Short-term effect of ozone on the pulmonary function of children in primary school

Association between elevated serum bilirubin levels with preserved lung function under conditions of exposure to air pollution

BACKGROUND

High serum bilirubin levels have been shown to be associated with an improved pulmonary function test results. Their potential ability to similarly benefit pulmonary function in an environment of polluted air has not been tested. We retrospectively analyzed data of 15,605 apparently healthy individuals in order to evaluate the effect of serum bilirubin levels on forced expiratory volume in 1 s (FEV1).

METHODS

Individuals attended the Tel-Aviv Medical Center Inflammatory Survey for a routine annual health check between February, 2002 and June, 2009 and were divided into low, medium and high serum bilirubin levels. Their FEV1 results were compared under various levels of air pollution. Air pollution and weather data were obtained from air pollution monitoring stations of the Israeli Ministry of Environmental Protection.

RESULTS

The elevated serum bilirubin concentrations on FEV1 were evaluated under moderate and high pollution levels FEV1 and were significantly higher in participants with high blood bilirubin levels compared to medium or low levels (p < 0.001 and p = 0.018, respectively). Participants with high levels of bilirubin had preserved FEV1 under exposure to high and medium pollution levels of both Nitrogen Oxide (NOx) and Carbon Monoxide (CO) pollutants (p = 0.003 and p = 0.022, respectively). The multivariate regression analysis revealed that the influence of bilirubin under conditions of air pollution remained significant even after adjustment for FEV1 confounders, but the interaction was not significant.

CONCLUSIONS

Elevated serum bilirubin concentrations are associated with preserved lung function in healthy individuals in Israel exposed to high levels of air pollution.

Indoor air pollution, physical and comfort parameters related to schoolchildren's health: Data from the European SINPHONIE study

Substantial knowledge is available on the association of the indoor school environment and its effect among schoolchildren. In the same context, the SINPHONIE (School indoor pollution and health: Observatory network in Europe) conducted a study to collect data and determine the distribution of several indoor air pollutants (IAPs), physical and thermal parameters and their association with eye, skin, upper-, lower respiratory and systemic disorder symptoms during the previous three months. Finally, data from 115 schools in 54 European cities from 23 countries were collected and included 5175 schoolchildren using a harmonized and standardized protocol. The association between exposures and the health outcomes were examined using logistic regression models on the environmental stressors assessed in classroom while adjusting for several confounding factors; a VOC (volatile organic compound) score defined as the sum of the number of pollutants to which the children were highly exposed (concentration > median of the distribution) in classroom was also introduced to evaluate the multiexposure - outcome association. Schoolchildren while adjusting for several confounding factors. Schoolchildren exposed to above or equal median concentration of PM_2.5, benzene, limonene_, ozone and radon were at significantly higher odds of suffering from upper, lower airways, eye and systemic disorders. Increased odds were also observed for any symptom (sick school syndrome) among schoolchildren exposed to concentrations of limonene and ozone above median values. Furthermore, the risks for upper and lower airways and systemic disorders significantly increased with the VOCs score. Results also showed that increased ventilation rate was significantly associated with decreased odds of suffering from eye and skin disorders whereas similar association was observed between temperature and upper airways symptoms. The present study provides evidence that exposure to IAPs in schools is associated with various health problems in children. Further investigations are needed to confirm our findings.

Cardiorespiratory responses to low-level ozone exposure: The inDoor Ozone Study in childrEn (DOSE)

BACKGROUND

Indoor air pollution has emerged as a significant environmental and public health concern in recent years. However, evidence regarding the cardiorespiratory effects of indoor ozone is limited, and the underlying biological mechanisms are unclear, especially in children. Our study aimed to assess the cardiorespiratory responses to indoor ozone exposure in children.

METHODS

A repeated-measure study was conducted in 46 middle-school children in Beijing, China. Real-time concentrations of ozone, along with co-pollutants including particulate matter (PM) and black carbon (BC), were monitored in classrooms from Monday to Friday. Three repeated health measurements of cardiorespiratory functions, including ambulatory electrocardiogram (ECG), blood pressure, fractional exhaled nitric oxide (FeNO) and lung function, were performed on each participant. Mixed-effect models were used to evaluate the effects of indoor ozone exposure.

RESULTS

The mean (SD) indoor ozone concentration was 8.7 (6.6) ppb during the study period, which was largely below the current guideline and standards. However, even this low-level ozone exposure was associated with reduced cardiac autonomic function and increased heart rate (HR) in children. For instance, per interquartile range (IQR) increase in ozone at 2-hour moving average was associated with -7.8% (95% CI: -9.9%, -5.6%) reduction in standard deviation of all normal-to-normal intervals (SDNN), and 2.6% (95% CI: 1.6%, 3.6%) increment in HR. In addition, the associations were stronger at high BC levels (BC ≥ 3.7 μg/m³). No significant associations were found for airway inflammation and pulmonary function.

CONCLUSIONS

Exposure to low-level indoor ozone that is not associated with respiratory effects was significantly related to disturbed cardiac autonomic function and increased HR in children, which suggested a possible mechanism through which ozone may affect cardiovascular health in children, and indicated more protective measures should be taken to alleviate the acute adverse effects of indoor ozone in this susceptible population.

Lifetime exposure to particulate air pollutants is negatively associated with lung function in non-asthmatic children

BACKGROUND

Pulmonary function is known to be affected by acute and subacute exposure to ambient air pollution. However, the impacts of lifetime exposure to air pollution on the pulmonary function of children have been inconsistent. The present study investigated the impact of lifetime residential exposure to intermediate levels of air pollution on the pulmonary function of schoolchildren.

METHODS

In 2011, a survey of children aged 6-15 years was conducted in 44 schools in Taiwan. Atopic history, residential history, and environmental factors were recorded. Spirograms were obtained from a random sample of children without asthma. A total of 535 girls and 481 boys without a history of asthma were enrolled. Lifetime residential exposure to air pollutants, including particulate matter with an aerodynamic diameter less than 10 μm (PM₁₀), ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO), was estimated using the kriging method, based on monitored data from the Taiwan Environmental Protection Administration. Multiple linear regression was used to analyze the association between lifetime air pollution exposure and pulmonary function, after adjustment for potential confounders and recent exposure.

RESULTS

After adjustment for 7-day average air pollutant levels, a 10 μg/m³ increase in PM₁₀ was related to reductions in the forced expiratory volume in 1 s (-2.00%; 95% confidence interval [CI] -3.09% to -0.90%), forced vital capacity (-1.86%; CI: -2.96% to -0.75%), and maximal midexpiratory flow (-2.28%; CI: -4.04% to -0.51%). These associations were independent of the other pollutants.

CONCLUSION

Lifetime exposure to 25-85 μg/m³ of PM₁₀ has negative impacts on the pulmonary function of children.

Climate Change and Underserved Communities

Climate change is the greatest global health threat of the twenty-first century, yet it is not widely understood as a health hazard by primary care providers in the United States. Aside from increasing displacement of populations and acute trauma resulting from increasing frequency of natural disasters, the impact of climate change on temperature stress, vector-borne illnesses, cardiovascular and respiratory illnesses, and mental health is significant, with disproportionate impact on underserved and marginalized populations. Primary care providers must be aware of the impact of climate change on the health of their patients and advocate for adaptation and mitigation policies for the populations they serve.

Short-term Effects of Outdoor Air Pollution on Lung Function among Female Non-smokers in China

Short-term exposures to outdoor air pollutants have been associated with lower lung function, but the results are inconsistence. The effects of different pollutant levels on lung function changes are still unclear. We quantified the effects of outdoor air pollution exposure (NO₂, PM₁₀, O₃, and PM_2.5) on lung function among 1,694 female non-smokers from the Wuhan-Zhuhai Cohort in China by using linear mixed model. We further investigated the associations in the two cities with different air quality levels separately to quantify the effects of different pollutant level exposure on lung function. We found the moving averages of NO₂, PM₁₀, and PM_2.5 concentrations were significantly associated with reduced FVC. In city at high pollutant level, the moving average of NO₂, PM₁₀, O₃, and PM_2.5 exposures were significantly associated with both FVC and FEV₁ reductions. In the low-level air pollution city, PM₁₀ (Lag03-Lag05) and O₃ concentrations (Lag01-Lag03) were significantly associated with reduced FVC, while PM₁₀ (Lag03-Lag05), O₃ (Lag0-Lag03), and PM_2.5 (Lag04-Lag06) exposure were significantly associated with reduced FEV₁. Our results suggest that outdoor air pollution is associated with short-term adverse effects on lung function among female non-smokers. The adverse effects may persist for longer durations within 7 days at higher air pollutant levels.

Multilevel analysis of air pollution and early childhood neurobehavioral development

To investigate the association between the ambient air pollution levels during the prenatal and postnatal stages and early childhood neurobehavioral development, our study recruited 533 mother-infant pairs from 11 towns in Taiwan. All study subjects were asked to complete childhood neurobehavioral development scales and questionnaires at 6 and 18 months. Air pollution, including particulate matter ≤10 μm (PM10), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and hydrocarbons, was measured at air quality monitoring stations in the towns where the subjects lived. Multilevel analyses were applied to assess the association between air pollution and childhood neurobehavioral development during pregnancy and when the children were 0 to 6 months, 7 to 12 months, and 13 to 18 months old. At 18 months, poor subclinical neurodevelopment in early childhood is associated with the average SO2 exposure of prenatal, during all trimesters of pregnancy and at postnatal ages up to 12 months (first trimester β = -0.083, se = 0.030; second and third trimester β = -0.114, se = 0.045; from birth to 12 months of age β = -0.091, se = 0.034). Furthermore, adverse gross motor below average scores at six months of age were associated with increased average non-methane hydrocarbon, (NMHC) levels during the second and third trimesters (β = -8.742, se = 3.512). Low-level SO2 exposure prenatally and up to twelve months postnatal could cause adverse neurobehavioral effects at 18 months of age. Maternal NMHC exposure during the 2nd and 3rd trimesters of pregnancy would be also associated with poor gross motor development in their children at 6 months of age.

Lungs in a warming world: climate change and respiratory health

Climate change is a health threat no less consequential than cigarette smoking. Increased concentrations of greenhouse gases, and especially CO₂, in the earth's atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, temperature variability, air pollution, forest fires, droughts, and floods, all of which put respiratory health at risk. These changes in climate and air quality substantially increase respiratory morbidity and mortality for patients with common chronic lung diseases such as asthma and COPD and other serious lung diseases. Physicians have a vital role in addressing climate change, just as they did with tobacco, by communicating how climate change is a serious, but remediable, hazard to their patients.

Indoor air quality and sources in schools and related health effects

Good indoor air quality in schools is important to provide a safe, healthy, productive, and comfortable environment for students, teachers, and other school staff. However, existing studies demonstrated that various air pollutants are found in classrooms, sometimes at elevated concentrations. Data also indicated that poor air quality may impact children's health, in particular respiratory health, attendance, and academic performance. Nevertheless, it should be noted that there are other adverse health effects that are less documented. Few data exist for teachers and other adults that work in schools. Allergic individuals seem to be at a higher risk for adverse respiratory health consequences. Air quality improvement represents an important measure for prevention of adverse health consequences in children and adults in schools.

The short-term effects of air pollution on adolescent lung function in Taiwan

A mass screening of lung function associated with air pollutants for children is limited. This study assessed the association between air pollutants exposure and the lung function of junior high school students in a mass screening program in Taipei city, Taiwan. Among 10,396 students with completed asthma screening questionnaires and anthropometric measures, 2919 students aged 12-16 received the spirometry test. Forced vital capacity (FVC) and forced expiratory flow in 1s (FEV(1)) in association with daily ambient concentrations of particulate matter with diameter of 10 μm or less (PM(10)), sulfur dioxide (SO(2)), carbon monoxide (CO), nitrogen dioxide (NO(2)), and ozone (O(3)) were assessed by regression models controlling for the age, gender, height, weight, student living districts, rainfall and temperature. FVC, had a significant negative association with short-term exposure to O(3) and PM(10) measured on the day of spirometry testing. FVC values also were reversely associated with means of SO(2), O(3), NO(2), PM(10) and CO exposed 1 d earlier. An increase of 1-ppm CO was associated with the reduction in FVC for 69.8 mL (95% CI: -115, -24.4 mL) or in FEV(1) for 73.7 mL (95% CI: -118, -29.7 mL). An increase in SO(2) for 1 ppb was associated with the reductions in FVC and FEV(1) for 12.9 mL (95% CI: -20.7, -5.09 mL) and 11.7 mL (95% CI: -19.3, -4.16 mL), respectively. In conclusion, the short-term exposure to O(3) and PM(10) was associated with reducing FVC and FEV(1). CO and SO(2) exposure had a strong 1-d lag effect on FVC and FEV(1).

Effects of ambient air pollution on pulmonary function among schoolchildren

Literature has shown adverse effects of ambient air pollution exposure on various asthma related outcomes in childhood. However, the associated evidence on pulmonary function effects is still inconsistent. We conducted a population-based study comprised of seventh-grade children in 14 Taiwanese communities. Pulmonary function tests and questionnaires were completed on 3957 subjects. We evaluated the effects of ambient air pollution exposures based on the data collected in 2005-2007 by existing air monitoring stations. Multiple linear mixed effect models were fitted to estimate the relationship between community pollutant levels and pulmonary function indices. After adjustment for individual-level confounders, pulmonary function differed only slightly between communities with different levels of air pollution. We found greater effects of ambient air pollutants on pulmonary function for boys than for girls. Among boys, traffic-related pollutants CO, NOx, NO(2), and NO were generally associated with chronic adverse effects on FVC and FEV(1), and subchronic adverse effects mainly on maximal mid-expiratory flow (MMEF) and peak expiratory flow rate. Among girls, only NOx and NO(2) showed subchronic adverse effects on MMEF. Although effect estimates of SO(2), PM(10), and PM(2.5) were generally negative for boys, none achieved statistical significance. Our data suggests that ambient traffic-related pollution had chronic adverse effects on pulmonary function in schoolchildren, especially for boys.

Environmental air pollution has decremental effects on pulmonary function test parameters up to one week after exposure

BACKGROUND

Recent exposure to air pollution has a decremental effect on pulmonary function. This short-term effect has only been studied for up to a few days postexposure. Our objective was to analyze the effect of air pollution on spirometric parameters in varying lag times of up to 1 week from the time of exposure.

METHODS

Healthy subjects, never smokers, who were participants in the Tel Aviv Sourasky Medical Center Inflammation Survey held between 2002 and 2007, were included if residing within an 11-km range to the nearest air pollution monitoring station. Linear regression models were applied to each lung function variable [first second of exhalation (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC] against air pollutant variables (particulate matter under 10 microns in diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) for increasing lag periods of up to 7 days, and they were adjusted for possible confounders that affect air pollution and spirometric measurements.

RESULTS

The study population comprised 2380 individuals. We found a statistically significant negative correlation between air pollutants, mainly SO(2), and between FEV(1) and FVC. This effect was significant from days 3 to 6, with a maximal effect noted for the fifth day and for the 7-day average before pulmonary function measurement. No significant change was found for FEV(1)/FVC ratio.

CONCLUSIONS

Air pollution has a decremental effect on lung function parameters for up to 6 days after exposure in healthy adults. SO(2) emerged as the most significant air pollutant affecting short-term lung function parameters.

Effects of ambient ozone exposure on mail carriers' peak expiratory flow rates

The extent to which occupational exposure to ozone in ambient air can affect lung function remains unclear. We conducted a panel study in 43 mail carriers by measuring their peak expiratory flow rates (PEFRs) twice daily for 6 weeks in 2001. The daily exposure of each mail carrier to O3, particulate matter < 10 microm in aerodynamic diameter (PM10), and nitrogen dioxide was estimated by one air monitoring station in the center of the mail carrier's delivery area. Hourly concentrations of air pollutants during their exposure periods were 6-96 ppb for O3, 11-249 microg/m3 for PM10, and 14-92 ppb for NO2. Linear mixed-effects models were used to estimate the association between air pollution exposures and PEFR after adjusting for subject's sex, age, and disease status and for temperature and humidity. We found that night PEFR and the deviation in night PEFR were significantly decreased in association with 8-hr O3 exposures with a lag 0-2 days and by daily maximum O3 exposures with a lag of 0-1 day in our multipollutant models. By contrast, neither PM10 nor NO2 was associated with a PEFR reduction. Daily 8-hr mean concentrations of O3 had greater reduction effects on PEFR than did daily maximum concentrations. For a 10-ppb increase in the 8-hr average O3 concentration, the night PEFR was decreased by 0.54% for a 0-day lag, 0.69% for a 1-day lag, and 0.52% for a 2-day lag. We found that an acute lung function reduction occurs in mail carriers exposed to O3 concentrations below current ambient air quality standards and occupational exposure limits.

Ambient air pollution: health hazards to children

Ambient (outdoor) air pollution is now recognized as an important problem, both nationally and worldwide. Our scientific understanding of the spectrum of health effects of air pollution has increased, and numerous studies are finding important health effects from air pollution at levels once considered safe. Children and infants are among the most susceptible to many of the air pollutants. In addition to associations between air pollution and respiratory symptoms, asthma exacerbations, and asthma hospitalizations, recent studies have found links between air pollution and preterm birth, infant mortality, deficits in lung growth, and possibly, development of asthma. This policy statement summarizes the recent literature linking ambient air pollution to adverse health outcomes in children and includes a perspective on the current regulatory process. The statement provides advice to pediatricians on how to integrate issues regarding air quality and health into patient education and children's environmental health advocacy and concludes with recommendations to the government on promotion of effective air-pollution policies to ensure protection of children's health.

Environmental ozone effects in different population subgroups

The study objective was to get more information on characteristics of ozone risk groups. We performed repeated (on average 16 times) lung function tests and interviews with 171 persons belonging to four different population subgroups (44 healthy children, 43 juvenile asthmatics, 43 athletes, and 41 elderly). The environmental half hour mean ozone concentrations ranged from 8 to 99 ppb. For two groups there was significant NO2 co-pollution. The asthmatics showed statistically significant ozone related increased ORs for eye irritations, the elderly for nose irritations. Significant lung function decrements (increase in ozone by 50 ppb) were found for asthmatics (FVC -4.3% afternoon one day lag, -4.9% afternoon two day lag, -3.6% morning one day lag) and children (FVC -3.2% same morning, PEF -11.9% same morning, PEF -4.6% morning one day lag). In the group of elderly, however, there were also some significant FVC and PEF increments. Ozone responders were found more often in the groups of asthmatics and children (21% resp. 18%) compared with elderly and athletes (both 5%). The results suggest that children and asthmatics have a higher risk of being ozone sensitive showing more ozone related acute lung function decrements than other population groups.

Nasal epithelial and inflammatory response to ozone exposure: a review of laboratory-based studies published since 1985

This article summarizes biological events in human and animal nasal epithelium after short- and long-term exposure to ozone, the principal agent in photochemical smog. Despite anatomical and histological interspecies differences, ozone exposures resulted in common nasal qualitative alterations with an anterior-posterior gradient of phenomena occurring immediately, and with a lag time postexposure: epithelial disruption and increased permeability, inflammatory cell influx, and proliferative and secretory responses. Described mechanisms of toxicity included a direct effect of ozone on epithelial lining fluid and cellular membranes and the subsequent release of cytokines and cyclooxygenase and lipoxygenase products. An indirect effect of ozone was indicated by a decreased mucociliary clearance, free radicals production interacting with a gene promoting factor, and increased DNA synthesis. Studies highlighted the pivotal role of activated neutrophils and mast cells leading to the release of deleterious enzymes (tryptase, eosinophil cationic protein) and numerous cytokines. Experiments performed with ozone exposure/allergen challenge reported that, besides the intrinsic deleterious properties of ozone, it also had a priming effect on the late-phase response to allergen challenge, providing new insights into the pathophysiology of respiratory allergic diseases.

Effect of ozone and aeroallergens on the respiratory health of asthmatics

The effect of ambient air pollutants, pollens, and mold spores on respiratory health was studied in an area with low concentrations of chemical pollutants and abundant aeroallergens. A panel of 40 asthmatic subjects living near East Moline, Illinois, recorded peak expiratory flow rates (PEFRs), respiratory symptoms, frequency of asthma attacks, and asthma medication use between April and October 1994. Daily outdoor concentrations of pollutants and aeroallergens were measured, and indoor levels of bioaerosols were measured on several occasions in each participant's home. Ozone was associated with increased morning and evening symptom scores and decreased evening PEFR, and these associations remained significant with adjustment for weather and aeroallergens. The association between ozone and asthma medication use was increased in magnitude and significance with adjustment for weather and aeroallergens; however, the association between ozone and morning PEFR became nonsignificant with weather and aeroallergen adjustment. Significant associations were also found between pollen concentration and decreased evening PEFR, as well as between increased morning and evening symptom scores and asthma medication use. In addition, associations were noted between total spore concentration and increased morning PEFR and decreased morning and evening symptom scores. The inverse associations found with mold spore concentrations were not consistent with the results of other studies; however, the associations between ozone and pollen concentration were consistent with previous studies. When results were stratified by a number of independent risk factors, no differences were noted relative to allergic status or presence of dampness or flooding in the home; however, the associations with outdoor ozone and pollens were seen mainly among participants with low levels of exposure to indoor bioaerosols (< 1,800 spores/m3) or with no environmental tobacco smoke exposure.