Exposure to Polycyclic Aromatic Hydrocarbons - Risk Factor for Lung Cancer

Abstract

P-200 Abstract: Occupational exposure to chemical carcinogens has been associated with high cancer incidence. Lung cancer is the most important cause of cancer death in many industrialized countries. Polycyclic aromatic hydrocarbons (PAH) are included in the group of the substances with increased risk for respiratory tract cancer. Chemical carcinogens -induced lung cancer develops through a secvence of the cellular alterations that have a lung time period of the reversible alterations, after that irreversible malignant transformations take place. Smoking habit is associated with alteration of the bronchial epithelium, reversible a long time period and with changes in the activation state of the inflammatory and immune cells by the respiratory tract. Recent studies associated the effects of the chemical carcinogenes and of the smoking with immune functions. The sensitived leukocytes to the anti-tumor immune factor lose their ability to adherence to glass or plastic surfaces then they are exposed. The aim of this study was to assess the effects of the smoking habit on the health of the 400 occupational exposed workers to the PAH, using radiological, cytological and immunological investigations. A standard questionnaire including informations on occupational exposure, respiratory symptoms, health history, and smoking habit was completed. Concomitantly, two groups of subjects without, one of them including smokers and other including non-smokers, were investigated. The cytological screening of the sputum was performed by Papanicolaou method and the results were included in the 5 types: I—normal; II—slight atypia; III—Moderate atypia; IV—marked atypia; V—cancer cells. Leukocyte adherence inhibition test (LAI test) was performed for the detection of the anti-tumor immune factor in the exposed subjects. PAH- exposed group presented 28% of the cytological examinations with moderate and marked atypia; 78% of them are high smokers. The LAI test disclosed positive responders against the crud tumor extract at the 74% of the subjects with III and IV type of the sputum cytology. 81% of them are high smokers. PAH-exposed workers present an increased risk for respiratory tract cancer. Smoking is a very important risk factor for lung cancer in the plants with exposure to PAH.