Elevated levels of urinary 8-hydroxy-2 -deoxyguanosine, lymphocytic micronuclei, and serum glutathione S-transferase in workers exposed to coke oven emissions

To investigate associations among occupational exposure to coke oven emissions (COEs), oxidative stress, cytogenotoxic effects, change in the metabolizing enzyme glutathione S-transferase (GST), and internal levels of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers, we recruited 47 male coke oven workers and 31 male control subjects from a coke oven plant in northern China. We measured the levels of 1-hydroxypyrene (1-OHP) and 8-hydroxy-2 -deoxyguanosine (8-OHdG) in urine, micronucleated binucleated cells (BNMNs) in peripheral blood lymphocyte, and GST in serum. Our results showed that the group exposed to COEs had significantly increased levels of 1-OHP [median 5.7; interquartile range (IQR), 1.4-12.0 micromol/mol creatinine] compared with the control group (3; 0.5-6.4 micromol/mol creatinine). In addition, the median levels (IQR) of 8-OHdG, BNMNs, and GST were markedly increased in the exposed [1.9 (1.4-15.4) micromol/mol creatinine; 6 (2-8) per thousand ; 22.1 (14.9-31.2) U/L, respectively] compared with controls [1.3 (1.0-4.0) micromol/mol creatinine, 2 (0-4) per thousand; and 13.1 (9.5-16.7) U/L, respectively]. These results appeared to be modified by smoking. However, multivariate logistic regression analysis revealed that exposure to COEs had the highest odds ratio among variables analyzed and that smoking was not a significant confounder of the levels of studied biomarkers. Overall, the present findings suggest that COE exposure led to increased internal PAH burden, genetic damage, oxidative stress, and GST activity. The consequences of the changes in these biomarkers, such as risk of cancer, warrant further investigations.     

焦炉工人血清谷胱甘肽硫转移酶活力和尿8-羟基脱氧鸟苷水平

目的 探讨血清谷胱甘肽硫转移酶（GST）和尿8-羟基脱氧鸟苷（8-OHdG）作为焦炉工人多环芳烃（PAHs）暴露生物监测标志的可行性.方法 用高效液相色谱-电化学方法和试剂盒分别检测47名男性焦炉工和31名男性对照者尿8-OHdG水平和血清GST活力;尿1-羟基芘（1-OHP）作为PAHs接触的内暴露标志,采用碱水解-高效液相色谱方法分析.结果 焦炉工人尿1-OHP浓度的中位数（P25～P75）为[5.7（1.4～12.0）μmol/mol Cr],血清GST活力为[22.1（14.9～31.2）U/ml],尿8-O-HdG水平为[1.9（1.4～15.4）μmol/mol Cr],均高于对照组工人[3.0（0.5～6.4）μmol/mol Cr、13.1（9.5～16.7）U/ml、1.3（1.0～4.0）μmol/mol Cr],差异均有统计学意义（P＜0.05或P＜0.01）.以吸烟分层,两组工人尿1-OHP浓度和血清GST活力仅在吸烟者中、尿8-OHdG水平仅在非吸烟者中差异有统计学意义（均P＜0.01）.焦炉工人血清GST活力和尿1-OHP浓度呈正相关（rs=0.31,P＜0.01,n=78）.多元Logistic回归分析显示,与对照工人相比,焦炉工人血清GST活力＞16.7 U/ml和尿8-OHdG水平＞1.8 μmol/mol Cr的OR值分别为13.2和4.4;高体重指数是影响尿8-OHdG水平下降的独立因素.结论 焦炉工人血清GST活力增强和氧化性DNA损伤增加,吸烟和职业暴露有交互作用;血清GST有可能作为PAHs暴露评价的生物标志;尿8-OHdG检测有助于焦炉工肺癌危险度评价.     

Exposure to diesel engine exhausts and increase of urinary 8-hydroxy-2′-deoxyguanosine among Male tank maintenance workers in the Republic of Korea Army

This study was conducted to evaluate the exposure of diesel engine exhaust (DEE) and oxidative stress among tank maintenance workers in the Republic of Korea Army. Airborne concentrations of elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), and metals were measured at two units. Urine analysis for 1-hydroxypyrene and 8-hydroxy-2′-deoxyguanosine (8-OHdG) was performed for tank maintenance workers from one unit (n=17). To compare the level of 8-OHdG, the analysis was performed in 17 unexposed controls. The airborne EC concentration was 8.6–24.3 µg/m³ in indoor unit. EC was not detected in the outdoor unit. As for the PAHs, trace −0.0004 mg/m³ of naphthalene was detected. I_TWA for 26 metals was calculated to be 0.009–0.027. The geometric mean urinary 1-hydroxypyrene was 0.08 µg/g creatinine. The geometric mean of 8-OHdG was 1.04 µg/g for the maintenance workers, while 0.45 µg/g for controls. The level of urinary 8-OHdG was significantly higher among maintenance workers in multivariate analysis. In conclusion, tank maintenance workers are exposed to various by-products from diesel engine combustion during work, and their level of oxidative stress marker was increased. Countermeasures for reducing hazardous substances in the military workplace are necessary.     

8-羟基脱氧鸟苷与吡啰红Y作用的共振光散射光谱及分析应用

目的：建立一种灵敏简便的样品中8-OH-dG分析新方法。方法：在pH9．0的R．B缓冲液中，吡啰红Y阳离子染料与8-OH-dG阴离子形成离子缔合物，导致体系的共振光散射增强。结果：在优化的实验条件下，体系的共振光散射强度随着8-OH-dG的加入在339nm处急剧增强。共振光散射的增强（△IRLS）与8-OH-dG加入量成线性关系．据此建立8-OH-dG的共振光散射检测新方法，方法的线性范围为50．0—226．4ng/ml、检出限15．2ng／ml。结论：该方法快速、简便，已成功用于加标样品的分析。     

Risk and incidence of asthma attributable to occupational exposure among HMO members

Occupational asthma may account for a significant proportion of adult-onset asthma, but incidence estimates from surveillance of physician reports and workers' compensation data (0.9 to 15/100,000) are lower than expected from community-based cross-sectional studies of asthma patients. We conducted a prospective cohort study of 79,204 health maintenance organization members between the ages of 15 and 55 at risk for asthma. Computerized files, medical records, and telephone interviews were used to identify and characterize asthma cases. Evidence for asthma attributable to occupational exposure was determined from work-related symptoms and workplace exposure. The annual incidence of clinically significant, new-onset asthma was 1.3/1,000, and increased to 3.7/1,000 when cases with reactivation of previously quiescent asthma were included. Criteria for onset of clinically significant asthma attributable to occupational exposure were met by 21% (95% CI 12–32%) of cases giving an incidence of 71/100,000 (95% CI 43–111). Physicians documented asking about work-related symptoms in 15% of charts, and recorded suggestive symptoms in three cases, but did not obtain occupational medicine consultation, diagnose occupational asthma, report to the state surveillance program, or bill workers' compensation for any of them. These data suggest that the incidence of asthma attributable to occupational exposures is significantly higher than previously reported, and accounts for a sizable proportion of adult-onset asthma. Am. J. Ind. Med. 33:1–10, 1998. © 1998 Wiley-Liss, Inc.     

Urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine and biopyrrins levels among construction workers with asbestos exposure history

It has been suggested that oxidative stress is associated with the cancers caused by asbestos. Since construction workers are sometimes exposed to low levels of asbestos, we investigated whether oxidative stress was elevated in construction workers who had been exposed to low levels of asbestos. The subjects were 48 Japanese construction workers. The defined asbestos-exposed group consisted of subjects who had the history of suspected exposure to asbestos and were diagnosed to have irregular opacities or pleural plaques. We measured the amount of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) and biopyyrins in the urine of the subjects. The results showed that 8-oxodG and biopyyrins levels in the defined asbestos-exposed group were higher, although they were not statistically significant, than those in the control group. In addition, the urinary 8-oxodG levels tended to correlate positively with the duration of suspected exposure to asbestos. These results suggest that even low-level asbestos exposure may induce oxidative stress and that the resulting's the oxidative stress might be related to lung cancer in construction workers.     

Increased blood pressure in schoolchildren related to high sodium levels in drinking water.

The relationship between sodium in drinking water and blood pressure was examined in 348 schoolchildren aged 7.7 to 11.7 years. They were born and living in three areas with different levels of sodium in the public drinking water. Sodium content of the water was either long-term low, long-term high, or short-term high. The three communities are closely comparable according to demographic characteristics. The mean values of systolic and diastolic blood pressure were higher in the high sodium areas. After adjustment for dissimilarities in distributions of weight, height, pulse rate, age, family history of hypertension, and time of blood pressure measurement, these differences remained constant, ranging from 1.8 to 4.0 mm Hg. Girls and boys showed essentially the same differences. Mean 24-hour sodium excretion was somewhat higher in the long-term low area; no differences were found in sodium-creatinine ratio. The regression coefficients between sodium excretion and blood pressure were not significant. The findings from this retrospective follow-up study support the hypothesis that sodium intake influences blood pressure. The association seems to be of a relatively short-term nature, as no differences in blood pressure levels were found between the long-term and short-term high areas.     

Indoor exposure to bioaerosol particles: levels and implications for inhalation dose rates in schoolchildren

Children spend most of their time inside schools and bioaerosol particles are part of their everyday environment. Although bioaerosol particles are considered to be a potential risk factor for various health concerns, information concerning the indoor exposures and inhalation doses is still limited. This study aimed (i) to quantify bacterial and fungal particles levels in indoor and outdoor air of public primary schools, (ii) to assess the influence of ambient air on bacteria and fungi presence indoors, and (iii) to estimate the inhalation dose rates for respective children (8–10 years old) in comparison with adult staff. Air samples were collected in 20 primary schools in a total of 71 classrooms during heating season with a microbiological air sampler. The results showed that indoor bacterial and fungal concentrations were higher than outdoor levels (p?<?0.05), which could be explained by differences in density of occupation, occupant’s activities, and inadequate ventilation. CO₂ levels were significantly correlated with indoor bacteria concentrations. Moreover, mean indoor bacteria concentrations were above national limit values in all the evaluated Porto primary schools, from two to nine times higher. Regarding fungi concentrations, indoor levels were above the reference value in 75% of the schools and overall indoor levels registered a 3-fold increase compared with outdoor values. Children had two times higher inhalation dose rates to bioaerosol particles when compared to adult individuals. Thus, due to their susceptibility, special attention should be given to educational settings in order to guarantee the children healthy development.     

Increased levels of serum uric acid among ex-smokers

Background

It remains unclear whether serum uric acid level increases after the cessation of smoking.

Methods

In 2000, we conducted a cross-sectional study on the effects of smoking cessation on serum uric acid levels by analyzing the results of annual health check-ups in the Japanese male working population (n = 16,642).

Results

The serum uric acid level (6.18 mg/dL) was the highest in ex-smokers, followed by that in never-smokers (6.10 mg/dL) and that in current smokers (5.98 mg/dL). Ex-smokers weighed 0.6 kg more than the never-smokers and 1.5 kg more than the current smokers. The frequency of alcohol intake was closely correlated to the smoking habits. The serum uric acid levels declined in all groups, after adjustments for age, body mass index, and alcohol intake, though the levels in ex-smokers were 0.2 mg/dL higher than those in current smokers.

Conclusion

The results suggested that alcohol intake contributed considerably to the serum uric acid levels and that smoking itself may have suppressed these levels via metabolic effects or the action of superoxides.Key words: Smoking Cessation, Uric Acid, Body Mass Index, Alcohol Drinking     

高效液相色谱-紫外法检测尿中8-羟基脱氧鸟苷

目的:观察利用高效液相色谱-紫外法检测尿液8-羟基脱氧鸟苷(8-OHdG)的效果.方法:尿液经前处理后,利用美国Agilent高效液相色谱仪检测8-OH-dG水平.结果:8-OHdG峰与杂质峰分离良好,8-OHdG浓度在0.5～20μg/ml之间旱良好线性,流动相最佳的pH为3.5,回收率在98.6%～100.1%之间,批内差异(CV)均低于8%.结论:高效液相色谱-紫外法是一种灵敏度较高、重复性好、易推广的尿液8-OHdG简便检测方法,值得推广.     

云南省白族居民归因于吸烟和被动吸烟的脑卒中经济负担研究

目的 分析云南省白族居民脑卒中与吸烟/被动吸烟的关系,估算出归因于吸烟/被动吸烟的脑卒中经济负担。方法 采用多阶段分层随机抽样方法,于2018年4-5月在云南省大理州剑川县抽取2501名≥35岁白族居民进行面对面问卷调查和体格检查。脑卒中直接经济负担的测算采用直接法,间接经济负担测算采用人力资本法 ,并与归因危险度 (PAR) 相结合测算归因于吸烟/被动吸烟的疾病经济负担。结果 云南省白族居民脑卒中患者的人均直接和间接负担分别为8720.33元和152.28元,总经济负担为101.653百万元,其中男性患者的人均直接经济负担高于女性（t=2.288, P=0.027）;多因素logistic回归分析结果显示,现在吸烟者和被动吸烟者患脑卒中的风险为非吸烟者和非被动吸烟者的3.596倍（OR=3.596,95%CI=2.468～5.238）和3.361倍（OR=3.361,95%CI=2.266～4.983）;归因于吸烟的脑卒中经济负担为44.920百万元,归因于被动吸烟的为33.802百万元。结论 云南省白族居民归因于吸烟和被动吸烟的脑卒中经济负担较重。采取有效措施减少吸烟和被动吸烟率,可进一步降低脑卒中的疾病经济负担。     

Interval estimation of the attributable risk for multiple exposure levels in case-control studies with confounders

The attributable risk (AR) is one of the most important and commonly-used epidemiological indices to assess the public health importance of an association between a risk factor and a disease. When the underlying risk factor has multiple exposure levels in the presence of confounders, we consider the case-control studies using random sampling to collect the cases and controls here. We develop four asymptotic interval estimators for AR, including the interval estimator using Wald's statistic, the interval estimator using the logarithmic transformation, the interval estimator using the logit transformation, and the interval estimator derived from a quadratic equation. We apply Monte Carlo simulation to evaluate the finite-sample performance of these interval estimators in a variety of situations. We demonstrate that given an adequately large sample size, all the estimators developed here can actually perform reasonably well. We note that the interval estimator using the logit transformation may be of limited use when the number of studied subjects is not large. We also note that the interval estimator using the logarithmic transformation can lose efficiency compared to the interval estimator using Wald's statistic or the interval estimator derived from a quadratic equation developed in this paper. Finally, we use the data taken from a case control study of the oral contraceptive use in myocardial infarction patients with various smoking levels to illustrate he practical usefulness of these estimators.     

Assessment of exposure to carcinogenic N-nitrosamines in the rubber industry

Exposures to volatile nitrosamines were measured at 24 rubber manufacturing plants from 1992 to 1995. A total of 709 exposure measurements were taken in general areas or personal breathing zones to estimate exposure according to production types (seals, joints, tyres, gloves, etc.) and production steps, from mixing to storage. Five different nitrosamines were identified. N-Nitrosodimethylamine is the most frequently encountered nitrosamine and represents the most important fraction of the total nitrosamine concentration measured in a given sample. This fact is consistent with the use of rubber additives containing corresponding amine precursors. One hundred and forty-one of the 709 values exceeded the German target value (TRK) of 2.5 μg/m³ for all nitrosamines present from rubber vulcanisation, the only available standard for occupational nitrosamine exposures. The salt bath curing process generates particularly high nitrosamine levels, 90% of the 96 measurements being over the TRK, with many values exceeding 20 μg/m³. The reasons why the TRK is exceeded are generally well identified. To reduce nitrosamine emission levels it would be advisable to eliminate nitrogen oxide sources, principally by using a process other than salt bath curing, and to develop different rubber stocks that do not contain secondary aliphatic amine functional groups (“safe amines”). Received: 30 December 1996 / Accepted: 21 February 1997     

Occupational exposure to dust and lung disease among sheet metal workers.

A previous large medical survey of active and retired sheet metal workers with 20 or more years in the trade indicated an unexpectedly high prevalence of obstructive pulmonary disease among both smokers and non-smokers. This study utilised interviews with a cross section of the previously surveyed group to explore occupational risk factors for lung disease. Four hundred and seven workers were selected from the previously surveyed group on the basis of their potential for exposure to fibreglass and asbestos. Selection was independent of health state, and excluded welders. A detailed history of occupational exposure was obtained by telephone interview for 333 of these workers. Exposure data were analysed in relation to previously collected data on chronic bronchitis, obstructive lung disease, and personal characteristics. Assessment of the effects of exposure to fibreglass as distinct from the effects of exposure to asbestos has been difficult in previous studies of construction workers. The experienced workers studied here have performed a diversity of jobs involving exposure to many different types of materials, and this enabled exposure to each dust to be evaluated separately. The risk of chronic bronchitis increased sharply by pack-years of cigarettes smoked; current smokers had a double risk compared with those who had never smoked or had stopped smoking. The occurrence of chronic bronchitis also increased with increasing duration of exposure to asbestos. Workers with a history of high intensity exposure to fibreglass had a more than doubled risk of chronic bronchitis. Obstructive lung disease, defined by results of pulmonary function tests at the medical survey, was also related to both smoking and occupational risk factors. Number of pack years smoked was the strongest predictor of obstructive lung disease. Duration of direct and indirect exposure to welding fume was also a positive predictor of obstructive lung disease. Duration of exposure to asbestos was significantly associated with obstructive lung disease but the dose-response relation was inconsistent, especially for those with higher pack-years of smoking exposure. Exposure to fibreglass was not a risk factor for obstructive lung disease.     

Residential exposure to motor vehicle emissions and the risk of wheezing among 7-8 year-old schoolchildren: a city-wide cross-sectional study in Nicosia,Cyprus

Background  

Several studies have reported associations between respiratory outcomes in children and a range of self-reported, administrative or geographical indicators of traffic pollution. First-time investigation into the frequency of asthmatic symptoms among 7-8 year-old Cypriot children in 1999-2000 showed increased prevalence in the capital Nicosia compared to other areas. Geographical differences on an island the size of Cyprus may reflect environmental and/or lifestyle factors. This study investigates the relationship between self-reported symptoms and residential exposure to motor vehicle emissions among Nicosia schoolchildren.     

Chronic arsenic exposure and urinary 8-hydroxy-2'-deoxyguanosine in an arsenic-affected area in Inner Mongolia, China

OBJECTIVE: Recent studies have shown that generation of reactive oxidants during arsenic metabolism can play an important role in arsenic-induced injury. The purpose of this study was to examine the relationship between arsenic in drinking water and oxidative stress in humans by measuring 8-Hydroxy-2'-deoxyguanosine (8-OHdG). METHODS: We performed a cross-sectional study in an arsenic-affected village in Hetao Plain, Inner Mongolia, China. A total of 134 of the 143 inhabitants (93.7%) of the village participated in the study. The levels of 8-OHdG, arsenic and its metabolites were measured in urine collected from the participants. Regression analyses were performed to investigate the relationship between arsenic species and 8-OHdG levels in urine. RESULTS: In the polluted village, monomethylarsenic was significantly higher in subjects with arsenic dermatosis than those without dermatosis despite no difference in mean levels of arsenic in well water between both types of subject. For subjects with arsenic dermatosis, arsenic species and metabolites in urine are significantly associated with 8-OHdG, while there was no statistically significant relationship for subjects without arsenic dermatosis. For all residents of the polluted village, the levels of dimethylarsenic and 8-OHdG were significantly higher for those who had been exposed to well water for more than 12 years. CONCLUSIONS: These results provide evidence of a link between exposure to arsenic from drinking water and oxidative stress, which may play an important role in arsenic-involved injuries.