Key words: Silicosis, asbestosis, lung cancer, extrinsic allergic alveolitis, occupational asthma, industrial bronchitis, lung functions
Abbrevations:
Co: cobalt
CT: computertomography
FEV1: forced expiratory volume in one second
IgE: immunglobulin E
ILO: International Labour Office
MDI: methyl-diisocyanate
Raw:airways resistance
TDI: toluene-diisocyanate
VC: vitalcapacity.
In my memorial lecture remembering on Professor Pacséri I would like to present a short overview on the evolution, changes and trends of the incidence, diagnostic methods and clinical manifestations of the most important occupational respiratory diseases in the last 40 years in Hungary.
Detailed medical investigations, lung function measurements including
spirometry, lung mechanics – lung compliance, later measurement of airways
resistance by body pletysmography, flow-volume curves – and blood gas analysis
were introduced in the ’60-s. Our studies, in good agreement with the data
of British and German authors (Cochrane 1973, Ulmer et al. 1968), proved
the following: in cross-sectional studies respiratory complaints characteristic
to chronic simple bronchitis – chronic cough and expectoration – were significantly
more frequent among silica dust exposed persons than in non exposed persons
(Table 1), but the mean values of the airways
resistance (Raw) of these groups were statistically equal (Table
2) i.e. while occupational silica dust exposure itself caused an
increased rate of simple chronic bronchitis, it didn’t induce general airway
obstruction characterized by elevated airways resistance. In another cross
sectional study comparing the airways resistance values of silica dust
exposed persons grouped according to their radiological grades of silicosis
we observed a significant elevation of this parameter only in the most
severe group with B–C grade of silicosis (Table 3)
(Mándi et al. 1972).
The airways obstruction has a significant effect on the surviving prognosis
of the dust exposed persons with chronic bronchitis: in our first 10-years
follow-up study (Mándi and Galgóczy 1972) we found that the
starting FEV1/VC values of dust exposed persons were significantly higher
in survivors than among patients dying of respiratory illness during the
observation period (Table 4). In our second
follow-up study (Table 5) the same surviving
rate of dust exposed persons with and without silicosis was found with
the exception of the most severe radiological (B–C) group at the start,
in which the bad prognosis was determined by the massive fibrosis and the
airways obstruction, respectively (Mándi et al. 1984).
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Our above mentioned results contributed to the elaboration of Hungarian measures concerning silicosis. As it was mentioned in our previous article the sharply decreased incidence due to prevention and early diagnosis meets the requirements of “The eradication of the silicosis by 2000” WHO program.
Lung cancer and mesothelioma of patients with proven occupational asbestos exposure even in cases without a previously diagnosed asbestos fibrosis have been accepted as compensated occupational diseases since 1993.
Although cancerogenity of silica dust is generally more and more accepted we haven’t observed this effect in our silicotic patients, neither Kádas could detect a higher lung cancer incidence among coal workers of the coal mines in Pécs, southern Hungary (Kádas 1996).
Among the etiologic factors of extrinsic allergic alveolitis thermophilic actinomycetes play the most important role causing an inflammatory process characterized by fever, leucocytosis, lung infiltration, cough, dyspnoea and crepitation over the lung. The first cases published in Hungary were those of paprika splitters and mill workers in the early ’30s, the most frequently observed form in the last years is mushroom worker’s lung (Csepura et al. 1995).
The real incidence of occupational asthma in Hungary is not known. While in the majority of highly developed countries occupational asthma is the most frequent occupational respiratory disease of the 90s the number of registered cases in Hungary had been a one figure number which only in 1995 outnumbered 10 with the 17 new cases. This misleadingly low number can be explained by the fact that although occupational asthma is a registerable disease in Hungary, it is not eligible for compensation. In consequence patients are not interested in the registration from a financial viewpoint. The asthma register in Hungary, therefore, seriously underrecords the true incidence of the disease and is not at all comparable with that in other countries.
In the diagnosis of occupational asthma we apply the internationally recommended criteria (Sterk et al. 1993).
A specific bronchial challenge test is the gold standard for the diagnosis. Tests of this kind generally involve inhalation exposure of the suspected workplace material(s) to see if such an exposure provokes bronchoconstriction. Great caution is needed in the application of such tests.
Skin tests (prick tests) using standard non-occupational and occupational solutions are also widely used. Such tests have proven their value in the detection of sensitization but not in the diagnosis of asthma.
The detection of specific IgEs has diagnostic value in some cases.
The non-specific airway responsiveness can be determined by histamine or metacholine challenge. The reaction is positive if there is a decrease in the FEV1 value by 20% or more after the inhalation of small concentrations or doses of histamine or metacholine (PC20 or PD20: provocative concentration or provocative dose, respectively).
The main causes of occupational asthma in Hungary are similar to those
in other countries. (Table 6)
High-molecular-weight compounds | Low-molecular weight compounds |
Laboratory animals (e.g. rats and mice)
Flour (e.g. wheat and rye) Textiles (e.g. cotton) Pollens Algae Biological enzymes (e.g. papain, pancreatin, amylase) Herbs (e.g. soap root Saponaria officinalis L.) |
Di-isocyanates (TDI,MDI)
Anhydrides (phtalic) Metals (Co) Drugs (e.g. a-methyl-dopa, hexachlorophene) Resins (e.g. colophony, epoxy, phenol- formaldehyde) Formaldehyde |
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For the future the research of allergic occupational lung diseases, occupational cancers, occupational bronchitis, research of new methods for the early diagnosis and the preservation of the results achieved on the field of pneumoconioses seem to have a great importance.
CSEPURA, O., ANDRÁSSY, K. and SZÉKELY, K. (1995). (In Hungarian) “Mass allergic respiratory disease in mushroom workers.” Egészségtudomány 39:181–183.
COCHRANE, A. L. (1973). “Relation between radiographic categories of coalworkers’ pneumoconiosis and expectation of life.” Brit. Med. J. II:532–534.
ILO (1958). “Meeting of experts on the international classification of radiographs of the pneumoconioses.” ILO, Geneva, 1958.
KÁDAS, I. (1996). “Simultaneous Occurrence of Silicosis and Lung Cancer. Coincidental or Associated?” Cent. Eur. J. Occup. Environ. Med. 2:37–46.
MÁNDI, A. and GALGÓCZY G. (1971). (In German) “Follow-up study of dust exposed persons with chronic bronchitis.” Pneumonologie 144:315–322.
MÁNDI, A., GALGÓCZY, G., CSUKÁS, M., VILLÁNYI, GY. and MÁGA R. (1972). (in German) “Relationship between clinical symptoms, smoking habits and lung functions in dust exposed persons.” Int. Arch. Arbeitsmed. 30:245–71.
MÁNDI, A., GALGÓCZY, G., GALAMBOS, É., HORVÁTH, F. and CSUKÁS., M. (1975). “The Prevalence of Obstructive Bronchial Diseases among the Workers of Aluminum Electrolysis and Iron Casting Factories. “VIII. Interasma Congress, Vlissingen, pp. 484–499.
MÁNDI, A., GALGÓCZY, G., GALAMBOS, É., NÉMETH, L. and DOMBOS K. (1984). “Changes in Clinical Status and Lung Functions of Patients with Chronic Respiratory Diseases over 10 Years.” Respiration 46:151–159.
MÁNDI, A., Galambos, É. and Galgóczy, G. (1995). “Silicosis in Hungary.” Centr. Eur. J. Occup. Environ. Med. 1:262–5.
POSGAY, M., NÉMETH, L. and MESTER, Á. (1995). “About Classification in High Resolution Computed Tomography of the Chest after Asbestos Exposure.” Centr. Eur. J. Occup. Environ. Med. 1:125–131.
STERK, P. J., FABBRI, L. M., QUANJER, Ph. H., COCKROFT, D. W., O’BYRNE, P. M., ANDERSON, S. D., JUNIPER, E. F. and MALO, J. L. (1993). “Airway Responsiveness: Standardized Challenge Testing with Pharmacological, Physiological and Sensitizing Stimuli in Adults.” Eur. Respir. J. 6 (Suppl. 16):53–83.
ULMER, W. T., REICHEL, G. and WERNER, U. (1968). (In German) “Chronic
obstructive Bronchitis of the Coal Miner. An Epidemiological Study of its
Incidence in the Normal Population and in Coal Miners. The Importance of
Dust and Smoking”. Int. Arch. Gewerbepath. Gewerbehyg. 25:75–98.