Serum Adenosine Deaminase Estimation in Petrol Filling Station Workers

Abstract

V. Durga Rao, K.S.D. Kumar, V. Sridevi, M. Hema Prasad and P.P. ReddyINTRODUCTIONPetrol, Diesel and their products have becomeinevitable in all areas of human activity and havebecome an inseparable element of life. Petrol anddiesel particles contain aliphatic hydrocarbons,polycyclic aromatic hydrocarbons, heterocyclicand polar organic compounds and are thought tobe mutagenic and/or carcinogenic as well as cyto-toxic to bacteria and mammals ( Pederson, 1981;Kotin et al., 1995).Petrol filling station workers have great riskas the workers are exposed chronically to variouspetroleum derivatives directly related to their workareas. Chronic occupational exposure to suchderivatives is considered to possess genotoxicrisk (Pitarque et al., 1997).Adenosine deaminase (ADA) participates inthe degradation of purines by converting ade-nosine to inosine and deoxyadenosine to deoxy-inosine (Pettersson et al., 1984). ADA is essentialfor the differentiation of lymphoid cells parti-cularly T-cells and plays a role in the maturationof monocytes to macrophages (Fischer et al.,1976). The ADA activity increases during anti-genic and mitogenic responses of lymphocytesand it is considered as an important immuno-enzyme marker for assessing cell mediated immu-nity (Mishra et al., 1997).Recently, Uma Devi et al, 2001 pioneered thestudy on the role of serum ADA activity in toba-cco factory workers occupationally exposed totobacco dust and reported increase in the ADAactivity in factory workers compared to controls.Keeping this study in view, the present studywas undertaken with an aim to determine theserum ADA activity to assess immunologicaldisturbance in petrol filling station workers asthey are chronically exposed to petrol and its deri-vatives in their work areas.MATERIALS AND METHODSA total of 89 male workers in the age group of20-45 years who employed in the petrol fillingstations in Hyderabad and Secunderabad,Andhra Pradesh for a period of 2-18 years wereselected for the study. The study was carried outover a period of 2 years (July 1999- July 2001).The workers were clinically examined and infor-mation pertaining to the duration of service, healthstatus, medication, exposure to chemicals, smok-ing and drinking habits, type of marriage andreproductive history was collected using a stand-ard questionnaire. All the subjects underwentlung function tests and tests to rule out low gradeinfections. Due care was taken during the selectionof the subjects for serum ADA estimation becau-se past or present infections is well able to giveelevated serum ADA activity.Among 89 males, 65 were included in thestudy because they had no previous illness andwere clinically normal during sample collection.The majorities among the study group 41 werenon-smokers and 24 were smokers. 65 individualswith the same age group and socio-economic sta-tus were matched as controls.For ADA estimation 2ml of blood sample wascollected into the serum separation tubes fromboth control and exposed subjects. The bloodsamples were centrifuged at 3000 rpm for 10 minu-tes and the serum was assayed immediately forADA activity as described by Guisti and Galanti(1984).50 µl of serum was incubated for 1 hour at37