Lung health in sawmill workers exposed to pine and spruce.

Workers exposed to a variety of wood dusts have been shown to exhibit occupational asthma, lung function deficits, and elevated levels of respiratory symptoms. Despite the popularity of pine and spruce, the health effects of exposures to these woods have not been extensively investigated. A study was undertaken to investigate the respiratory health of a group of sawmill workers processing pine and spruce (n = 94). Data collection included a respiratory symptom questionnaire, spirometry, and allergy skin testing. The sawmill workers were compared with a group of oil field workers from the same geographic area who underwent the same study protocol (n = 165). The results showed that the sawmill workers had significantly lower average values for FEV1 and FEV1/FVC (%), adjusted for age, height, and smoking. The largest differences were for current smokers. Significantly elevated age and smoking-adjusted odds ratios (OR) were detected for shortness of breath (2.83; 95% confidence interval [CI], 1.47 to 5.46) and wheeze with chest tightness (2.58; 95% CI, 1.18 to 5.62). Nonsignificant elevations were also seen for usual cough (1.47; 95% CI, 0.68 to 3.16), usual phlegm (1.94; 95% CI, 0.98 to 3.87), shortness of breath with exercise (1.45; 95% CI, 0.66 to 3.20), chest tightness (1.43; 95% CI, 0.80 to 2.57), and attacks of wheeze (1.70; 95% CI, 0.79 to 3.68). Sawmill workers were 2.5 times as likely as oil field workers to report current asthma (95% CI, 0.76 to 8.32). Workers employed more than 3 years showed significantly more asthma (OR = 3.67; 95% CI, 1.00 to 13.5) and bronchitis (OR = 2.14; 95% CI, 1.02 to 4.52). Sawmill workers were only 43% as likely to report a history of hay fever (95% CI, 0.20 to 0.94). These health effects were noted despite an average concentration of respirable dust of 1.35 mg/m3 (range, 0.1 to 2.2 mg/m3). These levels are below the present occupational standard.

Lung health in Alberta farmers.

SETTING: A study conducted in the rural areas of two counties in east-central Alberta, Canada. OBJECTIVE: To investigate the relationship between lung health and dust exposure in farmers. DESIGN: A cross-sectional study of 781 farmers growing grain crops and raising livestock. Measurements included a questionnaire on respiratory symptoms, smoking habits and occupation, skin prick tests using common aeroallergens, and spirometry. RESULTS: Immediate skin reactivity to common aeroallergens was less prevalent in farmers with higher reported intensity of dust exposure. Respiratory symptoms suggestive of bronchitis had a significant dose-response relationship with the reported intensity of dust exposure. Respiratory symptoms consistent with bronchial responsiveness were significantly positively associated with cumulative dust exposure. There was a significant positive association between a physician's diagnosis of bronchitis and intensity of dust exposure. FEV1 and FEV1/FVC were significantly negatively associated with cumulative dust exposure. Ten years of exposure to a moderate dust level was associated with a deficit of 43 ml in the FEV1 and a deficit of 0.44% in the FEV1/FVC. CONCLUSIONS: Despite evidence of worker selection related to dust exposure, these farmers experienced respiratory symptoms, respiratory conditions, and reduced lung function associated with reported occupational dust exposure.

Pulmonary effects of simultaneous exposures to MDI formaldehyde and wood dust on workers in an oriented strand board plant.

A study was undertaken in a plant producing oriented strand board (OSB) from aspen and balsam wood, bonded by methylene diisocyanate (MDI) and phenol formaldehyde. A group of 127 production workers in the plant was compared to 165 oil workers from the same geographic area. Measurements of MDI ranged from 6 to 33 micrograms/m3 (0.001-0.003 ppm), of respirable dust ranged from 0.05 to 0.5 mg/m3, and of formaldehyde were 0.05 ppm or less. The ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) was significantly lower among the OSB workers compared to the oil workers, and this was more pronounced for ex-smokers and current smokers. A number of respiratory symptoms suggestive of airway reactivity were significantly more common among the OSB workers. It was known that changes to reduce worker exposure had been made in the plant before the study, and it is unclear whether the health effects documented were the result of these low levels or if previous, probably higher levels were responsible.

Lung health among electricians in Edmonton, Alberta, Canada.

Respiratory symptoms, lung function, and radiographic changes among 100 actively employed electricians in Edmonton, Alberta, Canada, with 20 or more years of union membership were compared with those of 100 telephone workers. Posteroanterior chest radiographs were evaluated by two experienced chest physicians, with a third arbitrating films that were disagreed upon. Employment in a number of industrial sectors was compared for time and for time-weighted exposure to dust and fumes. Compared with telephone workers, electricians had more usual cough (odds ratio [OR] = 3.36; 95% confidence interval [CI], 1.36-8.31), usual phlegm (OR = 2.44; 95% CI, 1.01-5.86), chronic phlegm (OR = 2.74; 95% CI, 1.13-6.60), and shortness of breath (OR = 2.26; 95% CI, 1.10-4.67), but no differences in lung function. The prevalence of radiographic changes in both groups was low. The electricians had more radiographic changes, but only for the category "any change" was the difference statistically significant (OR = 5.2; 95% CI, 1.06-23.93). Only two electricians had small irregular opacities. Phlegm, chronic phlegm, and chest tightness were significantly associated with cumulative exposure to fumes in the gas and oil industry and to total industrial construction.

Respiratory consequences of exposure to wood dust and formaldehyde of workers manufacturing oriented strand board.

A cross-sectional study was performed at a plant in which 99 workers were employed in the manufacture of oriented strand board. This group was compared with 165 unexposed workers from the petroleum industry. Both groups were assessed, using a questionnaire, spirometry, and skin prick tests to common environmental antigens. Environmental studies showed a low dust level of 0.27 mg/m3, consisting of particles of a mass median aerodynamic equivalent diameter of 2.5 microns. There were variable concentrations of formaldehyde, up to 0.27 ppm. A significant difference between the oriented strand board workers and oil field workers was noted for the forced expiratory volume in 1 s/forced vital capacity ratio, without significant differences in either the forced expiratory volume in 1 s or the forced vital capacity. Oriented strand board workers who were current smokers were three times as likely to have a forced expiratory volume in 1 s/forced vital capacity ratio of less than 75% of that found in the currently smoking oil field workers. Significant reductions in forced expiratory volume in 1 s (p = .044) and forced vital capacity (p = .022) in oriented strand board workers were noted across the work shift. The oriented strand board workers complained of self-reported asthma and of lower respiratory tract symptoms significantly more frequently than did oil workers for all of the symptoms examined. The prevalence of atopy was not different in the two groups. Lung function was significantly better in oriented strand board workers who had no symptoms, compared with oriented strand board workers who were symptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung health in relation to hydrogen sulfide exposure in oil and gas workers in Alberta, Canada.

A study was undertaken to assess pulmonary health effects of hydrogen sulfide (H2S) exposure in a group of workers (n = 175) extracting and processing oil and natural gas in west-central Alberta. Exposure to H2S was assessed by questioning the workers about "exposures strong enough to cause symptoms," and exposures that resulted in loss of consciousness (a "knockdown"). Exposures strong enough to cause symptoms were reported by 34% of the workers. Fourteen workers (8%) reported having had a knockdown. Exposures severe enough to cause symptoms were not associated with lower spirometric values or excess symptoms. Knockdowns were not associated with lower spirometric values but were associated with statistically significant excesses of (1) shortness of breath while hurrying on the level or walking up a slight hill (OR = 3.55; 95%CI = 1.02-12.4); (2) wheeze with chest tightness (OR = 5.15; 95%CI = 1.29-20.6); and (3) attacks of wheeze (OR = 5.08; 95%CI = 1.28-20.2). The pattern of excess respiratory symptoms is consistent with bronchial hyperresponsiveness, which has been documented in studies of high-level exposure to other irritant gases. Additional study is warranted and should include assessment of bronchial reactivity.

Lung health among plumbers and pipefitters in Edmonton, Alberta.

OBJECTIVES: A cross sectional study was undertaken to assess lung health among plumbers and pipefitters. Respiratory symptoms, lung function, and radiographic changes among 99 actively employed plumbers and pipefitters with > or = 20 years of union membership were compared with 100 telephone workers. METHODS: A respiratory symptom questionnaire was administered, including smoking and occupational histories. Spirometry was conducted according to standard criteria. Posteroanterior chest radiographs were evaluated by two experienced chest physicians, with a third arbitrating disagreed films. Members of the union were categorised as pipefitters (n = 57), plumbers (n = 16), or welders (n = 26), based on longest service, and compared with the telephone workers and internally (between groups). Lung health was also compared with employment in several work sectors common to Alberta for time, and for time weighted by exposure to dust and fumes. RESULTS: Compared with the telephone workers, plumbers and pipefitters had more cough and phlegm, lower forced vital capacity, and more radiographic changes (20% with any change), including circumscribed (10%) and diffuse pleural thickening (9%). None of the plumbers and pipefitters had small radiographic opacities. Among the three subgroups of workers, plumbers had the highest prevalence of radiographic changes. Both plumbers and pipefitters showed higher odds ratios for cough and phlegm than the welders. No differences between groups were found for lung function. Indicators of lung health were not related to work in any sector. CONCLUSIONS: Plumbers and pipefitters had increased prevalence of symptoms suggestive of an irritant effect with no evidence of bronchial responsiveness. The chest radiographs showed evidence of asbestos exposure, especially in the plumbers, but at lower levels than previously reported. Health screening programmes for these workers should be considered, although the logistical problems associated with screening in this group would be considerable.

Lung health among boilermakers in Edmonton, Alberta.

BACKGROUND: Construction boilermakers may be exposed to a variety of substances, including asbestos and welding fumes. Past studies of boilermakers have shown increases in mortality from lung cancer and asbestosis and radiographic changes consistent with asbestos exposure. METHODS: Respiratory symptoms, lung function, and radiographic changes were compared for 102 actively employed boilermakers with 20 or more years of union membership and 100 telephone workers. Posteroanterior chest radiographs were evaluated by two experienced chest physicians, with a third arbitrating disagreed films. Union members were further categorized as boilermakers (n = 50) or welders (n = 52), based on longest service. Lung health was also compared with employment in a number of work sectors for time, and time-weighted exposure to dust and fumes. RESULTS: Boilermakers had more respiratory symptoms than telephone workers, but lung function did not differ. Radiographic changes were more common among the boilermakers (20% with any change, 8% circumscribed, and 9% diffuse pleural thickening). None of the boilermakers had small radiographic opacities. Several symptoms suggestive of bronchial responsiveness were associated with fume exposures in the gas and oil industry. Workers whose longest service was as a boilermaker demonstrated more symptoms than did welders. FEV1, FEV1/FVC, FEF25-75, and FEF50 were significantly lower among boilermakers compared with welders. CONCLUSION: Health screening programs for these workers are warranted.