Sister chromatid exchanges in human peripheral blood lymphocytes after ingestion of high doses of arsenicals

  Objective – To evaluate the cytogenetic effects following the ingestion of high doses of arsenicals. Methods – Determination of the mean sister chromatid exchange (SCE) frequency and the population of high-frequency cells (HFC, cells with a high SCE frequency) in the peripheral blood lymphocytes in four patients who ingested 150 mg KAsO₂, 1 g, 10 g and 20 g As₂O₃ respectively. Results – Doses of 10 g and 20 g significantly increased the HFC frequency and produced a shift in the distribution of the cells in accordance with the number of SCEs. The mean frequency of SCEs/cell was affected only after the highest dose (20 g). Conclusion – These results strongly suggest that cytogenetic methods are inappropriate for biomonitoring people occupationally exposed to arsenicals. Received: 11 December 1995/Accepted 18 January 1996     

Sister chromatid exchanges in peripheral lymphocytes of workers exposed to benzene,trichloroethylene, or tetrachloroethylene,with reference to smoking habits

Summary The frequencies of sister chromatid exchanges (SCE) were studied in peripheral lymphocytes from four groups of solvent workers, i.e. 36 nonsmoking women exposed to benzene at about 50 ppm on the average, 38 men and women (male smokers and nonsmokers, and female nonsmokers) exposed to trichloroethylene (TRI) at 7 ppm, 27 men and women (both smokers and nonsmokers) with tetrachloroethylene (TETRA) exposure, and 19 workers (both smokers and nonsmokers in men, and nonsmokers in women) exposed to a mixture of TRI (at 8 ppm) and TETRA (at 17 ppm) (TRI + TETRA). The results were compared with the findings in control subjects matched by age, sex, smoking habits and place of residence. No significant increase in SCE frequencies was observed in association with exposure to benzene, TRI, TETRA or TRI + TETRA. The SCE frequency was, however, significantly higher in the TRI-, TETRA-or TRI + TETRA-exposed smoking men than in the concurrent nonsmoking controls of the same sex. Possible synergism between solvent exposure and smoking is discussed.     

染色单体互换频率与铅砷等危害的探讨

目的　探讨铅、镉、砷等职业有害因素致人外周血淋巴细胞染色体畸变的特征性改变。方法　采集职业作业人群及正常人群外周血淋巴细胞培养 72h ,观察染色体畸变类型及其特征。结果　因镉污染接触人群及实验室条件下对淋巴细胞进行高浓度染铅时染色单体互换畸变细胞率为 0 ;染砷浓度 <0 1mg/L时未发生染色单体互换 ,染砷浓度达 0 2～ 0 4mg/L时染色单体互换畸变细胞率为 1 2 4%。　结论　染色单体互换畸变细胞率的增加与接触因素砷及砷的浓度密切相关 ,砷是否可作为染色单体互换产生的主要原因还需作进一步深入的研究     

Respiratory symptoms and lung function in bauxite miners

Objectives: To determine whether cumulative bauxite exposure is associated with respiratory symptoms or changes in lung function in a group of bauxite miners. Methods: Current employees at three bauxite mines in Australia were invited to participate in a survey comprising: questionnaire on demographic details, respiratory symptoms, and work history; skin prick tests for four common aeroallergens; and spirometry. A task exposure matrix was constructed for bauxite exposure in all tasks in all jobs based on monitoring data. Data were examined for associations between cumulative bauxite exposure, and respiratory symptoms and lung function, by regression analyses. Results: The participation rate was 86%. Self-reported work-related respiratory symptoms were reported by relatively few subjects (1.5%–11.8%). After adjustment for age and smoking no significant differences in the prevalence of respiratory symptoms were identified between subjects, in the quartiles of cumulative bauxite exposure distribution. The forced expiratory volume in 1 s (FEV₁) of the exposed group was found to be significantly lower than that for the unexposed group. After adjustment for age, height, and smoking there were no statistically significant differences between quartiles in FEV₁, forced vital capacity (FVC) and FEV₁/FVC ratio. Conclusions: These data provide little evidence of a serious adverse effect on respiratory health associated with exposure to bauxite in an open-cut bauxite mine in present day conditions. Received: 14 August 2000 / Accepted: 12 April 2001     

Blood benzene concentrations in workers exposed to oxygenated fuel in Fairbanks,Alaska

 Objective: In November 1992 residents of Fairbanks, Alaska became concerned about the potential health effects of an oxygenated fuel program during which 15% (by volume) methyl tertiary butyl ether (MTBE) was added to gasoline. To address those concerns, we earlier completed a survey of occupational exposure to MTBE. We conducted a follow-up survey of workers’ exposure to benzene from gasoline in Fairbanks. Design: Cross-sectional exposure survey. Methods: We examined blood concentrations of benzene from a convenience sample of workers taken in December 1992 during the oxygenated fuel program and from another convenience sample of workers taken in February 1993 after the program was suspended. Results: In December, the median blood benzene concentration of samples taken from four mechanics after their workshift (postshift) was 1.32  μg/l (range, 0.84–2.61 μg/l), and seven nonmechanics (drivers and other garage workers) had a median postshift blood benzene concentration of 0.27 μg/l (range, 0.09– 0.45 μg/l). In February, nine mechanics had a median postshift blood benzene concentration of 1.99 μg/l (range, 0.92–3.23 μg/l), and nine nonmechanics had a median postshift blood benzene concentration of 0.26 μg/l (range, 0.2–0.46 μg/l). Conclusion: Mechanics had higher blood benzene concentrations than did nonmechanics, but further study is needed to determine the impact of the oxygenated fuel program on exposure to benzene. Received: 6 November 1995/Accepted: 2 April 1996     

δ-Aminolevulinic acid in plasma or whole blood as a sensitive indicator of lead effects,and its relation to the other home-related parameters

 To evaluate the subclinical effect of lead exposure, we determined δ-aminolevulinic acid (ALA) levels in plasma (ALA-P), blood (ALA-B), and urine (ALA-U) and the activity of δ-aminolevulinic acid dehydratase (ALAD) in lead workers. Almost all of the ALA molecules in blood were present in plasma and not in blood cells, irrespective of the blood lead concentration (Pb-B). ALA-P or ALA-B levels increased slowly at Pb-B levels below 40 μg/dl (slow phase) and rapidly at levels above 40 μg/dl (rapid phase). In both phases, ALA-P and ALA-B were well correlated with Pb-B and ALAD activity. The threshold value (no-effect level) of Pb-B for elevation of the ALA-P or ALA-B level was coincident with that for ALAD inhibition; the value was around 5 μg/dl. In the rapid phase, ALA-P increased continuously up to 100 μg/dl of Pb-B, while ALAD activity reached a plateau. Receiver operative characteristic (ROC) plot analyses indicated that ALA-P and ALAD activity [ALAD(u)] had a similar diagnostic value at Pb-B levels between 10 and 40 μg/dl, although ALAD(%), the remaining ALAD activity as a percentage of the whole activity restored by zinc and dithiothreitol, had the most powerful diagnostic efficiency at these Pb-B levels. By contrast, ALA-U and zinc protoporphyrin were less effective for the diagnosis of lead exposure than ALAD and ALA-P. These findings indicate that ALA-P is the best discriminators of lead exposure form baseline to high levels of exposure. Received: 18 October 1994/Accepted: 11 September 1995     

Effects of a single saturation dive on lung function and exercise performance

 We studied the effects of an experimental saturation dive to 360 and 450 m in a simulation chamber on spirometric lung function, diffusing capacity, pulmonary compliance, and exercise performance in eight professional divers (age 22–40 years). To assess intraindividual variability, all parameters were measured on 2 days before and on 2 consecutive days immediately after the dive. For the group as a whole there was a significant increase in vital capacity and alveolar volume, and a decrease in Krogh factor and specific compliance (P<0.01) . These changes were reduced on the 2nd day after the dive. All subjects showed lowered exercise performance after the dive. Arterial pressure of oxygen and ventilation during exercise increased (P<0.01), whereas arterial pressure of carbon dioxide, oxygen uptake, and anaerobic threshold decreased (P<0.01). Exercise parameters showed only a slight trend towards pre-dive values on the 2nd day after a dive. The individual analysis revealed that after the dive two subjects showed a marked decrease in diffusing capacity and a more than average decrease in Krogh factor (TL_CO/V_A). One of them had signs of mild decompression sickness and the other, signs of pre-existing obstructive airways disease. Our data are compatible with the hypothesis that the effects of a single deep saturation dive on pulmonary function and exercise performance are the results of counteracting mechanisms. We suggest that lung volumes increase due to the enhanced work of breathing during a deep saturation dive and that these changes could mask an impairment in gas exchange. Furthermore, a saturation dive can induce an apparent deterioration of pulmonary function. Received: 23 January 1996/Accepted: 11 March 1996     

Enzyme exposure, smoking and lung function in employees in the detergent industry over 20 years

This study was undertaken to examine the long term relationshipbetween lung function, smoking and exposure to enzymes in thedetergent industry. A total of 731 male workers from five locationsin the United Kingdom were subject to respiratory health surveillanceincluding lung function testing over a period of 4–20years. Exposure groups were defined by job history. Significantlydifferent rates of fall in FEV1 and FVC with time were fourtdby geographical location and by smoking habit, but there wereno consistent trends with enzyme exposure.     

肝性低氧血症与肺功能、一氧化氮和内皮素-1相关性研究

呈负相关(r=-0.287,P=0.026),二者均与肝性低氧血症无相关性(P>0.05).结论 肝性低氧血症在肝硬化早期肺功能即有改变,一氧化氮及内皮素-1虽共同参与肝硬化发展,但非促成肝性低氧血症的因素.     

Critical evaluation and review of cadmium concentrations in blood for use in occupational health according to the TRACY protocol

 Cadmium in blood (B-Cd) may be used to assess recent exposure to cadmium in the working or general environment. In a paper published elsewhere pooled reference values using meta-analysis of B-Cd values in general-population studies were calculated. In the present study tentative reference intervals were described which can be used for comparison with data from occupationally exposed groups or individuals. The selection of studies was done according to criteria as published by the international project TRACY. For this purpose, 800 publications covering the period 1983–1992 were reviewed on their suitability for establishing tentative reference intervals. From these 800 publications, four finally met the selection criteria. Most important criteria for selection were the check for contamination during sampling of the blood, the storage and pretreatment procedures, and the existence of internal and external quality control programs. Also, stratifications into sex, smoking habits and occupation were important selection criteria. It turned out that for non-smoking white-collar workers in the age range of 19–65 years, B-Cd values were below 0.8 μg/l for most areas. All other groups within this age group, e.g., white collar workers in Japan, blue-collar workers, and smokers tend to have higher B-Cd values in these sequences. Blue-collar workers not clearly exposed to Cd have higher values than white-collar workers, indicating still some minor exposure. It is not clear if this small exposure has an occupational or lifestyle (e.g., diet) origin. Geographic regions also show an influence on B-Cd levels, e.g., values in Japan are higher than elsewhere. This influence may be due to differences in diet. The conclusion will be that reference values for B-Cd in fact are area-dependent. Received: 10 June 1996/Accepted: 16 October 1996     

Comparative analysis of the effects of flavonoids on proliferation, cytotoxicity, and apoptosis in human colon cancer cell lines

Summary Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Their proposed protective role in tumor development may prevail especially in the intestinal tract due to direct exposure of intestinal epithelia to these dietary ingredients. We have screened more than 30 flavonoids for their effects on cell proliferation and potential cytotoxicity in the human colon cancer cell lines Caco-2, displaying features of small intestinal epithelial cells, and HT-29, resembling colonic crypt cells. In addition, for selected compounds we assessed whether they induce apoptosis by determining caspase-3 activation. Studies on the dose dependent effects of the flavonoids showed antiproliferative activity of all compounds with EC₅₀ values ranging between 39.7 ± 2.3 μM (baicalein) and 203.6 ± 15.5 μM (diosmin). In almost all cases, growth inhibition by the flavonoids occured in the absence of cytotoxicity. There was no obvious structure-activity relationship in the antiproliferative effects either on basis of the subclasses (i.e., isoflavones, flavones, flavonols, flavanones) or with respect to kind or position of substituents within a class. In a subset of experiments we examined the antiproliferative activities of the most potent compound of each flavonoid subgroup in addition in LLC-PK₁, a renal tubular cell line, and the human breast cancer cell line MCF-7. Out of four flavonols tested, three displayed almost equal antiproliferative activities in all cell lines but fisetin was less potent in MCF-7 cells. The flavanones bavachinin and flavanone inhibited growth of Caco-2 and HT-29 cells with lower EC₅₀ values than that obtained in LLC-PK₁ and MCF-7 cells. The lower susceptibility of LLC-PK₁ and MCF-7 cells towards growth arrest was even more pronounced in the case of the flavone baicalein. Half maximal growth-inhibition in LLC-PK₁ and MCF-7 required 2.5 and 6.6 fold higher concentrations than that needed in the intestinal cell lines. The flavonoids failed to affect apoptosis in LLC-PK₁ and MCF-7, whereas baicalein and myricetin were able to induce apoptosis in HT-29 and Caco-2 cells. In conclusion, flavonoids of the flavone, flavonol, flavanone, and isoflavone classes possess antiproliferative effects in different cancer cell lines. The capability of flavonoids for growth inhibition and induction of apoptosis can not be predicted on the basis of their chemical composition and structure. Received: 28 December 1998, Accepted: 18 March 1999     

Determination of platinum in workroom air and in blood and urine from nursing staff attending patients receiving cisplatin chemotherapy

 Aim: A cross-sectional investigation was carried out to assess possible relations between styrene-induced changes in three peripheral markers of catecholaminergic dysfunction and self-reported symptoms of neurotoxicity. Subjects: Male workers (n=46) aged 14–60 (mean 29.5) years who had been exposed to styrene for an average of 6 (0.2–29) years were recruited in glassfiber reinforced plastics plants. A control group of 30 blue-collar workers aged 22–52 (mean 35) years and with no history of exposure to chemicals was recruited from local industries. Styrene exposure ranged from 5 to 120 ppm (8 h-TWA), the median level being relatively low (25 ppm, 8 h-TWA). Styrene metabolites, mandelic and phenylglycoxylic acids (MAPGA) in the “next morning” urine spot samples ranged from 32.0 to 931.1 mg/g creatinine (median 186.5). Methods: Platelet monoamine oxidases B (MAO B) and dopamine β-hydroxylase (DBH) activities were assessed using methods based on HPLC and electrochemical detection. Plasma prolactin (PRL) was measured by a commercially available immunoassay. Questionnaire 16 (Q16) was used to survey self-reported symptoms. Results: Although there was no difference in DBH activity between exposed workers and controls, the most highly exposed workers had significantly lower activity than control subjects. A tendency to lower platelet MAO B activity in exposed than in control subjects was observed. The prevalence of plasma DBH and platelet MAO B values below the lower reference limit was similar in the two groups. PRL values exceeding the upper reference limit were higher (14/46 vs 2/30) among styrene-exposed workers, who also exhibited significantly higher median levels (10.0 vs 5.7 μg/l) than control subjects. Although the number of reported symptoms was similar among exposed and control subjects, in the exposed group it was positively associated with urinary MAPGA (Rho=0.30, P=0.04). Of the three peripheral markers of catecholaminergic dysfunction, plasma DBH was the only parameter negatively related to both urinary MAPGA (F=9.56, P=0.003) and the number of reported symptoms (Rho=0.23, P=0.05). Conclusions: Plasma PRL appears to be a sensitive marker of styrene-induced tubero-infundibular dopaminergic dysfunction in male subjects. DBH in plasma and MAO B in platelets seem to be less suitable markers for biomonitoring effect at the individual level, although DBH was related to the number of reported symptoms and to internal dose. Further studies on a larger and more exposed population are necessary to clarify the significance of these markers for health and their predictive value with regard to both subjective disturbances and concurrently administered performance tests. Received: 9 January 1996/Accepted: 11 April 1996     

Allergic disease, immunoglobulins, exposure to mercury and dental amalgam in Swedish adolescents

 High-dose exposure to inorganic mercury in man can influence the immune system and in rare cases cause immune-related disease. Some experimental animals also react with autoimmunity after low doses of inorganic mercury. Glomerulonephritis and an increased formation of immunoglobulin type E (IgE) are characteristic of these reactions. A recent study of 15-year-old adolescents demonstrated an association between immunoglobulin type A (IgA) and mercury concentration in plasma (P-Hg). There was also an association between allergic disease and IgA levels. The present study included 54 male and 23 female 19-year-old students who were recruited from a cohort that had been previously defined in a survey of allergic disease. Of the students, 39 (51%) had asthma, allergic rhino-conjunctivitis or eczema. Similar amalgam burden and P-Hg levels were observed in students with (n=39) and without (n=38) allergic disease (P=0.48 and P=0.98, respectively). As expected, IgE levels were significantly higher in the group with allergic disease (P=0.006), but there was no association between P-Hg and IgE. The P-Hg levels were very low (median 1.50 nmol/l) and correlated significantly (r=0.31) with the small number of amalgam surfaces (P=0.007). Thirty-seven students had no amalgam fillings. P-Hg levels did not associate significantly with IgA, but did so with IgG₂ (r=0.33; P=0.003). No conclusive correlation was observed between IgG₂ and amalgam fillings. The findings of this study in 19-year-old subjects differ from earlier data obtained in a sample 4 years younger. The possibility of chance in the association between P-Hg levels and IgG₂ must, however, be considered. Received: 15 April 1996/Accepted: 23 August 1996     

Occupational exposure to Cr(VI): comparison between chromium levels in lymphocytes,erythrocytes, and urine

 The relationships between chromium (Cr) levels in lymphocytes, erythrocytes, urine, and ambient air were compared among 14 chrome-platers from a metallurgic plant in Bulgaria and two groups of local controls, one from the same heavily polluted industrial town as the chrome-platers (n=11) and one from a seaside resort town 100 km away (n=6). Among the chrome-platers, the Cr concentration in peripheral lymphocytes was positively correlated with total Cr and Cr(VI) levels in ambient air and with Cr excretion in urine. As compared to the controls, the chrome-platers had mean Cr levels in lymphocytes twice as high, in erythrocytes ninefold higher, and in urine fourfold to eightfold higher. Although Cr levels in urine and lymphocytes were similar between the two control groups, levels in erythrocytes were 3 times higher among subjects from the industrial area than among those from the seaside town. The study suggests that lymphocyte Cr could be a good indicator of the Cr body burden caused by high exposures to Cr(VI), such as in electroplating operations. In these conditions, erythrocyte Cr may be less useful, possibly owing to increased toxicity due to the high affinity of erythrocytes for Cr. However, when exposure is lower, such as in most environmental situations, erythrocyte Cr should provide a better and more sensitive index than lymphocyte Cr. By contrast, urinary Cr, which provides information on total Cr exposure, including Cr(III) from dietary and environmental sources, does not seem to be of value for studying occupational exposure to Cr(VI). Received: 22 September 1995/Accepted: 2 January 1996     

Combined effects of hand-arm vibration and noise on temporary threshold shifts of hearing in healthy subjects

 Object: To investigate whether hand-arm vibration and noise have a combined effect on temporary threshold shift (TTS) of hearing among healthy subjects. Method and design: Nineteen healthy subjects with an average age of 25.7 (SD 7.7) years were exposed to vibration (30 m/s², 60 Hz), noise [90 dB(A)] and both, respectively. The subject’s right hand was placed on the plate of a vibrator and the right ear exposed to noise via headphones. Subjects were exposed to vibration and/or noise for 3 min and after a 1-min pause the exposure was repeated five times. Hearing thresholds at 1, 4 and 6 kHz were measured during the time periods before, between (during pauses) and after exposure. Results: Exposure to vibration alone caused almost no hearing threshold changes at every frequency tested. But exposure to noise or a combination of vibration and noise caused a significant increase in TTSs at 4 and 6 kHz. Moreover, exposure to a combination of vibration and noise caused significantly higher TTSs than exposure to noise at 4 and 6 kHz. Conclusion: The present results demonstrate the combined effects of hand-arm vibration and noise on hearing: simultaneous exposure to hand-arm vibration and noise can enhance the TTS of hearing more than noise exposure, though hand-arm vibration alone may hardly affect TTS. Received: 14 May 1996/Accepted: 20 September 1996     

Nested case-control study on associations between lung function, smoking and mortality in Japanese population

Objectives Only a few long-term follow-up studies with a focus on the association between lung function and mortality in the Japanese population have been undertaken. In this study, we examined the associations of lung function, smoking and the results of allergy skin tests with mortality in a longitudinal study of the Japanese population. Methods Baseline measurements were performed on residents of Fukui, Japan in 1972, and a follow-up survey was conducted in 2002. By employing a nested case-control design, 596 cases (deaths) and 596 age and sex-matched controls (survivals) were selected. Lung function was assessed using forced vital capacity (FVC) expressed as the normal percent predicted (FVC %pred) and the ratio of forced expiratory volume in 1 second (FEV₁) to FVC (FEV₁/FVC). Allergy skin tests were performed with extracts of house dust, candidia and mixed fungal samples (bronchomycosis). The Brinkman index was used to assess smoking intensity. The Cox proportional hazards model was used to evaluate whether lung function was associated with mortality after adjustment for other potential confounding variables. Results Those categorized into the first- or second-lowest quartile of FVC %pred had a higher mortality [hazard ratios (HRs) and 95% confidence intervals (CIs): 2.01 (1.26–3.19) and 1.84 (1.11–3.05)], respectively. On top of these, heavy smoking (BI≥400) was associated with a higher mortality [HR and 95% CI: 1.73 (1.18–2.53)]. There were only weak of associations between the results of allergy skin tests and mortality. Conclusions These results suggest that FVC %pred of lung function and smoking can serve as long-term independent predictors of mortality.     

Quantifying work load in neck, shoulders and wrists in female dentists

Objective:?To assess the work load in neck and upper limbs of dentists. Methods:?Twelve right-handed female dentists (six with and six without a history of definite neck/shoulder disorders, pair-wise matched for age) were studied when performing authentic dental work. Electromyography (EMG) was used to quantify the muscular load of the shoulders bilaterally and of the right forearm. Positions and movements of the head and wrists were measured, using inclinometers and electrogoniometers. Results:?During work, the median load for the right upper trapezius muscle was 8.4% of the maximal voluntary EMG activity (MVE); during 90% of the time the load was ?3.3% MVE (“static” load). The figures were somewhat lower on the left side (7.0% and 2.5% MVE, respectively). Subjects with disorders had over all lower load levels for the trapezius muscles, although not statistically significant at <0.05, than those without disorders. During a standardized reference contraction for the trapezius, the load was 17% MVE, and the quotient between MVE and torque [normalized to maximal voluntary torque (MVC)] was 0.5. These figures may be used for transformations. The muscular load on the right forearm was similar to the loads on the trapezius. The head was, on average, forward tilted ?39°, and during 10% of the time ?49°. The left hand was held in more static positions, with palmar flexion and ulnar deviation, also reflected by lower angular velocities and repetitiveness, as compared with the right one, which was dorsiflexed. Conclusions:?Dentists are exposed to high load on the trapezius muscles bilaterally, and steep, prolonged forward bending of the head. Further, for the wrists the postures were constrained, but the dynamic demands were low.     

The epidemiology and surveillance of blood lead in Taiwan (R.O.C.): A report on the PRESS-BLL project

 To monitor the lead hazards in industries and to investigate the prevalence of elevated blood lead levels (BLLs) in lead-exposed workers, a lead surveillance system (PRESS-BLLs) has been established and operated in Taiwan, Republic of China, since July 1993. A cohort of lead-exposed workers who received a periodic annual health examination at 55 accredited hospital laboratories was constructed. A total of 9807 separate BLL measurements were reported to the system in 1994. The mean BLL was 15.8 μg/dl in male workers and 11.6 μg/dl in female workers. The mean BLL of lead-exposed workers was significantly (P<0.05, z-test) higher than that of the general Taiwanese population (8.6 μg/dl for males and 6.7 μg/dl for females). In addition, the BLLs of 983 (10.0%) workers exceeded the regulatory action level (40 μg/dl for males; 30 μg/dl for females). The workplaces and homes of 57% of the workers with elevated BLLs were thoroughly investigated to determine the sources of lead contamination. These actions identified the causes of elevated BLLs and set up strategies to reduce workers’ lead exposure. The establishment of this occupational lead surveillance system represents a method for monitoring of lead hazards from occupational and environmental settings to prevent lead poisoning. The information acquired from the system can help in the setting up of a priority of prevention and the development of control measures. It is also useful for further monitoring of changes in the BLLs of the lead-exposed-worker cohort. The Health Department of Taiwan can use this information to evaluate the effectiveness of current industrial hygiene practice. Subjects with elevated BLLs have been medically treated and placed on long-term follow-up for sequelae. Received: 2 September 1996/Accepted: 29 November 1996     

地沟油对小鼠肝肾功能及脂肪代谢的影响

目的观察摄食地沟油对小鼠肝肾功能及脂肪代谢的影响。方法将72只小鼠平均分为6组,其中地沟油组与食用油组各3组,按照5、10和20μL/g剂量的地沟油或食用油连续隔天给予小鼠灌胃8周,比较两组小鼠灌胃前后丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)、血尿素氮(BUN)、血肌酐(Scr)、甘油三酯(TG)和总胆固醇(TC)水平。结果地沟油的水分含量、酸价和过氧化值指标均超标。连续灌胃8周后,5μL/g剂量地沟油组小鼠ALT明显高于食用油组(P0.05);10μL/g剂量地沟油组小鼠AST高于食用油组(P0.05)。5、10和20μL/g剂量地沟油组小鼠Scr均高于同剂量食用油组(P0.05);10和20μL/g剂量地沟油组小鼠BUN均高于同剂量食用油组(P0.05);但相同剂量地沟油和食用油组小鼠的TG和TC未见统计学差异(P0.05)。结论连续8周摄食地沟油对小鼠肝、肾功能均有明显损害作用。     

Frequency of patients with acute asthma in relation to ozone, nitrogen dioxide, other pollutants of ambient air and meteorological observations

 Objective. To study the association of the daily frequency of registration of patients with acute asthma at the emergency department of a central hospital in the south-west of Sweden with levels of air pollution and meteorological observations. Methods. A retrospective longitudinal study was made of asthma patients taken from a hospital registry. This information was correlated with measurements of ozone, nitrogen dioxide, sulphur dioxide, toluene, temperature and relative humidity. Patients were from the catchment area of the Central Hospital of Halmstad containing around 120 000 inhabitants. A total of 4127 visits of patients with acute asthma to the emergency department at the Central Hospital of Halmstad were registered during a period of 1247 days from January 1990 to May 1993. The differential optical absorption spectroscopy (DOAS) technique was used to monitor levels of air pollutants over a distance of 1000 m in the central part of the town of Halmstad. Data on temperature, relative humidity, precipitation, wind speed and wind direction for the time period were supplied by the Swedish Meteorological and Hydrological Institute (SMHI). Results. There were many statistically significant correlations between the levels of air pollutants and the meteorological measurements and a strong negative correlation between ozone and nitrogen dioxide. There was a statistically significant effect on asthma visits in children of low temperature and high nitrogen dioxide levels, and on asthma visits in adults of high temperature and high levels of ozone. Conclusions. There was a different reaction pattern in children and adults with asthma regarding temperature and ozone/nitrogen dioxide. The strong correlations between temperature and air pollution and between the levels of ozone and nitrogen dioxide made the true relation between asthma, air pollution and temperature hard to evaluate statistically. Received 18 March 1996/Accepted 21 June 1996