ABSTRACT
The aim of the study was to establish whether changes occur in respiratory function, particularly mucociliary clearance, among second fusion smeltery workers. The research covered 93 male smelters employed in steel forming and casting and 116 male workers of an electric power station, considered as non-exposed. Physiological, pathological and occupational histories of all subjects under study were available. An ECCS respiratory symptoms questionnaire was administered to all subjects ad the two groups also underwent a general medical examination, a spirometry and a chest X-ray. During the medical examination sputum was collected from the subjects to measure mucus transport rate on frog palate, expressed as Normalised Frog Palate Transport Rate (NFPTR). For the environmental research, dust, fumes and gas samplings were taken either at a fixed station or by means of personal dosimeters. Environmental research revealed very low concentrations of respiratory irritants (total dust: 0.2-6.8 mg/m3; respirable dust: 0.1-4.9 mg/m3; total silica: < 2-15.5%; respirable silica: < 0.004-0.3 mg/m3; iron: 0.008-0.085 mg/m3; chromium and manganese: < 0.001 mg/m3; fumes and gases: well below the TLV. The two groups were homogeneous with regard to age and smoking habits. Exposed workers showed rales, dyspnoea and spontaneous phlegm more frequently than non-exposed workers. NFPTR alterations were checked in 49 out of 81 exposed and in 18 out of 81 non-exposed subjects (chi squared = 22.9; p < 0.001). Stratification of the results according to smoking habits further confirmed the strong association between occupational exposure and NFPTR alterations. Smelters showed significantly lower mean NFPTR values compared to non-exposed subjects; also, the mean value of NFPTR in the exposed was below 0.70, which is considered the lowest individual limit in normal subjects. The only variable which explains a large part of the variability of NFPTR is past work in a smeltery rather than in an electric power station. The spirometries showed that only the mean PEF values were significantly lower among the exposed. Stratified analysis of the results according to smoking habits in the two groups revealed a close association between smeltery work and reduction of PEF to under 80% of the ECCS 1983 theoretical values, independently of smoking habits. We also compared the mean PEF values, both as measured values and as percent values of the ECCS 1983 theoretical values, stratified for occupational exposure and smoking; the results again showed that differences between these mean values were mainly due to current or past work in the foundry.(ABSTRACT TRUNCATED AT 400 WORDS)
Subject(s)
Bronchitis/etiology , Metallurgy , Mucociliary Clearance , Occupational Diseases/diagnosis , Occupational Exposure , Respiration , Adult , Air Pollutants, Occupational/analysis , Bronchitis/diagnosis , Chronic Disease , Environmental Monitoring , Humans , Male , Middle Aged , Occupational Diseases/etiology , Radiography, Thoracic , Smoking , SpirometryABSTRACT
The aim of this study is to verify whether inhaling metallic dusts, containing a lower concentration of Mn (as Mn3O4) than current TLV can cause alterations in exposed workers tracheobronchial mucociliary clearance. We studied 20 grinders using an 11.5-13% Mn steel, and a control group of 21 standard steel grinders, employed in the same foundry. Environmental Mn dust was measured by personal samplers. All workers were administered a questionnaire about chronic bronchitis; the following examinations were also carried out: medical examination, spirometry, chest standard X-ray and urinary Mn dosage. Mucociliary clearance was measured by human respiratory mucus transportability on frog palate and expressed as normalized frog palate transport rate (NFPTR). Mucus was obtained through a sputum so protected as to avoid salivary contamination. Environmental measurements showed a Mn concentration from 0.1 to 1 mg/m3 with respect to a TLV of 5 mg/m3. Exposed workers and control group were homogeneous as far as age, working period, tobacco smoking habit and spirometric parameters are concerned. Chest X-ray examination showed no evidence of pneumoconiosis. Mn exposed workers showed a NFPTR reduction, if compared to normal level (0.70). NFPTR average value in exposed group has come out to be much lower than in control group. NFPTR alteration in Mn exposed group appears to be strictly linked to a longer than 15 years working seniority. Urinary Mn values resulted extremely low in each worker and their average was not significantly different between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)
