 30.1% among females, and from 7.9% to 2.6% to 27.3% among males over the three time points. The changes in blood pressure over the three study periods were not very clear, although there is an increase in diastolic pressure and a decrease in pulse pressure among males during the games.

CONCLUSIONS

The results suggest that exposure to different air pollution levels has significant effects on respiratory function. Smoking, age and gender appear to modify participants' biological response to changes in air quality.

Ratio of waist circumference to chest circumference is inversely associated with lung function in Chinese children and adolescents

BACKGROUND AND OBJECTIVE

In White children, waist circumference (WC) is positively correlated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)). Because fat distribution differs among different races, the relationship between WC and lung function in Asian children may differ from that in White children. The present study aimed to examine the effect of WC on ventilatory function in Chinese children.

METHODS

A cross-sectional study was performed on 1572 healthy subjects aged 9-18 years. Height, weight, chest circumference (CC), WC and lung function (FVC, FEV(1), peak expiratory flow (PEF) and maximal mid-expiratory flow (MMEF)) were measured. To avoid the problem of colinearity, a model that combined CC and WC as the waist-to-chest ratio (WCR) was used. The relative contributions of WCR and body mass index (BMI) to spirometric parameters were determined by linear regression analysis.

RESULTS

WCR was inversely associated with all spirometric parameters. On average, each 0.01 increase in WCR was associated with decreases of 8.14 mL for FVC, 9.36 mL for FEV(1), 6.54% for FEV(1)/FVC, 19.81 mL/s for PEF and 17.25 mL/s for MMEF. BMI was positively associated with all spirometric parameters except FEV(1)/FVC. These results suggest that WC was inversely associated with lung function parameters.

CONCLUSIONS

Inverse associations were identified between WCR, as well as WC, and lung function in a population of Chinese children. The underlying mechanisms need to be further explored.

Spirometric standards for healthy children and adolescents of Korean Chinese in northeast China

In China there are 1,923,842 Korean Chinese, who live mostly (92.27%) in the country's three northeast provinces. In spite of this sizeable number, no spirometric data are available at present on them. The present study investigated normal spirometric reference values for the Korean Chinese children and adolescents. Spirometry was performed in 443 healthy Korean Chinese children and adolescents aged 8-18 yr with measurements of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF) and maximum mid-expiratory flow (MMEF). Reference equations for FEV1, FVC, PEF and MMEF were derived by using multiple regression analysis. All of the measured spirometric parameters correlated positively with height and age significantly (P < 0.001). The predicted values of FVC and FEV1 were higher than values obtained by using Caucasian and other Asian equations (P < 0.001). A set of spirometric reference equations has been derived using a relatively large, healthy, non-smoking young Korean Chinese population with a wide range of ages and heights, the results of which differ from those gained from several other reference equations. These reference equations should be used for evaluation of lung function in this population.

Air pollution and children's respiratory symptoms in six cities of Northern China

OBJECTIVE

The associations between air pollution and children's respiratory health in the high pollution range have not yet been clearly characterized. We evaluated the effects of outdoor air pollution on respiratory morbidity in children selected from multiple sites in a heavy industrial province of northeastern China.

METHODS

The study included 11,860 children aged 3-12 years, selected from 18 districts of 6 cities in Liaoning province, the participation rate is 89.9%. Informed consent and written responses to surveys about children's historic and current health status, personal and household characteristics, and other information were obtained from parents. A two-stage regression approach was applied in data analyses.

RESULTS

There were wide gradients for TSP (188-689 μg/m(3)), SO(2) (14-140 μg/m(3) and NO(2) (29-94 μg/m(3)) across the 18 districts of 6 cities. The three air pollutants significantly increased the prevalence of persistent cough (21-28%), persistent phlegm (21-30%) and current asthma (39-56%) for each interquartile range increment (172 μg/m(3) for TSP, 69 μg/m(3) for SO(2), 30 μg/m(3) for NO(2)), showing larger between-city effects than within-city. Rates of respiratory symptoms were significantly higher for children with younger age, atopy, respiratory disease in early age, family history of asthma or chronic bronchitis, and tobacco smoke exposure.

CONCLUSION

The high levels of outdoor air pollution in north China are positively associated with children's respiratory symptoms, the associations with TSP appear to be stronger than SO(2) and NO(2).

Respiratory health effects among schoolchildren and their relationship to air pollutants in Korea

The objective of this study is to investigate the relationship between five air pollutants (PM(10), SO(2), NO(2), O(3), CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO(2) and NO(2) was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O(3) rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant.

Air pollution threatens the health of children in China

CONTEXT

. China's rapid economic development has come at the cost of severe environmental degradation, most notably from coal combustion. Outdoor air pollution is associated with >300000 deaths, 20 million cases of respiratory illness, and a health cost of >500 billion renminbi (>3% of gross domestic product) annually. The young are particularly susceptible to air pollution, yet there has been only limited recognition of its effects on children's health and development. DATA SOURCES/DATA EXTRACTION: To fill this gap, we reviewed relevant published environmental studies, biomedical and molecular/epidemiologic research, and economic and policy analyses.

RESULTS

China relies on coal for approximately 70% to 75% of its energy needs, consuming 1.9 billion tons of coal each year. In addition to CO(2), the major greenhouse gas, coal burning in China emits vast quantities of particulate matter, polycyclic aromatic hydrocarbons, sulfur dioxide, arsenic, and mercury. Automobiles emit nitrogen dioxide and benzene in addition to particulate matter and polycyclic aromatic hydrocarbons. Seventy percent of Chinese households burn coal or biomass for cooking and heating, which contaminates indoor air. Adverse effects of combustion-related air pollution include reduced fetal and child growth, pulmonary disease including asthma, developmental impairment, and increased risk of cancer. A prospective molecular epidemiologic study of newborns in Chongqing has demonstrated direct benefits to children's health and development from the elimination of a coal-burning plant.

CONCLUSIONS

Recognition of the full health and economic cost of air pollution to Chinese children and the benefits of pollution reduction should spur increased use of renewable energy, energy efficiency, and clean-fuel vehicles. This is a necessary investment for China's future.

Chronic exposure to ambient levels of urban particles affects mouse lung development

RATIONALE

Chronic exposure to air pollution has been associated with adverse effects on children's lung growth.

OBJECTIVES

We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development.

METHODS

The exposure occurred in two open-top chambers (filtered and nonfiltered) placed 20 m from a street with heavy traffic in São Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM(2.5) inside the filtered chamber (filtered = 2.9 +/- 3.0 microg/m(3), nonfiltered = 16.8 +/- 8.3 microg/m(3); P = 0.001). At this exposure site, vehicular sources are the major components of PM(2.5) (PM <or= 2.5 microm). Exposure of the parental generation in the two chambers occurred from the 10th to the 120th days of life. After mating and birth of offspring, a crossover of mothers and pups occurred within the chambers, resulting in four groups of pups: nonexposed, prenatal, postnatal, and pre+postnatal. Offspring were killed at the age of 15 (n = 42) and 90 (n = 35) days; lungs were analyzed by morphometry for surface to volume ratio (as an estimator of alveolization). Pressure-volume curves were performed in the older groups, using a 20-ml plethysmograph.

MEASUREMENTS AND MAIN RESULTS

Mice exposed to PM(2.5) pre+postnatally presented a smaller surface to volume ratio when compared with nonexposed animals (P = 0.036). The pre+postnatal group presented reduced inspiratory and expiratory volumes at higher levels of transpulmonary pressure (P = 0.001). There were no differences among prenatal and postnatal exposure and nonexposed animals.

CONCLUSIONS

Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth.

Effects of airborne particulate matter on respiratory morbidity in asthmatic children

Background

The effects of airborne particulate matter (PM) are a major human health concern. In this panel study, we evaluated the acute effects of exposure to PM on peak expiratory flow (PEF) and wheezing in children.

Methods

Daily PEF and wheezing were examined in 19 asthmatic children who were hospitalized in a suburban city in Japan for approximately 5 months. The concentrations of PM less than 2.5 µm in diameter (PM_2.5) were monitored at a monitoring station proximal to the hospital. Moreover, PM_2.5 concentrations inside and outside the hospital were measured using the dust monitor with a laser diode (PM_2.5(LD)). The changes in PEF and wheezing associated with PM concentration were analyzed.

Results

The changes in PEF in the morning and evening were significantly associated with increases in the average concentration of indoor PM_2.5(LD) 24 h prior to measurement (-2.86 L/min [95%CI: -4.12, -1.61] and -3.59 L/min [95%CI: -4.99, -2.20] respectively, for 10-µg/m³ increases). The change in PEF was also significantly associated with outdoor PM_2.5(LD) concentrations, but the changes were smaller than those observed for indoor PM_2.5(LD). Changes in PEF and concentration of stationary-site PM_2.5 were not associated. The prevalence of wheezing in the morning and evening were also significantly associated with indoor PM_2.5(LD) concentrations (odds ratios = 1.014 [95%CI: 1.006, 1.023] and 1.025 [95%CI: 1.013, 1.038] respectively, for 10-µg/m³ increases). Wheezing in the evening was significantly associated with outdoor PM_2.5(LD) concentration. The effects of indoor and outdoor PM_2.5(LD) remained significant even after adjusting for ambient nitrogen dioxide concentrations.

Conclusion

Indoor and outdoor PM_2.5(LD) concentrations were associated with PEF and wheezing among asthmatic children. Indoor PM_2.5(LD) had a more marked effect than outdoor PM_2.5(LD) or stationary-site PM_2.5.