Lung Function Growth In Children Research Articles

Exposure to PM2.5 and Lung Function Growth in Pre- and Early-Adolescent Schoolchildren: A Longitudinal Study Involving Repeated Lung Function Measurements in Japan.

RationaleEpidemiological evidence indicates that ambient exposure to particulate matter ⩽2.5 μm in aerodynamic diameter (PM2.5) has adverse effects on lung function growth in children, but it is not actually clear whether exposure to low-level PM2.5 results in long-term decrements in lung function growth in pre- to early-adolescent schoolchildren.ObjectivesTo examine long-term effects of PM2.5 within the 4-year average concentration range of 10–19 μg/m3 on lung function growth with repeated measurements of lung function tests.MethodsLongitudinal analysis of 6,233 lung function measurements in 1,466 participants aged 8–12 years from 16 school communities in 10 cities around Japan, covering a broad area of the country to represent concentration ranges of PM2.5, was done with a multilevel linear regression model. Forced expiratory volume in 1 second, forced vital capacity (FVC), and maximal expiratory flow at 50% of FVC were used as lung function indicators to examine the effects of 10-μg/m3 increases in the PM2.5 concentration on relative growth per each 10-cm increase in height.ResultsThe overall annual mean PM2.5 level was 13.5 μg/m3 (range, 10.4–19.0 μg/m3). We found no association between any of the lung function growth indicators and increases in PM2.5 levels in children of either sex, even after controlling for potential confounders. Analysis with two-pollutant models with O3 or NO2 did not change the null results.ConclusionsThis nationwide longitudinal study suggests that concurrent, long-term exposure to PM2.5 at concentrations ranging from 10.4 to 19.0 μg/m3 has little effect on lung function growth in preadolescent boys or pre- to early-adolescent girls.

Exposure to green and blue areas and children's lung function growth: results from the RESPOZE study

Exposure to green and blue areas and children's lung function growth: results from the RESPOZE study

Systematic Review of Ozone Effects on Human Lung Function, 2013 Through 2020

BackgroundOzone effects on lung function are particularly important to understand in the context of the air pollution-health outcomes epidemiologic literature, given the complex relationships between ozone and other air pollutants with known lung function effects.Research QuestionWhat has been learned about the association between ozone exposures and lung function from epidemiology studies published from 2013 through 2020?Study Design and MethodsOn March 18, 2018, and September 8, 2020, PubMed was searched using the terms health AND ozone, filtering to articles in English and about humans, from 2013 or later. An additional focused review searching for ozone AND (lung function OR FEV1OR FVC) was performed June 26, 2021. Articles were selected for this review if they reported a specific relationship between a lung function outcome and ozone exposure.ResultsOf 3,271 articles screened, 53 ultimately met criteria for inclusion. A systematic review with assessment of potential for bias was conducted, but a meta-analysis was not carried out because of differences in exposure duration and outcome quantification. Consistent evidence exists of small decreases in children’s lung function, even associated with very low levels of short-term ozone exposure. The effects on adult lung function from exposure to low-level, short-term ozone are less clear, although ozone-associated decrements may occur in the elderly. Finally, long-term ozone exposure decreases both lung function and lung function growth in children, although few new studies have examined long-term ozone and lung function in adults.InterpretationMuch of this literature involves concentrations below the current US Environmental Protection Agency’s National Ambient Air Quality Standard of 70 parts per billion over an 8-h averaging time, suggesting that this current standard may not protect children adequately from ozone-related decrements in lung function.

Blood eosinophils associate with reduced lung function growth in adolescent asthmatics.

Background and ObjectiveSome children with asthma have low lung growth, putting them at increased risk for COPD later in life. However, it is currently not clear who will experience this adverse growth pattern. We therefore investigated the predictive role of blood eosinophils as a type 2 inflammation marker in lung growth, focusing on the presence and severity of asthma.MethodsWe investigated blood eosinophils and lung function growth (percentage of predicted values) using linear mixed models in children and adolescents from two longitudinal cohorts. One cohort was hospital‐based and consisted of asthmatic children at their first outpatient clinic visit after referral by the general practitioner (n = 133, mean age 9.8), while the second was a general population‐based birth cohort (PIAMA, asthma n = 52 and non‐asthma n = 433, mean age 8.1). The hospital‐based cohort had not been treated with inhaled corticosteroids (ICS) before referral.ResultsSubjects in the hospital‐based asthma cohort had more severe asthma compared with the asthmatic subjects in the population‐based cohort, defined by lower lung function levels and a higher prevalence of bronchial hyper‐responsiveness. In the asthma cohort, higher blood eosinophil numbers were associated with less growth in FEV1 (estimated change in lung function per 1 unit increase in ln blood eosinophils (B): −0.66%/year (95% confidence interval (CI): −1.11 to −0.20, p < .01)) and FVC (B: −0.40%/year (95% CI: −0.75 to −0.05), p = .025)) during follow‐up in adolescence (min 7, max 17 years). These associations were not observed in the general population‐based birth cohort, regardless of asthma status during follow‐up (age 8–16).Conclusions and Clinical RelevanceBlood eosinophil counts in children with asthma not treated with ICS at referral were predictive of lower growth in FEV1 and FVC during follow‐up in adolescence. Our findings indicate that this association is dependent on the degree of asthma severity. Future studies should address whether anti‐eosinophilic treatments preserve lung function growth in children with asthma.

Air pollution and children's lung function growth in Hong Kong

Introduction: Few studies in Asian setting capture the relationship between long-term exposure to air pollution and children’s lung function growth. We therefore investigated the impact from particulate matters (PM2.5, PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3) on lung function growth in Hong Kong children. Methods: This is a cross-sectional analysis based on our longitudinal school cohort study on air pollution and children’s lung function, starting from 2012. Data were collected annually from standard spirometry tests, body examinations and questionnaires filled by parents. The monthly mean concentration of air pollutants during the study period was averaged to estimate the exposure. Lung function growth rates were calculated from differences scaled to time for forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1), expiratory peak flow (PEF) and maximal mid-expiratory flow (MMEF). A two-level linear regression model was used for data analysis. Results: 503 boys and 531 girls from 12 schools participated two rounds were included in the present analysis. Boys had larger growth rate in FEV1, FVC and MMEF, but smaller in PEF; significant gender difference was only observed for FVC (p=0.0010) after adjusted. The higher PM10 and PM2.5 was significantly associated with lower growth rates in PEF (b=-0.044, p=0.0243) and MMEF (b=-0.043, p=0.0015) after adjusting for a wide range of confounders. Such negative association also demonstrated for SO2 but without significance. Positive but non-significant associations with lung function growth for four parameters were observed for O3. Pollutant concentrations were highly correlated (p&lt;0.01) except for that between NO2 and SO2 (r=0.024, p=0.43), while O3 has significant negative correlations with all other pollutants. Conclusion: The results suggested PM2.5 and PM10 have adverse effects on children’s lung function growth in Chinese school children.

Association of Improved Air Quality with Lung Development in Children

BackgroundAir-pollution levels have been trending downward progressively over the past several decades in southern California, as a result of the implementation of air quality–control policies. We assessed whether long-term reductions in pollution were associated with improvements in respiratory health among children.MethodsAs part of the Children’s Health Study, we measured lung function annually in 2120 children from three separate cohorts corresponding to three separate calendar periods: 1994–1998, 1997–2001, and 2007–2011. Mean ages of the children within each cohort were 11 years at the beginning of the period and 15 years at the end. Linear-regression models were used to examine the relationship between declining pollution levels over time and lung-function development from 11 to 15 years of age, measured as the increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) during that period (referred to as 4-year growth in FEV1 and FVC).ResultsOver the 13 years spanned by the three cohorts, improvements in 4-year growth of both FEV1 and FVC were associated with declining levels of nitrogen dioxide (P<0.001 for FEV1 and FVC) and of particulate matter with an aerodynamic diameter of less than 2.5 μm (P= 0.008 for FEV1 and P<0.001 for FVC) and less than 10 μm (P<0.001 for FEV1 and FVC). These associations persisted after adjustment for several potential confounders. Significant improvements in lung-function development were observed in both boys and girls and in children with asthma and children without asthma. The proportions of children with clinically low FEV1 (defined as <80% of the predicted value) at 15 years of age declined significantly, from 7.9% to 6.3% to 3.6% across the three periods, as the air quality improved (P=0.001).ConclusionsWe found that long-term improvements in air quality were associated with statistically and clinically significant positive effects on lung-function growth in children. (Funded by the Health Effects Institute and others.)

Association between long-term exposure to traffic-related air pollution and lung function: the European Study of Cohorts for Air Pollution Effects (ESCAPE)

Background. Acute air pollution effects on lung function are well established and evidence is also strong for long-term effects on lung function growth in children. The chronic impact of ambient air pollutants on lung function in adults remains poorly understood. Aims. We investigated the association of residential traffic-related air pollution with level and decline of lung function in the context of five European cohorts of adults (ECRHS, EGEA, NSHD, SALIA, SAPALDIA). Methods. Residential exposure to nitrogen oxides (NO2, NOx) and particulate matter (PM) was obtained from standardized measurement protocols and land use regression models. Traffic load at the road nearest to participants’ home and on major roads within a 100 meter buffer was assessed. Study-specific analyses were performed with random effects linear regression adjusting for gender, age, height, BMI, education, smoking status. The level and annual decline in the spirometric parameters FEV1, FVC, and FEV1/FVC were considered as outcomes. Cohort-specific results were combined using random-effects meta-analysis. Results. Based on lung function data from 7,613 subjects undergoing spirometry twice over a period of 11 years on average, we observed that a 10 µg/m3 increase in NO2 exposure was associated with lower levels of FEV1 (-13.8 mL (95%CI: -25.82, -2.14)) and FVC (-14.93 mL (-28.73,-1.13)). A higher traffic load at the home address also went along with lower levels of FEV1 and FEV1/FVC. The observed associations were particularly observed in women and generally stronger in participants reporting use of respiratory medication. None of the lung function parameters was related to PM exposure. Conclusions. In this analysis of adults mostly living in urban environments, we observed a lung function decline with increased nitrogen oxide or traffic load exposure. The reported gender differences stimulate research into the underlying mechanisms.

Physical Activity and Lung Function Growth in a Cohort of Chinese School Children: A Prospective Study

Backgrounds/objectivesEvidence on the association between physical activity and lung function in children is sparse. The aim of this study was to evaluate children’s lung function growth in relation to their physical activity level in Chinese children.MethodsA total of 1713 school children aged 9.89±0.86 years who were asthma-free at baseline were followed-up for 18 months from 2006 to 2008 in Guangzhou, China. Information on physical activity and other socio-economic status were obtained from self-administered questionnaires. Lung function tests were performed with a standard procedure.ResultsAt the baseline survey, physically active girls had significantly higher forced vital capacity (FVC) than inactive girls (1.79 l vs. 1.75 l, p<0.05). The growth rates for lung function indices were significantly higher for girls who were physically active at either or both follow-up surveys than those inactive at both surveys during the follow-up period forced expiratory flows at 25% (FEF25) difference per year (dpy) (0.20 l/s vs. 0.15 l/s), forced expiratory flows at 75% (FEF75) dpy (0.57 l/s vs. 0.45 l/s) and forced expiratory flows between 25% and 75% (FEF25-75) dpy (0.36 l/s vs. 0.28 l/s) (all p<0.05).ConclusionsPhysical activity is positively associated with lung function growth among Chinese school-aged girls. Promotion of physical activity among children is of great importance.

Indoor air pollution and lung function growth among children in four Chinese cities

Ambient air pollution has been associated with decreased growth in lung function among children; but little is known about the impact of indoor air pollution. We examined relationships between indoor air pollution metrics and lung function growth, among children (n = 3273) aged 6-13 years living in four Chinese cities. Lung function parameters (FVC and FEV(1) ) were measured twice a year. Questionnaires were used to determine home coal burning and ventilation practices. Generalized estimating equations were used to examine associations. Use of coal as a household fuel was associated with 16.5 ml/year lower (33%, P < 0.001) and 20.5 ml/year lower (39%, P < 0.001) growth in children's FEV(1) and FVC, respectively. FEV(1) growth was 10.2 ml/year higher (20%, P = 0.009), and FVC growth was 17.0 ml/year higher (33%, P < 0.001) among children who lived in houses with the presence of a ventilation device. Among children living in houses where coal was used as a fuel and no ventilation devices were present, adjusted FVC and FEV(1) growth, respectively, were 37% and 61% that of the average growth per year in the full cohort. This suggests that household coal use may cause deficits in lung function growth, while using ventilation devices may be protective of lung development. Nearly 3.4 billion people use solid fuels in homes for cooking and/or heating. We report the following findings from a longitudinal study: (i) household coal use is significantly associated with reduction in children's lung function growth and (ii) the use of household ventilation devices is significantly associated with higher lung function growth, particularly among children living in households where coal is used as a fuel. These findings not only provide evidence that indoor coal use impairs children's lung development but also point to the importance of improving ventilation conditions in reducing harmful effects of indoor air pollution sources.

Psychological Stress: A Social Pollutant That May Enhance Environmental Risk

Evidence suggests an etiologic role for both physical toxins (1) and social determinants (2, 3) in the evolution and trajectory of children's lung function growth and development. Traffic-related air pollution is a global public health problem (4), and children may be most vulnerable (5). The adverse effects of air pollution on respiratory development in children have been extensively documented (6). In parallel, a growing body of literature suggests that psychological factors influence the programming of neuroendocrine, autonomic, and immune inflammatory processes implicated in respiratory development, suggesting they too play a role in lung development, although studies in humans remain scarce (2, 7).

Genetic Variation in the Glutathione Synthesis Pathway, Air Pollution, and Children's Lung Function Growth

Glutathione plays an important role in antioxidant and inflammatory processes in the lung. Alterations in glutathione metabolism are a central feature of several chronic lung diseases. To determine whether sequence variation in genes in the glutathione synthesis pathway alters susceptibility to air pollution effects on lung function. In this prospective study, 14,821 lung function measurements were taken on 2,106 children from 12 Southern California cities. Tagging single-nucleotide polymorphisms in glutathione metabolism pathway genes GSS, GSR, GCLM, and GCLC were genotyped by GoldenGate assay (Illumina, San Diego, CA). Mixed regression models were used to determine whether particular haplotypes were associated with FEV(1), maximal mid-expiratory flow rate, and FVC and whether any of the genetic associations varied with levels of exposure to air pollutants. We found that variation in the GSS locus was associated with differences in susceptibility of children for lung function growth deficits associated with NO(2), PM(10), PM(2.5), elemental carbon, organic carbon, and O(3). The negative effects of air pollutants were largely observed within participants who had a particular GSS haplotype. The effects ranged from -124.2 to -149.1 for FEV(1), from -92.9 to -126.7 for FVC, and from -193.9 to -277.9 for maximal mid-expiratory flow rate for all pollutants except O(3), which showed a larger decrease in lung function in children without this haplotype. Variation in GSS was associated with differences in susceptibility to adverse effects of pollutants on lung function growth.

Effect of Exposure to Traffic on Lung Development From 10 to 18 Years of Age: A Cohort Study

Gauderman WJ, Vora H, McConnell R, et al. Lancet. 2007;369(9561):571–577 PURPOSE OF THE STUDY. To investigate the association between residential exposure to traffic and 8-year lung-function growth in children. STUDY POPULATION. Two cohorts of 4th-grade children with a mean age of 10 years were recruited from 12 southern California communities and were followed for 8 years. All eligible children were invited, and 3677 (82%) participated; 1445 children were followed for the full 8 years. METHODS. Yearly pulmonary-function data were obtained for each participant by trained technicians using standard equipment. Indicators of residential exposure to traffic were determined by proximity of the child's residence to the nearest freeway or major nonfreeway road and by dispersion-model estimates including residence distance to roadways, vehicle counts, vehicle emission rates, and meteorological conditions. Regional air pollution was monitored at a central site within each community. Baseline questionnaires were completed regarding demographic data, doctor-diagnosed asthma, in utero exposure to maternal cigarette smoke, and household exposure to air pollutants. Yearly questionnaires updated information on asthma and personal or environmental tobacco-smoke exposure. Regression models also included adjustment for height, BMI, and recent exercise and respiratory illness. RESULTS. Children living &amp;lt;500 m from a freeway had reduced 8-year lung-function growth compared with children living &amp;gt;1500 m from a freeway (forced expiratory volume in 1 second deficit: −81 mL [95% confidence interval: −143 to −18]). This effect was slightly greater after adjustment for socioeconomic status and indoor air pollution and after omission of children who changed residence within the study area and continued to participate. Reduced lung-function growth was independently associated with freeway distance and regional air pollutant levels, including nitrogen dioxide, acid vapor, elemental carbon, and particulate matter with aerodynamic diameters of &amp;lt;10 and 2.5 μm. At 18 years of age, lung function was decreased among children who lived &amp;lt;500 m from a freeway (forced expiratory volume in 1 second: 97.0% [95% confidence interval: 94.6 to 99.4]; P = .013). CONCLUSIONS. The adverse effects of local exposure to freeway traffic on children's lung development are independent of regional air quality and may result in lung-function deficits later in life. REVIEWER COMMENTS. This well-designed study suggests a causal association between residential traffic exposure and adverse effects on children's lung function, especially for children living closest to freeways. A number of other recent cohort studies in children have also suggested associations between traffic-pollution exposure and asthma, respiratory symptoms, and allergic sensitization. Future studies are needed to determine minimum safe distances from major roadways for homes and schools and to continue evaluation of the guidelines restricting levels of airborne pollutants. Concerns regarding the effects of traffic pollutants on children's respiratory health should continue to be a focus of asthma research.

Lung Function Growth in Children with Long-Term Exposure to Air Pollutants in Mexico City

Although short-term exposure to air pollution has been associated with acute, reversible lung function decrements, the impact of long-term exposure has not been well established. To evaluate the association between long-term exposure to ozone (O(3)), particulate matter less than 10 mum in diameter (PM(10)), and nitrogen dioxide (NO(2)) and lung function growth in Mexico City schoolchildren. A dynamic cohort of 3,170 children aged 8 years at baseline was followed from April 23, 1996, through May 19, 1999. The children attended 39 randomly selected elementary schools located near 10 air quality monitoring stations and were visited every 6 months. Statistical analyses were performed using general linear mixed models. After adjusting for acute exposure and other potential confounding factors, deficits in FVC and FEV(1) growth over the 3-year follow-up period were significantly associated with exposure to O(3), PM(10), and NO(2). In multipollutant models, an interquartile range (IQR) increase in mean O(3) concentration (IQR, 11.3 ppb) was associated with an annual deficit in FEV(1) of 12 ml in girls and 4 ml in boys, an IQR range (IQR, 36.4 microg/m(3)) increase in PM(10) with an annual deficit in FEV(1) of 11 ml in girls and 15 ml in boys, and an IQR range (IQR, 12.0 ppb) increase in NO(2) with an annual deficit in FEV(1) of 30 ml in girls and 25 ml in boys. We conclude that long-term exposure to O(3), PM(10), and NO(2) is associated with a deficit in FVC and FEV(1) growth among schoolchildren living in Mexico City.

Lung Function Growth in Children with Long-Term Exposure to Air Pollutants in Mexico City

P-056 Introduction: Short-term exposure to air pollutants has been associated with acute reversible lung function decrements; however, long-term exposure has not been well established. We evaluated the association between long-term exposure to air pollutants and lung function growth in children. Methods: We studied a dynamic cohort of 3,181 children ages 8 to 14 living in Mexico City from April 1996, through May 2002. In 1996, this children attended 39 randomly selected elementary schools located near 10 air quality monitors and were visited every six months over 6 years. Statistical analyses were performed using general linear mixed models. Results: Multi-pollutant models shows a 10 ppb increment in mean nitrogen dioxide (NO2) concentration, was associated with a year percentage of predicted FVC deficit of 0.4% (95% CI: 0.6–0.2) and a year percentage of predicted FEV1 deficit of 0.26% (95% CI: 0.45–0.06) a 10 μm increment in mean particle matter <10 μm (PM10) was associated with a deficit of predicted FVC deficit of 0.3% (95% CI: 0.36–0.2), and percentage of predicted FEV1 deficit of 0.3% (95% CI: 0.37–0.2) for girls; and deficits of 0.55% (95% CI: 0.7–0.4), 0.2% (95% CI: 0.4–0.04), 0.22% (95% CI: 0.28–0.15), and 0.25% (95% CI: 0.3–0.17) respectively for boys. Discussion and Conclusions: We conclude that long-term exposure to NO2, and PM10 were associated to a deficit in the percentage of predicted FVC and FEV1 growth among school children residing in Mexico City.

Particulate matter and lung function growth in children: a 3-yr follow-up study in Austrian schoolchildren.

The effects of particulate matter <10 microm in diameter (PM10) and other air pollutants on lung function were assessed in 975 schoolchildren, from eight communities in Lower Austria between 1994-1997. In each community, air pollution data were collected. Spirometry was performed twice a year. PM10 concentration (mean concentration between two subsequent lung-function measures in spring and autumn (summer interval) or between autumn and spring (winter interval)) showed a mean value of 17.36 microg x m(-3) in the summer interval and 21.03 microg m(-3) in the winter interval. A slower increase in the forced expiratory volume in one second (FEV1) and midexpiratory flow between 25 and 75% of the forced vital capacity (MEF25-75) with age in children exposed to higher summer PM10 was observed in the 3-yr study period. After adjusting for potential confounders (sex, atopy, passive smoking, initial height, height difference, site, initial lung function) an increase of summer PM10 by 10 microg x m(-3) was associated with a decrease in FEV1 growth of 84 mL x yr(-1) and 329 mL x s(-1) x yr(-1) for MEF25-75. Nitrogen dioxide and ozone also showed a negative effect on lung-function growth, confirming previous work. The authors concluded that long-term exposure to particulate matter <10 microm in diameter had a significant negative effect on lung-function proxy for the development of large (forced expiratory volume in one second) and small (midexpiratory flow between 25 and 75% of the forced vital capacity) airways, respectively, with strong evidence for a further effect of ozone and nitrogen dioxide on the development of forced vital capacity and forced expiratory volume in one second.

Association between air pollution and lung function growth in southern California children.

Average growth of lung function over a 4-yr period, in three cohorts of southern California children who were in the fourth, seventh, or tenth grade in 1993, was modeled as a function of average exposure to ambient air pollutants. In the fourth-grade cohort, significant deficits in growth of lung function (FEV(1), FVC, maximal midexpiratory flow [MMEF], and FEF(75)) were associated with exposure to particles with aerodynamic diameter less than 10 micrometer (PM(10)), PM(2.5), PM(10)-PM(2.5), NO(2), and inorganic acid vapor (p < 0.05). No significant associations were observed with ozone. The estimated growth rate for children in the most polluted of the communities as compared with the least polluted was predicted to result in a cumulative reduction of 3.4% in FEV(1) and 5.0% in MMEF over the 4-yr study period. The estimated deficits were generally larger for children spending more time outdoors. In the seventh- and tenth-grade cohorts, the estimated pollutant effects were also negative for most lung function measures, but sample sizes were lower in these groups and none achieved statistical significance. The results suggest that significant negative effects on lung function growth in children occur at current ambient concentrations of particles, NO(2), and inorganic acid vapor.

Trees and tracking.

Epidemiologists have used the term 'tracking' to connote an individual's maintenance of relative rank of some longitudinally measured characteristic over a given time span. To assess the extent to which an attribute tracks we have first to summarize individual growth curves, and second to quantify the notion of maintenance of relative rank, both in the face of random error. A sequence of papers appearing in 1981 provided differing methodologies for appraising tracking. Here we take a different approach to tracking by using regression trees for longitudinal data. The above two concerns are simultaneously addressed in that the procedure identifies subgroups, defined in terms of covariates, within which the collection of growth curves is homogeneous. After reviewing the existing approaches to tracking we describe the tree-structured methodology, and present an illustrative example pertaining to lung function growth in children.