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At least 19 recordsLinked to original sources
PubMedDate not supplied

Urinary 1-hydroxypyrene levels in workers exposed to coke oven emissions at various locations in a coke oven plant.

Polycyclic aromatic hydrocarbons, which are carcinogenic and mutagenic to humans, are primary compounds in coke oven emissions generated by the coking process. The authors examined the relationship between coke oven workers' urinary 1-hydroxypyrene levels and their exposure to polycyclic aromatic hydrocarbons, as determined on the basis of work category and pre- and postshift effects in a steel plant in Taiwan. Eighty-eight coke oven workers constituted the exposed group, and 61 office workers in a steel plant located 1.5 km from the coke plant constituted the control group. The benzene-soluble fraction in personal air samples, and 1-hydroxypyrene in urine samples, were measured for 3 consecutive days. The 3-day urinary 1-hydroxypyrene sampling results for topside workers (i.e., those most heavily exposed to emissions) in the coke oven group, and for the control group, as determined from postshift geometric means, were 23.8 microg/gm creatinine and 0.3 microg/gm creatinine, respectively. These values increased to 13.4 and 0.1 microg/gm creatinine, respectively, after an 8-hr work period. The major source of polycyclic aromatic hydrocarbons for the exposed group was occupational; therefore, the closer workers were to the coke oven, the greater their exposure, and, consequently, the greater their metabolite level. Urinary 1-hydroxypyrene levels of the exposed group were 80 times higher than those of the control group. Smoking had no significant effect on the excretion of urinary 1-hydroxypyrene. 1-hydroxypyrene levels in the workers' urine during an 8-day period was cumulative (half-life = 18.6 hr). The authors concluded that it would be desirable to switch highly exposed workers to a low-exposure work area, after a period of rest. In addition, urinary 1-hydroxypyrene was a confirmed, useful biological indicator for exposure to polycyclic aromatic hydrocarbons.

Air Pollutants, Occupational↗
PubMedDate not supplied

Assessment of coke oven emissions exposure among coking workers.

Coking workers are regularly exposed to coke oven emissions, which consist primarily of polycyclic aromatic hydrocarbons and volatile organic compounds. This study measured the workers' exposure to the benzene soluble fraction of total particulates (BSF). The study population consisted of 88 coking workers as an exposure group and 59 referents. Personal breathing-zone samples of BSF and total particulates were taken from all study subjects for 3 consecutive days. The highest BSF concentrations were found among the topside oven workers (geometric mean; range) (microgram/m3): lidman (515; 72-18, 181), tar chaser (432; 51-4334), and larry car operator (185; 55-649). The lowest was 7 micrograms/m3 in the referents. Among the samples at the topside oven 84% exceeded the Occupational Safety and Health Administration standard (150 micrograms/m3 BSF). The percentage of BSF in total particulates varied across job classifications, ranging from 0.3% in wharfmen to 24% in tar chasers. Area sampling indicated that the BSF concentration at the topside area was sixtyfold higher than that at the administrative area, which was approximately 2 km from the coke oven plant.

Air Pollutants, Occupational↗
PubMed2002

Relationship of exposure to coke-oven emissions and urinary metabolites of benzo(a)pyrene and pyrene in coke-oven workers.

Coke-oven workers are occupationally exposed to a high concentration of polycyclic aromatic hydrocarbons (PAH). r-7,t-8,9,c-10-Tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene (trans-anti-BaP-tetraol) and 1-hydroxypyrene (1-OHP) are urinary metabolites of benzo(a)pyrene and pyrene, respectively. In this study, we investigated the relationship among individual air exposure to benzene soluble fraction (BSF) of total particulates, as a surrogate marker of ambient PAH exposures, and urinary trans-anti-BaP-tetraol and 1-OHP concentrations in coke-oven workers at a steel plant in Taiwan. Fifty-seven subjects, including 41 male workers who work in one coke-oven plant and 16 men (referents) from an administrative area, were studied. The mean trans-anti-BaP-tetraol and 1-OHP concentrations (mean +/- SD) were 0.4 +/- 0.3 nmol/mol creatinine and 9.7 +/- 21.6 micromol/mol creatinine, respectively, in coke-oven workers. These levels were significantly higher than those in referents (0.03 +/- 0.03 nmol/mole creatinine, P < 0.001 and 0.4 +/- 0.2 micromol/mol creatinine, P < 0.01, respectively). Urinary trans-anti-BaP-tetraol concentrations were significantly and positively correlated with individual average BSF and urinary 1-OHP concentrations. That is, the higher the urinary trans-anti-BaP-tetraol concentrations, the more ambient BSF exposure and urinary 1-OHP concentrations (Spearman correlation coefficients r = 0.68 and 0.70, respectively; P < 0.0001; n = 57). These findings suggest that urinary 1-OHP and trans-anti-BaP-tetraol might be considered as potential biomarkers for the assessment of uptake of known PAH carcinogens in the air.

Adult↗
PubMed1990

[Effect of the work environment of the coke-processing industry on the respiratory system of coke factory workers].

The influence of the working environment in a coke factory on the respiratory system of workers was examined in 253 workers employed for at least 5 years at coke production in baking ovens, or at coke sorting and processing. They were exposed to high air concentrations of benzo(a)pyrene (BaP) and tar substances as well as other numerous toxic substances e.g. benzene++ derivatives, the level of which however, did not exceed the MAC values. Medical examination comprising the MRC questionnaire and spirometry , using Godart Expirograph, was carried out Among the exposed workers the non-specific chronic respiratory diseases with obstructive symptoms and chronic bronchitis were revealed more often than in the control group such factors as tobacco smoking and the duration of work also had their influence on the frequency of respiratory diseases. The possibility of the impact of high air concentrations of BaP and carbon monoxide cannot be excluded either.

Adult↗
PubMed1993

[Characterization of coke derivate distillation departments in coke plants. Hygienic and ergonomic conditions].

The studies were carried out in three coke plants mostly with the use of individual dosimetric methods but also with the stationary method. They revealed the values 2-5 times exceeding the MAC of the tar substances in the air of all workposts, and benzo(a)pyrene at several posts only. The other toxic substances like benzene homologous and benzologous and dust exceeded the MAC value only incidentally so that the workers of this department were less exposed than the people employed directly at the coke production. The ergonomic examinations did not reveal any excess of energetic expenditure or physiological cost. The results of medical studies will be presented in further papers.

Air Pollutants, Occupational↗
PubMed2005

Fast determination of sugars in Coke and Diet Coke by miniaturized capillary electrophoresis with amperometric detection.

The fast separation capability of a novel miniaturized capillary electrophoresis with amperometric detection (CE-AD) system was demonstrated by determining sugar contents in Coke and diet Coke with an estimated separation efficiency of 60,000 TP/m. Factors influencing the separation and detection processes were examined and optimized. The end-capillary 300 microm Cu wire amperometric detector offers favorable signal-to-noise characteristics at a relatively low potential (+0.50 V vs. Ag/AgCl) for detecting sugars. Three sugars (sucrose, glucose, and fructose) have been separated within 330 s in a 8.5 cm length capillary at a separation voltage of 1000 V using a 50 mM NaOH running buffer (pH 12.7). Highly linear response is obtained for the above compounds over the range of 5.0 to 2.0 x 10(2) microg/mL with low detection limit, down to 0.8 microg/mL for glucose (S/N = 3). The injection-to-injection repeatability for analytes in peak current (RSD < 3.6%) and for migration times (RSD < 1.4%) was excellent. The new miniaturized CE-AD system should find a wide range of analytical applications involving assays of carbohydrates as an alternative to conventional CE and micro-CE.

Carbohydrates↗
PubMed2005

[Emission and source characterization of monoaromatic hydrocarbons from coke production].

Monoaromatic hydrocarbons (MAHs) from indigenous and industrial coking processes are studied in Shanxi province. They are sampled on the top of coke ovens and in the chimneys using stainless steel canister and determined by GC/MSD after preconcentration with liquid nitrogen. Benzene, toluene and xylene are the main components among MAHs emitted from coking processes. Benzene and the total MAHs concentrations were as high as 3421.0 microg/m3 and 4 865.9 microg/m3 in the air from indigenous coking, 548.7 microg/m3 and 1 054.8 microg/m3 in the oventop air from industrial coking, and 1 376.4 microg/m3 and 1 819.4 microg/m3 in stack gas from industrial coking, respectively. The MAHs concentrations vary greatly during the indigenous coking process, which in the prophase (from firing to 10 days) is obviously higher than in the anaphase (10 days to quenching the coke). In industrial coking the MAHs in the oventop air are highest when charging the coal and next when transferring the hot coke, but in stack gas they are highest when charging coal and lowest when transferring the coke. Benzene, toluene, ethylbenzene and xylene (BTEX) in industrial coking samples show good linearity, indicating that MAHs in industrial coking might come predominantly from coal pyrolysis; but BTEX distribute dispersedly in indigenous coking samples, indicating that its emission might be affected by many factors. In all samples BTEX ratios especially high B/E ratio, is unique among MAHs sources, and might be helpful to characterize pollution from coking.

Air Pollutants↗
PubMed1997

Serum liver function profiles in coking workers.

Coking workers are regularly exposed to coke oven emissions (COE), which consist mainly of polycyclic aromatic hydrocarbons and volatile organic compounds. In a previous cross-sectional study, we found that coking and by-product workers with heavy exposure to COE in the older of two coke operation areas in Taiwan had higher serum activities of hepatic aminotransferase than the controls. In this study, we further examine the relationship of exposure to COE with liver function profiles in coking workers. Liver function profiles included serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and total bilirubin (BIL). The exposed group included 88 workers working 3 months or more in the older coke oven plant. Fifty-nine referents, not visiting the coke operation areas in the last 3 months, came from the administrative area in the same company. Each participant wore a personal monitor that was used to measure benzene soluble fraction (BSF) of total particulates, as a surrogate of COE, for 3 consecutive days between August 1995 and February 1996. Serum liver function profiles, hepatitis B surface antigens, and anti-hepatitis C antibodies were examined in the morning following the exposure measurements. Exposure levels were categorized by exposure situations (high, medium, low) among coking workers. The high exposure group (n = 23) worked topside of the oven. The medium exposure group (n = 44) worked at the sideoven for more than 4 hr/day, whereas the low exposure group (n = 21) worked at the sideoven for less than 4 hr/day and mostly remained in the control rooms. The low exposure group was used as an internal comparison group. The median BSF concentrations for various exposure situations were as follows, high exposure group: 372 micrograms/m3, medium exposure group: 61 micrograms/m3, low exposure group: 49 micrograms/m3, and referents: 10 micrograms/m3. The coking workers (n = 88) did not significantly differ from the referents (n = 59) in any of the liver function profiles. Excluding the referents, workers in the high exposure group had a mean AST level that was 31% higher (95% confidence interval (CI) = 9-57%) and a mean ALT level that was 46% higher (95% CI = 7-98%) than those in the low exposure group after adjusting for appropriate confounders in multivariate models. The prevalence of an abnormal hepatocellular pattern (AST > 37 IU/L or ALT > 39 IU/L) was more common in the high exposure group than in the low exposure group (adjusted odds ratio = 4.4; 95% CI = 0.9-22.6). However, these associations were not found in GGT, ALP, or BIL. After controlling for the possible effects of nonoccupational factors on serum activity of AST and ALT, we conclude that increased AST and ALT levels among topside coking workers may be caused by heavy inhalation exposure to COE. Additionally, the adverse hepatic effect seems to be caused by a mixture of hazards, rather than a unique identifiable chemical.

Adult↗
PubMed2001

Color and chlorinated organics removal from pulp mills wastewater using activated petroleum coke.

Delayed petroleum coke, a waste by-product from the oil sand industry, was utilized in the production of activated carbon. The activated carbon was then evaluated for color and chlorinated organics reduction from pulp mill wastewater. The activation of the petroleum coke was evaluated using a fixed bed reactor involving carbonization and activation steps at temperature of 850 degrees C and using steam as the activation medium. The activation results showed that the maximum surface area of the activated coke was achieved at an activation period of 4 h. The maximum surface area occurred at burnoff and water efficiency of 48.5 and 54.3%, respectively. Increasing the activation period to 6 h resulted in a decrease in the surface area. Methylene blue adsorption results indicated that the activation process was successful. Methylene blue adsorbed per 100 g of applied activated coke was 10 times higher than that adsorbed by raw petroleum coke. Adsorption equilibrium results of the bleached wastewater and the activated coke showed that significant color, COD, DOC and AOX removal (> 90%) was achieved when the activated coke dose exceeded 15,000 mg/L. Adsorption isotherms, in terms of COD, DOC, UV and color were developed based on the batch equilibrium data. Based on these isotherms, the amount of activated coke required to achieve certain removal of color and AOX can be predicted. The utilization of the petroleum coke for the production of activated carbon can provide an excellent disposal option for the oil sand industry at the same time would provide a cheap and valuable activated carbon.

Charcoal↗
PubMed2005

Investigation on activated semi-coke desulfurization.

An activated semi-coke with industrial-scale size was prepared by high-pressure hydrothermal chemistry activation, HNO3 oxidation and calcination activation in proper order from Inner Mongolia Zhalainuoer semi-coke, which is rich in resource and cheap in sale. SO2 adsorption capacity on this activated semi-coke was assessed in the fixed bed in the temperature range of 60-170 degrees C, space velocity range of 500-1300 h(-1), SO2 concentration of 1000-3000 ppmv, and N2 as balance. The surface area, elemental and proximate analysis for both raw semi-coke and activated semi-cokes were measured. The experimental results showed that the activated semi-coke has a high adsorption capacity for sulfur dioxide than the untreated semi-coke. This may be the result of increase of surface area on activated semi-coke and surface oxygen functional groups with basicity characteristics. Comparison to result of FTIR, it is known that group of -C-O-C- may be active center of SO2 catalytic adsorption on activated semi-coke.

Adsorption↗