Chronic PM2.5 exposure and risk of infant bronchiolitis and otitis media clinical encounters

Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study

BACKGROUND

Acute bronchiolitis and air pollution are both risk factor of pediatric asthma. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis. This study aimed to assess subsequent exposure to air pollutants related to the inception of preschool asthma in infants with acute bronchiolitis.

METHODS

A nested case-control retrospective study was performed at the Kaohsiung Medical University Hospital systems between 2009 and 2019. The average concentration of PM10, PM2.5, SO2, NO, NO2, and NOX was collected for three, six, and twelve months after the first infected episode. Adjusted regression models were employed to evaluate the association between asthma and air pollution exposure after bronchiolitis.

RESULTS

Two thousand six hundred thirty-seven children with acute bronchiolitis were included. Exposure to PM10, PM2.5, SO2, NO, NO2, and NOX in the three, six, and twelve months following an episode of bronchiolitis was found to significantly increase the risk of preschool asthma in infants with a history of bronchiolitis.(OR, 95%CI: PM10 = 1.517-1.559, 1.354-1.744; PM2.5 = 2.510-2.603, 2.148-3.061; SO2 = 1.970-2.040, 1.724-2.342; ; NO = 1.915-1.950, 1.647-2.272; NO2 = 1.915-1.950, 1.647-2.272; NOX = 1.752-1.970, 1.508-2.252) In a sensitive analysis of hospitalized infants, only PM10, PM2.5, SO2, and NO were found to have significant effects during all time periods. (OR, 95%CI: PM10 = 1.613-1.650, 1.240-2.140; PM2.5 = 2.208-2.286, 1.568-3.061; SO2 = 1.679-1.622, 1.197-2.292; NO = 1.525-1.557, 1.094-2.181) CONCLUSION: The presence of ambient PM10, PM2.5, SO2 and NO in the three, six, and twelve months following an episode of acute bronchiolitis has been linked to the development of preschool asthma in infants with a history of acute bronchiolitis.

Increased risk of emergency department presentations for bronchiolitis in infants exposed to air pollution

Air pollution has been linked to an increased risk of several respiratory diseases in children, especially respiratory tract infections. The present study aims to evaluate the association between pediatric emergency department (PED) presentations for bronchiolitis and air pollution. PED presentations due to bronchiolitis in children aged less than 1 year were retrospectively collected from 2007 to 2018 in Padova, Italy, together with daily environmental data. A conditional logistic regression based on a time-stratified case-crossover design was performed to evaluate the association between PED presentations and exposure to NO₂ , PM2.5, and PM10. Models were adjusted for temperature, relative humidity, atmospheric pressure, and public holidays. Delayed effects in time were evaluated using distributed lag non-linear models. Odds ratio for lagged exposure from 0 to 14 days were obtained. Overall, 2251 children presented to the PED for bronchiolitis. Infants' exposure to higher concentrations of PM10 and PM2.5 in the 5 days before the presentation to the PED increased the risk of accessing the PED by more than 10%, whereas high concentrations of NO₂ between 2 and 12 days before the PED presentation were associated with an increased risk of up to 30%. The association between pollutants and infants who required hospitalization was even greater. A cumulative effect of NO₂ among the 2 weeks preceding the presentation was also observed. In summary, PM and NO₂ concentrations are associated with PED presentations and hospitalizations for bronchiolitis. Exposure of infants to air pollution could damage the respiratory tract mucosa, facilitating viral infections and exacerbating symptoms.

PM2 .5, PM10 and bronchiolitis severity: A cohort study

BACKGROUND

A few studies suggest that particulate matter (PM) exposure might play a role in bronchiolitis. However, available data are mostly focused on the risk of hospitalization and come from retrospective studies that provided conflicting results. This prospective study investigated the association between PM (PM_2.5 and PM₁₀ ) exposure and the severity of bronchiolitis.

METHODS

This prospective cohort study was conducted between November 2019 and February 2020 at the pediatric emergency department of the Fondazione IRCCS Ca' Ospedale Maggiore Policlinico, Milan, Italy. Infants <1 year of age with bronchiolitis were eligible. The bronchiolitis severity score was assessed in each infant and a nasal swab was collected to detect respiratory viruses. The daily PM₁₀ and PM_2.5 exposure in the 29 preceding days were considered. Adjusted regression models were employed to evaluate the association between the severity score and PM₁₀ and PM_2.5 exposure.

RESULTS

A positive association between the PM_2.5 levels and the severity score was found at day-2 (β 0.0214, 95% CI 0.0011-0.0417, p = .0386), day-5 (β 0.0313, 95% CI 0.0054-0.0572, p = .0179), day-14 (β 0.0284, 95% CI 0.0078-0.0490, p = .0069), day-15 (β 0.0496, 95% CI 0.0242-0.0750, p = .0001) and day-16 (β 0.0327, 95% CI 0.0080-0.0574, p = .0093).Similar figures were observed considering the PM₁₀ exposure and limiting the analyses to infants with respiratory syncytial virus.

CONCLUSION

This study shows for the first time a direct association between PM_2.5 and PM₁₀ levels and the severity of bronchiolitis.

Exposure to ambient fine particulate matter impedes the function of spleen in the mouse metabolism of high-fat diet

Epidemiological and experimental evidence has been associating the exposure with ambient fine particulate matter (PM_2.5) with metabolic malfunctions such as obesity and cardiovascular disease. As the blood-filter and the important lymphatic organ, spleen participates in the regulation of metabolic balance. In this work, liquid chromatography-mass spectrometry (LC-MS)-based lipidomics, metabolomics and proteomics were performed to study the effects of PM_2.5 exposure and high-fat diet (HFD) induced obesity on mice spleen. By comparing the differences in lipids, metabolites, and proteins in the spleens from PM_2.5 and HFD treated mice, we discovered the individual and combined effects of the two risk factors. The results showed the PM_2.5 exposure altered energy metabolism of the mice, as evidenced by the upregulation of TCA cycle. In addition, the metabolism of branched-chain amino acids was also significantly changed, which might be related to the preventive function of spleen in lipid metabolism. The PM_2.5-induced metabolic changes in spleen could further aggravate the adverse impacts of HFD on mice, resulting in impeded splenic metabolism of lipids. This study revealed the effects of PM_2.5 and obesity mice spleen, which might be of great significance to public health.

Proximity to Major Roads and Risks of Childhood Recurrent Wheeze and Asthma in a Severe Bronchiolitis Cohort

Air pollution exposures have been suggested as risk factors for childhood respiratory diseases. We investigated proximity to major roads, an indicator of air pollution exposure, and its associations with childhood recurrent wheeze and asthma. We used data from a multicenter prospective cohort study of 921 infants hospitalized for bronchiolitis and recruited from 14 U.S. states. Primary exposure was residential proximity to the nearest major road at birth through age 3 years. Residential distance from nearest major road was divided into four categories: <100, 100–200, 201–300, and >300 m. Outcomes were parent-reported recurrent wheeze by age 3 years and asthma by age 5 years. Associations between residential proximity to major roads and respiratory outcomes were investigated using multivariable Cox proportional hazards modeling and logistic regression, adjusted for confounders. Out of 920 participants with home address data, pooled estimates identified 241 (26%) participants resided within 300 m of a major road, 296 (32%) developed recurrent wheeze by age 3, and 235 out of 858 participants (27%) developed asthma by 5 years. Participants who resided close to a major road had the highest risk of recurrent wheeze (adjusted hazards ratio for <100 m, 1.59, 95%CI: 1.08–2.33) and asthma (adjusted odds ratio for 201–300 m, 1.62, 95%CI: 1.16–2.25), compared to those residing >300 m from a major road. Proximity to major roads is associated with increased risks of recurrent wheeze and asthma in young children.

Associations between Particulate Matter and Otitis Media in Children: A Meta-Analysis

Particulate matter (PM), a primary component of air pollution, is a suspected risk factor for the development of otitis media (OM). However, the results of studies on the potential correlation between an increase in the concentration of PM and risk of developing OM are inconsistent. To better characterize this potential association, a meta-analysis of studies indexed in three global databases (PubMed, EMBASE, and The Cochrane Library) was conducted. These databases were systematically screened for observational studies of PM concentration and the development of OM from the time of their inception to 31 March 2020. Following these searches, 12 articles were analyzed using pooled odds ratios generated from random-effects models to test for an association between an increased concentration of PM and the risk of developing OM. The data were analyzed separately according to the size of particulate matter as PM_2.5 and PM₁₀. The pooled odds ratios for each 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration were 1.032 (95% confidence interval (CI), 1.005–1.060) and 1.010 (95% CI, 1.008–1.012), respectively. Specifically, the pooled odds ratios were significant within the short-term studies (PM measured within 1 week of the development of OM), as 1.024 (95% CI, 1.008–1.040) for PM_2.5 concentration and 1.010 (95% CI, 1.008–1.012) for PM₁₀ concentration. They were significant for children under 2 years of age with pooled odds ratios of 1.426 (95% CI, 1.278–1.519) for an increase in the concentration of PM_2.5. The incidence of OM was not correlated with the concentration of PM, but was correlated with an increase in the concentration of PM. In conclusion, an increase in the concentration of PM_2.5 is more closely associated with the development of OM compared with an increase in the concentration of PM₁₀; this influence is more substantial in shorter-term studies and for younger children.

[Urban air pollution and hospital admissions for asthma and acute respiratory disease in Murcia city (Spain)]

INTRODUCTION

Urban air pollution is a major threat to child and adolescent health. Children are more vulnerable to its effects, being associated with higher morbidity and mortality due to acute and chronic diseases, especially respiratory ones. A study is performed on the relationship between urban air pollution and the rate of hospital admissions due to acute respiratory diseases.

PATIENTS AND METHODS

An ecological study was conducted on young people under 17 years-old in the city of Murcia, who had visited hospital emergency departments due to respiratory diseases (ICD-9) during 2015. A logistic regression was performed on the risk of hospital admission that included consultations in relation to the average daily levels of environmental pollutants (NO₂, O₃, PM10, SO₂) obtained from the Air Quality Surveillance and Control network of the Region of Murcia. Other control variables, such as gender, age, average daily ambient temperature, and season of the year.

RESULTS

A total of 12,354 (56% boys and 44% girls) children consulted in the emergency department for respiratory disease. Of those, 3.5% were admitted, with a mean age of 2.54 (95% CI; 2.16-2.91) years. The odds ratio (OR) of hospital admission for respiratory diseases: NO₂ 1.02 (95% CI; 1.01-1.04; P<.01), O₃ 1.01 (95% CI; 1.00-1.03; P<.01) male 1.4 (95% CI 1.11-1.79; P<.01) and winter 2.10 (95% CI 1.40-3.21; P<.01). Admissions for asthma: PM10 1.02 (95% CI; 1.01-1.04; P<.05), O₃ 1.04 (95% CI; 1.01-1.06; P<.01). Admissions for bronchiolitis: Age 0.69 (95% CI; 0.48-0.99; P<.05); NO₂ 1.03 (95% CI; 1.01-1.05; P<.01).

CONCLUSIONS

Urban air pollution increases hospital admissions in children due to acute respiratory diseases, especially asthma and bronchiolitis. Implementing preventive measures, expanding time series and collaborative studies with open data, would help improve public health and air quality in the cities.

The effect of outdoor air pollution on the risk of hospitalisation for bronchiolitis in infants: a systematic review

OBJECTIVE

To systematically review the evidence around the effect of ambient levels of particulate and gaseous pollutants, and the risk of hospitalisation with bronchiolitis for infants under two years of age.

DESIGN

Systematic review of observational epidemiological studies including cohort, time series, case crossover and case control study designs.

DATA SOURCES

Medline, Scopus, and Web of Science searched to November 2017 with no language restrictions.

ELIGIBILITY CRITERIA

Studies investigating impact of air pollution levels on particulate pollutants (diameter <2.5 μm (PM2.5) or <10 μm (PM10) and gaseous pollutants (nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), ozone (O3)) on hospital admission for bronchiolitis.

MAIN OUTCOME MEASURE

Risk of hospitalisation from bronchiolitis.

RESULTS

Eight studies were eligible for review. Long term exposure to PM2.5 may be associated with increased risk of hospitalisation for bronchiolitis. SO2 may also be associated with hospitalisation, but results for other pollutants are inconsistent between studies. In three of the five studies that showed a positive association between air pollutants and hospitalisation, measured concentrations were below World Health Organization (WHO) recommended levels.

CONCLUSIONS

Certain particulate and gaseous pollutants may have a clinically relevant effect on hospital admissions for bronchiolitis in children below age two years old. Large cohort or time series studies are needed to examine this possible association.

PROTOCOL

The protocol can be found at PROSPERO (CRD42017080643).

Characterization of Fine Particulate Matter and Associated Health Burden in Nanjing

Particulate matter (PM) air pollution has become a serious environmental problem in Nanjing and poses great health risks to local residents. In this study, characteristics of particulate matter with an aerodynamic diameter less than 2.5 μm (PM_2.5) over Nanjing were analyzed using hourly and daily averaged PM_2.5 concentrations and meteorological parameters collected from nine national monitoring sites during the period of March 2014 to February 2017. Then, the integrated exposure-response (IER) model was applied to assess premature mortality, years of life lost (YLL) attributable to PM_2.5, and mortality benefits due to PM_2.5 reductions. The concentrations of PM_2.5 varied among hours, seasons and years, which can be explained by differences in emission sources, secondary formations and meteorological conditions. The decreased ratio of PM_2.5 to CO suggested that secondary contributions decreased while the relative contributions of vehicle exhaust increased from increased CO data. According to the values of attributable fractions (AF), stroke was the major cause of death, followed by ischemic heart disease (IHD), lung cancer (LC) and chronic obstructive pulmonary disease (COPD). The estimated total deaths in Nanjing due to PM_2.5 were 12,055 and 10,771, leading to 98,802 and 87,647 years of life lost in 2014 and 2015, respectively. The elderly and males had higher health risks than youngsters and females. When the PM_2.5 concentrations meet the World Health Organization (WHO) Air Quality Guidelines (AQG) of 10 μg/m³, 84% of the premature deaths would be avoided, indicating that the Nanjing government needs to adopt more stringent measure to reduce PM pollution and enhance the health benefits.

Associations of mobile source air pollution during the first year of life with childhood pneumonia, bronchiolitis, and otitis media

Supplemental Digital Content is available in the text.

Background:

Exposure to air pollution from motor vehicles in early life may increase susceptibility to common pediatric infections.

Methods:

We estimated associations between residential exposure to primary fine particulate matter, nitrogen oxides, and carbon monoxide from traffic during the first year of life and incident pneumonia, bronchiolitis, and otitis media events by age 2 years in 22,441 children from the Kaiser Air Pollution and Pediatric Asthma Study, a retrospective birth cohort of children born during 2000–2010 and insured by Kaiser Permanente Georgia. Time to first clinical diagnosis of each outcome was defined using medical records. Exposure to traffic pollutants was based on observation-calibrated estimates from A Research LINE-source dispersion model for near surface releases and child residential histories. Associations were modeled using Cox proportional hazards models, with exposure as a continuous linear variable, a natural-log transformed continuous variable, and categorized by quintiles.

Results:

During follow-up, 2,181 children were diagnosed with pneumonia, 5,533 with bronchiolitis, and 14,374 with otitis media. We observed positive associations between early-life traffic exposures and all three outcomes; confidence intervals were widest for pneumonia as it was the least common outcome. For example, adjusted hazard ratios for a 1-unit increase in nitrogen oxides on the natural log scale (a 2.7-fold increase) were 1.19 (95% CI = 1.12, 1.27) for bronchiolitis, 1.17 (1.12, 1.22) for otitis media, and 1.08 (0.97, 1.20) for pneumonia.

Conclusions:

Our results provide evidence for modest, positive associations between exposure to traffic emissions and common pediatric infections during early childhood.