Biological monitoring of occupational exposure to benzene and toluene

This study was carried out to evaluate the biological monitoring of occupational exposure to benzene and toluene in a total number of 31 male exposed workers and 30 control subjects. The present study showed a statistically significant higher level of biological indices of exposure (p < 0.01) of phenol and hippuric acid in urine of workers exposed to benzene and toluene than control subjects. Significant changes (p < 0.05, 0.01) in the levels of hematological and biochemical findings have been observed among exposed workers and control group. In addition, statistically significant higher levels of Mg, Mn and Ca were found among workers exposed to benzene and toluene while statistically significant lower levels of serum iron (p < 0.05) have been observed. No significant variations could be detected in the level of Zn and Cu between exposed and control subjects.     

Changes in some metalloenzymes and trace metals among workers occupationally exposed to lead in battery manufacture

The present study was conducted aiming to evaluate the impact of lead [Pb] exposure on the activities of some metaloenzymes as TIBC, SOD, ALP and MAO and their related trace metals among workers. Ninety workers occupationally exposed to Pb in a battery manufacturing plant in Alexandria city were included in this study, 50 of them were the exposed group and 40 control subjects. The present study showed a statistically significant higher level of biological indices of exposure (p < 0.01) of lead in blood among the exposed group than the control subjects. Exposure to Pb led to decreased levels of Zn and Fe which was accompanied by increase in the level of TIBC and decrease in activity of ALP. However, no significant variation could be detected in the level of Cu and its metalloenzyme as SOD and MAO between exposed and control subjects.     

Epidemiological study on the hepatotoxicity of occupational toluene exposure

Summary In a cross-sectional study of 181 male workers of a rotogravure printing plant, most of whom were exposed to toluene levels well above the GDR threshold limit values, 55 subjects revealed pathological liver screening values (activities of serum aspartate aminotransferase, alanine amino-transferase, gamma glutamyltransferase; liver size). The differential diagnostic examination showed in 51 out of these 55 subjects an association with competing factors such as alcohol abuse (78%) and overweight (40%), to a slight extent disorders of fat and carbohydrate metabolism and of the gallbladder. Drug intake did not play any role. The variance and regression analyses of the biochemical data have shown that alcohol significantly and considerably increases the activities of all three enzymes tested. Bodyweight had a similar, but less pronounced, significant effect. On the other hand, in subjects with a higher alcohol intake the activities of liver enzymes in highly toluene exposed subgroups were significantly and clearly lower than among slightly toluene exposed workers.     

Influence of free radicals on cardiovascular risk due to occupational exposure to mercury

This study was designed to investigate the relation between occupational exposure to mercury and cardiovascular risk, as well as free radicals. The study subjects included 30 male workers exposed to mercury from a fluorescent lamp plant in Alexandria after exclusion of 12 workers with conditions that may bias the results. A matched control group of 20 male subjects were selected from a food industrial plant. The participants were subjected to interview, clinical examination, electrocardiography and R-R deep breathing variability test as a measure of cardiac autonomic function. Spot urine and venous blood samples were collected to measure mercury levels. Free radicals related markers were measured in serum namely lipid peroxide, superoxide dismutase (SOD) activity, catalase activity and glutathione S-transferase. Results showed significant longer electrocardiographic Q-Tc interval, which is corrected to heart rate, in exposed workers than in controls (p=0.002). The R-R deep breathing variability indices were significantly increased among exposed workers in comparison to controls (maximal variation (MV) ratio, p=0.024 & MV rate, p=0.019). The mercury levels in both urine and blood of exposed workers were significantly higher than controls (p<0.0001), with mean levels exceeding the permissible limits. Free radicals related markers revealed significant higher level of lipid peroxide, as well as significant lower levels of SOD activity, catalase activity and glutathione S-transferase among exposed workers than among controls (p<0.0001 for all). Independent relations were observed between Q-Tc and lipid peroxide, and between MV rate and SOD and catalase activities among exposed workers after adjustment for the confounders by multivariate regression analyses. These findings may suspect a cardiac autonomic dysfunction probably related to free radicals in mercury exposed workers. Also, it may through light on some preventive implications.     

Antioxidative activity of hen egg ovalbumin hydrolysates

To evaluate the antioxidative activity of the hydrolysates of ovalbumin, the antioxidative activities of the enzymatic extracts were evaluated using three different methodologies scavenging assays such as superoxide anion, hydroxyl radical, and inhibitory oxidation of linoleic acid in vitro, and the activities of SOD, GSH-PX, CAT and the level of MDA were determined in serum and liver of aged mice induced by G-gal. The results showed that the hydrolysates had a distinctly inhibitory action to superoxide anion made by alkaline pyrogallic acid, HO. produced by Fenton reaction, the oxidation of linoleic acid in linoleic acid autoxidation system, and presented a positive correlation. The inhibition capacity of hydrolysates against superoxide anion and HO. were more than 45% and 56% respectively at the concentration 5 mg/mL. And the hydrolysates could significantly (p< 0.01) prevented the activities of SOD, GSH-Px, and CAT against reducing and all three concentrations could significantly (p< 0.01) decrease the MDA contents in the serum and liver of aged mice induced by G-gal. The antioxidative activity of high concentration was similar to that of control group.     

氯化镍对大鼠离体肝脏的毒性研究

应用大鼠离体肝灌流技术，研究了氯化镍对大鼠离体肝脏的毒性损害。结果发现：在１０ｍｍｏｌ／Ｌ氯化镍染毒组即可导致离体大鼠肝脏某些生化指标异常改变，流出液丙氨酸转氨酶（ＡＬＴ）活性显著高于对照组（Ｐ＜０．０５），总蛋白（ＴＰ）、白蛋白（ＡＬＢ）的含量显著低于对照组（（Ｐ＜０．０１）。不同剂量染毒组间的ＡＬＴ酶活性呈现明显的剂量－效应和时间－效应关系（ｒ＝０．７４２７，ｒ＝０．５４２１，Ｐ＜０．０１）。ＴＰ、ＡＬＢ含量也呈现明显的剂量－效应关系（ｒ＝－０．７７４９，ｒ＝－０．７４０３，Ｐ＜０．０１）。病理学检查发现，肝细胞明显浊肿变性，并有不同程度的灶性细胞坏死，表明较低剂量的氯化镍即可对离体大鼠肝脏产生毒性作用。     

不同浓度正己烷对接触者肝脏的影响

目的了解慢性正己烷中毒是否对肝脏有损害.方法对33例慢性正己烷中毒病例、60例接触正己烷的员工和无毒物接触史的30名工人进行肝功能及肝脏B超检查.结果①中毒组出现食欲不振占78.8%、恶心占30.3%,而接触组食欲不振占16.7%,无恶心主诉;②正己烷中毒组人员球蛋白(GP)异常高,与接触组及对照组比较,差异均有显著性(P＜0.05);③接触正己烷的员工以及中毒病人肝脏B超回声稍粗差异有显著性(P＜0.01),接触时间越长,肝脏B超回声增粗的比例越大.结论正己烷接触者肝功能部分指标异常率高,肝脏B超显示肝脏的纤维化率较高,提示接触正己烷有肝脏损害的可能.     

淮河水有机提取物对小鼠遗传毒性和脂质过氧化作用

目的探讨N市淮河原水及出厂水中有机提取物对小鼠遗传毒性和脂质过氧化作用。方法XAD-Ⅱ树脂吸附原水及出厂水中有机污染物,采用腹腔注射染毒小鼠,进行微核实验、精子畸形实验及血清、肝、脑组织中脂质过氧化物(LPO)含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性测定。结果在0.01ml/g(相当100L/kg原水、出厂水及末梢水连续染毒5d)的条件下,微核率和精子畸形率显著高于阴性对照组(P<0.05或P<0.01),同时相应组小鼠血清中LPO含量及SOD、GSH-Px活性均有不同程度的改变(P<0.01);N段上游水组小鼠血清SOD和脑组织中GSH-Px活性改变明显(P<0.01)。微核率及精子畸形率与LPO呈显著正相关(P<0.05)。结论淮河N段水有机提取物对小鼠有潜在的遗传毒性,并能影响小鼠的脂质过氧化作用。     

A study of left ventricular function of workers exposed to fluorine

The left ventricular function of 26 workers exposed to fluorine was investigated. The results demonstrated that the LVET in the higher urine fluorine group (greater than 1.5 mg/L) was significantly shorter than the control group (P less than 0.01), the PEP was much longer than the control group (P less than 0.05), and the rate of PEP/LVET compared with the control group was increased. The difference was statistically significant (P less than 0.01). In the lower urine fluorine group (less than 1.5 mg/L) the time of LVET and PEP and the rate of PEP/LVET was not significantly different from the control group. The results showed that excessive fluorine ion in the body could cause decrease of myocardial contraction. The reason may be, that the fluorine ion inhibits the activities of certain enzymes in the body, thereby producing inhibition of ATP supply and utilization.     

Semen quality of industrial workers occupationally exposed to chromium

A total of sixty-one subjects occupationally exposed to chromium in an industry which manufactures chromium sulphate and fifteen control subjects from a nearby industry which does not manufacture any chromium related compounds were studied. The history of each subject was recorded on pre-designed form through interview and a routine medical examination was carried out. Blood samples (5-6 ml) were collected for the estimation of chromium and semen samples were collected for semen analysis and the determination of copper and zinc levels in the seminal plasma. Clinical examination revealed nasal perforation in 10 subjects (out of 61) in the exposed group as compared to none in the control group. A significantly higher level of chromium was observed in the blood of the exposed workers as compared to the control. The concentration of zinc in seminal plasma was lower while the level of copper was higher in the exposed group as compared to the control. However, these changes were not statistically significant. Statistically significant higher numbers of morphologically abnormal sperms were noticed in the exposed group with respect to the control. Further analysis of the data indicated that about 53% of the exposed subjects showed less than 30% normal forms as compared to 10% in control subjects. However, no significant alterations in semen volume, liquefaction time, mean pH value, sperm viability, concentration or motility, were noticed between chromium exposed and unexposed workers. The data also indicates that exposure to chromium has some effect on human sperm as a significant positive correlation (r=0.301) was observed between percentages of abnormal sperm morphology and blood chromium levels (p=0.016) after pooling all the data of the control and exposure groups.     

Histopathological liver alterations in juvenile rabbit fish (Siganus canaliculatus) exposed to light Arabian crude oil, dispersed oil and dispersant

With the heavy transport of crude oil there is an increasing risk of a major oil spill in the Gulf waters; however, there have been few studies on the impact of oil spills and subsequent remedial action on Gulf fish. The aim of the experiment was to investigate the effects of acute exposure to water soluble fraction (WAF) of light Arabian crude oil, dispersed oil and dispersant on the liver of the juvenile rabbit fish (Siganus canaliculatus), observing several histopathological biomarkers of the liver at different time points and different doses. The concentrations used (3-100 percent WAF) simulated a range of possible oil pollution events. The main alterations observed in this study include hepatocyte swelling and cytoplasmic vacuolisation, megalocytosis, coagulative dispersed necrosis, lymphocytic infiltration, melanomacrophage aggregates, spongiosis hepatis, pericholangiitis, and bile stagnosis. Treated livers showed significantly higher total index values than the control group (p<0.01). According to the total liver index, liver exposed to WAF, dispersed oil or dispersant showed significant histopathologic alterations compared with the control fish (Mann-Whitney U-test; p<0.01). Components of the total liver index, (circulatory, degenerative, proliferative, and inflammatory changes) differed significantly from the control groups. There was a significant correlation between exposure time and the total liver index values and the different reaction pattern indexes of treated fish (Spearman correlation; p>0.05). The present study indicates that dispersed oil is not more toxic, to livers of juvenile rabbit fish, than crude oil or dispersant.     

锰对新生鼠肝组织微量元素的影响

目的研究大鼠染锰后对其子代新生鼠肝组织内微量元素的影响。方法 :将妊娠雌性大鼠随机分为 4组 ,腹腔注射氯化锰 ,剂量分别为 0、7.5、1 5和 30 mg/kg,待其自然分娩后采用原子吸收光谱法测定子代新生鼠肝组织内微量元素锰、铜、锌和铁含量。结果 :与对照组相比 ,实验各组肝组织内锰含量明显增高 ( P<0 .0 1 ) ;锌含量则低于对照组 ( P<0 .0 5,P<0 .0 1 ) ;实验各组铜含量与对照组间差异无显著性 ( P>0 .0 5) ;1 5mg/kg和 30 mg/kg组铁含量高于对照组 ( P<0 .0 5,P<0 .0 1 )。结论 :大鼠孕期染锰 ,使其新生鼠肝组织内锰、锌、铁等微量元素的含量发生明显变化 ,影响了锰、锌、铁在体内的代谢 ,从而对其子代的生长发育可能产生不利影响     

Effect of exposure to occupational noise and shift working on blood pressure in rubber manufacturing company workers

This study aimed to assess the relationship between shift working and occupational exposure to noise with blood pressure (BP). The study was carried out in a rubber manufacturing company in 2010. Demographic, medical and occupational information for carrying out the study were collected through direct interview. All 331 under study workers were divided into four groups according to work shift and noise exposure severity, from non-noise exposed day time workers (Group 1) to noise exposed shift workers (Group 4). Finally, systolic and diastolic blood pressure levels were compared among these four groups. The results of this study showed that there was a significant difference between average systolic and diastolic BP and hypertension (HTN) frequency in the four groups (p<0.05). The highest rate of HTN and mean systolic and diastolic BP were observed among shift workers who were exposed to noise higher than permissible limit (Group 4). Also the results of logistic regression analysis showed that there was a significant relationship between simultaneous exposures to noise more than the permitted limit and shift work with HTN (p<0.05). The results of our study showed that shift working and simultaneous exposure to noise have an additive effect on occurrence of HTN. It is recommended that during periodic physical examinations of noise exposed shift workers, assessment of the cardiovascular system and BP should be done as well as the auditory system.     

二甲基甲酰胺暴露性肝损伤与脂质过氧化关系

目的探讨二甲基甲酰胺（DMF）作业工人肝损害与血清脂质过氧化水平的关系。方法选取DMF作业工作136人作为接触组,健康献血员30人作为对照组。接触组按肝功能是否异常分为肝损害组和正常接触组;正常接触组再按接触空气DMF浓度不同分为高浓度组和低浓度组,检测各组血清超氧化物歧化酶（SOD）、谷胱甘肽过氧化酶（GSH-Px）活力和丙二醛（MDA）水平。结果不同接触组MDA水平、SOD活力较对照组升高,其中肝损害组最明显,除低浓度组MDA水平与对照组比较差异无统计学意义外,各不同接触组与对照组及低浓度组与肝损害组、高浓度组差异均有统计学意义（P〈0.05）;GSH-Px活力除正常接触组外,各接触组与对照组及低浓度组与肝损害组、高浓度组差异均有统计学意义（P〈0.05）;肝损害组与正常接触组MDA水平、GSH-Px活力差异有统计学意义（P〈0.05）。结论高浓度DMF接触工人机体的脂质过氧化水平升高,肝损害增多,选用含有巯基的抗氧化剂解毒具有一定意义。     

噪声作业275名工人心电图分析

目的了解噪声作业工人心电图的改变。方法某炼铁厂275名噪声作业工人心电图检查结果与对照人群199名心电图进行比较。结果噪声作业工人心电图改变异常率为50．91％,明显高于对照组的25．63％,差异有统计学意义（P〈0．01）,主要改变为sT—T改变,窦性心律不齐。结论接触噪声对心脏产生一定影响,应加强防护措施。     

Effects of Crude Oil and Diesel Exposures on Biochemical Activities of Polymorphonuclear Leukocytes in Cattle

Cattle exposed to low doses of an Alberta crude oil, Pembina Cardium crude oil (PCCO), or a winter diesel oil no. 2 (WDO-2) were assessed for their biochemical activities in polymorphonuclear leukocyte (PMNL) cells (mainly neutrophils). The study used a randomized block design containing five treatment groups (8 animals/group). The animals were dosed per gavage with the test substance on study days 0, 14, 28, and 42. The dosages given (on per kg body weight) were: Group 1 (control), 10 mL/kg of potable water; Group 2, 5 mL/kg WDO-2; Group 3, 2.5 mL/kg PCCO; Group 4, 5 mL/kg PCCO; and Group 5, 10 mL/kg PCCO. Blood was collected at the specified intervals during the pre- and post-exposure periods, and the biochemical activities of isolated PMNL were analyzed. Cattle groups exposed to WDO-2 and PCCO showed moderate and statistically significant reductions (p < 0.01) in the activities of (1) phorbol myristate acetate (PMA) stimulated cellular respiration (respiratory burst), (2) NADPH-oxidase (PMA-stimulated production of superoxide anion), (3) myeloperoxidase, and (4) n-acetylglucosidase as compared to the control group. These biochemical parameters also showed statistically significant (p < 0.01) dose-related periodic (study day) trends. In general, these biochemical activities were decreased after each dosing; however, they subsequently recovered to near the pre-dosing levels. Such a biochemical response in PMNL provides a valuable biological tool to follow exposure effects in cattle accidentally exposed to low doses of petroleum hydrocarbons.     

Subjective symptoms of female workers sorting goods in summer

Subjective musculoskeletal symptoms are more frequently complained about in cold store work and in related conditions than those experienced in normal temperature work. This cross sectional study was undertaken to evaluate the effects of indoor cooling and cold storage goods on the prevalence of subjective symptoms in summer. Female workers sorting cold storage goods (exposed group) were the main subjects of this study (n=47). We also included a group of female workers engaged sorting dry goods as the unexposed to cold group (n=86). Work load for the two groups were estimated according to the recommended criteria. A self-administered questionnaire covering age, occupational career, smoking, alcohol drinking and physical exercise, present or past history of diseases, individual protective measures against cold or heat, and subjective symptoms (60 items) was used. The air temperature of the site at the start of working time for the workers sorting cold storage goods was 22.2℃ which was significantly lower than those measured for the other two work places (25.4℃ and 25.4℃) of the unexposed to cold group. Environmental temperatures at the foot level at the sorting workshop of cold storage goods and dry goods were ca.16℃ and 26℃ all day, respectively. The surface temperatures of cold storage goods were between -2.8℃ and 9.4℃. The surface temperature of dry goods was 26.5℃. Among the working characteristic items, only daily working hours in the exposed group (5.6 ± 0.6 h) were significantly longer than those in the unexposed to cold group (4.6 ± 0.9 h) (p<0.01). The prevalence rates of finger cold sensation, stiffness in the fingers, pain in the wrist, pain in the elbow, back dullness, back pain, low-back cold sensation, foot cold sensation and pain in the foot in the exposed group were significantly higher than those in the unexposed to cold group (p<0.05 or p<0.01). Pain in the fingers, numbness in the fingers, pain in the foot and foot numbness due to the cold in the exposed group were significantly higher than those in the unexposed to cold group (p<0.05 or p<0.01). These results suggest that indoor cooling and/or job activities related to cold storage goods could, to some extent, affect peripheral circulatory disturbances; and it could be regarded as a factor related to musculoskeletal symptoms among the exposed workers.     

Risk of hepatitis C virus infection in a population exposed to biological materials

BACKGROUND: Hepatitis C virus is an important cause of acute and chronic hepatitis and it is an agent parenterally transmitted. Workers handling biological materials may be exposed to high concentration of virus-infected fluids. METHODS: The seroprevalence of hepatitis C virus antibodies was investigated in a population of 809 subjects exposed to varying levels of biological risk owing to the handling of human fluids or tissues and in 408 controls. The exposed group was subdivided in three subgroups according to low and occasional (262), intermediate but continuous (311), and high (236) exposure to biological materials. RESULTS: The seroprevalence of hepatitis C antibodies was low (1.40%) in all subjects. The risk groups showed no significant differences with respect to the control group; the most exposed group showed a seroprevalence of 1.27%. Age but not sex appeared significantly correlated with seroprevalence of positive antibodies (chi 2 = 5.949, P < 0.025). Aspartate aminotransferase and alanine aminotransferase showed a highly significant increase (P < 0.01 and P < 0.001, respectively) in subjects with positive hepatitis C antibodies, other than a high significant prevalence of values above the normal limit (chi 2 = 26.613, P < 0.001 and chi 2 = 39.164, P < 0.001, respectively). Among 17 positive hepatitis C virus subjects, 8 (47.1%) were positive for hepatitis B virus, but not for its antigen. CONCLUSIONS: Hepatitis C virus infection appears to be a low risk for people employed in the biomedical field, yet infection is associated with a significant liver involvement.     

金属硫蛋白排铅和肝脏保护作用的实验研究

目的探讨金属硫蛋白(metallothionein,MT)对染铅小鼠的排铅作用以及对肝脏的保护作用。方法小鼠连续30d饮用0.55g/L醋酸铅水溶液制作铅中毒模型组,以MT灌胃的小鼠作为治疗组,并以依地酸二钠钙作为阳性药物对照组。结果MT组小鼠股骨铅含量为(8.50±4.53)μg/g,明显低于铅模型组(P<0.05);MT组小鼠血清中丙氨酸氨基转移酶(ALT)为(27.44±3.43)U/L,明显低于铅模型组(P<0.05),但肝脏中ALT为(232.83±18.08)U/L,明显高于铅模型组(P<0.05)。MT组、正常组和铅模型组小鼠血清和肝脏中的天冬氨酸氨基转移酶(AST)比较,差异无统计学意义(P>0.05);染铅小鼠肝细胞膜Na+-K+ATP酶和Ca2+-Mg2+ATP酶活力没有明显变化。结论MT具有明显的促排铅作用;但对肝脏的保护作用不明显。     

火力发电厂噪声作业工人脑血流图动态观察

目的研究噪声作业工人在一个工作班中脑血流图（ＲＥＧ）变化情况及其性质。方法ＲＥＧ测定采用上海产ＲＧ－９４１１单道血流图仪。测定了某火力发电厂２０６例噪声作业工人（接触组）和８１例非接触噪声者（对照组）班中、班前ＲＥＧ。对５６例噪声作业工人进行了硝酸甘油试验。结果接触组班前、班中ＲＥＧ异常率、波幅高度、波形异常、两侧波幅差＞３０％发生率均显著高于相应对照组（Ｐ＜００５或Ｐ＜００１）。接触组班中ＲＥＧ各指标均较班前呈升高趋势,但只有流入时间和扩张波与班前比较有统计学差异（Ｐ＜００１）。５６例噪声作业工人经硝酸甘油试验,ＲＥＧ异常波绝大部分（９４６４％）消失。结论接触高频稳态噪声４ｈ可引起ＲＥＧ改变。噪声作业工人ＲＥＧ改变多属功能性的。