Six year follow up of lung function in men occupationally exposed to formaldehyde

The long term effects of formaldehyde on the respiratory tract have been investigated in a group of 164 workers exposed daily to the chemical during the production of urea formaldehyde resin, together with 129 workers not exposed to free formaldehyde. Exposure was classified as high (corresponding to an eight hour time weighted exposure of more than 2.0 ppm), medium (0.6 to 2.0 ppm), or low (0.1 to 0.5 ppm). Twenty five per cent of workers had had high exposure at some time and 17% moderate exposure. Both the exposed and unexposed groups had an annual assessment that included lung function. The proportion with self reported respiratory symptoms was similar in the two groups, 12% and 16% reporting breathlessness on hurrying and 26% and 20% wheezing. The initial forced expiratory volume in one second (FEV1) was within 0.5 l (approximately one standard deviation (SD)) of the predicted value (by age and height) in 65% of the exposed and 59% of unexposed workers and more than 0.5 l below the predicted value in 9% of exposed and 11% of unexposed workers. The mean decline in FEV1 was 42 ml a year (SD 45) in the exposed group and 41 ml a year in the unexposed group (SD 40 ml a year). The rate of decline showed the expected association with smoking in the unexposed group, but in the exposed group the mean rate of decline in the never smokers was similar to that in current smokers. There were, however, relatively few never smokers and considerable variation in the rates of decline. In the exposed group no association was found between the rate of decline and indices of exposure to formaldehyde. Thus there is no evidence from this study of an excess of respiratory symptoms or decline in lung function in the workers exposed to formaldehyde. The similar rate of decline of FEV1 however in never smokers and smokers of the exposed group is consistent with findings of other studies for workers exposed to formaldehyde and to toluene di-isocyanate.     

Across-shift lung function variation in cottonseed oil workers

BACKGROUND: The effects of cotton dust on pulmonary function among workers employed in cotton-spinning mills are well known. However, little data exist on the prevalence of this disorder in 'non-textile' cotton industries, including cottonseed oil mills, where high levels of exposure to dust have been demonstrated. AIMS: This study was performed in order to determine the across-shift and across-week decline of FEV(1) and respiratory symptoms among workers in a cottonseed oil mill. METHODS: Sixty-six exposed and 48 unexposed workers of a cottonseed oil mill in Turkey were investigated by questionnaire and lung function test (LFT). LFTs were performed before and after shift on all the working days of the week. Acute airway response was defined as an across-shift decline in FEV(1) of 5% or more on the first working day. RESULTS: Smoking was the only risk factor for having respiratory symptoms. Acute airway response was more frequently observed in the exposed group as compared to the unexposed group (OR = 6.2, 95% CI = 2.3-16.7). The median across-shift decline in FEV(1) on the first day (120 ml) significantly improved on the following days (10, 50, 60 and -30 ml). CONCLUSION: Smoking appears to be the main risk factor for having respiratory symptoms. Cottonseed dust may cause an acute pulmonary function decline on the first working day, but not on the following days of the week. This decline is associated with respiratory symptoms in exposed workers.     

Respiratory diseases, symptoms and ventilatory function in workers involved in processing food for livestock

The prevalence of chronic and acute respiratory symptoms and ventilatory capacity were studied in a group of 71 workers employed in animal food processing. A control group of 55 unexposed workers was also included in the study. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed than among control workers. Exposed smokers had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis and chest tightness than control smokers. The values for FVC, FEV1 and FEF50 measured in the exposed workers were significantly lower in comparison to predicted normal lung function values. In smokers all the measured parameters of ventilatory capacity were significantly lesser than predicted. For non-smokers only FVC and FEV1 were below normal. Our data indicate that occupational exposure to animal food may cause the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.     

Respiratory function in animal food processing workers

A group of 71 men employed in animal food processing was studied to assess the prevalence of acute and chronic respiratory symptoms and the presence of lung function abnormalities. In addition, a control group of 55 unexposed men was studied for the prevalence of chronic respiratory symptoms. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed workers compared to the control workers. Those workers who smoked had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than the smokers in the control group. For nonsmokers, the differences between exposed and control workers were significant for chronic phlegm and chest tightness. The frequency of acute symptoms associated with the work shift was high among the animal food workers. There were significantly lower measured values for FVC, FEV1, and FEF50 in the exposed group (smokers and nonsmokers) compared to predicted lung function values. In smokers, all measured parameters of ventilatory capacity were significantly less than predicted; for nonsmokers, the FVC and FEV1 were less than normal. Our data indicate that exposure to dust in the animal food industry may be associated with the development of acute and chronic respiratory symptoms and the impairment of lung function. Smoking, in this setting, appears to aggravate these changes.     

Respiratory illnesses and ventilatory function among workers at a cement factory in a rapidly developing country

Chronic exposure to Portland cement dust has been reported to lead to a greater prevalence of chronic respiratory symptoms and a reduction of ventilatory capacity. The seriousness of pulmonary function impairment and respiratory disease has not been consistently associated with the degree of exposure. Regular use of appropriate personal protective equipment, if available at the worksite, could protect cement workers from adverse respiratory health effects. For a variety of reasons, industrial workers in rapidly developing countries do not adequately protect themselves through personal protective equipment. This study explores the prevalence of chronic respiratory symptoms and ventilatory function among cement workers and the practice of use of personal protective equipment at work. An interviewer-administered questionnaire was used to collect information on sociodemographic characteristics, smoking profile and history of respiratory health among workers at a Portland cement plant (exposed) and workers occupationally unexposed to dust, fumes and gases (unexposed). Pulmonary function was assessed and pulmonary function impairment was calculated for the exposed and the unexposed workers. A higher percentage of the exposed workers reported recurrent and prolonged cough (30%), phlegm (25%), wheeze (8%), dyspnoea (21%), bronchitis (13%), sinusitis (27%), shortness of breath (8%) and bronchial asthma (6%). Among the unexposed, prevalences of these symptoms were 10, 5, 3, 5, 4, 11, 4 and 3%, respectively. Ventilatory function (VC, FVC, FEV(1), FEV(1)/VC, FEV(1)/FVC and PEF) was significantly lower in the exposed workers compared with unexposed workers. These differences could not be explained by age, body mass index (BMI) or pack-years smoked. Ventilatory function impairment, as measured by FEV(1)/FVC, showed that 36% of the exposed workers had some ventilatory function impairment compared with 10% of those unexposed. Certain jobs with greater exposure to cement dust had lower ventilatory function compared with others among the exposed workers. It was concluded that adverse respiratory health effects (increased frequency of respiratory symptoms and decreased ventilatory function) observed among cement workers could not be explained by age, BMI and smoking, and were probably caused by exposure to cement dust.     

Methacholine bronchial responsiveness and variations in lung function among workers exposed to flour

OBJECTIVES: Methacholine bronchial responsiveness and variations in the pulmonary function of workers exposed to wheat flour and a reference group were compared. METHODS: Each subject [140 men exposed to flour (bakers and pastry makers) and 77 controls] completed a standardized questionnaire. Bronchial responsiveness was quantified by measuring the slope between percentage decrements in forced expiratory volume in 1 second (FEV1) and cumulative methacholine dose. FEV1 and peak expiratory flow (PEF) were recorded four times a day for 15 days using a handheld electronic spirometer. The variability in the FEV1 and PEF readings was expressed as variation coefficients (100 x standard deviation/mean). RESULTS: The mean duration of exposure to flour was 14 (SD 9) years. Rhinitis was significantly more common in the exposed group than in the control group (30.7% versus 11.7%, P = 0.001). The mean FEV1 and PEF did not significantly differ between the two groups. The slope of the dose-response to methacholine and the variation coefficients were lower among the unexposed nonsmokers than among the exposed workers and smokers. The differences were significant for the exposed smokers. The two variation coefficients correlated with each other (r = 0.82) but not with the slope of the methacholine challenge. Conclusions Occupational exposure to flour and smoking increase bronchial responsiveness, as measured by the slope of the dose-response to methacholine and the variation coefficients of airflow. However, methacholine bronchial responsiveness and the variability of lung function do not measure exactly the same aspect of airway behavior.     

Work related decrement in pulmonary function in silicon carbide production workers.

The relation between pulmonary function, cigarette smoking, and exposure to mixed respirable dust containing silicon carbide (SiC), hydrocarbons, and small quantities of quartz, cristobalite, and graphite was evaluated in 156SiC production workers using linear regression models on the difference between measured and predicted FEV1 and FVC. Workers had an average of 16 (range 2-41) years of employment and 9.5 (range 0.6-39.7) mg-year/m3 cumulative respirable dust exposure; average dust exposure while employed was 0.63 (range 0.18-1.42) mg/m3. Occasional, low level (less than or equal to 1.5 ppm) sulphur dioxide (SO2) exposure also occurred. Significant decrements in FEV1 (8.2 ml; p less than 0.03) and FVC (9.4 ml; p less than 0.01) were related to each year of employment for the entire group. Never smokers lost 17.8 ml (p less than 0.02) of FEV1 and 17.0 (p less than 0.05) of FVC a year, whereas corresponding decrements of 9.1 ml (p = 0.12) in FEV1 and 14.4 ml (p less than 0.02) in FVC were found in current smokers. Similar losses in FEV1 and FVC were related to each mg-year/m3 of cumulative dust exposure for 138 workers with complete exposure information; these findings, however, were generally not significant owing to the smaller cohort and greater variability in this exposure measure. Never smokers had large decrements in FEV1 (40.7 ml; p less than 0.02) and FVC (32.9 ml; p = 0.08) per mg-year/m3 of cumulative dust exposure and non-significant decrements were found in current smokers (FEV1: -7.1 ml; FVC: -11.7 ml). A non-significant decrement in lung function was also related to average dust exposure while employed. No changes were associated with SO(2) exposure or and SO(2) dust interaction. These findings suggest that employment in SiC production is associated with an excessive decrement in pulmonary function and that current permissible exposure limits for dusts occurring in this industry may not adequately protect workers from developing chronic pulmonary disease.     

Work related decrement in pulmonary function in silicon carbide production workers

The relation between pulmonary function, cigarette smoking, and exposure to mixed respirable dust containing silicon carbide (SiC), hydrocarbons, and small quantities of quartz, cristobalite, and graphite was evaluated in 156SiC production workers using linear regression models on the difference between measured and predicted FEV1 and FVC. Workers had an average of 16 (range 2-41) years of employment and 9.5 (range 0.6-39.7) mg-year/m3 cumulative respirable dust exposure; average dust exposure while employed was 0.63 (range 0.18-1.42) mg/m3. Occasional, low level (less than or equal to 1.5 ppm) sulphur dioxide (SO2) exposure also occurred. Significant decrements in FEV1 (8.2 ml; p less than 0.03) and FVC (9.4 ml; p less than 0.01) were related to each year of employment for the entire group. Never smokers lost 17.8 ml (p less than 0.02) of FEV1 and 17.0 (p less than 0.05) of FVC a year, whereas corresponding decrements of 9.1 ml (p = 0.12) in FEV1 and 14.4 ml (p less than 0.02) in FVC were found in current smokers. Similar losses in FEV1 and FVC were related to each mg-year/m3 of cumulative dust exposure for 138 workers with complete exposure information; these findings, however, were generally not significant owing to the smaller cohort and greater variability in this exposure measure. Never smokers had large decrements in FEV1 (40.7 ml; p less than 0.02) and FVC (32.9 ml; p = 0.08) per mg-year/m3 of cumulative dust exposure and non-significant decrements were found in current smokers (FEV1: -7.1 ml; FVC: -11.7 ml). A non-significant decrement in lung function was also related to average dust exposure while employed. No changes were associated with SO(2) exposure or and SO(2) dust interaction. These findings suggest that employment in SiC production is associated with an excessive decrement in pulmonary function and that current permissible exposure limits for dusts occurring in this industry may not adequately protect workers from developing chronic pulmonary disease.     

Pulmonary function in fur-processing workers: a dose-response relationship

Pulmonary function tests were conducted in 212 male workers exposed to fur dust in a fur-processing factory, and in 148 unexposed male workers. The authors used the cumulative dose of dust exposure (mg-yr) as an exposure index to relate to pulmonary function injury, as measured by pulmonary function tests, in exposed workers. The results showed that fur workers had lower percentages of predicted pulmonary function, as measured by forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1.0), and maximal flow rate of expiration at 50% and 25% of forced vital capacity (V50 and V25, respectively), compared with controls (p < 0.01). As the cumulative dose of fur dust exposure increased, average levels of pulmonary function declined significantly (p < 0.01), and pulmonary function abnormalities (i.e., < 80% of predicted FVC and FEV1.0, or < 70% of predicted V50 and V25) increased significantly (p < 0.05). Multiple-regression results identified fur dust exposure as the leading risk factor associated with the decline in pulmonary function in the exposed group. The results demonstrated a dose-response relationship between fur dust exposure and respiratory system injury, as measured by pulmonary function tests in fur-processing workers. On the basis of this dose-response relationship and the use of lifetables, the authors proposed an exposure limit of 4 mg/m3 for fur dust.     

Respiratory disease in foundry workers

A survey was carried out in a steel foundry in Brisbane to evaluate the nature and frequency of respiratory symptoms and to assess ventilatory function. The foundry used many moulding processes including the Furane, Isocure, Shell, carbon dioxide, and oil sand systems. Nasal symptoms and wheeze were often reported, particularly by workers in the general foundry and core shop, and on a semiautomated line. By contrast, workers in the aftercast section not exposed to fumes or vapours from the various moulding processes reported these symptoms less often. Of 46 workers exposed to moulding fumes and vapours, 11 had developed a wheeze while working at the foundry. Wheeze and other respiratory tract symptoms were often attributed by the workers to exposure to substances at work, particularly from the Shell process which uses phenol formaldehyde resin and hexamethylenetetramine. Symptoms were reported also, but less often, on exposure to materials used in the Furane process (urea formaldehyde and furfuryl alcohol) and the Isocure process (methylene diphenyl diisocyanate, phenol formaldehyde, and dimethylethylamine). Ventilatory function studied over Monday and Friday showed a small and inconsistent changes. The six subjects working on the semiautomated line showed a small decrease in FEV1 (+/- SEM) (208 +/- 70 ml) only on Monday; this differed significantly from that in 17 aftercast workers (9 +/- 50 ml, p less than 0.05). Ventilatory function recorded before work on Monday morning showed no evidence of chronic airway obstruction in any group. Most environmental measurements were below the threshold limit values (TLV) except in the general foundry, where furfuryl alcohol was detected at concentrations of up to 50 ppm and formaldehyde at 4 ppm. The onset of symptoms in relation to exposure to various fumes and vapours suggests that both irritant and hypersensitivity mechanisms are present. As environmental modifications had occurred recently the apparent hypersensitivity may relate to past exposure levels above the TLV.     

Respiratory disease in foundry workers.

A survey was carried out in a steel foundry in Brisbane to evaluate the nature and frequency of respiratory symptoms and to assess ventilatory function. The foundry used many moulding processes including the Furane, Isocure, Shell, carbon dioxide, and oil sand systems. Nasal symptoms and wheeze were often reported, particularly by workers in the general foundry and core shop, and on a semiautomated line. By contrast, workers in the aftercast section not exposed to fumes or vapours from the various moulding processes reported these symptoms less often. Of 46 workers exposed to moulding fumes and vapours, 11 had developed a wheeze while working at the foundry. Wheeze and other respiratory tract symptoms were often attributed by the workers to exposure to substances at work, particularly from the Shell process which uses phenol formaldehyde resin and hexamethylenetetramine. Symptoms were reported also, but less often, on exposure to materials used in the Furane process (urea formaldehyde and furfuryl alcohol) and the Isocure process (methylene diphenyl diisocyanate, phenol formaldehyde, and dimethylethylamine). Ventilatory function studied over Monday and Friday showed a small and inconsistent changes. The six subjects working on the semiautomated line showed a small decrease in FEV1 (+/- SEM) (208 +/- 70 ml) only on Monday; this differed significantly from that in 17 aftercast workers (9 +/- 50 ml, p less than 0.05). Ventilatory function recorded before work on Monday morning showed no evidence of chronic airway obstruction in any group. Most environmental measurements were below the threshold limit values (TLV) except in the general foundry, where furfuryl alcohol was detected at concentrations of up to 50 ppm and formaldehyde at 4 ppm. The onset of symptoms in relation to exposure to various fumes and vapours suggests that both irritant and hypersensitivity mechanisms are present. As environmental modifications had occurred recently the apparent hypersensitivity may relate to past exposure levels above the TLV.     

Respiratory health of plywood workers occupationally exposed to formaldehyde

This study was undertaken to enlarge our understanding of the adverse health effects of formaldehyde exposure in the workplace and community environment. The respiratory health status of 186 male plywood workers was evaluated by spirometric tests, respiratory questionnaires, and chest x-rays. Area concentrations of formaldehyde were measured in the work environment and found to range from 0.28 to 3.48 ppm. The average personal exposure was to 1.13 ppm of formaldehyde. Exposure to formaldehyde was associated with decrements in the baseline spirometric values, i.e., forced expiratory volume in 1 sec (FEV1.0), forced expiratory volume/forced vital capacity (FEV/FVC), and FEF25%-75%, and with several respiratory symptoms and diseases, including cough, phlegm, asthma, chronic bronchitis, and chest colds. The results of the study support the hypothesis that chronic exposure to formaldehyde induces symptoms and signs of chronic obstructive lung disease.     

Lung function among asbestos cement factory workers: cross-sectional and longitudinal study

Ventilatory capacity tests and standardized respiratory questionnaires were used in 1973 and in 1980 to measure the effect of mixed dust exposure in the asbestos cement industry on respiratory symptoms and lung function in 65 exposed workers and 30 controls (exposed to polyvinyl chloride but not to asbestos). Workers exposed to asbestos had 1) a higher prevalence of breathlessness and chest pain, and a higher incidence of breathlessness; 2) lower 1980 values of forced vital capacity (FVC) (0.27-0.83 liters) and forced expiratory volume in 1 sec (FEV1) (0.23-0.62 liters); and 3) a faster decline (nearly 40 ml/year) in FVC and FEV1 between 1973 and 1980. The FVC annual decrease was 52.5 ml in the subjects with more than 15 years since first asbestos exposure, whereas it was 24.3 ml in those with less than 15 years, suggesting a faster decline after 15 years of exposure. The effect of asbestos exposure and smoking habits was less than additive as regards pulmonary function.     

Health effects of low-level exposure to formaldehyde

Twenty-one subjects exposed to formaldehyde (at levels between 0.12 and 1.6 parts per million [ppm]) in two mobile trailers and the remaining 18 unexposed workers of the same workforce were examined by questionnaire and spirometry. Symptoms of eye and throat irritation and increased headache and fatigue were significantly more common among the exposed group than the comparison group. Irritation of the nose, chest tightness, and shortness of breath were also more common among the exposed. Spirometry revealed no decrease in ventilatory function among the exposed workers. The significant increase in frequency of individuals with symptoms indicated an adverse health effect from exposure to formaldehyde at levels between 0.12 and 1.6 ppm. This may have implications regarding the adequacy of the US permissible exposure limit value and suggests the need for further examination of the health effects of formaldehyde in the nonoccupational environment.     

Longitudinal decline in lung function in patients with occupational asthma due to western red cedar.

BACKGROUND: There are few reports about longitudinal changes in lung function in asthmatic patients. Patients with asthma had a greater loss of lung function than normal healthy adults. To date, there have been no studies about the longitudinal changes in lung function in patients with occupational asthma. METHODS: 280 male patients with red cedar asthma (RCA) who were followed up for at least one year were the study group. The exposed controls consisted of 399 male sawmill workers. Forced expiratory volume in one second (FEV1) was measured with a Collins water spirometer. Changes in FEV1 over time (FEV1 slope) were calculated by a two point method for each subject. Atopy was considered to be present if the subjects showed at least one positive response to three allergens by skin prick test. RESULTS: Multiple regression analysis was carried out to examine factors that might affect longitudinal decline in FEV1. Patients with RCA who were still exposed had a greater decline in FEV1 slope (-26 ml/y) than sawmill workers. Smokers also showed a greater rate of decline in FEV1 (-43 ml/y) than non-smokers. CONCLUSIONS: Patients with RCA who continued to be exposed had a greater rate of decline in FEV1 than sawmill workers. Early diagnosis of occupational asthma and removal of these patients from a specific sensitiser is important in the prevention of further deterioration of lung function and respiratory symptoms.     

Respiratory symptoms and lung function in jute processing workers: a primary investigation

This paper presents the results of an investigation of respiratory symptoms and lung function of 404 workers who had been exposed to jute dust in a jute mill. Measurement of total dust concentration and analysis of dust composition were also conducted. Most workers in the jute mill were exposed to jute dusts containing less than 5% silica, whereas a few workers were exposed to dusts containing approximately 10-15% silica. Male smokers and nonsmokers in the dust-exposed group had a higher prevalence of cough and chest tightness compared with those in the control group. Among dust-exposed workers, female nonsmokers had a significantly higher prevalence of cough, chronic bronchitis, chest tightness, and dyspnea than those in the control group. Lung function tests showed that dust-exposed workers had a greater incidence of abnormal lung function than did control workers, as measured by percentage of predicted forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and FEV1.0/FVC. Dust exposure was the main cause of respiratory symptoms and abnormal values of FEV1.0, but both cigarette smoking and dust exposure contributed to the abnormal values reported for FEV1.0.     

Respiratory findings in chemical workers exposed to low concentrations of organic and inorganic air pollutants

BACKGROUND: Occupational exposure to respiratory irritants may effect respiratory function in workers exposed to ambient air pollutants in the workplace. METHODS: We studied 567 male and 135 female workers employed in two chemical plants in Zagreb, Croatia. Measurements of the ambient concentrations of air pollutants were performed. The mean age of the men was 37 years and mean duration of employment was 12 years; a majority of these workers were smokers. The mean age of the women was 37 years with a mean duration of employment of 14 years; only one-third of the women smoked. An unexposed group of 340 male and 110 female unexposed workers was also studied. Acute and chronic work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. RESULTS: There were higher prevalences for all chronic respiratory symptoms in exposed than in unexposed workers particularly among women, a majority of which were nonsmokers. Occupational asthma was recorded in three (0. 5%) of the men and in two (1.5%) of the women workers. Logistic regression analysis indicated that the presence of chronic respiratory symptoms among exposed workers was primarily associated with the amount of smoking. Additionally, there were high prevalences of acute symptoms during the work shift. Among the chemical workers these were greatest for eye irritation (male: 43. 9%; female: 51.9%), dryness of the throat (male: 43.4%; female: 57. 0%) and irritation of the throat (male: 37.4%; female: 56.6%). Ventilatory capacity data among the chemical workers demonstrated that most of the measured tests, particularly the FVC and FEV1 were significantly decreased compared to predicted (P < 0.01 or P < 0. 05)). In particular nonsmoking women exhibited abnormal lung function. The effect of smoking among exposed workers was demonstrated on all ventilatory capacity tests by regression analysis for all measured respiratory parameters. Both length of exposure and age were correlated with lung function loss for FVC. Measured pollutant levels were for the most part within acceptable standard limits. CONCLUSIONS: Our data suggest that in this population of chemical workers exposed to low levels of pollutants respiratory symptoms were primarily associated with smoking. Environmental effects, possibly due to an interaction of pollutants were also suggested.     

Respiratory Effects of Occupational Exposure to an Epoxy Resin System

A standardized respiratory questionnaire and pulmonary function tests were used to examine thirty-four employees of a snow-ski manufacturing plant, including twenty-five workers who were exposed to an epoxy resin system containing the amine hardener 3- dimethylamino propylamine (3-DMAPA). Maximum expiratory flow-volume curves were obtained on Monday and Thursday, before and after each shift, and FVC, FEV 1.0, MEF50%, and MEF25% were calculated. Environmental measurements of the total amine levels were found to range from 0.41 to 1.38 ppm. The group with the greatest exposure (0.55-1.38 ppm) showed significant decreases in lung function over Monday and over the week. Although all employees in this group showed decreases in pulmonary function, acute changes were greater in present cigarette smokers and in subjects who reported respiratory symptoms upon exposure to the epoxy resin system. There was no evidence of permanent loss of lung function in subjects with either the highest or longest exposure.     

Occupational exposure to lignite and impact on respiratory system among heavy industry personnel

Objective is to evaluate the impact of occupational exposure to lignite dust on respiratory system. 103 blue-collar workers exposed to lignite dust and 62 controls completed a questionnaire on respiratory symptoms and underwent spirometry. Levels of lignite dust in workplace were measured. Univariate and multivariate analysis of the data were performed. The concentration of lignite dust varied from 0.6 to 1.4 mg/m3. Current smokers and workers exposed to lignite dust presented higher prevalence of chronic bronchitis symptoms and of FEV<80% and FEV1/FVC<70%. Multivariate analysis has shown that smoking and occupational exposure to lignite dust were independent predictors of chronic bronchitis symptoms, as well as of an obstructive ventilation pattern. Further analysis showed that exposed workers who were current smokers presented a five fold rate for developing an obstructive ventilation pattern in comparison to exposed workers non currently smokers. Occupational exposure to lignite dust and smoking were independent determinants of chronic bronchitis symptoms and obstructive ventilation pattern. There is some evidence for a combined effect of smoking and lignite dust exposure on respiratory system.     

Pulmonary and neurobehavioral effects of formaldehyde exposure

Two groups of male workers who were exposed to formaldehyde, the first group in phenol-formaldehyde-plastic foam matrix embedding of fiberglass (batt making), and the second in the fixation of tissues for histology, were studied for work-related neuro-behavioral, respiratory, and dermatological symptoms; and for pulmonary functional impairment. Forty-five male fiberglass batt makers who were studied across the initial work-shift after a holiday had average frequencies of combined neurobehavioral, respiratory, and dermatological symptoms of 17.3 for the hot areas and 14.7 for the cold areas of the process. Their symptom counts were significantly greater than those for 18 male histology technicians who averaged 7.3, and for 26 unexposed male hospital workers who averaged 4.8. During their first workshift after holidays, 58% of the batt makers had a decrease in one or more tests of pulmonary function. Nine nonsmokers had decreases more frequently than did 35 smokers; forced expiratory volume in one second FEV1.0 decreased in 16%, diffusing capacity for carbon monoxide (sb) decreased in 30%, forced expiratory flow 25-75 decreased in 16%, and forced expiratory flow) 75-85 decreased in 36%. Thirty-five percent of all 44 men had drops in FEV1.0, forced vital capacity, or in diffusing capacity (sb).