Associations between air pollution and peak expiratory flow among patients with persistent asthma

The impact of the air pollution on health in New York City

New York City is attempting to find a solution to an issue that many states and cities face: how to minimize air pollution so that it has fewer negative impacts on human health. Despite having the highest population in the United States (US), New York City typically has reasonably clean air. As the City and State of New York have worked to reduce emissions from local and regional sources, the air quality in New York City has improved during the past few decades. Despite these advancements, air pollution still poses a severe hazard to the health of everyone living in New York's environment. Various diseases including respiratory, circulatory, neurological, gastrointestinal, and urinary illnesses, which can be fatal, are intimately associated with air pollution. This review article will concentrate on how air pollution affects respiratory diseases such as asthma in children. In addition to analyzing the severe effects of air pollution on the vulnerable population, this review article will highlight the health repercussions of air pollution on New York City and its residents. furthermore, we argue for potential ideas and discoveries while also putting up a policy option to lower air pollution.

The effect of acute outdoor air pollution on peak expiratory flow in individuals with asthma: A systematic review and meta-analysis

OBJECTIVES

Acute exposures to outdoor air pollution have been shown to reduce lung function in children with asthma, but the effect on adults with asthma has not been established in a meta-analysis. The objective of this study was to conduct a systematic literature review and meta-analysis of studies that assessed the relationship of outdoor air pollution and peak expiratory flow (PEF) in adults with asthma.

METHODS

Studies that contained data on outdoor air pollution levels (PM_10, PM_2.5, or NO₂) and PEF in adults with asthma were eligible for inclusion. Effect estimates were quantified for each air pollution measure using random effects models. Heterogeneity was investigated with the Q-test and I² statistics. Meta-regression and subgroup analyses were conducted to determine differences in effect by air pollution measures and the inclusion of smokers.

RESULTS

A total of 22 effect estimates from 15 studies were included in this review. A 10 μg/m³ increase in acute PM₁₀ exposure was associated with a -0.19 L/min (95% CI: 0.30, -0.09) change in PEF. For both PM₁₀ and PM_2.5, the inclusion of current smokers was a significant source of heterogeneity among studies (meta-regression: p = 0.04 and p = 0.03). Among studies that only included non-smokers, a 10 μg/m³ increase in acute exposure to PM₁₀ and PM_2.5 was associated with changes in PEF of -0.25 L/min (95% CI: 0.38, -0.13) and -1.02 L/min (95% CI: 1.79, -0.24), respectively.

CONCLUSIONS

This study provides evidence that acute increases in PM₁₀ and PM_2.5 levels are associated with decreases in PEF in adults with asthma, particularly among non-smokers.

Traffic related air pollution and development and persistence of asthma and low lung function

BACKGROUND AND AIMS

Traffic Related Air Pollution (TRAP) exposure is known to exacerbate existing respiratory diseases. We investigated longer term effects of TRAP exposure for individuals with or without existing asthma, and with or without lower lung function.

METHODS

Associations between TRAP exposure and asthma (n = 689) and lung function (n = 599) were investigated in the prospective Tasmanian Longitudinal Health Study (TAHS). TRAP exposure at age 45 years was measured using two methods based on residential address: mean annual NO₂ exposure; and distance to nearest major road. Adjusted multinomial logistic regression was used to model the association between exposure to TRAP at 45 years and changes in asthma and lung function, using three follow ups of TAHS (45, 50 and 53 years).

RESULTS

For those who never had asthma by 45, living <200 m from a major road was associated with increased odds of new asthma that persisted from 50 to 53 years (adjusted Odds Ratio [aOR] 5.20; 95% CI 1.07, 25.4). Asthmatic participants at 45 had an increased risk of persistent asthma up to 53 years if they were living <200 m from a major road, compared with asthmatic participants living >200 m from a major road (aOR = 5.21; 95% CI 1.54, 17.6).

CONCLUSION

For middle aged adults, living <200 m for a major road (a marker of TRAP exposure) influences both the development and persistence of asthma. These findings have public health implications for asthma prevention strategies in primary and secondary settings.

Acute effects of air pollutants on pulmonary function among students: a panel study in an isolated island

Background

Many epidemiological studies on the health effects of air pollutants have been carried out in regions with major sources such as factories and automobiles. However, the health effects of air pollutants in regions without major sources remain unclear. This study investigated the acute effects of ambient air pollution on pulmonary function among healthy students in an isolated island without major artificial sources of air pollutants.

Methods

A panel study was conducted of 43 healthy subjects who attended a school in an isolated island in the Seto Inland Sea, Japan. We measured the forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) every morning for about 1 month in May 2014. Ambient concentrations of particulate matter ≤ 2.5 μm in diameter (PM_2.5), particulate matter between 2.5 and 10 μm in diameter (PM_10-2.5), black carbon (BC), ozone (O₃), and nitrogen dioxide (NO₂) were measured. The associations between the concentrations of air pollutants and pulmonary function were analyzed using mixed-effects models.

Results

A decrease in FEV₁ was significantly associated with BC concentrations (−27.28 mL [95%confidence interval (CI):−54.10,−0.46] for an interquartile range (IQR) increase of 0.23 μg/m³). The decrease in PEF was significantly associated with indoor O₃ concentrations (−8.03 L/min [95% CI:−13.02,−3.03] for an IQR increase of 11 ppb). Among subjects with a history of allergy, an increase in PM_2.5 concentrations was significantly associated with low FEV₁. In subjects with a history of asthma, an inverse association between the indoor O₃ concentration and pulmonary function was observed.

Conclusions

Our results demonstrate that increases in BC and O₃ concentrations have acute effects on the pulmonary function among students in an isolated island without major artificial sources of air pollutants.

Electronic supplementary material

The online version of this article (doi:10.1186/s12199-017-0646-3) contains supplementary material, which is available to authorized users.

Acute respiratory response to traffic-related air pollution during physical activity performance

BACKGROUND

Physical activity (PA) has beneficial, whereas exposure to traffic related air pollution (TRAP) has adverse, respiratory effects. Few studies, however, have examined if the acute effects of TRAP upon respiratory outcomes are modified depending on the level of PA.

OBJECTIVES

The aim of our study was to disentangle acute effects of TRAP and PA upon respiratory outcomes and assess the impact of participants TRAP pre-exposure.

METHODS

We conducted a real-world crossover study with repeated measures of 30 healthy adults. Participants completed four 2-h exposure scenarios that included either rest or intermittent exercise in high- and low-traffic environments. Measures of respiratory function were collected at three time points. Pre-exposure to TRAP was ascertained from land-use-modeled address-attributed values. Mixed-effects models were used to estimate the impact of TRAP and PA on respiratory measures as well as potential effect modifications.

RESULTS

We found that PA was associated with a statistically significant increases of FEV₁ (48.5mL, p=0.02), FEV₁/FVC (0.64%, p=0.005) and FEF_25-75% (97.8mL, p=0.02). An increase in exposure to one unit (1μg/m³) of PM_coarse was associated with a decrease in FEV₁ (-1.31mL, p=0.02) and FVC (-1.71mL, p=0.01), respectively. On the other hand, for an otherwise equivalent exposure an increase of PA by one unit (1%Heart rate max) was found to reduce the immediate negative effects of particulate matter (PM) upon PEF (PM_2.5, 0.02L/min, p=0.047; PM₁₀, 0.02L/min p=0.02; PM_coarse, 0.03L/min, p=0.02) and the several hours delayed negative effects of PM upon FVC (PM_coarse, 0.11mL, p=0.02). The negative impact of exposure to TRAP constituents on FEV₁/FVC and PEF was attenuated in those participants with higher TRAP pre-exposure levels.

CONCLUSIONS

Our results suggest that associations between various pollutant exposures and respiratory measures are modified by the level of PA during exposure and TRAP pre-exposure of participants.

[Seasonality in asthma: Impact and treatments]

The role of seasons should be taken into account in the management of asthma. The environment varies between seasons and it is well documented that asthma is modulated by environment. Viruses cause asthma exacerbations peak, in winter, in adults while the peak is present in September in children. Allergens are probably a less powerful source of asthma exacerbation than viruses but pollen involvement in spring and summer and dust mites in autumn are indisputable. Air pollutants, present in summer during the hottest periods, are also highly involved in asthma exacerbations. Indoor air pollution, in winter, is also implicated in asthma disease. All these environmental factors are synergistic and increase the risk of asthma exacerbation. Therapies should be adapted to each season depending on environmental factors potentially involved in the asthma disease.

Effect of Personal Exposure to PM2.5 on Respiratory Health in a Mexican Panel of Patients with COPD

Background: Air pollution is a problem, especially in developing countries. We examined the association between personal exposure to particulate matter with an aerodynamic diameter less than 2.5 µm (PM_2.5) on respiratory health in a group of adults with chronic obstructive pulmonary disease (COPD). Methods: All participants resided in Mexico City and during follow-up, personal exposure to PM_2.5, respiratory symptoms, medications, and daily activity were registered daily. Peak expiratory flow (PEF) was measured twice daily, from February through December, 2000, in 29 adults with moderate, severe, and very severe COPD. PEF changes were estimated for each 10 µg/m³ increment of PM_2.5, adjustment for severity of COPD, minimum temperature, and day of the sampling. Results: For a 10-µg/m³ increase in the daily average of a two-day personal exposure to PM_2.5, there was a significant 33% increase in cough (95% CI, range, 5‒69%), and 23% in phlegm (95% CI, range, 2‒54%), a reduction of the PEF average in the morning of −1.4 L/min. (95% CI , range, −2.8 to −0.04), and at night of −3.0 L/min (95% CI, range, −5.7 to −0.3), respectively. Conclusions: Exposure to PM_2.5 was associated with reductions in PEF and increased respiratory symptoms in adults with COPD. The PEF reduction was observed both at morning and at night.

Increased Levels of 8-Isoprostane in EBC of NO2-Exposed Rats

Several epidemiological studies have shown the impact on respiratory health of pollution of nitrogen dioxide (NO2), particulate matter (PM10), and ozone (O3) as an environmental mixture. However, the influence of individual components of airborne pollutants is less well known. Our study examined the cumulative effects of a single pollutant, NO2, on sensitized rats by measurement of isoprostane release in exhaled breath condensate (EBC). Three groups of six rats were used: (1) controls (only exposed to air), (2) sensitized and challenged by ovalbumin and exposed to air, and (3) sensitized, challenged by ovalbumin, and exposed to NO(2). There was no marked change in 8-isoprostane levels in EBC of sensitized rats, whereas a significant increase of 8-isoprostane was found in rats sensitized and exposed to NO2. Data indicate effect of exposure to NO2 is evident as increased 8-isoprostane levels in EBC, a relevant marker for assessment of pulmonary inflammation or oxidant stress and conventionally found in EBC of asthmatic subjects.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children

OBJECTIVES

Increased air pollutant concentrations have been linked to several asthma-related outcomes in children, including respiratory symptoms, medication use, and hospital visits. However, few studies have examined effects of ultrafine particles in a pediatric population. Our primary objective was to examine the effects of ambient concentrations of ultrafine particles on asthma exacerbation among urban children and determine whether consistent treatment with inhaled corticosteroids could attenuate these effects. We also explored the relationship between asthma exacerbation and ambient concentrations of accumulation mode particles, fine particles (≤2.5 micrograms [μm]; PM2.5), carbon monoxide, sulfur dioxide, and ozone. We hypothesized that increased 1-7 day concentrations of ultrafine particles and other pollutants would be associated with increases in the relative odds of an asthma exacerbation, but that this increase in risk would be attenuated among children receiving school-based corticosteroid therapy.

METHODS

We conducted a pilot study using data from 3 to 10 year-old children participating in the School-Based Asthma Therapy trial. Using a time-stratified case-crossover design and conditional logistic regression, we estimated the relative odds of a pediatric asthma visit treated with prednisone (n=96 visits among 74 children) associated with increased pollutant concentrations in the previous 7 days. We re-ran these analyses separately for children receiving medications through the school-based intervention and children in a usual care control group.

RESULTS

Interquartile range increases in ultrafine particles and carbon monoxide concentrations in the previous 7 days were associated with increases in the relative odds of a pediatric asthma visit, with the largest increases observed for 4-day mean ultrafine particles (interquartile range=2088p/cm(3); OR=1.27; 95% CI=0.90-1.79) and 7-day mean carbon monoxide (interquartile range=0.17ppm; OR=1.63; 95% CI=1.03-2.59). Relative odds estimates were larger among children receiving school-based inhaled corticosteroid treatment. We observed no such associations with accumulation mode particles, black carbon, fine particles (≤2.5μm), or sulfur dioxide. Ozone concentrations were inversely associated with the relative odds of a pediatric asthma visit.

CONCLUSIONS

These findings suggest a response to markers of traffic pollution among urban asthmatic children. Effects were strongest among children receiving preventive medications through school, suggesting that this group of children was particularly sensitive to environmental triggers. Medication adherence alone may be insufficient to protect the most vulnerable from environmental asthma triggers. However, further research is necessary to confirm this finding.

Acute effects of air pollution on peak expiratory flow rates and symptoms among asthmatic patients in Chiang Mai, Thailand

The open burnings and forest fires have been recognized as the major sources of severe air pollution in the upper north of Thailand; however, there have been no clear evidences to show the associations between the air pollution and health effects in the area. We assessed the effects of air pollutants on the peak expiratory flow rates (PEFR) and symptoms in asthmatics. A cohort of 121 asthmatics was followed daily, for 306 days, for their PEFR and asthma symptoms. The daily air pollutants, including particulate matter with aerodynamic diameter <2.5 μm, particulate matter with aerodynamic diameter <10 μm (PM(10)), carbon monoxide, ozone, nitrogen dioxide (NO(2)), and sulfur dioxide (SO(2)), and the meteorological parameters, including pressure, temperature, relative humidity, rain quantity, and sunshine duration, were monitored. The PEFRs were fitted with general linear mixed models. The asthma symptoms were analyzed with the generalized estimating equations. There were positive associations of NO(2) with morning PEFR, with a coefficient of 0.06 [95% confidence interval (CI), 0.00-0.12]; of SO(2) with evening PEFR [with a range of coefficients of 0.88-1.00 (95% CI, 0.31-1.54)] and daily average PEFR [with a coefficient of 0.47 (95% CI, 0.00-0.94)]; of PM(10) with evening PEFR, with a coefficient of 0.02 (95% CI, 0.00-0.04). There was also negative association of PM(10) with ΔPEFR, with a coefficient of -0.01 (95% CI, -0.01 to -0.00). No pollutants were related to asthma symptoms. More studies are needed, particularly at low dose in adult asthmatics, to validate our findings.

Acute effects of walking environment and GSTM1 variants in children with asthma

BACKGROUND

Exercise in air polluted by traffic emissions may aggravate airway inflammation in children with asthma, particularly those who produce decreased glutathione-S transferase (GST) as a result of GSTM1 gene deletion.

OBJECTIVES

This pilot crossover study investigated whether children with asthma experience more airway changes when exercising outdoors near roadways than when exercising indoors. It also examined differences in risk between children with and without GSTM1 deletion.

METHOD

Children between the ages of 5 and 12 years were assigned to groups and walked daily for 1 week in each exercise condition. Airway inflammation indicated by exhaled nitric oxide (eNO) and pulmonary functions measured as forced expiratory volume in 1 s (FEV1) and mid-expiratory flow rate were measured at baseline and at three intervals during the walking program. Independent variables of interest included walking condition (place), time of walking, genotype, and particulate matter (PM) exposure.

RESULTS

A linear mixed models approach was used to investigate the contributions of targeted variables to respiratory outcomes. Results indicated that walking location and ambient level of ultrafine particulates during walking influenced function of small airways. Absence of one or both alleles for the GSTM1 gene did not influence airway function acutely.

DISCUSSION

Mid-expiratory flow (FEF(25-75)) may be more informative than FEV1 in studies of acute lung function changes in children with asthma. Further study of the effects of varied environmental conditions on lower airway function of children is needed to optimize exercise experiences for urban children with asthma.

Air pollution-related peak expiratory flow rates among asthmatic children in Chiang Mai, Thailand

The severity of air pollution in northern Thailand has long been recognized; in spite of that there have been no epidemiological studies regarding the associations between the air pollution and health effects in the area. The authors followed a cohort of 31 asthmatic children (4-11 years of age) residing in Muang district, Chiang Mai, Thailand, from 29 August 2005 to 30 June 2006, for 306 days. The daily air pollutants, including particulate matter with aerodynamic diameter < 2.5 microm, particulate matter with aerodynamic diameter < 10 microm, carbon monoxide, ozone (O(3)), nitrogen dioxide, and sulfur dioxide (SO(2)), and the meteorological parameters, including pressure, temperature, relative humidity, rain quantity, and sunshine duration, were recorded. The peak expiratory flow rates (PEFRs) were fitted with pollutants and meteorological covariates using general linear mixed models to account for random effects and autocorrelation. The authors found that there were inverse associations of SO(2) and evening PEFR, with a coefficient of -2.12 (95% confidence interval (CI) = -3.22 to -0.28); of SO(2) and daily percent deviation of PEFR, with a coefficient of -0.73 (95% CI = -1.33 to -0.12); and of O(3) combining with SO(2) and daily average PEFR, with a coefficient of -0.16 (95% CI = -0.31 to -0.00) and -1.60 (95% CI = -3.10 to -0.11), respectively. The associations of O(3) and SO(2) with PEFR were found even when SO(2) concentrations never exceeded the standard level.