Effects of vinyl chloride on liver function of exposed workers, evaluated by measurements of plasma clearance of the 99mTc-N-2,4-dimethylacetanilido-iminodiacetate complex.

In 77 males exposed occupationally to vinyl chloride (VC), the plasma clearance (Cl) of 99mTc-N(2,4-dimethylacetanilido)iminodiacetate ('HEPIDA' complex) was determined. The results were juxtaposed with a scaled assessment of liver parenchyma performance based upon clinical examination and a series of biochemical tests. Detection of the diagnosable damage of liver parenchyma by means of the reduced clearance was sensitive (90%) at the reasonable specificity of 74%. Probability of exclusion of liver damage in patients with the clearance above 240 ml min-1 1.73 m-2 amounted to 92%. There was a significant correlation between degree of exposure to VC and the frequency of low clearance values. It appears that the periodic determination of the 99mTc-HEPIDA clearance in workers exposed to VC allows the assessment of incipient liver damage and signals the need for prophylactic measures.