IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 Effect of Benzene on Some haeMatological Parameters of Oil Statio n Workers F. R. Hameed , A.Abd-Alhusein, A. Salim , M. Hus sein De partment of Medical Analys is , College of Health and Medical Teqnique s Abstract Benzene is a hy drocarbon chemical consist ing of six atoms arranged in a ring struct ure. At normal ambient temp eratures; it is a liquid, which evap orates rap idly at room temp erature and is highly flammable. It has a characterist ic of aromatic odor and is slightly soluble in water (1.5 g/liter at 20ºC) but miscible with most ot her organic solvent s [1]. Long-term inhalation of benzene causes blood disorders. It sp ecifically affects bone marrow [2]. And it may cause anemia, excessive bleeding, damage to the immune sy stem and DNA [3, 4]. Increased incidence of leukemia (cancer of the tissues that form white blood cells) has been observed in p eop le occupationally exp osed to benz ene; so (EPA ) Environmental Prot ection Agency has class ified benz ene as a known human carcinogen [5]. The p resent st udy was conducted to evaluate the effect of benz ene on some hematological p arameters on 60 males working in different oil stations that p rovide benzene products for p eop le at Waset governorate with a mean y ear for work duration 1 to 20 y ears, 8 hours of work as a mean p er day . A haemoglobin (Hb) concentrations as well as white blood cells count (W.B.Cs) and p latelets count (Plt) were well observed to evaluate the effect of benzene on t hese parameters. Results showed that workers in oil st ations indicated normal values for haemoglobin 13.2 and white blood cells (5640 cell/cmm) and p latelets 261000 during the first 10 y ears of w ork. As the duration of work p rogress es, results indicated that there was a gradually reduction in all p arameters . Introduction Air toxicant s are generally defined as air p ollutant s known or susp ected to cause serious health p roblems, serious health effects including cancer, birth defects, lung damage and nerve damage [2]. Although benz ene is a naturally-occurring chemical, found in crude p etroleum at levels of up to 4 g/liter, almost all the benz ene found at ground level comes from human activities. It is p roduced in extremely large quantities worldwide (14.8 million tons) and emissions arise during the p rocessing of petroleum p roducts, in the coking of coal, during the p roduction of toluene, xy lene and ot her aromatic comp ounds, and from its usage as a comp onent of p etrol and in other consumer p roduct s as a chemical intermediate . The distribut ion to fat ty tissue is reflected in the toxic effects of benzene, extremely high concentrations which may cause narcot ic or anest hetic effects and deaths of workers, have been recorded after exp osures to concentrations of several IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 thousand p pm. Very high levels of exp osure (over 5000 p p m) on rep eated occasions have led to the development of severe and sometimes fatal damage to the blood-forming element s of the bone marrow, p reventing the manufacture of essential blood cells [6 ,7]. Such serious consequences are not a risk associated with exp osure to the concentration of benz ene observed in ambient air and will not occur in workers except as a result of unforeseen and accident al exp osure to very high concentrations. Benz ene is a hematop oietic toxin (benzene is toxic to t he blood and blood forming organs) leukemia is of most concern for human health [8], in ؛ p articular, several ty p es of leukemia known collectively as non-ly mp hocyt ic leukemia’s (or my eloid leukemia’s).Also benzene or its derivatives cause chromosomal aberrations in humans and laboratory animals and such chromosomal re-arrangements are relevant st ep s in the carcinogenic p rocess. Several ty p es of neoplasm have been rep ort ed t o be associated with benz ene exp osure in rats and mice after oral dosing or inhalation exp osures. These tumors were p rimarily of ep ithelial origin (e.g. liver, mammary gland, nasal cavity ) Ly mp homas and leukemia’s were observed less frequently in rat s and mice [5]. T he earliest rep ort for toxic effects of benz ene was frank blood disease; this is resulted from heavy occupational exp osure to benzene. The rep ort ed diseases included leucop enia (decrease in white blood cells count ), anemia (decrease in red blood cells count ), t hrombocyt op enia (decrease in platelets count ), and p ancy topenia (decrease in all blood content s count s) and a p last ic anemia [9]. T he st udies also showed that females which had been occup ationally exp osed to benzene suffered from a decrease in the size of the ovaries as well as menst rual p roblems. Some st udies, although not y et conclusive, had also suggest ed that the high level exp osure to the chemicals like benzene could also affect the fertility of women; some women who breathed high levels of benzene for many mont hs had irregular menst rual p eriods and a decrease in the size of their ovaries. It is not know n yet whether benzene exp osure affects the develop ing fetus in p regnant women or fertility in men [10]. The st udies on animals had shown a low birth weights, delay ed in bone formation, and bone marrow damage when p regnant animals breathed benz ene. In animal test s; p regnant animals that were exp osed to benz ene via inhalation sustained fetus damage including low birth weight , bone marrow p roblems, and p roblems with bone formation. Breathing very high levels of benz ene can result in death, while high levels can cause drowsiness, dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness . Also Eating or drinking foods cont aining high levels of benzene can cause vomiting, irritation of the st omach, dizziness , sleepiness, convulsions, rap id heart rate, and sometimes death [6]. Additionally, [11] showed that exposing of p eop les w orked within 1.5 to 72 mont hs consequently (average: 14 mont hs ) have different ty p es of disorders such as leukop enia, agranulocy tosis, anemia, pancy topenia, ap lastic anemia (AA), my elody sp last ic syndrome (M DS), and leukemia M aterial and Me thods - S amples Sixty males working in different oil st ations that p rovide benzene p roduct for p eop le in Waset governorate with a mean years of work durations 1-20 years , working 8 hours / day as a mean . on the ot her hand 60 males were used as a controls from the same governorat e who never work in this field - blood analysis : a- Hb IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 This test is based on the reaction between haemoglobin in RBCs with Drabkins solution. It acts by convert ing haemoglobin to cyanomethmoglobin and then measured by haemoglobin meter [12]. b-White blood cells count 0.02 ml of blood is mixed with 0.4 ml glacial acetic acid that causes RBCs and p latelets break down , keeps white blood cells intact , then transfers to Neubour chamber and left it for 1-2 min for the WBCs to settle down , then count s the WBCs on the four square under low p ower objective lenses [13 ] . c- Platelets count Blood is mixed with diluent s which has the ability to haemoly ze red corp uscles and p reserve p latelets in p rop ortion sufficient to the relatively large number of p latelets to be count able.[13] - st atist ical analy sis st atist ical analysis was p erformed to compare t wo different group s by using ANOVA-test [14 ] Results and Discussion Table (1) shows that workers in oil st ations indicated normal value for the haemoglobin concentration 13.2 g% and white blood cells 5640 count / cmm and for the p latelet was 261000 count / cmm at the first 10 y ears from work . A nd as the duration of the work p rogresses; result s indicate that there was a decrease in the haemoglobin concentrations (11.7), white blood cells (2910) and in the platelet count (1333000). As the work duration progresses up to 20 years of work, result indicated a decrease in the haemoglobin concentrations (9.9), also there was a decrease in the value of WBCs (2840); as well as t he p latelets count (132600). It is well known that Phenol, hy droquinone, catechol, and benzene oxide are the major derivative of benzene [15 ] .T he metabolism of benzene initially involves the formation of hy droxy lated benzenes. Only small amount s of ring-opened metabolites are formed due to t he st ability of the aromatic ring. The enzy mes cataly zing these hy droxy lations are the mixed function cytochrome monoxy genase enzymes, which are found p redominantly in the liver, but also in the bone marrow, which is the put ative target organ of benz ene toxicity . The oxidizing moieties p roduced by the enzymes p robably involve a cascade of reactive oxy gen sp ecies, including free radicals. These reactive oxy gen sp ecies may cont ribute to benz ene-induced cell damage. The substitut ion of hy droxy l group s ont o the benz ene ring p roceeds by at least two p athway s: an indirect p athway through an ep oxide intermediate and a direct pathway involving direct insertion of hy droxy l group s. Bot h p athway s ap p ear to proceed through an enone intermediate. The hy droxylated benz enes can undergo conjugation reactions to form glucuronides and sulfate est ers [15,16], or can be further oxidized to benz oquinones. The benz oquinones are p robably the electrop hilic sp ecies which covalently bind to macromolecules including DNA, and therefore may be the ultimate carcinogenic forms of benz ene [17]. , also research indicated that DNA damage(as examined with the single-cell gel assay for single-st rand breaks) was detected in p eripheral blood cells, bone marrow and liver in mice exposed to benz ene at 900 mg/m3 [18,19 ]. Reference s 1- WHO Regional Office for Europe, (2000).Cop enhagen, Denmark, IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 2- Bruce Gillis , Igor M . Gavin , Zarema Arbieva , Step hen T. King , (2005) ,Sundararajan Jayaraman , Bellur S. Prabhakar . Ident ification of human cell resp onses to benz ene and benz ene metabolites exp osed workers, Environ. Health Persp ect. 113: 801–807. 3-M AJO R, J. ET AL. (1994).Chromosome aberration, sister-chromatid exchange, proliferative rate index, and serum t hiocy anate concent ration in smokers exposed to low-dose benzene. Environmental and molecular mutagenesis, 23: 137–142 4- Benzene. Geneva, World Health Organization, (1993), (Environmental Health Criteria, No.150). 5-Aksoy , M. (1985). M alignancies Due to Occup ational Exp osure to Benzene. American Journal of Industrial M edicine. 7: 395-402 6- Smith,M.T .; Vermeulen, R. ; Li, G.; Zhang, L.; Lan, Q.; Hubbard, A.E. ; Forrest ,M .S. ; Forrest,C. ; Zhao, X. Gunn, Kitada,L.; Gunn, M . ; Rap p ap ort,S.M. ; Yin,S.; Chanock,S. and Rothman,N. (2005) Use of ‘omic’ technologies to st udy humans exp osed to benz ene, Chem. Biol. Int eract. 153–154, 123–127. 7- Yoon,B.I. ; Li, G.X. ; Kitada,K. ; Kawasaki,Y. ; Igarashi,K. ; Kodama,Y. ; Inoue,T. ; Kobay ashi,K. ; Kanno,J. ; Kim,D.Y. ; Inoue,T. and Hirabayashi, Y. (2003) , M echanisms of benzene-induced hematotoxicity and leukemogenicity : cDNA microarray analy ses using mouse bone marrow tissue, Environ. H ealth Persp ect. 111 :1411–1420. 8- Jae, Y. C. (2008) Suppressive Effect of Hydroquinone, a Benz ene M etabolite, on In Vitro Inflammatory Resp onses M ediated by M acrophages, M onocy tes, and Ly mp hocy tes Hindawi Publishing Corp oration Mediators of Inflammation Volume, Article ID 298010, 11 p ages 9-Burnett, C.; Robinson, C.; Walker, J. (1999).Cancer mort ality in health and science technicians.American Journal of Industrial M edicine. 36(1): 155-158 10- Forrest , M .S. ; Lan, Q. A.; Hubbard,E.; . Zhang, L; Vermeulen,R.; Zhao,X. ; Li, G.; Wu,Y.Y.; Shen, M.; Yin,S.; Chanock, S.J. ; Rothman,N.and Smith,M.T . (2005) Discovery of novel biomarkers by microarray analy sis of p erip heral blood mononuclear cell gene exp ression in benzene-exposed workers, Environ.Health Persp ect. 113 :801–807. 11- Shouren , K and W eihui , L : (2005) ,c linical analysis of 43 cases of chronic b enzene p oisoning . Chemico-Biolo gical Int eractions.153-154 ,129-135. 12-brown B. hematology : p rincip les and p rocedures . (1993 ) Philadelp hia : lea and febiger ,pp. 13- lewis , S.M . (1972). biomedical technology in hos p ital diagnos 14- Al-mohammed , N.T .; Al-rawi,K.M .;y ounis,M .A.and Al-Morani,W.K. (1986) . princip al of st atist ics . j.Al-M ousl university (in A rabic). 15- tokantins , L.M Archives of pathology . 16- Kalf, G.F.; Post , G.B. and Sny der, R. (1987). Solvent toxicology: recent advances in the toxicology of benzene, the glycol ethers and carbon tetrachloride. Ann. Rev. Pharmacol. Toxicol. 27: 399-427 17- Snyder, C.A . (1987). In: Ethel Brow ning's t oxicity and met abolism of industrial solvents, 2nd ed. Hy drocarbons. R. Sny der, ed. Elsevier, New York, 1, 3-37. 18 - ATSDR. (1992). Agency for Toxic Subst ances and Disease Regist ry . Toxicological Profile for Benzene. Up date. Prep ared by Clement Corp oration under cont ract no. 205-88-0608. U.S. Public Health Service, Chamblee, GA. Draft for public comment IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 19 - Forrest ,M .S. ; Lan,Q. ; Hubbard,A.E. ; Zhang,L. ; Vermeulen,R. ; Zhao, X. ; Li,G. ; Wu,Y.Y. ; . Shen, M; Yin,S. ; Chanock,S.J. ; Rothman, N . and Smith,M .T . (2005) Discovery of novel biomarkers by microarray analy sis of p erip heral blood mononuclear cell gene exp ression in benzene-exposed workers, Environ. Health Perspect. 113 :801–807. Table (1): the relationship between durati on of works and haemoglobin concentration for oi l stati ons worke rs Table (2]): the relati onship between duration of works and white blood cells count for oil stations worke rs Hb concentration (g%) mean ± S D Durati on of work ( ye ars ) Worke rs Control 1_10 13.2± 1.398 14.4±0.894 11_20 11.7±0.949 14.4±0.894 20_ 9.9± 0.994 14.4±0.894 WBCs count /cmm mean ± S D Durati on of work ( years ) Worke rs Control 1_10 5640± 884.685 5980± 807.465 11_20 2910 ± 703.088 5980± 807.465 20_ 2840± 1863.807 5980± 807.465 IBN AL- H AITHAM J. FO R PURE & APPL. S CI VO L.22 (4) 2009 Table (3): the relationship between duration of works and total platelets count for oil stati ons workers Platelets count / cmm me an ± S D Durati on of work ( years ) Worke rs Control 1_10 261000± 73249.953 189000 ± 34351.12807 11_20 133000± 30568.684 189000 ± 4351.12807 20_ 132600± 37500.222 189000 ± 34351.12807 الصرفة والتطبیقیة المجلد 200) 4 (22مجلة ابن الھیثم للعلوم 9 نسب بعض ألمعاییرالدمیة فيتاثیر مادة البنزین المستعمل في محطات الوقود املین فیها للع شید حمید سین ، فاتن ر میثم حسین، احمد سالم ، احمد عبد الح ة التقنیات ، قسم التحلیالت المرضیة یة كلی الطبیة والصح الخالصة ي ســـریعة االنتــشار والتبخـــر تیادیـــة وهــ درجـــات الحــرارة اإلع یـــة الهیدروكربونیــة الـــسائلة فــي تعــد مـــادة البنــزین مـــن المــواد الكیمیائ ان في الماء بمعدل تراق ولها قابلیة ذوب عض المذیبات كما ان لها قابلیة ألذوبان في ب، درجة مئویة 20 غرام بأللتر في 1.5واالح .العضویة ب تاثیره على سببا فقـر الـدم و النـزف نخـاعان االستنشاق طویل االمد لمادة البنزین یعد مسببا رئیسا المراض الدم بسب ، العظـم ـم ن الــدم ، كمـا انــه یــسبب دمــارا فــي الجهــاز المنــاعي و الــوراثي یة لــسرطا ات الرئیــس میــا(وهــو مــن المــسبب ظــتالــذي لوح) اللوكی حسب تقریر منظمة حمایة البیئة[5]اعراضه في العاملین بتماس مباشر مع هذه المادة ات الـــدم عـــض مكونـــ ــادة علــى ب ر هـــذه المـ ة ـتــاثی ــات الـــدم البـــیض ( لــذلك تمـــت هـــذه الدراســـة لمعرفــ تركیــز الهیموكلـــوبین و كریـ .)الصفیحات الدمویةو نت الدراسة عامل محافظة واسـطٲتظم ب سـنوات الخدمـة ، في محطات الوقود في 8وبمعـدل ، قـسم العمـال الـى ثـالث فئـات حـس ات . یومیا عملساع اظهرت النتائج ان قیم تركیز الهیموغلوبین وكریات الدم البیضاء و اعداد الـصفیحات الدمویـة كانـت طبیعیـة فـي االشـخاص التـي ت 10-1تراوحت فترة عملهم بین دمة في حین اظهرت النتائج انخفاضا في ، سنوا .القیم كلما زادت سنوات الخ 60