Epidemiology of respiratory diseases and associated factors among female textile workers in Pakistan.

Objective. The study aimed to estimate the prevalence of byssinosis and other respiratory symptoms among women textile workers and the associated risk factors in 18 spinning mills of Faisalabad and Lahore districts of Punjab, Pakistan. Method. In this case-control study of 1054 female workers, we used the dose-response function to measure the association between dust level and respiratory disorders in cotton textile workers. Results. Working overtime and long working hours per week are significantly associated with self-reported symptoms of byssinosis. Women's age, marital status and wages were significantly associated with mitigating actions (seeing the doctor), while the education of the women was significantly associated with averting action (use of a mask). Conclusion. Regulating working hours and ensuring employees' compliance with the safety standards are expected to mitigate the health problems of female workers.

[Histamine-related reactions in patients with byssinosis]. / Gistaminzavisimnye reaktsii u bol'nykh bissinozom.

The purpose of the study was to analyze the mechanism of histamine action in histamine-dependent reactions of neutrophils and lymphocytes in patients with byssinosis and chronic asthmatic bronchitis under cotton and flax dust effect. The appraisal of histamine content in blood serum, receptor/histamine distribution of lymphocyte and neutrophil subpopulations (rosette-forming double and triple reactions), determination of histamine modeling effect on lymphocyte-neutrophil cooperation in the inhibition reaction of leukocyte migration revealed that under cotton dust effect neutrophils and the complement system were involved into the histamine liberation process in byssinosis patients, lymphocytes were most likely not involved into the process. Flax dust-affected histamine reactions were not so distinct: lymphocyte and neutrophil reactivity in byssinosis patients did not exceed the standards. Patients with chronic asthmatic bronchitis had high blood concentration of histamine and experienced some changes in cells' migration characteristics. It was assumed that primarily nonimmune mechanisms of histamine liberation and activation of the complement system were involved into byssinosis pathological process in patients exposed to cotton and flax dust effect. In patients with chronic asthmatic bronchitis there occurred all 3 activation mechanisms of biologically active substances, i.e., allergic and nonantigenic ways of histamine liberation and activation of the complement system.

Discrepancies in the study of byssinosis in China.

The existence of byssinosis in China was first reported in 1964. Detailed studies only started in the late 1970s and early 1980s. The work of the WHO study group as edited by the Technical Report Series no. 684, "Recommended health-based occupational exposure limits for selected vegetable dusts," promotes the further study of occupational disease in China; a few points need further discussion. The word byssinosis translated in Chinese is misleading as to the real pathogenesis of the disease. Some still believe cotton dust causes interstitial fibrosis, while the majority of researchers agree with the WHO study group. A poorly designed animal model may have led to the (incorrect) conclusion that dust from carding room is toxic if it is injected intratracheally. The reasons for the controversy in the prevalence of byssinosis in different reports in earlier years are the different diagnosis criteria and the fact that dust sampling methods were not standardized; pulmonary function tests were not used as a routine index; chronic bronchitis and smoking are now recognized as confounders and should have been considered. This Institute initiated the hygiene standards study on cotton dust and recommended 1 mg/m3 for respirable dust and 3 mg/m3 for total dust. If a reduction in dust levels could prevent byssinosis, it would likely also control the risk factor for developing bronchitis.

Physiological evidence that emphysema is not a feature of byssinosis.

A group of women with byssinosis of grades 2 and 3 were seen consecutively over three years in an occupational outpatient clinic. Detailed lung function tests were performed and the results for smokers and non-smokers compared. One hundred and fifty three patients were seen and 50 of these were life time non-smokers, 35 smoked one to nine cigarettes a day, and 68 smoked 10 or more cigarettes a day. After correction for age the mean FEV1 was found to be significantly lower (p less than 0.01) in heavy smokers than in non-smokers. In a subgroup of 89 subjects who were able to perform the carbon monoxide gas transfer test significantly lower values were obtained for the carbon monoxide transfer factor (TLCO), (p less than 0.001), TLCO % predicted (p less than 0.001), and the transfer coefficient (KCO) (p less than 0.001) in the heavy smokers than in the non-smokers, despite the fact that the non-smokers had worked longer in the cotton mills (p less than 0.02). The mean TLCO was significantly lower than predicted in the heavy smokers (p less than 0.001) but not in the non-smokers. A significant negative correlation was found between the number of cigarettes smoked per day and the TLCO (p less than 0.01), TLCO % predicted (p less than 0.001), and KCO (p = 0.005), but not with the number of years spent in the carding area. These results provide evidence supporting recent pathological observations that emphysema is probably due to concomitant cigarette smoking and is not itself a feature of byssinosis.

The effect of sodium cromoglycate, beclomethasone diproprionate and salbutamol on the ventilatory response to cotton dust in mill workers.

A double-blind placebo controlled study of sodium cromoglycate, beclomethasone dipropionate and salbutamol by inhalation was designed to test their effect on respiratory symptoms and changes in ventilatory capacity in cotton mill workers. All three drugs showed some beneficial effect. Salbutamol was the most effective drug studied, in all groups of workers. Beclomethasone dipropionate was also significantly effective particularly in workers with byssinosis or exertional dyspnoea. Sodium cromoglycate was the least effective of the three. Possible mechanisms of action of these drugs are described.

Change in the respiratory response to coarse cotton dust over a ten-year period.

Changes in respiratory function during a 10-year period were studied in a group of 34 men and 19 women exposed to coarse cotton dust. The prevalence of byssinosis increased significantly in the 10-year period both in men and women; in addition, there was an increase in the prevalence of all other chronic respiratory symptoms in 1973 compared to 1963. There was a significant decrease in forced expiratory volume in 1 sec and forced vital capacity over the Monday shift both in 1963 and 1973. In subjects who were without byssinosis in 1963 but who had developed it by 1973, there was a considerable decrease in forced expiratory volume in 1 sec in 1973. The mean annual decline of forced expiratory volume in 1 sec (70 ml) during the 10-year period in the men was much greater than expected on the basis of the prediction equation for normal males, and it was most pronounced in those with byssinosis at the time of both surveys (111 ml).