The Effects of Benzo(a)pyrene and 2, 3, 7, 8-Tetrachlorodibenzo-p-diox:in from Automobile Exhaust...

Incomplete combustion process is a potential source ofbenzo(a)pyrene (BaP) and tetrachlorodibenzo-p-dioxin(TCDD ). These compounds have been detected in effluents ofmunicipal incinerators, sewage sludge, cigarette smoke, automobileexhaust etc. Although BaP and TCD have carcinogenicpotential, in recent years these agents have received great attentiondue to their environmental persistence and remarkablyacute toxicity.To assess health risks associated with human exposure toBaP and TCDD, it was of interest to evaluate their effects uponhuman polymorphonuclear leucocytes by measuring the releaseof lysosomal and cytoplasmic enzymes.Suspensions of human polymorphonuclear leucocytes(PMNL) were treated with BaP, TCDD and BaP+ TCDD atconcentrations of 1 0·1, 1 Q-6M. These agents provoked a progressivetime- and dose-dependent release of lysosomal enzymebeta-N-acetyl-glucosaminidase and cytoplasmic enzyme lactate dehydrogenase, beta-GLM and LDH respectively. Atconcentrations listed TCDD was much more effective in realisingboth enzymes beta -G LM and LDH than BaP. In the experimentswith the combination of BaP+ TCDD, extracellular releaseof beta-GLM or LDH was significantly higher as comparedto BaP or TCDD-treated samples. lt seems possible thatTCDD affected the solubility of beta-GLM and LDH to agreater extent than the activity of BaP.The observations obtained in these studies suggest that BaPand TCDD damage the lysosomal and cellular membranes.