Short-term exposure to ambient ozone and inflammatory biomarkers in cross-sectional studies of children and adolescents: Results of the GINIplus and LISA birth cohorts

Associations of personal exposure to domestic heating and cooking fuel emissions and epidemiological effects on rural residents in the Fenwei Plain, China

Solid fuel combustion for domestic heating in northern China in the wintertime is of great environmental and health concern. This study assesses personal exposure to particulate matter with different aerodynamic diameters and multiple gaseous pollutants from 123 rural residents in Yuncheng, the Fenwei Plain. The subjects are divided into groups based on the unique energy source applied, including biomass, coal, and electricity/no heating activities. The health effects of the exposures are expressed with four urinary biomarkers. The personal exposure levels to three different aerodynamic particle sizes (i.e., PM₁₀, PM_2.5, and PM₁) of the electricity/no heating group are 5.1 % -12 % lower than those of the coal group. In addition, the exposure levels are 25 %-40 % lower for carbon monoxide (CO) and 10.8 %-20.3 % lower for ozone (O₃) in the electricity/no heating group than the other two fuel groups. C-reactive protein (CRP) in the urine of the participants in biomass and coal groups is significantly higher than that in the electricity/no heating group, consistent with the observations on other biomarkers. Increases in 8-hydroxy-2 deoxyguanosine (8-OHdG), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) are observed for the exposures to higher concentrations of air pollutants. For instance, PMs and nitrogen dioxide (NO₂) show significant impacts on positive correlations with 8-OHdG and IL-8, while O₃ positively correlates with CRP. PM₁ exhibits higher effects on the biomarkers than the gaseous pollutants, especially on VEGF and IL-8. The study indicates that excessive use of traditional domestic solid fuels could pose severe health effects on rural residents. The promotion of using clean energy is urgently needed in the rural areas of northern China.

Effects of Ozone on Sickness and Depressive-like Behavioral and Biochemical Phenotypes and Their Regulation by Serum Amyloid A in Mice

Ozone (O₃) is an air pollutant that primarily damages the lungs, but growing evidence supports the idea that O₃ also harms the brain; acute exposure to O₃ has been linked to central nervous system (CNS) symptoms such as depressed mood and sickness behaviors. However, the mechanisms by which O₃ inhalation causes neurobehavioral changes are limited. One hypothesis is that factors in the circulation bridge communication between the lungs and brain following O₃ exposure. In this study, our goals were to characterize neurobehavioral endpoints of O₃ exposure as they relate to markers of systemic and pulmonary inflammation, with a particular focus on serum amyloid A (SAA) and kynurenine as candidate mediators of O₃ behavioral effects. We evaluated O₃-induced dose-, time- and sex-dependent changes in pulmonary inflammation, circulating SAA and kynurenine and its metabolic enzymes, and sickness and depressive-like behaviors in Balb/c and CD-1 mice. We found that 3 parts per million (ppm) O₃, but not 2 or 1 ppm O₃, increased circulating SAA and lung inflammation, which were resolved by 48 h and was worse in females. We also found that indoleamine 2,3-dioxygenase (Ido1) mRNA expression was increased in the brain and spleen 24 h after 3 ppm O₃ and that kynurenine was increased in blood. Sickness and depressive-like behaviors were observed at all O₃ doses (1-3 ppm), suggesting that behavioral responses to O₃ can occur independently of increased SAA or neutrophils in the lungs. Using SAA knockout mice, we found that SAA did not contribute to O₃-induced pulmonary damage or inflammation, systemic increases in kynurenine post-O₃, or depressive-like behavior but did contribute to weight loss. Together, these findings indicate that acute O₃ exposure induces transient symptoms of sickness and depressive-like behaviors that may occur in the presence or absence of overt pulmonary neutrophilia and systemic increases of SAA. SAA does not appear to contribute to pulmonary inflammation induced by O₃, although it may contribute to other aspects of sickness behavior, as reflected by a modest effect on weight loss.

Ambient ozone exposure and bone turnover markers in children: Results from the GINIplus and LISA birth cohorts

BACKGROUND

Multiple environmental factors can regulate bone metabolism, and it is hypothesized that air pollution may be deleteriously involved in this regulation. However, only a few studies considered bone turnover markers (BTMs) - sensitive and specific markers of bone metabolism - as outcomes, and no study investigated the exposure to ambient ozone. Here, we intended to explore the associations between long-term exposure to ambient ozone and concentrations of two BTMs, osteocalcin and β-isomer of C-terminal telopeptide of type I collagen (CTx), amongst 10-year-old children.

METHODS

Based on the GINIplus and LISA birth cohorts, our cross-sectional analysis included 1848 children aged 10 years from Munich and Wesel. Serum osteocalcin and CTx concentrations were measured. We estimated ozone exposures by optimal interpolation, assessed nitrogen dioxide and particulate matter with an aerodynamic diameter <10 μm concentrations by land use regression models, and assigned the exposures to home addresses. Linear regression models were built and adjusted for covariates as well as co-pollutants.

RESULTS

The mean concentrations were 93.09 ng/mL and 663.66 ng/L for osteocalcin and CTx, respectively. In general, higher levels of ozone were associated with decreased concentrations of both BTMs. This held true for the two areas and different exposure metrics. The number of days per year with a maximum 8-h average concentration exceeding 120 μg/m³ showed consistent results across different models. Specifically, models adjusted for co-pollutants illustrated that the beta estimates and 95% confidence intervals on osteocalcin and CTx were -2.51 (-3.78, -1.14) and -44.53 (-57.12, -31.93), respectively, for an increase of 10 days.

CONCLUSIONS

We found that long-term exposure to ambient ozone was associated with decreased concentrations of BTMs in German children. This association might potentially affect bone metabolism. Nevertheless, unless other prospective studies confirm our results, the detrimental effects of ambient ozone on bone development in children should be interpreted cautiously.

Acute effects of exposure to fine particulate matter and ozone on lung function, inflammation and oxidative stress in healthy adults

Both fine particulate matter (PM_2.5) and ozone (O₃) may have adverse effects on human health. However, previous studies on the effects of air pollutants mainly have focused on susceptible population, and evidence on healthy young adults is limited. We aimed to examine the associations of the two main air pollutants (PM_2.5 and O₃) with lung function, inflammation and oxidative stress in healthy young adults. We recruited 30 healthy young adults for a longitudinal panel study in Beijing and implemented health examination seven times, including lung function (FEV₁ and PEF) and biomarkers of inflammation and oxidative stress (i.e. C-reactive protein, CRP; interleukin-6, IL-6; malondialdehyde, MDA) from December 2019 to May 2021. Hourly ambient air pollutants data were obtained from the closest air quality monitoring station. Linear mixed-effect model was applied to explore the associations between air pollutants and lung function, inflammation and oxidative stress. We observed higher PM_2.5 exposure was associated with decrement in lung function and increment in CRP and MDA. Each 10 μg/m³ increase in PM_2.5 (lag 2 day) is associated with a 17.06 ml (95% CI: -31.53, -2.58) decrease in FEV₁, 46.34 ml/s (95% CI: -76.41, -16.27) decrease in PEF and increments of 2.86% (95% CI: 1.47%, 4.27%) in CRP, 1.63% (95% CI: 0.14%, 3.14%) in MDA respectively. However, there is no significant association between ozone exposure and health indicators. The study suggested that short-term exposure to PM_2.5 may decrease lung function and induce inflammation and oxidative stress in healthy adults, but there is no association between O₃ and each outcome.

Long-Term Effects of Ambient Particulate and Gaseous Pollutants on Serum High-Sensitivity C-Reactive Protein Levels: A Cross-Sectional Study Using KoGES-HEXA Data

Ambient air pollutants reportedly increase inflammatory responses associated with multiple chronic diseases. We investigated the effects of long-term exposure to ambient air pollution on high-sensitivity C-reactive protein (hs-CRP) using data from 60,581 participants enrolled in the Korean Genome and Epidemiology Study-Health Examinees Study between 2012 and 2017. Community Multiscale Air Quality System with surface data assimilation was used to estimate the participants' exposure to criteria air pollutants based on geocoded residential addresses. Long-term exposure was defined as the 2-year moving average concentrations of PM₁₀, PM_2.5, SO₂, NO₂, and O₃. Multivariable linear and logistic regression models were utilized to estimate the percent changes in hs-CRP and odds ratios of systemic low-grade inflammation (hs-CRP > 3 mg/L) per interquartile range increment in air pollutants. We identified positive associations between hs-CRP and PM₁₀ (% changes: 3.75 [95% CI 2.68, 4.82]), PM_2.5 (3.68, [2.57, 4.81]), SO₂ (1.79, [1.10, 2.48]), and NO₂ (3.31, [2.12, 4.52]), while negative association was demonstrated for O₃ (-3.81, [-4.96, -2.65]). Elevated risks of low-grade inflammation were associated with PM₁₀ (odds ratio: 1.07 [95% CI 1.01, 1.13]), PM_2.5 (1.08 [1.02, 1.14]), and SO₂ (1.05 [1.01, 1.08]). The odds ratios reported indicated that the exposures might be risk factors for inflammatory conditions; however, they did not reflect strong associations. Our findings suggest that exposure to air pollutants may play a role in the inflammation process.

The type of previous abortion modifies the association between air pollution and the risk of preterm birth

BACKGROUND

Air pollution and previous abortion have been reported to be related to preterm birth (PTB). But rare study examined the effect of air pollution on PTB risk among mothers with previous abortion.

OBJECTIVE

To estimate the effect of air pollution on PTB and the potential effect modification of previous abortion on such an association in rural part of Henan province (China).

METHOD

Based on National Free Preconception Health Examination Project (NFPHEP), information from the medical records of 57,337 mothers with previous abortion were obtained. An inverse distance-weighted model was used to estimate exposure levels of air pollutants. The effect of air pollution on the risk of PTB was estimated with a multiple logistic regression model. Stratified and interaction analyses were undertaken to explore the potential effect modification of previous abortion on this association.

RESULTS

The risk of PTB was positively associated with exposure to levels of nitrogen dioxide (NO₂; OR: 1.03; 95%CI: 1.02-1.04)], and sulfur dioxide (SO₂; 1.04; 1.02-1.07), and negatively associated with ozone (O₃) exposure (0.97; 0.97-0.98) during the entire pregnancy. Besides, we observed a positive effect of carbon monoxide (CO) exposure during the third trimester of pregnancy on PTB (1.14; 1.01-1.29). The type of previous abortion could modify the effect of air pollution on the PTB risk (P-_interaction < 0.05). Compared with mothers with previous induced abortion, mothers with previous spontaneous abortion carried a higher risk of PTB induced by NO₂, CO, and O₃.

CONCLUSIONS

The risk of PTB was positively associated with levels of NO₂, SO₂ and CO, and negatively associated with the O₃ level. The types of previous abortion could modify the effect of air pollution on PTB. Mothers who had an abortion previously, especially spontaneous abortion, should avoid exposure to air pollution to improve their pregnancy outcome.

Impact of air pollution exposure on lung function and exhaled breath biomarkers in children and adolescents

A growing number of scientific papers focus on the description and quantification of the detrimental effects of pollution exposure on human health. The respiratory system is one of the main targets of these effects and children are potentially a vulnerable population. Many studies analyzed the effects of short- and long-term exposure to air pollutants on children's respiratory function. Aim of the present narrative review is to summarize the results of the available cohort studies which investigated how children's lung function is affected by exposure to air pollution. In addition, an overview is provided on the association, in children, between pollution exposure and exhaled breath biomarkers, as possible indicators of the pathogenetic mechanisms involved in pollution-related lung damages. The identified cohort studies suggest that, beside the possible impact of recent exposure, early and lifetime exposure are the variables most consistently associated with a reduction in lung function parameters in both children and adolescents. As for the effect of air pollution exposure on exhaled breath biomarkers, the available studies show an association with increased exhaled nitric oxide, with increased concentrations of malondialdehyde and 8-isoprostane in exhaled breath condensate (EBC), and with EBC acidification. These studies, therefore, suggest lung inflammation and oxidative stress as possible pathogenetic mechanisms involved in pollution related lung damages. Taken together, the available data underscore the importance of the development and application of policies aimed at reducing air pollutant concentration, since the protection of children's lung function can have a beneficial impact on adults' respiratory health in the future.

Prenatal exposure to air pollution and the risk of preterm birth in rural population of Henan Province

Due to the poor living and healthcare conditions, preterm birth (PTB) in rural population is a pressing health issue. However, PTB studies in rural population are rare. To explore the effects of air pollutants on PTB in rural population, we collected 697,316 medical records during 2014-2016 based on the National Free Preconception Health Examination Project. Logistic regression models were used to estimate the association between air pollutants and PTB and the modifying effects of demographic characteristics. Relative contribution and principal component analysis-generalized linear model (PCA-GLM) analysis were used to explore the most significant air pollutant and gestational period. Our results demonstrated that PTB risk is positively associated with exposure to air pollutants including PM₁₀, PM_2.5, SO₂, NO₂, and CO, while negatively associated with O₃ exposure (P < 0.05). In addition, we found that NO₂ was the largest contributor to the risk of PTB caused by air pollutants (26.5%). The third trimester of pregnancy was the most sensitive exposure window. PCA-GLM analysis showed that the first component (a combination of PM, SO₂, NO₂, and CO) increased the risk of PTB. Moreover, we found that rural women who are younger, had higher educated, multi-parity, or smoke appeared to be more sensitive to the association between air pollutants exposure and PTB (P_-interaction<0.05). Our findings suggested that increased air pollutants except O₃ were associated with elevated PTB risk, especially among vulnerable mothers. Therefore, the effects of air pollutants exposure on PTB should be mitigated by restricting emission sources of NO₂ and SO₂ in rural population, especially during the third trimester.

Association between preconceptional air pollution exposure and medical purposes for selective termination of pregnancy

BACKGROUND

Exposure to air pollutants is associated with adverse pregnancy outcomes. But evidence on the effects of preconceptional air pollution exposure on the risk of termination of pregnancy (TOP) caused by pregnancy losses and congenital malformations is lacking.

METHODS

The distributed lag nonlinear model (DLNM) was used to evaluate the impact of short-term air pollutants exposure on the risk of TOP. Stratified analyses by age (<35 years old, ≥ 35 years old) and season (warm season, cold season) were further conducted. Relative risk (RR) and 95 % confidential interval (95 % CI) were calculated for per interquartile range (IQR) increment in air pollutants during the study period.

RESULTS

PM_2.5, PM₁₀, and O₃ exposure were significantly associated with elevated risk of TOP. The risk of TOP was associated with PM_2.5 exposure from lag11 to lag15 in the single-pollutant model, and the strongest association was observed at lag13 (RR = 1.021, 95%CI:1.002-1.040). PM₁₀ exposure from lag10 to lag15 was associated with increased TOP risk, with the corresponding peak association being at lag13 (RR = 1.020, 95%CI: 1.004-1.037). For O₃, the single-day lag association appeared to be statistically significant from lag26 to lag27, with the highest RR of TOP cases being at lag27 (RR = 1.044, 95%CI: 1.005-1.084). Similar results were observed for pregnancy losses (PL). However, no significantly association between air pollution exposure and the risk of congenital malformations (CM) was found in this study. Stratified analyses showed that pregnant women with more advanced ages were more susceptible to PM_2.5, PM₁₀, and O₃ exposure. The effect of PM_2.5 exposure was statistically significant in cold season subgroups.

CONCLUSION

The findings suggest that exposure to PM_2.5, PM₁₀, and O₃ before pregnancy are associated with the risk of TOP in Lu'an, China, reflecting the significance of preconceptional environmental exposure in the development of adverse pregnancy outcomes.

Long-term exposure to ambient nitrogen dioxide and ozone modifies systematic low-grade inflammation: The CHCN-BTH study

The potential effect of long-term exposure to ambient air pollutants on low-grade systematic inflammation has seldom been evaluated taking indoor air pollution and self-protection behaviors on smog days into account. A total of 24,346 participants at baseline were included to conduct a cross-sectional study. The annual (2016) average pollutant concentrations were assessed by air monitoring stations for PM_2.5, PM₁₀, SO₂, NO₂, O₃ and CO. Associations between annual ambient air pollution and low-grade systematic inflammation (hsCRP>3 mg/L) were estimated by generalized linear mixed models. Stratification analysis was also performed based on demographic characteristics, health-related behaviors and disease status. Annual ambient NO₂ and O₃ were all associated with low-grade systematic inflammation in single-pollutant models after adjusting for age, sex, blood lipids, blood pressure, lifestyle risk factors, cooking fuel, heating fuel and habits during smog days (NO₂ per 10 μg/m³: OR = 1.057, P = 0.018; O₃ per 10 μg/m³: OR = 0.953, P = 0.012). The 2-year and 3-year ozone concentrations were consistently associated with lower systematic inflammation (2-year O₃ per 10 μg/m³: OR = 0.959, P = 0.004; 3-year O₃ per 10 μg/m³: OR = 0.961, P = 0.014). In two-pollutant models, the estimated effects of annual NO₂ and O₃ on low-grade systematic inflammation remained stable. The effect size of annual pollutants on inflammation increased in participants without air-purifier usage (NO₂ per 10 μg/m³: OR = 1.079, P = 0.009; O₃ per 10 μg/m³: OR = 0.925, P = 0.001), while the association was null in the air-purifier usage group. Thus, long-term exposure to ambient NO₂ and O₃ was associated with low-grade systemic inflammation, and the results were generally stable after sensitivity analysis. The usage of air purifiers on smog days can modify the association between gaseous pollutants and systematic inflammation.

Pneumothorax and the environment: A systematic review of the impact of air pollution and meteorology, and a meta-analysis on meteorology factors

A relationship between the occurrence of spontaneous pneumothorax (SP) and meteorological factors has been observed but with contradictory results. The objectives of this systematic review was to synthesis the current body of evidence to the relationships between the occurrence of SP and environmental determinants such as meteorological factors and air pollutants. We conducted a systematic search of MEDLINE, Scopus, Cochrane Library and gray literature from inception up to 31st December 2020, to find published scientific research articles based on the following eligibility criteria: original studies and population-based articles describing the relationship between meteorological factors or air pollutants and the occurrence of SP. For the meta-analysis, studies involving a quantitative analysis of the exposure variable (atmospheric pressure, temperature, humidity and wind speed) and the impact of the occurrence of SP with comparable methodology were selected. General characteristics and methodological information for each study were assessed. The quality was evaluated according to the Newcastle-Ottawa Scale. Fourty four and 13 studies were respectively included in the qualitative and quantitative analyses. The variability of the study design with moderate quality and the different measurements of the exposure variables highlight the contrasting results. The results of the meta-analyses are in favor of a higher temperature observed in the day with SP than in the days without SP (maximum: MD 0.25 (-0.08, 0.58) p = 0.14; I² = 26%, p = 0.21; mean: MD 0.22 (-0.15, 0.59) p = 0.24; I² = 45%, p = 0.07). The small number of studies focused on air pollution did not allow us to conclude to determine the potential impact of exposure to air pollutants on the occurrence of SP. Meteorological conditions seem to be related to SP occurrence, especially increased temperature.

Outdoor air pollution and hormone-assessed pubertal development in children: Results from the GINIplus and LISA birth cohorts

BACKGROUND

Air pollution is hypothesized to affect pubertal development. However, the few studies on this topic yielded overall mixed results. These studies did not consider important pollutants like ozone, and none of them involved pubertal development assessed by estradiol and testosterone measurements. We aimed to analyze associations between long-term exposure to four pollutants and pubertal development based on sex hormone concentrations among 10-year-old children.

METHODS

These cross-sectional analyses were based on the 10-year follow-up medical examinations of 1945 children from the Munich and Wesel centers of the GINIplus and LISA German birth cohorts. Female and male pubertal development was assessed by dichotomizing the concentration of hormones in serum at 18.4 pmol/L and 0.087 nmol/L using the lower limits of quantification for estradiol and testosterone, respectively. Land-use regression models derived annual average concentrations of particulate matter with an aerodynamic diameter < 2.5 and 10 µm (PM_2.5 and PM₁₀), as well as spatial models assessed yearly average concentrations of nitrogen dioxide (NO₂) and ozone, were calculated at the 10-year residential addresses. To evaluate associations, we utilized logistic regressions adjusted for potential covariates. The analyses were stratified by area and sex.

RESULTS

Around 73% of the 943 females and 25% of the 1002 males had a high level of hormones and had already started puberty at the age of 10. Overall, we found no statistically significant associations between exposure to particles (PM_2.5 or PM₁₀) and pubertal development. Results on NO₂ and ozone were not significant as well; for instance, per 10 µg/m³ increase in ozone concentration, odds ratios and 95% confidence intervals were 0.900 (0.605, 1.339) and 0.830 (0.573, 1.203) for females and males, respectively. Stratified by area, the aforementioned results did not reveal any associations either.

CONCLUSIONS

Our study did not observe the associations between ambient air pollutants and pubertal development determined by estradiol and testosterone levels in children. However, due to the current limited number of studies on this topic, our results should be cautiously interpreted. Future longitudinal studies are needed to assess the association.

The effect of ambient ozone on glucose-homoeostasis: A prospective study of non-diabetic older adults in Beijing

OBJECTIVE

To investigate potential effects of short- and medium-term exposure to low levels of ozone (O3) on glucose-homeostasis in non-diabetic older adults.

METHODS

166 non-diabetic, older participants in Beijing were deemed eligible to partake in this longitudinal population-based study. Observations were recorded on three separate occasions from November 2016 up until January 2018. Concentrations of outdoor O3 were monitored throughout the study period. Biomarkers indicative of glucose-homeostasis, including fasting blood glucose, insulin, HbAlc, glycated albumin percentage (glycated albumin/albumin), HOMA-IR and HOMA-B were measured at 3 sessions. A linear mixed effects model with random effects was adopted to quantify the effect of O3 across a comprehensive set of glucose-homeostasis markers.

RESULTS

Short-term O3 exposure positively associated with increased fasting blood glucose, insulin, HOMA-IR and HOMA-B. The effect on glucose occurred at 3-, 5-, 6- and 7-days, although the largest effect manifested on 6-days (5.6%, 95% CI: 1.4, 9.9). Significant associations with both insulin and HOMA-IR were observed on the 3- and 4-days. For HOMA-B, positive associations were identified from 3- to 7-days with estimates ranging from 40.0% (95% CI: 2.3, 91.5) to 83.1% (95% CI: 25.3, 167.5). Stratification suggests that women may be more susceptible to short-term O3 exposure. There does not appear to be a significant association between O3 and glucose-homeostasis in medium-term exposures.

CONCLUSIONS

In this study, we found that O3 exposure is at least partially associated with type II diabetes in older adults with no prior history of this condition. O3 therefore appears to be a potential risk factor, which is a particular concern when we consider the rise in global concentrations. Evidence also suggests that women may be more susceptible to short-term O3 exposure although we are not quite sure why. Future research may look to investigate this phenomenon further.

Inhalants other than personal cigarette smoking and risk for developing rheumatoid arthritis

PURPOSE OF REVIEW

The current review summarizes the current evidence on inhalants other than personal cigarette smoking and risk for developing rheumatoid arthritis (RA).

RECENT FINDINGS

Personal cigarette smoking has been implicated as an environmental risk factor for seropositive RA, perhaps by inducing autoimmunity at pulmonary mucosa. Since many patients with RA are nonsmokers, other inhalants are being investigated as potential RA risk factors. Recent case-control and cohort studies have investigated passive cigarette smoking, air pollution, inhalant-related occupations, silica, pesticides, household environment, and allergic inhalants as inhalant exposures for RA risk. Inhalant-related occupations and silica inhalants have the most consistent evidence for associations with increased RA risk. However, most studies relied on retrospective designs and had limited ability to adjust for personal cigarette smoking or investigate associations among nonsmokers.

SUMMARY

Several inhalants other than personal cigarette smoking may be associated with increased risk for developing RA. These results support the hypothesis that inhalants, pulmonary mucosal inflammation, and RA pathogenesis may be linked. Future studies are needed to firmly establish the independence of these findings from personal cigarette smoking and to determine the specific inhalants and biologic mechanisms related to RA pathogenesis.

Ozone exposure and health effects: a protocol for an umbrella review and effect-specific systematic maps

INTRODUCTION

Ambient ozone exposure may be adverse to health. Since the reported associations between ozone and health effects are heterogeneous and the underlying pathways are indistinct, the overall relationship remains unclear. Only a few overall syntheses of the evidence regarding ozone and health effects are available to date.

METHODS AND ANALYSIS

We plan to summarise the current evidence on ozone-related health effects systematically. First, to identify the possible associations between ambient ozone exposure and health outcomes, we will conduct an umbrella review. PubMed, Web of Science and grey literature will be searched for systematic reviews on exposure to ambient ozone and any possible health endpoints published before 31 May 2019. Data selection and extraction will be carried out by one reviewer, and a second reviewer will check the agreement of a sample of the studies. The methodological quality of the eligible systematic reviews and level of evidence regarding ozone and every specific health effect will be evaluated. Second, for each of the identified effects with a high level of evidence, comprehensive information retrievals will be conducted, considering both epidemiological and experimental studies. The study selection and data mapping will be carried out by one reviewer and checked by the second reviewer. We will summarise the information of the filtered epidemiological and experimental studies to conduct several systematic maps presenting the currently available evidence for the specific health effect. Because the association between ozone exposure and chronic obstructive pulmonary disease (COPD) is relatively well investigated, we will at least conduct one systematic map of ozone and COPD.

ETHICS AND DISSEMINATION

No ethical approval is required for this study. The completed umbrella review and systematic maps will be considered for publication and presentation. We will additionally upload the relevant data to publicly accessible online databases.

PROSPERO REGISTRATION NUMBER

CRD42019123064.

The influence of chlorine in indoor swimming pools on the composition of breathing phase of professional swimmers

OBJECTIVES

Swimming is one of the most popular forms of physical activity. Pool water is cleaned with chlorine, which - in combination with compounds contained in water - could form chloramines and trichloromethane in the swimmer's lungs. The aim of the present study was to examine the effect of swimming training in an indoor pool on the composition of swimmers' respiratory phase metabolomics, and develop a system to provide basic information about its impact on the swimmer's airway mucosa metabolism, which could help to assess the risk of secondary respiratory tract diseases i.e. sport results, condition, and health including lung acute and chronic diseases).

DESIGN

A group of competitive swimmers participated in the study and samples of their respiratory phase before training, immediately after training, and 2 h after training were assessed.

METHODS

Sixteen male national and international-level competitive swimmers participated in this study. Respiratory phase analysis of the indoor swimming pool swimmers was performed. Gas chromatography combined with mass spectrometry (GCMS) was used in the measurements. All collected data were transferred to numerical analysis for trends of tracking and mapping. The breathing phase was collected on special porous material and analyzed using GCMS headspace.

RESULTS

The obtained samples of exhaled air were composed of significantly different metabolomics when compared before, during and after exercise training. This suggests that exposition to indoor chlorine causes changes in the airway mucosa.

CONCLUSION

This phenomenon may be explained by occurrence of a chlorine-initiated bio-reaction in the swimmers' lungs. The obtained results indicate that chromatographic exhaled gas analysis is a sensitive method of pulmonary metabolomic changes assessment. Presented analysis of swimmers exhaled air indicates, that indoor swimming may be responsible for airway irritation caused by volatile chlorine compounds and their influence on lung metabolism.