Document QJZYYwG3ae76xxEMOr2XRXbg7

AHLMARK-FORSSMAN--TRICHLOROETHYLENE EXPOSURES 391 The above-mentioned difficulties in estimating whether trichloroethylene effects have existed or not have been pronounced in many cases in this investigation. Especially in those few cases in which the premorbid personality has manifested marked neurasthenic features has it been impossible to decide whether effects from trichloroethylene have existed or not. Such cases have therefore not been included in our material. From table 4, which gives the results from the whole material, it appears that the dubious cases have been especially numerous among persons with an excretion of trichloroacetic acid of up to 30 mg. per liter of urine, whereas among persons excreting larger amounts only a small number of cases have been assessed as dubious. The final scrutiny of the material has shown that the workers who have been referred to the group "probably not affected" have had extremely mild and uncer tain symptoms and that they have not differed much from the group designated as "not affected." Table 4.--Correlation Between Excretion of Trichloroacetic Acid and the Degree of Effect of Trichloroethylene in Continuously Exposed Workers Trichloro acetic Acid in Urine, Mg./L. 0- 10 11- 20 21- 30 31- 40 41- 50 51- 75 76-100 101-150 151-200 . 201-300 301-400 401-500 501-600 601-700 Totals No Effect /A Men Women 11 2 5 11 i i i i i Probably No Effect t\ Men Women Possible Effect A Men Women 10 1 5 3 3 1 .5 2 21 2 113 1 13 V 1 . ^ ' 22 3 19 4 16 7. Actual Effect A Men Women 31 32 1 12 3 31 21 52 4 .2 42 2 ,1 4 11 f Men 29 16 4 6 4 5 3 10 4 5 2 4 1 36 15 93 Totals Women 7 5 4 3 1 .1 2 2 2 1 1 Total 36 21 8 9 4 6 4 12 6 7 2 1 4 2 29 122 In order to throw light on the connection between the excretion of trichloroacetic acid and the effects of trichloroethylene, the materialhas been classified according to Behrens 11 in chart 2. As may be seen from chart 2, there is a rising percentage of affected workers with increased excretion of trichloroacetic acid. The difference in the degree of trichloroethylene effect is probably due to the varying degree of exposure experi enced by the persons in their work. In judging the percentage extent of the effect within the groups, however, one must take into account the above-mentioned circumstance that even among, persons who are not exposed to any injurious environmental factors one often finds neurasthenic symptoms in a certain number. A further factor to be considered in this material, especially in assessing the affected persons with low values for the excretion of trichloroacetic acid, is that the majority of these persons have earlier experienced a more pro- 11,. Behrens, B.: Zur Auswertung der Digitalisblatter im Froschversuch, Arch. f. exper. Path. u. Phafmakol. 140:237, 1929. I f I. L* i