Changes in lung function and respiratory symptoms during pesticide spraying season among male sprayers

Abstract

Exposure to pesticides via inhalation might impair lung function and develop further severe respiratory symptoms and diseases. Thus, the purpose of the study was to compare lung function between pre- and post-pesticide spraying seasons among male sprayers. The study also evaluated the association of lung function changes and other factors with respiratory symptoms. The follow-up study was conducted on 58 male sprayers. The subjects were interviewed and measured lung function before and after pesticide spraying season. The results found that forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and peak expiratory flow rate in the post-spraying season were significantly lower than in the pre-spraying season. With regard to respiratory symptoms, cough symptoms were associated with changes in FEV₁/FVC [odd ratio (OR) = 1.29, 95% confidence interval (CI) = 1.01–1.67)] and smoking status (OR = 12.95, 95%CI = 1.35–124.34). Phlegm symptoms were also associated with changes in FVC (OR = 2.07, 95%CI = 1.01–4.25) and FEV₁ (OR = 0.41, 95%CI = 0.18–0.91). The study provides evidence that pesticide spraying may increase risks for significant alteration of lung function and respiratory symptoms.     

The association of biomass fuel combustion on pulmonary function tests in the adult population of Mid-Anatolia

Objectives:To assess the association of biomass as domestic energy source on respiratory function in rural areas of Mid-Anatolia in Turkey where biomass use is frequent.Methods:In a cross-sectional study, pulmonary functions measurements of 112 cow-dung users and 153 modern energy source users, all non-smokers, were assessed and compared. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements included forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), FEV₁/FVC ratio and the flow between the first 25 and 75 of forced expiratory flow (FEF_25–75), and were compared, deploying univariate and multivariate methods, between the two groups.     

The association of biomass fuel combustion on pulmonary function tests in the adult population of Mid-Anatolia

Summary Objectives:To assess the association of biomass as domestic energy source on respiratory function in rural areas of Mid-Anatolia in Turkey where biomass use is frequent.Methods:In a cross-sectional study, pulmonary functions measurements of 112 cow-dung users and 153 modern energy source users, all non-smokers, were assessed and compared. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements included forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), FEV₁/FVC ratio and the flow between the first 25 and 75 of forced expiratory flow (FEF_25–75), and were compared, deploying univariate and multivariate methods, between the two groups.Results:The individuals in the biomass exposed and unexposed group were similar regarding demographic characteristics: 67.0% were female (exposed) vs 60.1% (unexposed) with an age range of 17 to 64 (exposed) and 18 to 70 years (unexposed), and with 36% of biomass users having had pulmonary tract infections (20% in non-users). For all pulmonary function test parameters FEV₁, FVC, FEV₁/FVC, and FEF_25–75 a highly significant (p<0.0001) reduction was observed in biomass users. A 12.4% (95% confidence interval: 7.0% to 17.7%) reduction in forced vital capacity was observed in multivariate linear regression.Conclusions:It is well known that biomass combustion is a relevant public health problem. The substantial differences in pulmonary functions associated with biomass use as an energy source observed in this cross-sectional study in non-smokers support that also in rural Turkey measures may be in need to reduce this public health problem.     

The impact of adiposity indices on lung function in children with respiratory allergic diseases

IntroductionThe effect of obesity on lung function in children stratified by asthma status is not fully elucidated. We evaluated the impact of adiposity indices, including Body Mass Index (BMI) and estimated fat mass (eFT), on lung changes in asthmatic and non-asthmatic children with rhinitis.Patients and MethodsWe performed a retrospective review of 400 pediatric patients, classified into an asthma group (n = 200) and a no-asthma group (n = 200). According to the BMI z-score all subjects were classified into normal-weight patients (NW; ?2 ≤ BMI z-score <1) and overweight patients/patients with obesity (OW/OB; BMI z-score ≥1). Lung function parameters were measured by spirometry. BMI and eFM were considered as adiposity indices.ResultsExcess weight/obesity was present in 37 % of patients. The OW/OB group showed higher basal forced expiratory vital capacity (FVC) and lower forced expiratory volume in 1 s (FEV₁), FEV₁/FVC ratio compared to the NW group (p ≤ 0.01). FVC and FEV₁ were correlated with the BMI z-score, and FEV₁/FVC with eFT (p ≤ 0.01). No differences were noted between the NW and the OW/OB groups in terms of respiratory parameters except for FVC (p < 0.01). In the OW/OB group, asthma patients were significantly different based on FEV₁, FEV₁/FVC, and forced expiratory flow at 25–75 % of FVC (FEF_25/75) (p < 0.01). The BMI z-score was correlated with FVC and FEV₁ in both the no-asthma and asthma groups (p ≤ 0.01 and p ≤ 0.05, respectively), while eFM was correlated with FEV₁/FVC (p = 0.007) in the asthma group only.ConclusionObesity seems to have a significant impact on lung function in children with respiratory allergic diseases. BMI and eFM may be used to evaluate the impact of adiposity on lung function.     

The association between personal care products and lung function

PurposeChemical exposures are important determinants of respiratory health. The objective of the present study was to determine the association between the use of personal care products, which may contain respirable components, and lung function.MethodsUsing questionnaire and spirometry data collected during the Canadian Health Measures population survey, the association was tested between 1-second forced expiratory volume (FEV_l) and forced vital capacity (FVC) expressed as a percentage of predicted, and the frequency of use of personal care products categorized as eye makeup, fragrances, hairstyle products, lipstick, and scented body products.ResultsFive thousand sixteen of the 5604 participants in the survey reported using at least one personal care product in the past 3 months. Among men and women, an interquartile increase in hairstyle products was associated with an approximate 2% decrease in both FEV₁ and FVC (P < .05). Among women, each product category was associated with a significant decrease in lung function with the largest observed effect being a 4.08% (95% confidence interval, 7.71–0.45) decrease in FVC associated with an interquartile range increase in the frequency of use of scented body products.ConclusionsThis study provides data suggesting that using personal care products may have a small adverse effect on lung function. Further research is warranted to investigate this possibility.     

Rubberwood Dust and Lung Function among Thai Furniture Factory Workers

Abstract

The objective of this study was to assess factors affecting lung function among 685 workers in the rubberwood (Hevea brasiliensis) furniture industry in the Chonburi and Rayung provinces of eastern Thailand. Study data were gathered using questionnaires, by sampling wood dust, and by spirometry. The mean wood dust exposure level in the factories was 4.08 mg/m³ (SD = 1.42, range: 1.15–11.17 mg/m³). The mean overall percent of predicted forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and FEV₁ /FVC values were 84 % (SD = 13.41), 86 % (SD = 14.40), and 99% (SD = 10.42), respectively. Significant negative correlations were found between mean dust exposure levels and FVC (p = 0.0008), and FEV₁ /FVC% (p < 0.001), but not FEV₁ (p = 0.074). An association between decline in lung function and wood dust levels among wood workers suggests that rubberwood dust exposure negatively affects lung function.     

Relative chronic effects of different occupational dusts on respiratory indices and health of workers in three Ethiopian factories

The respiratory effects of dusts in different sections of yarn, cement, and cigarette factories were studied in 211 nonsmoking male and female workers aged 21–57 years. The controls used were 211 healthy nonsmoking and nonexposed male and female subjects aged 20–57 years from the general population. Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV₁), FEV₁/FVC ratio, forced expiratory flow (FEF_{200–1,200 ml}), forced mid-expiratory flow (FMF_25–75%) and peak expiratory flow rate (PEFR) were recorded in all subjects with and without respiratory symptoms. Taking exposures to all dusts of different concentrations together, it was found that the frequency of respiratory illness was greater among exposed workers (40.5% in males, 36% in females) than it was among controls (21.6% in males,18% in females). In exposed subjects, the symptom prevalence was only 4.5% higher in males than in females.The mean lung function indices, including FEV₁, FEV_1%, FEF_{200–1,200 ml}, FMF_25–75%, and PEFR, in subjects exposed to all dusts in general decreased markedly, with dust concentration being more important than duration of exposure, and FMF being affected slightly more consistently. About 38.4% of the dust-exposed subjects developed corresponding respiratory illnesses including chronic cough (24.7%), chronic bronchitis (21.8%) and bronchial asthma (24.2%). The respective control values were 9.0%, 9.5%, and 8.5%. Exposure to different occupational dusts resulted in the development of respiratory illness with different rates of prevalence. The effects of exposure to cotton and cement dusts on respiratory health of exposed subjects were relatively more significant (p < 0.001) than that of exposure to tobacco dust (p < 0.05). Am. J. Ind. Med. 34:373–380, 1998. © 1998 Wiley-Liss, Inc.     

Comparison of spirometry performed on the same subjects by two teams using similar instruments: An investigation of variability in prevalence of impairment

To investigate variability in results of spirometric testing, spirometry was performed with similar automated equipment by two independently trained teams employing their customary procedures in 181 asbestos insulation workers. Results were analyzed for forced vital capacity (FVC), forced expiratory volume ? 1 sec (FEV₁), $\text{FEV}{}_1\text{FVC}$, and forced expiratory flow (FEF)_25–75. Differences > 10% were found for FVC in 31 workers (17%), for FEV₁ in 36 workers (20%), and for FEF_27–75 in 110 workers (61%). Prevalence of impairment as conventionally defined varied considerably, e.g., 13% decreased FVC vs 22% and 40% decreased $\text{FEV}{}_1\text{FVC}$ vs 30%. Variability in results was related to failure to monitor subject effort by recording a flow-volume or volume-time curve and failure to calibrate the instrument physically. External calibration of automated equipment and monitoring of subject effort by inscribed curves are essential for pulmonary function testing in epidemiologic surveys. Standardization of techniques must include these procedures. Otherwise the value of these investigations will be limited.     

Improved Air Quality and Attenuated Lung Function Decline: Modification by Obesity in the SAPALDIA Cohort

Background: Air pollution and obesity are hypothesized to contribute to accelerated decline in lung function with age through their inflammatory properties.Objective: We investigated whether the previously reported association between improved air quality and lung health in the population-based SAPALDIA cohort is modified by obesity.Methods: We used adjusted mixed-model analyses to estimate the association of average body mass index (BMI) and changes in particulate matter with aerodynamic diameter ≤ 10 µm (PM₁₀; ΔPM₁₀) with lung function decline over a 10-year follow-up period.Results: Lung function data and complete information were available for 4,664 participants. Age-related declines in lung function among participants with high average BMI were more rapid for FVC (forced vital capacity), but slower for FEV₁/FVC (forced expiratory volume in 1 sec/FVC) and FEF_25–75 (forced expiratory flow at 25–75%) than declines among those with low or normal average BMI. Improved air quality was associated with attenuated reductions in FEV₁/FVC, FEF_25–75, and FEF_25–75/FVC over time among low- and normal-BMI participants, but not overweight or obese participants. The attenuation was most pronounced for ΔFEF_25–75/FVC (30% and 22% attenuation in association with a 10-μg/m³ decrease in PM₁₀ among low- and normal-weight participants, respectively.)Conclusion: Our results point to the importance of considering health effects of air pollution exposure and obesity in parallel. Further research must address the mechanisms underlying the observed interaction.Citation: Schikowski T, Schaffner E, Meier F, Phuleria HC, Vierkötter A, Schindler C, Kriemler S, Zemp E, Krämer U, Bridevaux P-O, Rochat T, Schwartz J, Künzli N, Probst-Hensch N. 2013. Improved air quality and attenuated lung function decline: modification by obesity in the SAPALDIA cohort. Environ Health Perspect 121:1034–1039; http://dx.doi.org/10.1289/ehp.1206145     

Milk Consumption and Respiratory Function in Asthma Patients: NHANES Analysis 2007–2012

Per the Centers for Disease Control and Prevention, asthma prevalence has steadily risen since the 1980s. Using data from the National Health and Nutrition Examination Survey (NHANES), we investigated associations between milk consumption and pulmonary function (PF). Multivariable analyses were performed, adjusted for a priori potential confounders for lung function, within the eligible total adult population (n = 11,131) and those self-reporting asthma (n = 1,542), included the following variables: milk-consumption, asthma diagnosis, forced vital capacity (FVC), FVC%-predicted (%), forced expiratory volume in one-second (FEV₁), FEV₁% and FEV₁/FVC. Within the total population, FEV₁% and FVC% were significantly associated with regular (5+ days weekly) consumption of exclusively 1% milk in the prior 30-days (β:1.81; 95% CI: [0.297, 3.325]; p = 0.020 and β:1.27; [0.16, 3.22]; p = 0.046). Among participants with asthma, varied-regular milk consumption in a lifetime was significantly associated with FVC (β:127.3; 95% CI: [13.1, 241.4]; p = 0.002) and FVC% (β:2.62; 95% CI: [0.44, 4.80]; p = 0.006). No association between milk consumption and FEV₁/FVC was found, while milk-type had variable influence and significance. Taken together, we found certain milk consumption tendencies were associated with pulmonary function values among normal and asthmatic populations. These findings propound future investigations into the potential role of dairy consumption in altering lung function and asthma outcomes, with potential impact on the protection and maintenance of pulmonary health.     

Early Detection of Expiratory Airflow Obstruction in Cement Workers

In 39 nonsmoking cement workers and in 23 nonsmoking controls of similar age and size maximal expiratory flows at higher and at lower lung volumes were measured. All workers had the one second forced expiratory volume/forced vital capacity (FEV₁/FVC) ratio 75% or more. While there was no difference in mean values of maximal expiratory flow for the liter of air after 200 ml had been exhaled (MEFR_200–1,200) between two groups, the mean values of maximal midexpiratory flow (MMEF) and maximal expiratory flow in the third quarter of vital capacity (E_50–75) were substantially lower in cement workers than in controls. The difference in E_50–75 was statistically significant (P<.O5).

The use of indexes of maximal expiratory flow at lower lung volumes is, therefore, recommended for early detection of expiratory airflow obstruction in cement workers. The possible role of small airways obstruction, reduction in elastic recoil of the lung, or both, in the observed flow retardation is discussed.     

Nested case-control study on associations between lung function, smoking and mortality in Japanese population

Objectives Only a few long-term follow-up studies with a focus on the association between lung function and mortality in the Japanese population have been undertaken. In this study, we examined the associations of lung function, smoking and the results of allergy skin tests with mortality in a longitudinal study of the Japanese population. Methods Baseline measurements were performed on residents of Fukui, Japan in 1972, and a follow-up survey was conducted in 2002. By employing a nested case-control design, 596 cases (deaths) and 596 age and sex-matched controls (survivals) were selected. Lung function was assessed using forced vital capacity (FVC) expressed as the normal percent predicted (FVC %pred) and the ratio of forced expiratory volume in 1 second (FEV₁) to FVC (FEV₁/FVC). Allergy skin tests were performed with extracts of house dust, candidia and mixed fungal samples (bronchomycosis). The Brinkman index was used to assess smoking intensity. The Cox proportional hazards model was used to evaluate whether lung function was associated with mortality after adjustment for other potential confounding variables. Results Those categorized into the first- or second-lowest quartile of FVC %pred had a higher mortality [hazard ratios (HRs) and 95% confidence intervals (CIs): 2.01 (1.26–3.19) and 1.84 (1.11–3.05)], respectively. On top of these, heavy smoking (BI≥400) was associated with a higher mortality [HR and 95% CI: 1.73 (1.18–2.53)]. There were only weak of associations between the results of allergy skin tests and mortality. Conclusions These results suggest that FVC %pred of lung function and smoking can serve as long-term independent predictors of mortality.     

Association of generic health-related quality of life (EQ-5D dimensions) and inactivity with lung function in lung-healthy German adults: results from the KORA studies F4L and Age

Purpose

Among patients with lung disease, decreased lung function is associated with lower health-related quality of life. However, whether this association is detectable within the physiological variability of respiratory function in lung-healthy populations is unknown. We analyzed the association of each EQ-5D-3L dimension (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) and self-reported physical inactivity with spirometric indices in lung-healthy adults. Modulating effects between inactivity and EQ-5D dimensions were considered.

Methods

1132 non-smoking, apparently lung-healthy participants (48% male, aged 64?±?12 years) from the population-based KORA F4L and Age surveys in Southern Germany were analyzed. Associations of each EQ-5D dimension and inactivity with spirometric indices serving as outcomes (forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and mid-expiratory flow) were examined by linear regression, considering possible confounders. Interactions between EQ-5D dimensions (no problems/any problems) and inactivity (four categories of time spent engaging in exercise: inactive to most active) were assessed.

Results

Among all participants 42% reported no problems in any EQ-5D dimension, 24% were inactive and 32% exercised >?2 h/week. After adjustment, FEV₁ was ??99 ml (95% CI ??166; ??32) and FVC was ??109 ml (95% CI ??195; ??24) lower among subjects with mobility problems. Comparable estimates were observed for usual activities. Inactivity was negatively associated with FVC (β-coefficient: ??83 ml, 95% CI ??166; 0), but showed no interactions with EQ-5D.

Conclusions

Problems with mobility or usual activities, and inactivity were associated with slightly lower spirometric parameters in lung-healthy adults, suggesting a relationship between perceived physical functioning and volumetric lung function.

     

Maternal smoking during pregnancy, polymorphic CYP1A1 and GSTM1, and lung-function measures in urban family children

Purpose

Understanding the interplay between genes and in-utero tobacco exposure in affecting child lung development is of great significance. In this study, we tested the hypothesis that tobacco-related lung-function reduction in children differs by maternal polymorphic genes Cytochrome P450 1A1 (CYP1A1) and Glutathione S-transferase Mu 1 (GSTM1).

Materials and methods

Data were collected among 370 children (6–10 years old, 81.6% African-Americans) and their biological mothers visiting a large children’s hospital. Study hypotheses were tested using multiple regression method.

Results

Among the study sample, 143 mothers smoked throughout pregnancy and 72 smoked on a daily basis. Spirometric measures (mean±SD) included were: forced vital capacity (FVC)=1635±431 mL, forced expiratory volume in the first 1 s (FEV₁)=1440 ±360 mL, percent FEV₁/FVC ratio=89±12, and forced expiratory flow between the 25% and 75% of FVC (FEF_25–75)=1745±603 mL. In addition to a tobacco effect on FVC (−131 mL, 95% CI: −245, −17) and FEV₁/FVC ratio (42, 95% CI: 1, 83), regression analysis controlling for covariates indicated that for the subsample of children whose mothers were CYP1A1?2A homozygous, maternal daily smoking was associated with −734 mL (95% CI: −1206, −262) reductions in FEV₁ and −825 mL (95% CI: −909, −795) reductions in FVC; reduced smoking was still associated with −590 mL (95% CI: −629, −551) reductions in FVC. For children of mothers with GSTM1 deletion, persistent daily smoking was associated with −176 mL (95% CI: −305, −47) reductions in FVC.

Discussion and conclusions

Maternal smoking during pregnancy was significantly associated with lung-function reduction in children, particularly for those whose mothers possessed the polymorphic CYP1A1*2A and GSTM1 deletion.     

Lung function changes in coke oven workers during 12 years of follow up

Aims: To investigate the effect of exposure to coke oven emissions on the lung function of coke oven workers.

Methods: The study population, followed from 1978 and 1990, was 580 male workers with at least two sets of lung function measurements (FVC, FEV₁, FEV₁/FVC, and FEF_25–75%). An annual rate of change (time slope) for age and height adjusted lung function index was estimated for each subject. This "time slope" was then treated as the response variable in a weighted multiple regression analysis with selected predictors.

Results: For all 580 subjects, each year of working in the "operation" group (the most exposed) was found to increase the FVC decline by around 0.7 ml/year (95% CI 0.1 to 1.3 ml/year). After the exclusion of 111 subjects without detailed work history, the above finding was confirmed and each year of exposure in "operation" was also found to increase the FEV₁ decline by around 0.8 ml/year (95% CI 0.1 to 1.4 ml/year).

Conclusions: These findings are consistent with the results of previous cross-sectional studies. Work duration in the most exposed position in the coke ovens was associated with increased annual decline for FVC and FEV₁. The estimated effect of one year of work exposure in "operation" is equivalent, in terms of the reduction in lung function, to an estimated 2.1 pack-years of smoking for FVC and 1.2 pack-years of smoking for FEV₁.

     

Acute effect of sulphur dioxide from a power plant on pulmonary function of children, Thailand

BACKGROUND: Epidemiological studies have shown reversible declines of lung function in response to air pollution, but research on the independent effect of short-term exposure to ambient sulphur dioxide (SO2) on pulmonary function is limited. This study evaluated the association of short-term exposure to increased ambient SO2 and daily pulmonary function changes among children with and without asthma. METHODS: The associations of daily exposure to SO2 and particulate matter 10 microm in diameter (PM10) with pulmonary function were examined in 175 asthmatic and non-asthmatic children aged 6-14 years who resided near a coal-fired power plant in Thailand. Each child performed daily pulmonary function tests during the 61-day study period. General linear mixed models were used to estimate the association of air pollution and pulmonary function controlling for time, temperature, co-pollutants, and autocorrelation. RESULTS: In the asthmatic children, a daily increase in SO2 was associated with negligible declines in pulmonary function, but a small negative association was found between PM10 and pulmonary function. A 10-microg/m(3) increment was associated with changes in the highest forced vital capacity (FVC) (-6.3 ml, 95% CI: -9.8, -2.8), forced expiratory volume at 1 second (FEV(1)) (-6.0 ml, 95% CI: -9.2, 2.7), peak expiratory flow rate (PEFR) (-18.9 ml.sec(-1), 95% CI: -28.5, -9.3) and forced expiratory flow 25 to 75% of the FVC (FEF(25-75%)) (-3.7 ml.sec(-1), 95% CI: -10.9, 3.5). No consistent associations between air pollution and pulmonary function were found for non-asthmatic children. CONCLUSION: Declines in pulmonary function among asthmatic children were associated with increases in particulate air pollution, rather than with increases in SO2.     

Urinary Dialkyl Phosphate Concentrations and Lung Function Parameters in Adolescents and Adults: Results from the Canadian Health Measures Survey

Background:

Epidemiological studies have reported associations between lung function parameters and organophosphate (OP) pesticide exposures in agricultural occupations, but to our knowledge associations have not been evaluated in general populations.

Objectives:

We examined associations between OP metabolite dialkyl phosphates (DAPs) and lung function using data from the Canadian Health Measures Survey (CHMS) Cycle 1.

Methods:

Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC ratio, and forced expiratory flow between 25% and 75% of FVC (FEF25%–75%) were measured for 4,446 CHMS participants. Urinary concentrations of six DAP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP), smoking status, and other predictors of lung function were also measured in the CHMS-Cycle 1. Multiple linear regression analyses were used to examine the relationship between total DAP concentrations (ΣDAPs) and lung function in adolescents (12–19 years) and adults (20–79 years).

Results:

In adults, estimates from multiple regression analyses suggested that a 1-unit increase on natural logarithmic scale (171% increase on the original scale) in the creatinine-corrected urinary concentration (nanomoles per gram creatinine) of ΣDAP was associated with a 32.6-mL (95% CI: –57.2, –8.1) reduction in FVC, 32.6-mL (95% CI: –59.0, –6.3) reduction in FEV1, 0.2% (95% CI: –0.6, 0.2) reduction in FEV1/FVC ratio, and 53.1-mL/sec (95% CI: –113.9, 7.7) reduction in FEF25%–75%. In adolescents, associations between ΣDAP and FEV1 were closer to the null and positive for FVC, whereas associations with FEV1/FVC and FEF25%–75% were negative, as in adults. However, none of the associations were significant in adolescents.

Conclusions:

The negative association between ΣDAP and lung function in adult participants suggests a detrimental effect of OP pesticides on lung function in the adult general population. Further studies using prospective designs are warranted to confirm the findings reported in this study.

Citation:

Ye M, Beach J, Martin JW, Senthilselvan A. 2016. Urinary dialkyl phosphate concentrations and lung function parameters in adolescents and adults: results from the Canadian Health Measures Survey. Environ Health Perspect 124:491–497; http://dx.doi.org/10.1289/ehp.1509745     

Respiratory function in workers employed in the glassblowing industry

A group of 80 men employed in the glassblowing industry was studied in order to investigate the effect of this occupational exposure on respiratory function. Eighty nonexposed workers were included in the study as a control group. Glassblowers had a significantly higher prevalence of chronic bronchitis, nasal catarrh, chronic sinusitis, and nasal bleeding than control workers; length of employment in the industry did not affect the prevalence of symptoms. Many of the glassblowers complained of work shift related symptoms. Measurement of lung function among glassblowers showed there were significant increases in the forced vital capacity (FVC) and the maximum flow rates at 50% and 25% of FVC on maximum expiratory flow volume (MEFV) curves (FEF₅₀, FEF₂₅) across the work shift. Glassblowers had significantly larger preshift FVC and forced expiratory volume in 1-second (FEV₁) measurements when compared to controls. Additionally, residual volume (RV) and RV/TLC% for the glassblowers were significantly increased while the diffusing capacity (DLCO) was normal (when compared to predicted values). Our data indicate that employment in the glassblowing industry contributes to the development of chronic respiratory findings. © 1993 Wiley-Liss, Inc.     

Lung function over six years among professional divers

Aims: To analyse longitudinal changes in pulmonary function in professional divers and their relation with cumulative diving exposure.

Methods: The study included 87 men at the start of their education as professional divers. At follow up one, three, and six years later, 83, 81, and 77 divers were reexamined. The median number of compressed air dives in the 77 divers over the follow up period was 196 (range 37–2000). A group of non-smoking policemen (n = 64) were subjected to follow up examinations in parallel with the divers. Assessment of lung function included dynamic lung volumes, maximal expiratory flow rates, and transfer factor for carbon monoxide (Tl_CO). The individual rates of change of the lung function variables were calculated by fitting linear regression lines to the data, expressed as percent change per year.

Results: The annual reductions in forced vital capacity (FVC) and forced expired volume in one second (FEV₁) were 0.91 (SD 1.22) and 0.84 (SD 1.28) per cent per year in divers, which were significantly higher than the reductions in the policemen of 0.24 (SD 1.04) and 0.16 (SD 1.07) per cent per year (p < 0.001). The annual reduction in the maximal expiratory flow rates at 25% and 75% of FVC expired (FEF_25% and FEF_75%) were related to the log₁₀ transformed cumulative number of dives in a multiple regression analysis (p < 0.05). The annual reductions in Tl_CO were 1.33 (SD 1.85) and 0.43 (SD 1.53) per cent per year in divers and policemen (p < 0.05).

Conclusions: FVC, FEV₁, maximal expiratory flow rates, and Tl_CO were significantly reduced in divers over the follow up period when compared with policemen. The contrasts within and between groups suggest that diving has contributed to the reduction in lung function.

     

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.