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, NO₂, and NO were generally associated with chronic adverse effects on FVC and FEV₁, and subchronic adverse effects mainly on maximal mid-expiratory flow (MMEF) and peak expiratory flow rate. Among girls, only NOx and NO₂ showed subchronic adverse effects on MMEF. Although effect estimates of SO₂, PM₁₀, 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.     

Long-term air pollution exposure and lung function in 15 year-old adolescents living in an urban and rural area in Germany: The GINIplus and LISAplus cohorts

IntroductionThe impact of outdoor air pollution exposure on long-term lung development and potential periods of increased lung susceptibility remain unknown. This study assessed associations between early-life and current residential exposure to air pollution and lung function at 15-years of age in two German birth cohorts.MethodsFifteen year-old participants living in an urban and rural area in Germany underwent spirometry before and after bronchodilation (N = 2266). Annual average (long-term) exposure to nitrogen dioxide (NO₂), particles with aerodynamic diameters less than 2.5 μg/m³ (PM_2.5) mass and less than 10 μg/m³ (PM₁₀) mass, PM_2.5 absorbance and ozone were estimated to each participant's birth-, 10- and 15-year home address using land-use regression and kriging (ozone only) modelling. Associations between lung function variables and long-term pollutant concentrations were assessed using linear regression models adjusted for host and environmental covariates and recent short-term air pollution exposures.ResultsLong-term air pollution concentrations assessed to the birth-, 10- and 15-year home addresses were not associated with lung function variables, before and after bronchodilation, in the complete or study area specific populations. However, several lung function variables were negatively associated with long-term NO₂ concentrations among asthmatics. For example, NO₂ estimated to the 15-year home address was associated with the ratio of forced expiratory volume in one second to forced vital capacity (FEV₁/FVC) and the mean flow rate between 25% and 75% of FVC (−3.5%, 95% confidence interval [−6.0, −1.0] and −297.4 ml/s [−592.6, −2.1] per 5.9 μg/m³ increase in NO₂, respectively). Nearly all effect estimates for the associations between the short-term PM_2.5 mass, PM₁₀ mass and ozone concentrations and the lung function variables were negative in the complete population.ConclusionsEarly-life and current long-term air pollution exposures and lung function at the age of 15 years were not associated in the complete study population. Asthmatics may represent a vulnerable group.     

An epidemiological study of salt miners in diesel and nondiesel mines

A cross-sectional study of 5 NaCl mines and 259 miners addressed the following questions: 1) Is there an association of increased respiratory symptoms, radiographic findings, and reduced pulmonary function with exposure to nitrogen dioxide (NO₂) and/ or respirable particulate (RP) among these miners? 2) Is there increased morbidity of these miners compared to other working populations? Personal samples of NO₂ and respirable particulate for jobs in each mine were used to estimate cumulative exposure. NO₂ is used as a surrogate measure of diesel exposure. Cough was associated with age and smoking, dyspnea with age; neither symptom was associated with exposure (years worked, estimated cumulative NO₂ or RP exposure). Phlegm was associated with age, smoking, and exposure. Reduced pulmonary function (FVC, FEV₁, peak, flow, FEF₅₀, FEF₇₅) showed no association with exposure. There was one case of small rounded and one case of small irregular opacities; pneumoconiosis was not analyzed further. Compared to underground coal miners, above ground coal miners, potash miners, and nonmining workers, the study population after adjustment for age and smoking generally showed no increased prevalence of cough, phlegm, dyspnea, or obstruction (FEV₁/FVC<0.7). Obstruction in younger salt miners and phlegm in older salt miners was elevated compared to nonmining workers. Mean predicted pulmonary function was reduced 2–4% for FEV₁ and FVC, 7–13% for FEF₅₀, and 18–22% for FEF₇₅ below all comparison populations.     

Acute respiratory effects on workers exposed to metalworking fluid aerosols in an automotive transmission plant

Exposure to metalworking fluids has been linked to modest cross-shift reductions in FEV₁ and occupational asthma. To identify responsible agents, we measured personal exposures to thoracic particulate (TP), viable plus nonviable thoracic bacteria (BAC), and vapor phase nicotine (VPN) (as a surrogate for tobacco particulate) among 83 machinists exposed to soluble oils and 46 dry assemblers working in an automotive transmission machining plant using biocides infrequently. The participants completed interviews and performed pre- and postshift spirometry on Monday and Thursday of the same week in each of three rounds of data collection (June 1992, January 1993, June 1993). Generalized estimating equations were used to combine information across rounds in multiple regression models of cross-shift and cross-week changes in forced expiratory volume, I second (FEV₁) and forced vital capacity (FVC). Mean seniority was 19 years among machinists. Mean personal TP levels were 0.41 mg/m³ in machinists and 0.13 mg/m³ in assemblers. Six of the 83 machinists and none of the 46 assemblers experienced a greater than 19% cross-shift decrement in FEV₁ or FVC at least once (p = .07). In regression models using either TP or BAC, among subjects with lower baseline (Monday preshift) FEV₁/FVC ratios, increasing exposure was significantly associated with increasing cross-shift decrements in FEV₁ and FVC in linear models, and with increased likelihood of a 10% or greater cross-shift decrement in FEV₁ or FVC in logistic models. Adjustment of TP for VPN did not affect models significantly. We conclude that clinically important cross-shift decrements in pulmonary function are associated with exposure to metalworking fluid aerosols within a high-seniority population. Am. J. Ind. Med. 31:510–524, 1997. © 1997 Wiley-Liss, Inc.     

Metal dust exposure and lung function deterioration among steel workers: an exposure-response relationship

Background: Metallic dust is a heterogeneous substance with respiratory sensitizing properties. Its long term exposure adversely affected lung function, thus may cause acute or chronic respiratory diseases.

Methods: A cross-sectional study was conducted in a steel factory in Terengganu, Malaysia to assess the metal dust exposure and its relationship to lung function values among 184 workers. Metal dust concentrations values (Co, Cr, and Ni) for each worker were collected using air personal sampling. Lung function values (FEV₁, FVC, and %FEV₁/FVC) were determined using spirometer.

Results: Exposure to cobalt and chromium were 1–3 times higher than permissible exposure limit (PEL) while nickel was not exceeding the PEL. Cumulative of chromium was the predictor to all lung function values (FEV₁, FVC, and %FEV₁/FVC). Frequency of using mask was positively associated with FVC (Adj b = 0.263, P = 0.011) while past respiratory illnesses were negatively associated with %FEV₁/FVC (Adj b = –1.452, P = 0.026). Only few workers (36.4%) were found to wear their masks all times during the working hours.

Conclusions: There was an exposure-response relationship of cumulative metal dust exposure with the deterioration of lung function values. Improvement of control measures as well as proper and efficient use or personal protection equipment while at work could help to protect the respiratory health of workers.     

Epigenetic Influences on Associations between Air Pollutants and Lung Function in Elderly Men: The Normative Aging Study

Background: Few studies have been performed on pulmonary effects of air pollution in the elderly—a vulnerable population with low reserve capacity—and mechanisms and susceptibility factors for potential effects are unclear.Objectives: We evaluated the lag structure of air pollutant associations with lung function and potential effect modification by DNA methylation (< or ≥ median) at 26 individual CpG sites in nine candidate genes in a well-characterized cohort of elderly men.Methods: We measured forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV₁), and blood DNA methylation one to four times between 1999 and 2009 in 776 men from the Normative Aging Study. Air pollution was measured at fixed monitors 4 hr to 28 days before lung function tests. We used linear mixed-effects models to estimate the main effects of air pollutants and effect modification by DNA methylation.Results: An interquartile range (IQR) increase in subchronic exposure (3 to 28 days cumulated), but not in acute exposure (during the previous 4 hr, or the current or previous day), to black carbon, total and nontraffic particles with aerodynamic diameter ≤ 2.5 μm (PM_2.5), carbon monoxide, and nitrogen dioxide was associated with a 1–5% decrease in FVC and FEV₁ (p < 0.05). Slope estimates were greater for FVC than FEV₁, and increased with cumulative exposure. The estimates slopes for air pollutants (28 days cumulated) were higher in participants with low (< median) methylation in TLR2 at position 2 and position 5 and high (≥ median) methylation in GCR.Conclusions: Subchronic exposure to traffic-related pollutants was associated with significantly reduced lung function in the elderly; nontraffic pollutants (particles, ozone) had weaker associations. Epigenetic mechanisms related to inflammation and immunity may influence these associations.Citation: Lepeule J, Bind MAC, Baccarelli AA, Koutrakis P, Tarantini L, Litonjua A, Sparrow D, Vokonas P, Schwartz JD. 2014. Epigenetic influences on associations between air pollutants and lung function in elderly men: the Normative Aging Study. Environ Health Perspect 122:566–572; http://dx.doi.org/10.1289/ehp.1206458     

Pulmonary function in firefighters: A six-year follow-up in the boston fire department

Tests of ventilatory capacity, objective cough, and standardized respiratory questionnaires were used in a prospective study to measure the effect of firefighting on pulmonary function in a cohort of 951 white Boston firefighters between 1970-1976. During the six years of follow-up, the mean annual decrements in forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) were 36 and 29 ml per year, respectively. At the end of the study in 1976, the mean FEV₁ for this group was 98.3% of the level predicted for healthy nonsmoking adults, while the FVC was 97.8%. Current cigarette smoking was associated with an increased prevalence of bronchitis, a loose cough, reduced levels of FEV₁ and FVC, and increased longitudinal changes in FEV₁ and FVC. The longitudinal changes and current levels of FEV₁ and FVC were not correlated with any index of firefighting exposure in active firefighters. Increased use of protective respiratory apparatus and previously described selection effects within the Boston Fire Department appear to be protecting this group of firefighters from long-term effects of smoke exposure as measured by these techniques.     

Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study

Background

Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies.

Objectives

To compare effect estimates for traffic-related air pollution exposure and preeclampsia, preterm birth (gestational age less than 37 weeks), and very preterm birth (gestational age less than 30 weeks) based on four commonly used exposure assessment methods.

Methods

We identified 81,186 singleton births during 1997–2006 at four hospitals in Los Angeles and Orange Counties, California. Exposures were assigned to individual subjects based on residential address at delivery using the nearest ambient monitoring station data [carbon monoxide (CO), nitrogen dioxide (NO₂), nitric oxide (NO), nitrogen oxides (NO_x), ozone (O₃), and particulate matter less than 2.5 (PM_2.5) or less than 10 (PM₁₀) μm in aerodynamic diameter], both unadjusted and temporally adjusted land-use regression (LUR) model estimates (NO, NO₂, and NO_x), CALINE4 line-source air dispersion model estimates (NO_x and PM_2.5), and a simple traffic-density measure. We employed unconditional logistic regression to analyze preeclampsia in our birth cohort, while for gestational age-matched risk sets with preterm and very preterm birth we employed conditional logistic regression.

Results

We observed elevated risks for preeclampsia, preterm birth, and very preterm birth from maternal exposures to traffic air pollutants measured at ambient stations (CO, NO, NO₂, and NO_x) and modeled through CALINE4 (NO_x and PM_2.5) and LUR (NO₂ and NO_x). Increased risk of preterm birth and very preterm birth were also positively associated with PM₁₀ and PM_2.5 air pollution measured at ambient stations. For LUR-modeled NO₂ and NO_x exposures, elevated risks for all the outcomes were observed in Los Angeles only—the region for which the LUR models were initially developed. Unadjusted LUR models often produced odds ratios somewhat larger in size than temporally adjusted models. The size of effect estimates was smaller for exposures based on simpler traffic density measures than the other exposure assessment methods.

Conclusion

We generally confirmed that traffic-related air pollution was associated with adverse reproductive outcomes regardless of the exposure assessment method employed, yet the size of the estimated effect depended on how both temporal and spatial variations were incorporated into exposure assessment. The LUR model was not transferable even between two contiguous areas within the same large metropolitan area in Southern California.     

The influence of air pollution on cardiovascular and pulmonary function and exercise capacity: Canadian Health Measures Survey (CHMS)

Background

Air pollution has been associated with adverse cardiovascular effects.

Objective

To measure the association between air pollution, spirometry, blood pressure, and exercise capacity.

Methods

We used data from 5604 subjects collected during the Canada Health Measures Survey to test the association between air pollution measured on the day of the survey and spirometry (n=5011 subjects), blood pressure, and exercise capacity (n=3789 subjects).

Results

An interquartile range (IQR) increase in ozone (17.0 ppb) was significantly associated with a 0.883% higher resting heart rate, a 0.718% higher systolic and 0.407% higher diastolic blood pressure, a 0.393% lower FEV₁/FVC expressed as a percentage of predicted, and a 1.52% reduction in the aerobic fitness score (p<0.05). Resting systolic and diastolic blood pressure were approximately 0.5 mmHg higher for an (IQR 4.5 μg/m³) increase in PM_2.5 (IQR 4.5 μg/m³) and 1 mmHg higher for a 12.6 ppb increase in NO₂ (IQR 12.6 ppb). An increase in PM_2.5 was also associated with an approximate 0.4% decrease in percent predicted FEV₁ and FVC (p<0.05).

Conclusion

Exposure to higher concentrations of air pollution was associated with higher resting blood pressure and lower ventilatory function. Ozone was associated with reduced exercise capacity.     

Effect of prenatal exposure to fine particulate matter on ventilatory lung function of preschool children of non‐smoking mothers

Jedrychowski WA, Perera FP, Maugeri U, Mroz E, Klimaszewska‐Rembiasz M, Flak E, Edwards S, Spengler JD. Effect of prenatal exposure to fine particulate matter on ventilatory lung function of preschool children of non‐smoking mothers. Paediatric and Perinatal Epidemiology 2010. Impaired fetal development is associated with a number of adult chronic diseases and it is believed that these associations arise as a result of the phenomenon of prenatal programming, which involves persisting changes in structure and function of various body organs caused by ambient factors during critical and vulnerable periods of early development. The main goal of the study was to assess the association between lung function in early childhood and prenatal exposure to fine particulate matter (PM_2.5), which represents a wide range of chemical compounds potentially hazardous for fetal development. Among pregnant women recruited prenatally to the study, personal measurements of PM_2.5 were performed over 48 h in the second trimester of pregnancy. After delivery, infants were followed for 5 years; the interviewers visited participants in their homes to record children's respiratory symptoms every 3 months in the child's first 2 years of life and every 6 months thereafter. In the fifth year of the follow‐up, children were invited for standard lung function testing of levels of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and forced expiratory volume in 0.5 s (FEV_0.5). There were 176 children of non‐smoking mothers, who performed at least two acceptable spirometry measurements. Multivariable linear regression showed a significant deficit of FVC at the highest quartile of PM_2.5 exposure (beta coefficient = ?91.9, P = 0.008), after adjustment for covariates (age, gender, birthweight, height and wheezing). Also FEV₁ level in children was inversely correlated with prenatal exposure to PM_2.5, and the average FEV₁ deficit amounted to 87.7 mL (P = 0.008) at the higher level of exposure. Although the effect of PM_2.5 exposure on FEV_0.5 was proportionally weaker (?72.7, P = 0.026), it was also statistically significant. The lung function level was inversely and significantly associated with the wheezing recorded over the follow‐up. The findings showed that significant lung function deficits in early childhood are associated with prenatal exposure to fine particulate matter, which may affect fetal lung growth.     

Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing

Objectives

Transport hub is an important part of urban comprehensive transportation system. Traffic-related air pollution can reach high level because of difficulty of diffusion and increase of emission in transport hub. However, whether exposure in this semi-closed traffic micro-environment causes acute changes in pulmonary function of commuters still needs to be explored.

Methods

Forty young healthy adults participated in this randomized, crossover study. Each participant underwent 2 h exposure in a designated transport hub and, on a separate occasion, in an appointed park. Personal exposures to fine particulate matter (PM_2.5), black carbon (BC) and carbon monoxide (CO) were measured. Forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) were assessed pre-, during and post-exposure. Mixed linear models were used to analyze the pulmonary effects of traffic-related air pollutants.

Results

Participants had significantly higher exposures to PM_2.5, BC and CO in the transport hub than in the park. Exposure in transport hub induced significant reductions in FEV₁ and PEF compared with the park during exposure 1 and 2 h. The reductions were significant associated with traffic-related air pollutants. For instance, per 10 μg/m³ increment in PM_2.5 was associated with ?0.15 % (95 % CI ?0.28, ?0.02 %) reduction in FEV₁ during exposure 2 h. However, effects became attenuate after 2 h exposure.

Conclusions

Short-term exposure in transport hub had acute reduction effects on pulmonary function. More attention should be paid to the health effects of exposure in the semi-closed traffic micro-environment.

     

Admixture Mapping Identifies a Quantitative Trait Locus Associated with FEV1/FVC in the COPDGene Study

African Americans are admixed with genetic contributions from European and African ancestral populations. Admixture mapping leverages this information to map genes influencing differential disease risk across populations. We performed admixture and association mapping in 3,300 African American current or former smokers from the COPDGene Study. We analyzed estimated local ancestry and SNP genotype information to identify regions associated with FEV₁/FVC, the ratio of forced expiratory volume in one second to forced vital capacity, measured by spirometry performed after bronchodilator administration. Global African ancestry inversely associated with FEV₁/FVC (P = 0.035). Genome‐wide admixture analysis, controlling for age, gender, body mass index, current smoking status, pack‐years smoked, and four principal components summarizing the genetic background of African Americans in the COPDGene Study, identified a region on chromosome 12q14.1 associated with FEV₁/FVC (P = 2.1 × 10^?6) when regressed on local ancestry. Allelic association in this region of chromosome 12 identified an intronic variant in FAM19A2 (rs348644) as associated with FEV₁/FVC (P = 1.76 × 10^?6). By combining admixture and association mapping, a marker on chromosome 12q14.1 was identified as being associated with reduced FEV₁/FVC ratio among African Americans in the COPDGene Study.     

Effects of biomass burning on pulmonary functions in tribal women in northeastern India

Wood smoke causes adverse effects on pulmonary function (PF) in women in developing countries. This study compared PF among rural tribal women in northeastern India among 266 wood users and 82 liquefied petroleum gas (LPG) users, all healthy nonsmoking women from April to July, 2014. PF measurements included FVC, FEV₁, FEV₁/FVC, PEF, and FEF_25–75%. Information on participants’ health status, demographic, and socioeconomic characteristics were collected by questionnaire. Multiple linear regressions were performed to compare PF between the two groups, adjusting for potential confounders. Wood users had significantly lower pulmonary values than LPG users: FVC (2.65 vs. 2.85 L, p < .001), FEV₁ (1.46 vs. 1.92 L, p < .001), PEF (1.89 vs. 2.56 L/s, p < .001), and FEF_25–75% (1.12 vs. 1.68 L/s, p < .001) except for FEV₁/FVC (76.5 vs. 75.5 percent, p = .27). Wood use was associated with 7 percent lower FVC, 24 percent lower FEV₁, 1.3 percent lower FEV₁/FVC, 26 percent lower PEF, and 33 percent lower FEEF_25–75% compared to LPG use. Wood use was associated with a 0.27-L decrease in FEV₁, adjusted for covariates. Women cooking with wood had lower PF and more respiratory symptoms and gastritis than those using LPG. Thus, reducing indoor air pollution from biomass burning is needed to protect tribal women’s health.     

An epidemiology study of lung function changes of toluene diisocyanate foam workers in the United Kingdom

Objective: To determine whether longitudinal declines in ventilatory capacity and the occurrence of respiratory symptoms in workers manufacturing polyurethane foam were related to toluene diisocyanate (TDI) exposure. Methods : A population of 780 workers in 12 United Kingdom factories was followed for 5 years. Modified United Kingdom Medical Research Council (MRC) respiratory questionnaires and three or more lung function measurements were completed for each subject. Mean TDI exposures for all jobs in which subjects were employed were assessed by personal monitoring (2294 measurements) and related to their occupational histories. Results : The United Kingdom 8-h and 15-min maximum exposure limits for TDI were exceeded in 4.7% and 19.0% of the samples taken, respectively. There was some increase in reported respiratory symptoms amongst exposed workers, but the annual declines of 1-s forced expiratory volume (FEV₁) and forced vital capacity (FVC) were not related to TDI exposure and were typical of those observed in other longitudinal populations. FEV₁ declines were smoking-related. Evidence was found suggesting that a small excess decline in FEV₁ and FVC occurred in the first few years of employment for workers not previously exposed to TDI. Conclusion: This study does not provide evidence that there is a TDI-related decline in FEV₁ and FVC in workers exposed to less than the United Kingdom 8-h occupational exposure limit of 5.8 ppb. Received: 21 February 1997 / Accepted: 10 July 1997     

Long-term exposure to traffic-related air pollution associated with blood pressure and self-reported hypertension in a Danish cohort

Background: Short-term exposure to air pollution has been associated with changes in blood pressure (BP) and emergency department visits for hypertension, but little is known about the effects of long-term exposure to traffic-related air pollution on BP and hypertension.Objectives: We studied whether long-term exposure to air pollution is associated with BP and hypertension.Methods: In 1993–1997, 57,053 participants 50–64 years of age were enrolled in a population-based cohort study. Systolic and diastolic BP (SBP and DBP, respectively) were measured at enrollment. Self-reported incident hypertension during a mean follow-up of 5.3 years was assessed by questionnaire. We used a validated dispersion model to estimate residential long-term nitrogen oxides (NO_x), a marker of traffic-related air pollution, for the 1- and 5-year periods prior to enrollment and before a diagnosis of hypertension. We conducted a cross-sectional analysis of associations between air pollution and BP at enrollment with linear regression, adjusting for traffic noise, measured short-term NO_x, temperature, relative humidity, and potential lifestyle confounders (n = 44,436). We analyzed incident hypertension with Cox regression, adjusting for traffic noise and potential confounders.Results: A doubling of NO_x exposure during 1- and 5-year periods preceding enrollment was associated with 0.53-mmHg decreases [95% confidence interval (CI): –0.88, –0.19 mmHg] and 0.50-mmHg decreases (95% CI: –0.84, –0.16 mmHg) in SBP, respectively. Long-term exposure also was associated with a lower prevalence of baseline self-reported hypertension (per doubling of 5-year mean NO_x: odds ratio = 0.96; 95% CI: 0.91, 1.00), whereas long-term NO_x exposure was not associated with incident self-reported hypertension during follow-up.Conclusions: Long-term exposure to traffic-related air pollution was associated with a slightly lower prevalence of BP at baseline, but was not associated with incident hypertension.     

Improving the quality of spirometry in an epidemiological study: The Renfrew–Paisley (Midspan) family study

Population studies in Britain and elsewhere report deficiencies in quality of pulmonary function measurements. Methods were tested to improve the standardisation of spirometry in an epidemiological study.The spirometer provided visual feedback about acceptability and reproducibility to American Thoracic Society (ATS) standards. After 14 weeks technicians (research nurses) were given feedback and further training. Measurements were repeated in a 5% sample.Participant characteristics and technical factors (technician and technician feedback) predicted unacceptable forced expiratory volume in 1 second (FEV₁) and excessively variable FEV₁ and forced vital capacity (FVC). Only participant characteristics predicted unacceptable FVC. Feedback to technicians reduced test failure for FEV₁ by half and excessive within-session variability by one-third. In the reproducibility study, coefficients of variation for FEV₁ and FVC were 3%.Epidemiological studies can achieve standards of between-session reproducibility for spirometry comparable to levels reported by pulmonary function laboratories. Performance feedback to technicians improves the level of minimally acceptable spirometry, and within-session reproducibility. Public Health(2000) 114, 353–360     

Effects of air pollution on changes in lung function induced by exercise in children with chronic respiratory symptoms

Objective: To investigate how daily variations in ambient air pollution, especially in particles, during the cold of winter affect repeated measurements of baseline lung function and exercise induced bronchial responsiveness among primary school children with chronic respiratory symptoms.

Methods: During alternate school weeks (mamimum five) from February to April 1994, 33 children took part in exercise challenge tests (n=141 tests). The exercise challenges were conducted outdoors in a school yard in the centre of Kuopio, Finland. Spirometric lung functions were measured indoors before the exercise, and 3 and 10 minutes after. Daily mean concentrations of PM₁₀, black smoke (BS), NO₂, CO, SO₂, and particle size and numbers were monitored at a nearby fixed monitoring site.

Results: Daily variations in ambient air pollution were not associated with enhanced bronchial responsiveness. However, increased concentrations of BS, PM₁₀, particle numbers, NO₂, and CO were consistently associated with an impairment of baseline lung functions. The reductions in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) were 0.5% and 0.6%, respectively, for each 10 µg/m³ increase in BS (lag 2).

Conclusion: Particles derived from combustion affect baseline lung function rather than bronchial responsiveness among children with chronic respiratory symptoms.

     

Agricultural Work Exposures and Pulmonary Function Among Hired Farm Workers in California (The MICASA Study)

Despite California’s dependence on hired farm labor, scarce research has been conducted on the respiratory health of hired farm workers. Agricultural exposures to inorganic and organic dusts can adversely affect an individual’s respiratory health and differ by farm type and job task. The purpose of the present analysis was to examine associations between agricultural work exposures and pulmonary function among 450 California farm workers. Data were collected as part of the Mexican Immigration to California: Agricultural Safety and Acculturation (MICASA) study, a prospective cohort study examining occupational risk factors and health of hired farm worker families in Mendota, California. Time-weighted self-reported average (TWSRA) dust scores were calculated from assessments of past-12-month agricultural work history. Other dust exposure indicator variables included months worked in agriculture in the past 12 months and years worked in agriculture. Multiple linear regression modeled FEV₁ (forced expiratory volume in 1 second), FEF_25–75% (forced midexpiratory flow rate), FVC (forced vital capacity), FEV₆, FEV₁/FVC, and FEV₁/FEV₆ separately. Seventy-six percent of participants had worked in agriculture in the past year. In models conducted for crops and tasks separately, high TWSRA dust score was associated with better FEV₆. Crop and task models showed associations between greater months worked in agriculture in the past year and better FEV₁, FEF_25–75%, and FEV₆. Both models also found greater years worked in agriculture to be associated with worse FEV₁/FEV₆. Results were generally in the opposite direction as expected given past research but not uncommon. Future research should investigate relationships between pulmonary function and agricultural dust exposure over a lifetime and changes in pulmonary function over time.     

Lung function decline and blood lead among residents nearby to industrial complex

Purpose

This study was to ascertain the risk factors of pulmonary function decline (forced expiratory volume in 1?s [FEV₁], forced vital capacity [FVC]) among those exposed to lead in the vicinity of industrial complex.

Methods

In total, 263 men and women, aged over 30, were recruited from two cities during a 2-year follow-up. Spirometry testing was conducted first at baseline and then after 2-years of follow-up. The change in FVC and FEV₁ during the study period was analyzed according to blood lead (BPb), urinary cotinine, and 1-hydroxypyrene, after controlling for sex, height, baseline FVC or FEV₁, and airway hyperresponsiveness.

Results

With increase in age, both FEV₁ and FVC declined. More marked decline in FVC was noted for men than for women (p?<?0.05), while the decline in FEV₁ was not. Biological variables, especially height (p?<?0.05) and pulmonary status (p?<?0.0001), were associated with the decline in both FEV₁ and FVC. Even after controlling these other variables, blood lead level was also significantly associated with the decline of FVC.

Conclusions

Even though the decline in FEV₁ and FVC with aging was within a normal range, people with smaller height were more vulnerable to the decline of both FEV₁ and FVC and especially higher level of BPb was accompanied with larger decline of FVC. Oxidative stress in relation to lead accumulation in adult may contribute to rapid aging of pulmonary function.     

Reduced pulmonary function is associated with lower levels of endogenous total and free testosterone. The Tromsø Study

Men with chronic obstructive pulmonary disease have reduced endogenous testosterone levels. Little is known, however, about the relationship between pulmonary function and endogenous testosterone levels in a general population. In the present study we have examined the cross-sectional associations between sex hormones measured by immunoassay and pulmonary function assessed with spirometry and oxygen saturation in 2,197 men participating in the fifth Tromsø study. The data were analyzed by univariate correlations, multiple linear regression analyses and analyses of variance and covariance. Total and free testosterone were positively and independently associated with forced vitality capacity, FVC (% of predicted) (P = 0.001 and P = 0.006, respectively) and forced expiratory volume in 1 second, FEV₁ (% predicted) (P = 0.033 and P = 0.002, respectively), and men with severe pulmonary obstruction (FEV₁ % of predicted < 50) had lower free testosterone levels (P = 0.005). In this cross-sectional data from Tromsø, a reduction in pulmonary function was associated with lower levels of total and free testosterone. We suggest that the reduction of total and free testosterone could be due?to an alteration of the hypothalamic-pituitary response.