F. Valić

Respiratory function in coffee workers.

Respiratory function was studied in three groups of workers employed in processing coffee. The prevalence of almost all chronic respiratory symptoms was significantly higher in coffee processors than in control workers. In each group during the Monday work shift there was a significant mean acute decrease in the maximum expiratory flow rate at 50% vital capacity (VC), ranging from 4.0% to 8.7%, and at 25% VC, ranging from 6.0% to 18.5%. Acute reductions in FEV1.0 were considerably lower, ranging from 1.3% to 2.8%. On Thursdays the acute ventilatory function changes were somewhat lower than on Mondays. Acute decreases in flow rates at low lung volumes suggest that the bronchoconstrictor effect of the dust acts mostly on smaller airways. Administration of Intal (disodium cromoglycate) before the shift considerably diminished acute reductions in flow rates. A comparison of Monday pre-shift values of ventilatory capacity in coffee workers with those in controls indicates that exposure to dust in green or roasted coffee processing may lead to persistent loss of pulmonary function.

Histamine-releasing activity and bronchoconstricting effects of sisal

Nicholls, P. J., Evans, E., Valić, F., and Žuškin, E. (1973).British Journal of Industrial Medicine,30, 142-145. Histamine-releasing activity and bronchoconstricting effects of sisal. Extracts of dry and oiled sisal released histamine from pig and human but not from rat lung tissue. A suspension in Tyrode solution of the oil used for softening the sisal fibres had a pH of 8·1 and also released histamine from pig and human lung. The releasing activity was abolished when the pH of this suspension was adjusted to pH 7·4. As all the sisal extracts were adjusted to pH 7·4 for incubation with lung tissue, the histamine-releasing activity of sisal in vitro is unrelated to the presence of the oil. Significant (P < 0·01) mean reductions over the work shift of ventilatory capacity (PEF and FEV1·0) were recorded in all the workers exposed to airborne sisal dust. These reductions were greater in combers than in drawers and spinners. Sisal collected from combing machines possessed more histamine-releasing activity than material from drawing and spinning machines. These results indicate that histamine release by sisal may be the cause of acute ventilatory capacity changes in sisal exposure.

Lung function in textile workers.

Acute changes in ventilatory function during a workshift with exposure to hemp, flax, and cotton dust were measured on Mondays in a group of 61 textile workers, all working on carding machines. In addition, single-breath diffusing capacity (DLCOSB) was measured before dust exposure on Monday in 30 of the 61 workers. Large acute reductions during dust exposure were recorded in maximum expiratory flow rate at 50% VC (MEF50%), ranging from 38 to 22%. Acute reductions of FEV1-0 were considerably smaller, ranging from 17 to 9%. There was a statistically significant increase in residual volume (RV) with very small and insignificant changes in total lung capacity (TLC). Although preshift FEV1-0 and FVC were decreased, DLCOSB was within normal limits. Plethysmographic measurements in six healthy volunteers exposed to hemp-dust extract confirmed the results obtained in textile workers, that is, that TLC does not change significantly during dust-induced airway constriction and that maximum expiratory flow rate at 50% VC (MEF50%) is a more sensitive test than FEV1-0 in detecting acute ventilatory changes caused by the dust extract.

Effects of hemp dust exposure on nonsmoking female textile workers.

Symptoms of byssinosis were found in 39% of 102 female hemp workers who were nonsmokers. A higher prevalence of chronic bronchitis (P < 0.01) was found in workers with symptoms of byssinosis than in those without such symptoms. In hemp workers, either with or without symptoms of byssinosis, FEV1.0 and FVC significantly decreased during work on the study days, Mondays and Thursdays; significantly lower reductions were registered on Thursdays. Inhalation of metaproterenol sulfate (Alupent) before work significantly diminished FEV1.0 reduction, although not completely preventing it. Metaproterenol inhalation after work significantly increased FEV1.0, indicating the reversibility of acute lung function changes during work. Comparison of lung function values measured before work with values obtained in the control group indicates a chronic effect of hemp dust on ventilatory function.

A follow-up study of functional and radiological lung changes in carbon-black exposure.

SummaryA group of 35 carbon-black workers were examined twice within a period of 6 years. Gravimetric determination of total and respirable particles and particle size analysis of thermal precipitator samples were used to assess the exposure level. The forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were measured and X-rays were taken of each subject. Within the period of 6 years both FVC and FEV1 values deteriorated significantly, the average annual decline of FVC being four and of FEV1 more than three times higher than those expected for the normal male population. Radiological lung changes found in 17.1% of the workers progressed during the observation period.

Respiratory symptoms and ventilatory function in sisal dust exposure.

SummaryA study of respiratory symptoms and ventilatory function was made in a group of 51 non-smoking female workers exposed to sisal dust and 51 control subjects matched in age and height. A higher prevalence of persistent cough (17.6%), persistent phlegm (13.7%), chronic bronchitis (9.8%) and nasal catarrh (19.6%) was found in sisal workers than in controls (5.9, 5.9, 5.9 and 0%, respectively). Not a single case of byssinosis was found in the workers surveyed.In sisal workers, FEV1.0, FVC and PEF significantly decreased over the work shift (P<0.01). Control workers did not show significant acute changes in ventilatory function over the shift. Inhalation of Alupent (orciprenaline) before the shift significantly diminished acute reductions in ventilatory capacity during the shift. The results suggest that sisal dust does not cause byssinosis but affects ventilatory function of the exposed workers.

Respiratory-function changes in textile workers exposed to synthetic fibers.

The prevalence of respiratory symptoms and acute and chronic changes in ventilatory function were studied in three groups of textile workers: 68 workers with exposure to synthetic fibers only, 30 with previous exposure to cotton, and 77 with previous exposure to hemp. The prevalence of dyspnea, grade 3 to 4, was significantly lower (P less than .01) in workers with a history of exposure to synthetic fibers only than in those previously exposed to hemp or cotton. No case of byssinosis was found in any of the workers studied. Values in ventilatory-function tests (FEV 1.0, FVC and MEF 50%) were significantly reduced during the work shift on Monday and Thursday. The Monday MEF 50% preshift values were significantly lower than expected in all three groups of workers. A comparison of the 1963-1973 data on the 77 workers previously exposed to hemp showed a lower prevalence of most chronic respiratory symptoms and smaller acute FEV1.0 and FVC reductions when they worked with synthetic fibers (1973) than when they were exposed to hemp (1963).

Effects of aerosols in common use on the ventilatory capacity of the lung

SummaryA group of 17 volunteers were exposed to a body deodorant, an air freshener, air disinfectant, a furniture polish, spot remover, shoe spray, glass defroster, hair spray and, separately, to their volatile components.An immediate significant fall in ventilatory capacity was recorded upon exposure to each of the sprays. The maximum fall of FEV1.0 ranged from 3.3 to 7.4%, that of Vmax 50% VC from 5.3 to 11.3%, while Vmax 75% VC falls were most pronounced reaching up to 20.9%, suggesting a predominant effect on small airways. In the majority of cases changes in ventilatory capacity on exposure to sprays were similar to those recorded on exposure to their solvents.A significant drop in ventilatory capacity over the period of a work shift was found in a group of hairdressers exposed to hair sprays — more pronounced in Vmax 50% VC and Vmax 75% VC than in FEV1.0.When preliminary tests on the histamine-releasing activity of sprays were performed, evidence was found that sprays released histamine, but in quantities not likely to be inhaled in the normal use of sprays.

Annual decline of ventilatory capacity and change in acute respiratory response in hemp exposure over a 10-year period

SummaryA follow-up study of the effect of exposure to hemp dust on respiratory function over a 10-year period (1963–1973) was conducted in 24 female non-smoking hemp workers. The prevalence of byssinosis in 1973 (70.8%) was found to be significantly higher than 10 years earlier in 1963 (33%) (P<0.01). The prevalence of all other chronic respiratory symptoms was also considerably increased. In the control group the prevalence of all chronic respiratory symptoms was practically the same during both surveys.In hemp workers, there was a significant acute fall over the work shift in FEV1.0 (1-second forced expiratory volume) and FVC (forced vital capacity), both in 1963 and 1973 (P<0.01), except in the group of workers who did not have byssinosis either in 1963 or in 1973. The lowest mean annual decline of FEV1.0 within the 10-year period was found in the group without byssinosis in both 1963 and in 1973 (27 ml), followed by the group without byssinosis in 1963 but with byssinosis in 1973 (38 ml). The largest annual decline was observed in the subjects with byssinosis during both surveys (55 ml). The mean annual FEV1.0 decline in the control group was 22 ml.

EFFECTS ON THE COPROPORPHYRIN TEST OF DRUGS USED IN THE TREATMENT OF PARASITIC DISEASE

The effects of the following drugs on urinary coproporphyrin estimations were studied: fouadin, tartar emetic, coramine, emetine hydrochloride, carbon tetrachloride, hexylresorcinol, and atebrin. None of these substances interferes directly with the fluorimetric determination of urinary porphyrin if porphyrin is extracted from urine by ether or ethyl acetate and subsequently re-extracted into the aqueous phase with hydrochloric acid. Persons under treatment with tartar emetic showed a significantly higher coproporphyrin excretion. For this reason the coproporphyrin test for abnormal lead absorption is likely to be unreliable in persons treated with tartar emetic.