The relationship between epidemiological data and the toxicity of coalmine dusts. Final report on CEC Contract 7253-32/8/096

A collaborative study involving national research institutes of the principal CEC coalmining countries was set up to examine and compare the various methods of testing mine dusts for toxicity; the principal objective of the research was to establish which of the test methods best described the specific harmfulness (as indicated by epidenmiological data) of the dusts. This report describes the results of those tests carried out by the Institute of Occupational Medicine (lOM), Edinburgh; the style of presentation has been chosen to aid preparation of a joint report of the project under the auspices of CERCHAR, France.Dust samples were collected from 27 seams at 26 collieries (4 in the UK) with known epidemiological backgrounds. Aliquots of these dusts were distributed for testing to the four institutes participating in the study. The tests carried out on the dusts included mineralogical and particle size analyses, in vitro cytotoxicity studies and in vivo animal studies; these latter included both intratracheal injection, with subsequent estimation of reaction of lung tissue to the dust, and intraperitoneal injection followed by estimation of the extent of “”quartz typical area”” (QTA) in lymph nodes.The epidemiology of pneumoconiosis relating to the UK collieries (and hence to the dusts collected in the UK) was the only such information available; these data were used to rank the dusts epidemiclogically. Most methods of biological assay, in vitro and in vivo, suggest that toxicity is positively related to quartz and ash but, when compared with the data from the dust composition, cytotoxicity and animal studies,the epidemiological ratings were found to be inversely associated with quartz and ash composition. Only the assay for QTA appeared to relate correctly to the known epidemiological hazard of the dust, suggesting that QTA may be the single most useful indicator of long-term toxicity.The results of comparisons of the analytical, in vitro and in vivo tests, both inter- and intra-laboratory, are contained mainly in a series of appendices to the main report. “”