Air pollutants and hospital admission due to pneumonia in children: a time series analysis

Perinatal exposure to traffic related air pollutants and the risk of infection in the first six months of life: a cohort study from a low-middle income country

OBJECTIVE

There is limited study from low-and-middle income countries on the effect of perinatal exposure to air pollution and the risk of infection in infant. We assessed the association between perinatal exposure to traffic related air pollution and the risk of infection in infant during their first six months of life.

METHODS

A prospective cohort study was performed in Jakarta, March 2016-September 2020 among 298 mother-infant pairs. PM2.5, soot, NOx, and NO2 concentrations were assessed using land use regression models (LUR) at individual level. Repeated interviewer-administered questionnaires were used to obtain data on infection at 1, 2, 4 and 6 months of age. The infections were categorized as upper respiratory tract (runny nose, cough, wheezing or shortness of breath), lower respiratory tract (pneumonia, bronchiolitis) or gastrointestinal tract infection. Logistic regression models adjusted for covariates were used to assess the association between perinatal exposure to air pollution and the risk of infection in the first six months of life.

RESULTS

The average concentrations of PM2.5 and NO2 were much higher than the WHO recommended levels. Upper respiratory tract infections (URTI) were much more common in the first six months of life than diagnosed lower respiratory tract or gastro-intestinal infections (35.6%, 3.5% and 5.8% respectively). Perinatal exposure to PM2.5 and soot suggested increase cumulative risk of upper respiratory tract infection (URTI) in the first 6 months of life per IQR increase with adjusted OR of 1.50 (95% CI 0.91; 2.47) and 1.14 (95% CI 0.79; 1.64), respectively. Soot was significantly associated with the risk of URTI at 4-6 months age interval (aOR of 1.45, 95%CI 1.02; 2.09). All air pollutants were also positively associated with lower respiratory tract infection, but all CIs include unity because of relatively small samples. Adjusted odds ratios for gastrointestinal infections were close to unity.

CONCLUSION

Our study adds to the evidence that perinatal exposure to fine particles is associated with respiratory tract infection in infants in a low-middle income country.

Effects of intrauterine and post-natal exposure to air pollution on children's pneumonia: Key roles in different particulate matters exposure during critical time windows

BACKGROUND

Despite mounting evidence linked pneumonia with air pollution, it is unclear what main pollutant(s) exposure in which critical window(s) play a key role in pneumonia.

OBJECTIVE

To examine effects of intrauterine and post-natal exposure to air pollution on children's doctor-diagnosed pneumonia (DDP).

METHODS

A combination of cross-sectional and retrospective cohort study was conducted at Changsha, China during 2019-2020. Personal exposure to outdoor air pollutants at each child's home address was estimated using inverse distance weighted (IDW) method based on data from 10 air quality monitoring stations. Associations between personal air pollution exposure and DDP were evaluated.

RESULTS

Children's DDP was associated with intrauterine and post-natal exposure to PM2.5, PM2.5-10, and PM10, adjusted ORs (95% CI) of 1.17 (1.04-1.30), 1.09 (1.01-1.17), and 1.07 (1.00-1.14) for IQR increase in intrauterine exposure and 1.12 (1.02-1.22), 1.13 (1.06-1.21), and 1.28 (1.16-1.41) for post-natal exposure. Intrauterine PM2.5 exposure and post-natal PM10 exposure were associated with a higher risk of pneumonia. We identified the 2nd trimester, 3rd trimester, and first year as critical windows respectively for PM2.5, PM2.5-10, and PM10 exposure. Daytime exposure to traffic-related air pollution especially during early life increased DDP.

CONCLUSION

Intrauterine and post-natal exposure to particulate matters played a dominant role in children's DDP.

Short-term effects of air pollution on hospitalization for acute lower respiratory infections in children: a time-series analysis study from Lanzhou, China

BACKGROUND

Short-term exposure to air pollution is associated with acute lower respiratory infections (ALRI) in children. We investigated the relationship between hospitalization for ALRI in children and air pollutant concentrations from January 1, 2014 to December 31, 2020 in Lanzhou City.

METHODS

We collected data on air pollutant concentrations and children's hospitalization data during the study period. A time series regression analysis was used to assess the short-term effects of air pollutants on ALRI in children, and subgroup analyses and sensitivity analyses were performed.

RESULTS

A total of 51,206 children with ALRI were studied, including 40,126 cases of pneumonia and 11,080 cases of bronchiolitis. The results of the study revealed that PM2.5, PM10, SO2 and NO2 were significantly associated with hospitalization for ALRI in children aged 0-14 years. For each 10 µg/m3 increase in air pollutant concentration in lag0-7, the relative risk of ALRI hospitalization in children due to PM2.5, PM10, SO2 and NO2 increased by 1.089 (95%CI:1.075, 1.103), 1.018 (95%CI:1.014, 1.021), 1.186 (95%CI:1.154. 1.219) and 1.149 (95%CI:1.130, 1.168), respectively.

CONCLUSIONS

PM2.5, PM10, SO2 and NO2 short-term exposures were positively associated with ALRI, pneumonia and bronchiolitis hospitalizations in Lanzhou, China. Local governments should make efforts to improve urban ambient air quality conditions to reduce hospitalization rates for childhood respiratory diseases.

Associations between air pollutant and pneumonia and asthma requiring hospitalization among children aged under 5 years in Ningbo, 2015-2017

Introduction

Exposure to ambient air pollutants is associated with an increased incidence of respiratory diseases such as pneumonia and asthma, especially in younger children. We investigated the relationship between rates of hospitalization of children aged under 5 years for pneumonia and asthma and the concentration of air pollutants in Ningbo between January 1, 2015 and August 29, 2017.

Methods

Data were obtained from the Ningbo Air Quality Data Real-time Publishing System and the big data platform of the Ningbo Health Information Center. A generalized additive model was established via logarithmic link function and utilized to evaluate the effect of pollutant concentration on lag dimension and perform sensitivity analysis.

Results

A total of 10,301 cases of pneumonia and 115 cases of asthma were identified over the course of this study. Results revealed that PM2.5, PM10, SO2 and NO2 were significantly associated with hospitalization for pneumonia and asthma in children under 5 years of age. For every 10-unit increase in lag03 air pollutant concentration, hospitalization for pneumonia and asthma due to PM2.5, PM10, SO2 and NO2 increased by 2.22% (95%CI: 0.64%, 3.82%), 1.94% (95%CI: 0.85%, 3.04%), 11.21% (95%CI: 4.70%, 18.10%) and 5.42% (95%CI: 3.07%, 7.82%), respectively.

Discussion

Adverse effects of air pollutants were found to be more severe in children aged 1 to 5 years and adverse effects due to PM2.5, PM10 and SO2 were found to be more severe in girls. Our findings underscore the need for implementation of effective public health measures to urgently improve air quality and reduce pediatric hospitalizations due to respiratory illness.

Combined effect of preconceptional and prenatal exposure to air pollution and temperature on childhood pneumonia: A case-control study

Mounting evidence have linked ambient air pollution and temperature with childhood pneumonia, but it is unclear whether there is an interaction between air pollution and temperature on childhood pneumonia. We aim to assess the combined effect of ambient air pollution and temperature exposure during preconception and pregnancy on pneumonia by a case-control study of 1510 children aged 0-14 years in Changsha, China. We obtained the data of childhood pneumonia from XiangYa Hospital electrical records. We estimated personal exposure to outdoor air pollution (PM₁₀, SO₂ and NO₂) by inverse distance weighted (IDW) method and temperature indicators. Multiple logistic regression models were used to evaluate associations of childhood pneumonia with air pollution, temperature (T), and diurnal temperature variation (DTV). We found that exposure to industry-related air pollution (PM₁₀ and SO₂) during preconception and pregnancy were associated with childhood pneumonia, with ORs (95% CI) of 1.72 (1.48-1.98) and 2.96 (2.50-3.51) during 1 year before pregnancy and 1.83 (1.59-2.11) and 3.43 (2.83-4.17) in pregnancy. Childhood pneumonia was negatively associated with T exposure during 1 year before pregnancy and pregnancy, with ORs (95% CI) of 0.57 (0.41-0.80) and 0.85 (0.74-0.98). DTV exposure during pregnancy especially during the 1st and 2nd trimesters significantly increased pneumonia risk, with ORS (95% CI) of 1.77 (1.19-2.64), 1.47 (1.18-1.83), and 1.37 (1.07-1.76) respectively. We further observed interactions of PM₁₀ and SO₂ exposure with low T and high DTV during conception and pregnancy in relation to childhood pneumonia. This study suggests that there were interactions air pollution with temperature and DTV on pneumonia development.

Avoiding hospital admissions for respiratory system diseases by complying to the final Brazilian air quality standard: an estimate for Brazilian southeast capitals

According to the World Health Organization (WHO), in 2016, 91% of the global population was living in places where guidelines on air quality were not met, which results in an estimated figure of seven million deaths annually. The new Brazilian air quality standards, CONAMA 491/2018, was the first revision in over two decades and has as final target the WHO guidelines for air quality, although no deadline has been established for implementation. The goal of this work was to quantify public health gains of this new policy based on hospitalizations due to respiratory diseases, the most studied outcome in Brazilian time series studies, in four Brazilian Southeast capitals: São Paulo (SP), Rio de Janeiro (RJ), Belo Horizonte (MG), and Vitória (ES) for PM₁₀, PM_2,5, SO₂, CO, and O₃. Population and hospitalizations data for all respiratory diseases for people under 5 years old, over 64 years old, most vulnerable populations, and all ages were analyzed. The air quality monitoring data was analyzed in two different periods: 2016 to 2018 for São Paulo and Vitória; and between 2015 and 2017 for Belo Horizonte and Rio de Janeiro, according to available monitoring data. A literature review was carried out to determine the appropriate relative risk to be used in the estimations, and the public health gains were calculated based on the selected relative risks for each city. The highest estimate was for São Paulo, with 3454 avoidable respiratory hospital admissions (all ages). In total, the four cities accounted for 4148 avoidable hospitalizations, which was associated to $1.1 million public health gains. Results considering the day of exposure (lag 0) were superior to those with the 5-day moving average (lag 5). The results highlighted the importance of adopting more restrictive standards and called for public policies, the necessity of expanding the air quality monitoring network, mapping emission sources, and improve the knowledge about the interaction between air pollution and health outcomes beyond respiratory disease for the region.

Examining health disparities and characteristics in general practice utilization: based on outpatient data from 2014 - 2018 in Shanghai

BACKGROUND

Since 2000, China has been developing primary care institutions to serve as the gateway to the healthcare system. However, the investment of resources in primary care institutions is not based on the actual medical demands of the public. This study analysed primary care utilization to provide targeted guidance for the improvement of primary healthcare delivery in China.

METHODS

We extracted outpatient visit data from all community healthcare centres in Shanghai from 2014 to 2018. Diseases were then classified according to ICD-10 codes. The disease spectrum (frequency, proportion, rank) was stratified by sex, age, and region.

RESULTS

Most primary care outpatients were female (58.20%), 60-79 years old (57.91%), and in suburban regions (62.18%). Chronic diseases accounted for the majority (91.41%). Hypertension, chronic ischaemic heart disease, diabetes, and acute upper respiratory tract infections were the top four disorders for primary care visits regardless of sex. In the group aged 0-18 years, symptoms, signs and abnormal clinical and laboratory findings not elsewhere classified accounted for 37.96% of the top 20 reasons. Acute upper respiratory tract infections were the most common diseases in the groups aged 0-18 (11.20%) and 19-39 (11.14%) years. However, hypertension was the most common disease in the group aged > 39 years old (> 20%). There were more outpatients with respiratory and digestive diseases in suburban areas than in urban areas. In addition, problems associated with medical equipment and other healthcare deficiencies were relatively more common in suburban areas (suburban: 4.13%, rank 5; urban: 2.29%, rank 10).

CONCLUSIONS

To meet the patients' needs and to develop the primary care system, the Shanghai government should focus on diseases with regionally high proportions. Disease diagnosis and treatment should be improved in the younger and suburban populations.

Impact of air pollutants on pediatric admissions for Mycoplasma pneumonia: a cross-sectional study in Shanghai, China

BACKGROUND

Children are especially vulnerable to pneumonia and the effects of air pollution. However, little is known about the impacts of air pollutants on pediatric admissions for Mycoplasma pneumonia. This study was conducted to investigate the impacts of air pollutants on pediatric hospital admissions for Mycoplasma pneumonia in Shanghai, China.

METHODS

A cross-sectional design was applied to explore the association between pediatric hospital admissions and levels of air pollutants (fine particulate matter, particulate matter, ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide). Data on hospital admissions for pneumonia and levels of ambient air pollutants were obtained for the period of 2015 to 2018. Associations between pediatric admissions for Mycoplasma pneumonia and ambient air pollutants were calculated using logistic regression and described by the odds ratio and relevant 95% confidence interval. The hysteresis effects of air pollutants from the day of hospital admission to the previous 7 days were evaluated in single-pollutant models and multi-pollutant models with adjustments for weather variables and seasonality. Lag 0 was defined as the day of hospital admission, lag 1 was defined as the day before hospital admission, and so forth.

RESULTS

In the single-pollutant models (without adjustment for other pollutants), pediatric hospital admissions for pneumonia were positively associated with elevated concentrations of nitrogen dioxide and fine particulate matter. A 0.5% increase in daily admissions per 10-μg/m3 increase in the nitrogen dioxide level occurred at lag 1 and lag 2, and a 0.3% increase in daily admissions per 10-μg/m3 increase in fine particulate matter occurred at lag 1. In the multi-pollutant models, nitrogen dioxide and fine particulate matter remained significant after inclusion of particulate matter, ozone, sulfur dioxide, and carbon monoxide.

CONCLUSIONS

This study illustrated that higher levels of nitrogen dioxide and fine particulate matter increase the risk of pediatric hospitalization for Mycoplasma pneumonia in Shanghai, China. These findings imply that the high incidence of Mycoplasma pneumonia in children in Asia might be attributed to the high concentration of specific air pollutants in Asia.

Ambient air pollution and daily hospital admissions for respiratory system-related diseases in a heavy polluted city in Northeast China

Respiratory disease admission has been increasing in the recent 5 years due to heavy air pollutions and bad weather conditions in China. We investigated the short-term association of ambient air pollution with daily counts of hospital admissions due to respiratory infection diseases with stratified analysis by age (0-18, 19-65, and > 65 years old), gender (male, female), season (spring, summer, autumn, winter), and disease type (lung infections, asthma, COPD (chronic obstructive disease), URI (upper respiratory infections)) in heavy polluted city of Shenyang in China. Daily ambient air pollution concentrations, weather conditions, and hospital admission counts for 53 months (from November 1, 2013 to March 25, 2018) were extracted from related authorities in electronic databases. Associations between outdoor air pollution levels and hospital admissions were estimated for time lags of 0-7 days using quasi-Poisson additive regression models, adjusted for meteorological variables, holidays, day of week, and season, as well as eliminating autocorrelations. Single pollutant analysis results showed lung infection diseases were related to all pollutant concentration change with no lag effects. After adjusting for other pollutants and confounding factors, we found NO₂ was associated with daily admissions of lung infections (ER = 6.75%, 95% CI 1.24, 12.55), asthma (ER = 20.36%, 95% CI 4.26, 38.95; lag day 5, ER = 18.48%, 95% CI 2.83, 36.51), and COPD (ER = 13.27%, 95% CI 0.46, 27.71); CO was associated with lung infections and asthma with lag effects on lag days 1 and 4; and PM_2.5 was associated with COPD admissions on lag day 6. Respiratory hospital admissions in female over 65 years old and autumn were more associated with increased air pollutant levels. Our study results might add more detail evidences for relationship studies between air pollution exposure and respiratory diseases and contribute to the precise respiratory disease prevention and air pollution control strategies.

[The impact of sugarcane burning on hospitalization due to respiratory diseases]

The scope of this article is to evaluate the impact of emissions from sugarcane burning on hospital admission numbers for respiratory diseases in a sugarcane region. Hospital admission records for respiratory diseases were acquired from the database of the Hospital Information System of the Unified Health System (SIH-SUS) in the period from March 28, 2011 to December 28, 2012. Levels of PM10, NO2, O3, Temperature and Relative Humidity were recorded. Logistic regression models were created to analyze the association between the total number of hospitalizations, atmospheric pollutants and meteorological variables. A total of 1,179 hospitalization admissions were recorded, with a significant increase in cases of pneumonia in the burning period (p = 0.005). Likewise, it was observed that the cluster of PM10 and NO2 was influenced 67.9% (95% CI: 11.111-2.537) followed by cluster PM10, NO2, O3 and Temperature that influenced 91.1% (95% CI: 1.116; 3.271) in the total number of hospitalization admissions. During the sugarcane burning period there were more hospitalization admissions due to respiratory tract diseases, mainly pneumonia, where the influence of air pollutants and temperature in the process of illness in the population was detected.

Associations between ambient air pollution and mortality from all causes, pneumonia, and congenital heart diseases among children aged under 5 years in Beijing, China: A population-based time series study

BACKGROUND

Previous studies have mainly focused on the associations between particulate matters and infant mortality. However, evidence regarding the associations between gaseous pollutants and mortality among children aged <5 years remains sparse.

OBJECTIVES

The aim of this study was to investigate the associations between ambient air pollution and death among children aged <5 years in Beijing, China, and explore the impact of age, gender and specific causes of death on these associations.

METHODS

Concentrations of ambient air pollution and the number of deaths among children aged <5 years in Beijing from January 2014 to September 2016 were extracted from authoritative electronic databases. The associations were estimated for a single-month lag from the current month up to the previous 5 months (lag0-lag5) and moving averages of the current and previous months (lag01-lag05) using generalized additive Poisson regression (adjusted for time trends, season, meteorological variables and holidays). Subgroup analyses related to age, gender and specific diseases were performed. Two-pollutant models were used to evaluate the possible role of single pollutants.

RESULTS

Sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO) demonstrated the strongest associations with death among children aged <5 years at lag0, and the estimates decreased or even turned negative with the increasing lag periods. For an interquartile range increase in SO₂, NO₂ and CO at lag0, the odds ratios (OR) were 1.332 (95% CI 1.152-1.539), 1.383 (95% CI 1.113-1.718) and 1.273 (95% CI 1.028-1.575). However, CO lost significance after adjusting for SO₂ and NO₂, and PM_2.5 gained significance (OR 1.548, 95% CI 1.061-2.258) after adjusting for PM₁₀. The ORs for SO₂ and NO₂ remained the most stable across all two-pollutant models. The associations for children aged 1-5 years were stronger than those reported for infants at lag0 but lower at the other lag months. The pollutant associations were stronger for congenital heart disease-related death than overall and pneumonia-related death. We did not find significant differences in terms of gender.

CONCLUSION

Exposure to air pollution may increase the incidence of death among children aged <5 years. SO₂ and NO₂ may be the most stable pollutants reflecting associations between air pollution and death, deserving further attention. Children with congenital heart diseases are more susceptible to air pollution. Therefore, it is urgent to implement the clean air targets established by WHO and reduce the exposure of children to air pollution.

Impact of PM10 and meteorological factors on the incidence of hand, foot, and mouth disease in female children in Ningbo, China: a spatiotemporal and time-series study

Hand, foot, and mouth disease (HFMD) is a viral illness that is considered a critical public health challenge worldwide. Previous studies have demonstrated that meteorological parameters are significantly related to the incidence of HFMD in children; however, few studies have focused only on female children. This study quantified the associations of HFMD incidence with meteorological parameters and PM₁₀ (particulate matter with an aerodynamic diameter of 10 μm) among female children. Data were collected on daily HFMD cases, meteorological variables, and PM₁₀ levels in Ningbo, China, from January 2012 to December 2016. Data were assessed using a distributed lag nonlinear model (DLNM) with Poisson distribution. A total of 59,809 female children aged 0-15 years with HFMD were enrolled. The results showed that highest relative risk (RR) of HFMD for temperature was 3 °C and the lag effect was 3 days. The highest RR for PM₁₀ was 80 mg/m³ and the lag effect was 5 days. Spatial analysis showed that female HFMD incidence was mainly concentrated in the suburban of Ningbo city indicating that female children in this area should be more paid attention on avoiding this disease outbreak. Our findings suggest that HFMD prevention strategies should focus more attention on local meteorological parameters.

DIFFERENT RESPONSE TO EXPOSURE TO AIR POLLUTANTS IN GIRLS AND BOYS

Objective:

Identify the association between exposure to fine particulate matter and hospitalizations due to respiratory diseases in children up to ten years of age in the city of Cuiabá, Mato Grosso, stratifying the analysis by sex and calculating excess costs.

Methods:

Ecological study of time series. The dependent variable was daily hospitalizations according to the 10^th Revision of the International Classification of Diseases (ICD10): J04.0, J12.0 to J18.9, J20.0 to J21.9 and J45.0 to J45.0. The independent variables were the concentration of fine particulate, estimated by a mathematical model, temperature and relative air humidity, controlled by short and long-term trends. Generalized additive model of Poisson regression was used. Relative risks, proportional attributable risk (PAR) and excess hospitalizations and their respective costs by the population attributable fraction (PAF) were calculated.

Results:

1,165 children were hospitalized, 640 males and 525 females. The mean concentration, estimated by the mathematical model, was 15.1±2.9 mcg/m³ for PM_2.5. For boys, there was no significant association; for girls a relative risk of up to 1.04 of daily hospitalizations due to respiratory diseases was observed for exposure to PM 2.5 in lags 1, 2 and 6. Increase of 5 µg/m³ in these concentrations increased the percentage of the risk in 18%; with an excess 95 hospital admissions and with excess expenses in the order of US$ 35 thousand.

Conclusions:

Significant effect in daily hospitalizations due to respiratory diseases related to exposure to fine particulate matter was noted for girls, suggesting the need for stratification by sex in further studies.

Lifetime-ever pneumonia among pre-school children across China - Associations with pre-natal and post-natal early life environmental factors

BACKGROUND

Biomass burning is associated with childhood pneumonia but few studies exist on other indoor factors.

AIM

To study pneumonia in relation to pre-natal and post-natal exposure among children across China.

METHODS

Children (3-6 y) (n = 39,782) from randomized day care centres in seven cities in China. Information on pneumonia and pre-natal and post-natal exposure to home environment factors were assessed by a parental questionnaire. Life-time outdoor temperature and GDP per capita were assessed on city level. Associations were calculated by multilevel logistic regression adjusting for fourteen co-variates.

RESULTS

Totally 32.0% had ever had pneumonia diagnosed by a physician. Children of farmer mothers (OR = 0.65), with breastfeeding (OR = 0.91) and living in rural (OR = 0.85) or suburban (OR = 0.90) areas had less pneumonia. Buying new furniture one year before conception (OR = 1.11) and after first year of life (OR = 1.10) increased the risk. Redecoration one year before conception (OR = 1.20), during pregnancy (OR = 1.18) and after first year of life (OR = 1.17) increased pneumonia risk. Children with mould (OR = 1.17), window pane condensation (WPC) (OR = 1.20) and mould odour (OR = 1.15) at home at birth only had a higher risk of pneumonia. Similar associations were seen for dampness and mould in the current home. Children in the oldest and newest homes had less pneumonia. Cockroaches (OR = 1.08), mosquitos or flies in the current home (OR = 1.18), an exhaust fan in the bathroom (OR = 1.10) and higher economic development level, measured as GDP per capita on city level (OR 1.11 per 10,000 RMB/year) were associated with childhood pneumonia.

CONCLUSIONS

Perinatal and postnatal exposure to mould, mould odour and window pane condensation at home can be early life risk factors for childhood pneumonia in China. Moreover, pre-natal and post-natal exposure to chemical emissions from new furniture and renovation could increase the risk of childhood pneumonia. Breastfeeding, farm exposure, and living in rural or suburban areas could be protective.

Coarse particles and hospital admissions due to respiratory diseases in children. An ecological time series study

BACKGROUND

Exposure to particulate matter (PM) is associated with hospitalizations due to respiratory diseases among children.

DESIGN AND SETTING

An ecological time series study was carried out to identify the role of coarse fractions of particulate matter (PM10-2.5) in hospitalizations among children up to 10 years of age, in Piracicaba (SP) in the year 2015.

METHODS

A generalized additive model of Poisson regression was used to estimate the risk of hospitalization due to acute laryngitis and tracheitis, pneumonia, bronchitis, bronchiolitis and asthma. Lags of 0 to 7 days were considered, and the model was adjusted for the temperature and relative humidity of the air and controlled for short and long-term exposure. Proportional attributable ratios, population-attributable fractions and hospital costs were calculated with increasing concentrations of these pollutants.

RESULTS

638 hospitalizations were evaluated during this period, with a mean of 1.75 cases per day (standard deviation, SD = 1.86). The daily averages were 22.45 µg/m3 (SD = 13.25) for the coarse fraction (PM10-2.5) and 13.32 µg/m3 (SD = 6.38) for the fine fraction. Significant risks of PM10-2.5 exposure were only observed at lag 0, with relative risk (RR) = 1.012, and at lag 6, with RR = 1.011. An increase of 5 µg/m3 in the coarse fraction concentration implied an increase in the relative risk of hospitalizations of up to 4.8%, with an excess of 72 hospitalizations and excess expenditure of US$ 17,000 per year.

CONCLUSIONS

This study showed the impact of coarse-fraction exposure on hospital admissions among children due to respiratory diseases.

Short-term association between ambient air pollution and pneumonia in children: A systematic review and meta-analysis of time-series and case-crossover studies

Ambient air pollution has been associated with respiratory diseases in children. However, its effects on pediatric pneumonia have not been meta-analyzed. We conducted a systematic review and meta-analysis of the short-term association between ambient air pollution and hospitalization of children due to pneumonia. We searched the Web of Science and PubMed for indexed publications up to January 2017. Pollutant-specific excess risk percentage (ER%) and confidence intervals (CI) were estimated using random effect models for particulate matter (PM) with diameter ≤ 10 (PM₁₀) and ≤2.5 μm (PM_2.5), sulfur dioxide (SO₂), ozone (O₃), nitrogen dioxide (NO₂), and carbon monoxide (CO). Results were further stratified by subgroups (children under five, emergency visits versus hospital admissions, income level of study location, and exposure period). Seventeen studies were included in the meta-analysis. The ER% per 10 μg/m³ increase of pollutants was 1.5% (95% CI: 0.6%-2.4%) for PM₁₀ and 1.8% (95% CI: 0.5%-3.1%) for PM_2.5. The corresponding values per 10 ppb increment of gaseous pollutants were 2.9% (95% CI: 0.4%-5.3%) for SO₂, 1.7% (95% CI: 0.5%-2.8%) for O₃, and 1.4% (95% CI: 0.4%-2.4%) for NO₂. ER% per 1000 ppb increment of CO was 0.9% (95% CI: 0.0%-1.9%). Associations were not substantially different between subgroups. This meta-analysis shows a positive association between daily levels of ambient air pollution markers and hospitalization of children due to pneumonia. However, lack of studies from low-and middle-income countries limits the quantitative generalizability given that susceptibilities to the adverse effects of air pollution may be different in those populations. The meta-regression in our analysis further demonstrated a strong effect of country income level on heterogeneity.

The impact of airborne particulate matter on pediatric hospital admissions for pneumonia among children in Jinan, China: A case-crossover study

This study aims to examine the effect of short-term changes in the concentration of particulate matter of diameter ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀) on pediatric hospital admissions for pneumonia in Jinan, China. It explores confoundings factors of weather, season, and chemical pollutants. Information on pediatric hospital admissions for pneumonia in 2014 was extracted from the database of Jinan Qilu Hospital. The relative risk of pediatric hospital admissions for pneumonia was assessed using a case-crossover approach, controlling weather variables, day of the week, and seasonality. The single-pollutant model demonstrated that increased risk of pediatric hospital admissions for pneumonia was significantly associated with elevated PM_2.5 concentrations the day before hospital admission and elevated PM₁₀ concentrations 2 days before hospital admission. An increment of 10 μg/m³ in PM_2.5 and PM₁₀ was correlated with a 6% (95% CI 1.02--1.10) and 4% (95% CI 1.00-1.08) rise in number of admissions for pneumonia, respectively. In two pollutant models, PM_2.5 and PM₁₀ remained significant after inclusion of sulfur dioxide or nitrogen dioxide but not carbon monoxide. This study demonstrated that short-term exposure to atmospheric particulate matter (PM_2.5/PM₁₀) may be an important determinant of pediatric hospital admissions for pneumonia in Jinan, China.

IMPLICATIONS

This study demonstrated that short-term exposure to atmospheric particulate matter (PM_2.5/PM₁₀) may be an important determinant of pediatric hospital admissions for pneumonia in Jinan, China, and suggested the relevance of pollutant exposure levels and their effects. As a specific group, children are sensitive to airborne particulate matter. This study estimated the short-term effects attribute to other air pollutants to provide references for relevant studies.