Comparison of pulmonary function test abnormalities between stone crushing dust exposed and nonexposed agricultural workers

Objectives The aim of this study is to examine the effects of stone crushing in West Bengal, India, by comparing pulmonary functions of stone crushing workers with those of nonexposed agricultural workers. Methods Two hundred seventy two stone crushing workers and 123 nonexposed workers were analyzed in terms of occupational and personal histories, radiological findings, and pulmonary function test (PFT) results including slow vital capacity (FVC), forced vital capacity (FVC) and peak expiratory flow rate (PEFR). Different lung volumes i.e. FEV₁, FEV_1%, and flow rates i.e. FEF_200–1200ml, FEF_25–75% and FEF_75–85%, were analyzed with regard to sex, smoking habit, work status, age and work duration. Results Contrary to our expectations, the incidences of suspected (2.94%) and definite (1.84%) pneumoconioses were very low and the results of some PFT such as those for FVC and FEV_1%, in the exposed group were better than those in the nonexposed group, although a gradual decline the performance in PFT was observed with age and work duration. There was a higher prevalence of restrictive impairment among the exposed group and a higher prevalence of obstructive impairment in the nonexposed group. Conclusions Some of the results were unexpected. Possible reasons for these include (i) undetectable concentrations of free silica in the stone dust in the work environment of the exposed workers and (ii) factors, such as climate, in the work environment of the nonexposed agricultural workers that could cause pulmonary impairment. Further protective measures should be undertaken to prevent pulmonary impairment in both groups of workers.     

Agricultural Exposures in Patients with COPD in Health Systems Serving Rural Areas

ABSTRACT

Background: Agricultural exposure is a risk factor for the development of chronic obstructive pulmonary disease (COPD). However, there are no good estimates of the number of COPD patients with a history of agricultural exposure. Methods: We conducted a telephone interview of subjects with COPD identified by reviewing all pulmonary function tests at the Omaha Veterans Administration Hospital between November 2004 and March 2005. Obstructive lung disease was defined as a FEV₁/FVC ratio of less than 70%. The survey detailed demographic data, smoking history, pulmonary symptoms, and history of agricultural exposures. Results: Participants included 150 veterans (mean age 68.2 years ±10.8). A history of agricultural exposure was elicited in 68% of subjects. Of those who had worked in agriculture, the types of exposures varied, with 14% in hog confinement barns, 20% on dairy farms, 8% on poultry farms, and 87% exposed to grain dust. There was a trend of diminishing FEV₁ with increasing years of agricultural exposure. Conclusions: In health systems that serve rural areas, patients with COPD commonly have a history of agricultural exposures that may contribute to the development of COPD. Health care workers in these areas should include agricultural exposures as an important part of the social/occupational history in these patients.     

Pulmonary function impairment and airway allergy among workers in traditional bakeries

Objectives

To assess the effect of exposure to flour dust on pulmonary function tests, prevalence of symptoms (respiratory, allergic/irritating) and parameters of allergic sensitization in terms of skin prick test, and bronchial hyper-responsiveness.

Material and Methods

43 bakers (with at least 2 years of occupational exposure) working at different bakeries in Ismailia city, Egypt; and 64 control subjects of comparable socio demographic characteristics were compared. All participants were subjected to an interview questionnaire, clinical chest examination, skin prick test, bronchial hyper-responsiveness test and measurements of pulmonary function parameters.

Results

All respiratory and allergic symptoms were more prevalent among bakers compared to the control group, with the highest odds ratio for allergic symptoms (OR = 6.9; p < 0.0001) and dyspnea (OR = 6.3; p = 0.0004). Bakers had a higher percentage of SPT positive results with statistically significant difference between the two groups (p < 0.0001). Bakers had lower observed values compared to the control group with statistically significant difference for FVC, FEV₁/FVC ratio, FEF_75%, and FEF_25–75% parameters.

Conclusion

The present study suggested that occupational exposure to flour dust may affect respiratory irritation and sensitization, and reduce the pulmonary function tests such as FVC, FEV₁, and FEV₁/FVC ratio and FEF_25–75%.     

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.     

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.     

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 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.     

Cross-Sectional Study on the Association between Pulmonary Function and Sarcopenia in Brazilian Community-Dwelling Elderly from the Amazon Region

Objectives

To compare the obtained and expected values of pulmonary function variables between sarcopenic and non-sarcopenic elderly; verify the association between the pulmonary function and the indicators and diagnosis of sarcopenia; and establish cut-off points for pulmonary function variables to predict sarcopenia.

Design

Cross-sectional study.

Location

Macapá, Brazil.

Participants

community-dwelling elderly ≥ 60 years old (n=383), both sexes.

Measures

Were evaluated according to variables of pulmonary function (spirometry) and sarcopenia, according to the EWGSOP consensus. The association between pulmonary function and sarcopenia was performed using logistic regression and cut-off points established from the ROC Curve.

Results

The prevalence of sarcopenia was 12.53% (n = 48). Sarcopenic individuals had significantly lower mean values for FVC, FEV₁, FEF_25–75% and PEF than non-sarcopenic. After adjustment, spirometric variables were inversely associated with sarcopenia (the increase by one unit of liter in FVC, FEV₁ and FEF_25–75% decreased the probability of sarcopenia by 59%, 67% and 39%, respectively), and the majority of these variables with the muscular strength indicator. Cut-off points, for elderly men and women, were discriminant criteria for the presence of sarcopenia: FVC (≤2.52 L and ≤1.82 L), FEV₁ (≤2.1 L and ≤1.39 L), PEF (≤3.45 L/s and ≤2.93 L/s) and FEF_5–75% (≤1.97 L/s and ≤1.74 L/s).

Conclusions

There was loss of pulmonary function in sarcopenic elderly patients and an inverse association with the diagnosis of sarcopenia and its indicators. Cut-off points of pulmonary function variables can be used as a useful tool to discriminate sarcopenia.

     

Lung function over the first 3 years of a professional diving career

OBJECTIVES—To characterise diving exposure and pulmonary function in professional divers at the start of their formal education and during the first 3 years of their professional career.
METHODS—The study included 87 men at the start of their education as professional divers. At follow up 1 and 3 years after the school 83 and 81 divers respectively were re-examined. Assessment of lung function included dynamic lung volumes and flows and transfer factor for carbon monoxide (Tl_CO).
RESULTS—69 Divers had preschool SCUBA diving experience and had a median number of 70 dives (range 2-3000) to a median maximal depth of 40 (range 10-73) metres. During the 15 week introductory diving course, they had 44 dives (range 38-50) in the depth range 10-50 metres. The median number of dives over the follow up period was 95 (range 0-722) to a maximal median depth of 38 (range 0-98) metres. At the start of the diving course there were no differences in forced vital capacity (FVC), forced expired volume in 1 second (FEV₁), and in Tl_CO between the 69 pre-exposed divers and the 18 never exposed divers. The FVC was significantly larger than predicted in both groups. At follow up at 3 years there was a significant reduction in mean (SD) FEV₁ of 1.8% (6.5), in forced mid-expiratory flow rate (FEF_25-75%) of 6.5% (11.7) and in forced expiratory flow at 75% of FVC expired (FEF_75%) of 10.4% (16.8). There was no change in FVC. The Tl_CO was significantly decreased by 4.6% (8.8). No significant effects were found of cumulative diving exposure, including the number of dives, on the relative changes of any of the lung function variables.
CONCLUSIONS—The results indicate that divers initially belong to a selected group with large FVC. Exposure to diving may contribute to changes in pulmonary function, mostly affecting small airways conductance.


Keywords: diving; follow up study; pulmonary function     

Ventilatory function of factory workers exposed to tea dust

A cross-sectional study was conducted in order to determinethe prevalence of respiratory symptoms and the effect on ventilatorycapacity in workers exposed to tea dust for at least five yearsduring the sifting process of tea manufacture compared to acontrol group of field workers who were not exposed to tea dustpreviously. Fifty-three subjects each in the study and controlgroups were matched for age, sex, ethnic group and height. Prevalenceof chronic respiratory symptoms was obtained by questionnaire.Spirometric measurements included forced vital capacity (FVC),forced expiratory volume in the first second (FEV_1.0) and forcedmid-expiratory flow rate (FEF_25–75%). The study grouphad a chest radiograph. The odds ratio for any chronic respiratorysymptom was 11.6 (95% confidence interval [Cl] = 3.7–39.4)in the study group. Mean values for the spirometric tests werelower in the study group; the differences in FEV_1.0 and FEF_25–75%were significant. Tuberculosis was not found in the study group,while one subject (2.4%) had radiological evidence of bronchiectasis.It may therefore be concluded that chronic tea dust exposurecauses increased prevalence of respiratory symptoms and a significantdegree of small airways obstruction.     

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.     

Respiratory morbidity in workers exposed to dust containing phenolic resin

Summary Seventy-three men and women exposed to phenolic resin dust and/or processed cotton dust in a factory producing sound-deadening material were studied cross-sectionally. There was a statistically significant acute drop in FEV₁ and FVC over the shift in garnett-line workers exposed to dust containing phenolic resin. Pickers, exposed to processed cotton dust only, did not show a significant drop in FEV₁ and FVC over the work shift. Thirty-five percent of the workers that had smoked cigarettes and had worked in the plant 5 years or more had an FEV₁ less than 80% of predicted. This finding was not entirely explained by duration of cigarette smoking. Multiple regression analysis revealed that the longer the duration of exposure, the lower the ratio of FEV₁ to FVC. Respiratory symptoms were related to current cigarette smoking but not to duration of employment. The study suggests that exposure to dust containing phenolic resin had both acute and chronic effects on pulmonary function.     

Spirometric “abnormality” in a normal male reference population: Further analysis of the 1971 oregon survey

Conventional criteria for spirometric impairment (FVC and FEV₁ ? 79% predicted, FEF_25-75 ? 74% predicted, FEV₁/FVC ? 0.69 for most ages) were applied to 507 healthy nonsmoking male subjects in the 1971 Oregon survey. Frequency of air flow impairment was higher than expected for a normal population. Of all subjects, 17.8% had an “abnormal” FEF_25-75% and 19.7% an “abnormal” FEV₁/FVC. “Decreased” lung volumes were seen in older subjects; of those over 55 years of age, 8.8% had a reduced FVC and 11.8% a reduced FEV₁. These rates in a normal population may be used as a rough baseline for making inferences about a population under study. Similar rates were found in a cross-sectional survey of nonsmoking males representative of the population of a large industrial state. The major reason for these high rates of “abnormal” spirometry lies in the conventional definitions of abnormality. Tables showing cut-off points for abnormal spirometric values based on a 95% confidence interval for adult males of all ages and heights permit an alternative method for classification as abnormal.     

Respiratory symptoms and lung function in wool textile workers

Our study investigated a group of 216 wool textile workers (158 women and 58 men). Respiratory symptoms were assessed by questionnaire in wool textile workers and in 130 not exposed (control) workers. Ventilatory capacity was measured in wool workers by recording maximum expiratory flow-volume (MEFV) curves on Monday before and after the work shift. Forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁), and flow rates at 50% and the last 25% of the vital capacity (FEF₅₀, FEF₂₅) were measured on the MEFV curves. Analysis of the data demonstrated a significantly higher prevalence of all chronic respiratory symptoms in wool workers than in controls. being the highest in wool workers for nasal catarrh (M: 63.8%; F: 44.9%) and for sinusitis (M: 62.1%; F: 43.0%). A high prevalence of acute symptoms, associated with the work shift, was also noted in wool workers. Exposure to wool dust caused significant across-shift reductions of ventilatory capacity varying from 1.4% for FEV, to 9.1% for FEF₅₀. Textile workers exposed to wool for > 10 years in the workplace had similar across-shift reductions of ventilatory capacity tests as those with shorter exposures. In a large number of these wool workers, FEF₅₀ and FEF₂₅ were below 70% of predicted normal values. Smokers had acute and chronic lung function changes similar to those of nonsmokers, indicating that smoking did not account for all the respiratory effects seen in wool processing workers. Our data suggest that dust exposures in wool textile mills may be associated with the development of chronic respiratory symptoms and impaired lung function.     

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.     

Exposure to air pollution and pulmonary function in university students

Objectives: Exposure to air pollution has been reported to be associated with increase in pulmonary disease. The aims of the present study were to examine the use of personal nitrogen dioxide (NO₂) samplers as a means of measuring exposure to air pollution and to investigate the relationship between personal exposure to air pollution and pulmonary function. Methods: We measured individual exposures to NO₂ using passive personal NO₂ samplers for 298 healthy university students. Questionnaire interview was conducted for traffic-related factors, and spirometry was performed when the samplers were returned after 1 day. Results: Personal NO₂ concentrations varied, depending on the distance between residence and a main road (P=0.029). Students who used transportation for more than 1 h were exposed to higher levels of NO₂ than those using transportation for less than 1 h (P=0.032). In terms of transportation, riding in a bus or subway caused significantly higher exposure than not using them (P=0.046). NO₂ exposure was not significantly associated with forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV₁) but was associated with the ratio of FEV₁/FVC and mid-expiratory flow between 25% and 75% of the forced vital capacity (FEF_25–75) (P<0.05). Conclusions: This study indicates that concentrations of personal exposure to NO₂ are significantly influenced by traffic-related air pollution and are associated with decreased pulmonary function.     

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.

     

Byssinosis

A respiratory screening program, including the administration of a questionnaire and pulmonary function tests, including one-second forced expiratory volume (FEV₁) and forced vital capacity (FVC), was carried out on employees working in cotton textile plants. This identified employees with byssinosis and other pulmonary conditions. The results revealed a marked relationship between the incidence of byssinosis and bronchitis and between byssinosis and lowered pulmonary function. Cigarette smoking appeared to further increase the incidence of bronchitis and lower pulmonary function. A drop in FEV₁ during the working day, though associated with, was often present without byssinosis symptoms. A combined program of dust control with medical evaluation and surveillance is practical. Identification of reactors to cotton dust and those with other pulmonary conditions enables the employer to lessen risk by localization of areas in need of improved environmental control and by selective placement of employees.     

Airflow limitation among workers in a labour-intensive coal mine in Tanzania

Objectives To describe the relationship between cumulative respirable dust and quartz exposure and lung functioning among workers in a labour-intensive coal mine. Methods The study population comprised 299 men working at a coal mine in Tanzania. Lung function was assessed using a Vitalograph alpha III spirometer in accordance with American Thoracic Society recommendations. Multiple linear regression models were developed to study the relationship between forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC and the cumulative dust or quartz exposure while adjusting for age, height and ever smoking. To evaluate trends for dose response, cumulative exposure concentrations for respirable dust and quartz were ranked and categorized in quartiles and the highest decile, with the first quartile as the reference group. Logistic regression models were used to determine odds ratios for FEV₁/FVC < 0.7 and FEV₁% < 80 for categories of cumulative dust or quartz exposure. Results The prevalence of FEV₁/FVC < 0.7 among the workers was 17.3%. Workers in the development team (20.5%) had the highest prevalence of FEV₁% < 80%. The estimates of the effects of cumulative exposure on FEV₁/FVC were −0.015% per mg years m^–3 for respirable dust and –0.3% per mg years m^–3 for respirable quartz. In logistic regression models, the odds ratios for airway limitation (FEV₁/FVC < 0.7) for the workers in the highest decile of cumulative dust and quartz exposure versus the referents were 4.36 (95% confidence interval: 1.06, 17.96) and 3.49 (0.92, 13.21), respectively. The upper 10% of workers by cumulative dust and quartz exposure also had higher odds ratios for predicted FEV₁% < 80% than the reference group odds ratio: 10.38 (1.38, 78.13) and 14.18 (1.72, 116.59), respectively. The results must be interpreted with caution due to a possible healthy worker effect and selection bias. Conclusion Exposure to respirable coal mine dust was associated with airway limitation as measured by FEV₁/FVC and predicted FEV₁%.     

Pulmonary function in Sardinian fire fighters

Our study examined the respiratory function of 92 firemen whose main activity is fire fighting in forests and open country. Such fire fighting activities are to be considered a risk to the respiratory tract, taking into account studies already in the literature that have evaluated the nature and quantity of inhalable toxins present in activities of this kind. The control group was composed of 51 Carabinieri (policemen), who were asked to fill in a questionnaire about their work activities. Forced expiratory volume and flow, total lung capacity, respiratory volume, and the permeability of the alveolar-capillary barrier were measured. Firemen and Carabinieri (policemen) showed FVC rates higher than the European Community for Coal and Steel standards. The firemen showed a significant reduction in forced expiratory volume in 1 second (FEV₁) [3.90 (0.50) vs. 4.04 (0.44); p < 0.05] and forced expiratory flow at 75% of forced vital capacity (FVC) (FEF₇₅) [8.37 (4.11) vs. 8.38 (1.67) p < 0.05] and more markedly in the FEV₁/FVC relationship [80.07 (5.89) vs. 83.89 (1.67) p < 0.001] and in FEF₅₀ [4.73 (1.34) vs. 5.54 (1.44) p < 0.01] and FEF₂₅ [1.58 (.47) vs. 1.99 (.69) p < 0.001]. There were no marked differences in air-blood exchanges. No correlation was found between respiratory function data and years of service or the number of fires extinguished during work experience. © 1996 Wiley-Liss, Inc.