We carried gone out a study to ass...

We carried gone out a study to assess the prevalence of respiratory disease in lead miners and to investigate the characters of silica and lead. We used a questionnaire for symptoms and examinations for signs of respiratory disease, chest roentgenograms, and spirometric thought in 45 lead miners. Six underwent bronchoscopy and transbronchial lung biopsy (TBB) and five lung lead analysis. Lung lead of the same heights from five patients with no occupational lead prospect were obtained for comparison. originates showed restriction in five of 45 and reticulonodular opacities in 6 of 45 workers. Squamous metaplasia and other histopathologic changes were observ although silicotic nodules were absent on TBB. Lung lead evens above those of control controls were observed in four of five lead miners. These findings point out to that lead miners are at risk for lung disease. Although silica is a likely cause, elevated lung lead satisfaction found in these miners merits further investigation. (Chest 1989; 996:18-21)

Since miners of metals so as gold, tin, and copper money may be exposed to dusts with high independent silica content,[1] these occupations quick in emergencies a risk for silicosis. Respiratory disease among another collection of metal miners, those who mine lead, have not been well characterized. Lead miners have potential risk for silicosis and for systemic lead poisoning. Lead is a heavy metal with specific gravity of 1134 and atomic weight of 20721 The annual world lead production is 25 million tons,[2] 13 million tons of which are consum in the United States.[3] An important source of industrial plumbism in certain geographic areas is lead mining.[4] The chiefly common route of occupational exposing is by inhalation of lead oxide or lead particle.[5] Deposition rate in the lung varies between 30 and 50 percent at the disposal of on both ventilation rate and particle size.[6] Lung deposition appears due to sedimentation and diffusion by dint of brownian motion.[7] After deposition in the lower respiratory tract, about 35 to 50 percent of lead deposited is absorbed into the blood[68] Tissues and organs that arrive in contact with lead are damaged. plenteous information is available on assessing the systemic events of lead in various occupations, moreover to our knowledge the lung lead ease in exposed workers has not been reported.

This consideration was prompted by the observation of respiratory symptoms, especially in young lead miners with short front times who were exposed to ores containing the couple lead and silica. Our drift was to assess the prevalence of respiratory symptoms, physical findings, radiographic abnormalities, and pulmonary function impairment in lead miners and to investigate the histopathology of respiratory disease in a subgroup of lead miners. As a preliminary reflection to assess possible pulmonary toxicity to be paid to lead exposure, we also measured lung lead satisfaction in five miners and compared proceeds with those of patients with no occupational lead exposure

Material and Methods

The Donna mine is located in a mountain area in the north of Iran, about 90 km north of Tehran and 50 km southern of the Caspian Sea. The altitude of the area is about 960 m above sea horizontal The mine is spread surface, and dynamite is used for explosion. The dialy production is between 8 and 10 tons. Mining started in 1954 and, at the time of this contemplation 45 miners worked there.

Analysis of pair specimens of ores from the mine in 1981 showed lead concentrations of 1070 percent and 336 percent and [SiO.sub.2] concentrations of 3654 percent and 946 percent A specimen obtained by means of the usual production process of separating and concentrating metallic constituents of ore contained 60 percent lead. Other substances in this concentrated specimen included zinc, cauldron silica, sulfur, iron, manganese, aluminum, and magnesium. No quantitative analysis was available to assess the amounts of the non-lead constitutings of concentrated ore.

All 45 now passing lead miners were studied. Clinical examinations focused upon respiratory symptoms and signs. A brief questionnaire was used to determine the demeanor of symptoms, but the stage of impairment was not quantified during the interview. Chest x-ray films, as well-as; not only-but also; not only-but; not alone-but PA and lateral views, were done in succession all miners. Spirometric studies were performed with patients seated, using the Vitalograph Spirometer. The FVC [FEVsub1] [FEVsub1]/FVC and FEF25-75% were measured, and PEFR was measured using a Wright peak flowmeter The best of three determinations was used for FVC [FEVsub1] and PEFR The FEF25-75% was chosen from the exhibition with the highest [FEV.sub.1] + FVC quantity of money Observed values were compared with predicted normal values (P L Kamburoff and H J Woltowitz [1973] prediction nomogram by dint of Vitalograph Company). For abnormal ventilatory pattern definitions, the following criteria were used: restrictive defect: FVC < 80 percent predicted with [FEVsub1]/FVC% > 75 percent; and obstructive defect: [FEVsub1] < 80 percent and [FEVsub1]/FVC% < 75 percent Small airways abnormality (SAA) = FEF25-75% < 60 percent and no obstructive defect