Byssinosis in the Egyptian Cotton Industry: Changes in Ventilatory Capacity during the Day

Abstract

A study in Egypt of 99 male cotton workers in a cotton ginnery and spinning mill, and of a control group of 12 power station workers, showed that the groups exposed to cotton dust had significantly greater falls in indirect maximum breathing capacity (I.M.B.C.) during the shift than groups not exposed to dust. Long-term effects of exposure to cotton dust were studied by examining the I.M.B.C.s measured at the beginning of the shift after adjustment to allow for differences in age and sitting height. The adjusted mean value for those with byssinosis was 10-1 litres/min. lower than for normal cotton workers and 19-6 litres/min. lower than for the power station workers. Four men were judged by their breathlessness on slight exertion and low ventilatory capacities to be seriously disabled with byssinosis.In four other mills, all spinning similar types of cotton, changes in I.M.B.C. during the shift correlated highly with dust concentrations and indicated a safe level of dustiness of 1 mg./m.3 (total dust) at which the effects on ventilatory capacity were minimal. An epidemiological survey by Batawi (1962) provides the first published evidence of the occurrence of byssinosis in the Egyptian cotton industry. Batawi examined more than 600 workers and found that the prevalence of byssinosis was 38% in the ginneries where the cotton seeds are removed, 53 % in the bale pressing plants, and 27°' in the card rooms of spinning mills. Byssinosis was diagnosed on the characteristic history of tightness in the chest on the first working day of the week, which is Saturday in Arab countries. On this evidence it seemed to be a major problem demanding further investigation.Exposure to cotton dust has been found to be associated with a fall in ventilatory capacity during the work shift (McKerrow, McDermott, Gilson, and Schilling, 1958). This fall is particularly marked in workers suffering from byssinosis and provides additional and more objective evidence of the hazard of byssinosis to support that based on the characteristic history of chest tightness. It has been us.d in several recent field and laboratory investigations of persons exposed to vegetable dusts

Respiratory symptoms and ventilatory function changes in relation to length of exposure to cotton dust

“…While Molyneux and Tombleson (1970) found a steady increase of byssinosis with duration of exposure up to 29 years in their study of 1,359 cotton workers, Batawi, Schilling, Valic, and Walford (1964) and Bouhuys et al (1969) had not observed this relationship. Batawi et al (1964), however, found a high significant correlation between the fall of indirect maximum breathing capacity during the shift and the incidence of byssinosis.…”

“…ENVIRONMENTAL DUST MEASUREMENT Airborne dust samples were collected by means of two-stage dust samplers with a horizontal elutriator as the first stage (Hexhlet Sampler, Casella, London) (Wright, 1954 (Schilling et al, 1964). Definitions.…”

“…The severity of the symptoms of byssinosis was graded clinically according to Schilling et al (1964): grade 1/2: occasional chest tightness on Mondays grade 1: chest tightness or difficulty in breathing on every Monday at work grade 2: chest tightness or difficulty in breathing during work on Mondays and other working days.…”

“…Later, the same symptoms occur on subsequent days of the week, and chronic cough and dyspnoea may persist even during absence from work. Evidence of irreversible ventilatory insufficiency may then be found (Schilling et al, 1964).…”

A population study in cotton ginnery workers in the Sudan

“…The prevalence of byssinosis in cotton ginneries has been described in many different countries (Gilson, Stott, Hopwood, Roach, McKerrow, and Schilling, 1962;Batawi, 1962;Batawi et al, 1964;Kondakis and Pournaras, 1965). In the Sudan, byssinosis caused by cotton dust is a notifiable and compensatable industrial disease under the Workshops and Factories Ordinance, 1949 (Khogali, 1966 (Schilling, Vigliani, Lammers, Valid, and Gilson, 1964), translated into Arabic, was used.…”