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Concentration of selected metals in muscle of various fish species.

The purpose of this study was to assess concentration of selected metals (Fe, Mn, Zn, Cu, Ni, Co, Cr, Pb, Cd, and Hg) in the muscle of four common Slovak fish species (chub--Leuciscus cephalus, barbel--Barbus barbus, roach--Rutilus rutilus, and perch--Perca fluviatilis). Furthermore, correlations among the selected metals and order of metal accumulation in the fish muscle were determined. An electrofishing technique was used for collecting the fish from the Nitra River (Slovakia) in September 2003. Concentrations of selected metals were measured using an atomic absorption spectrophotometer Pye Unicam SP9. The concentrations of metals (mg/kg wet weight basis) ranged as follows: Fe 3.41-15.14; Mn 0.20-0.81; Zn 3.51-15.64; Cu 0.25-0.78; Ni 0.07-0.25; Co 0.05-0.19; Cr 0.11-0.42; Pb 0.20-5.81; Cd 0.06-0.56, and Hg 1.35-6.52. Significant correlations (P < 0.05) between Fe-Cu, Fe-Ni, Fe-Cr, Mn-Ni, Mn-Cr, Mn-Cr, Cu-Ni, and Ni-Cr were observed. The level of lead exceeded the maximum allowable concentration in Slovakia by Codex Alimentarius for safe human consumption (0.2 mg/kg) in the majority of samples (97.2%). Content of Cd (0.23 +/- 0.13 mg/kg wet weight) and Hg (2.85 +/- 1.22 mg/kg wet weight) in the fish muscle exceeded maximum allowed levels in all samples. On average, the order of metal concentrations in the fish muscle was: Fe > Zn > Hg > Pb > Cu > Mn > Cd > Cr > Ni > Co.

Animals↗

[Detection of numerical chromosome aberrations in sperm of workers exposed to benzene series by two-color fluorescence in situ hybridization].

OBJECTIVE: To study the numerical aberrations of sex chromosomes in sperm of workers exposed to benzene series. METHODS: The interphase sperm from workers of exposed and control groups were hybridized using two color fluorescence in situ hybridization with X and Y(alpha)-satellite chromosome specific DNA probes, and the aneuploidy frequencies of X and Y chromosome in X and Y sperms were detected simultaneously. RESULTS: Geometric mean concentration of benzene in workplace air was 83.95 mg/m(3), one fold higher than national maximum allowable concentration. A total of 74,517 sperm nuclei in 13 benzene-exposed workers and 89,662 sperm nuclei in 13 control workers were counted. Frequencies of disomic sperm for X, Y and XY were (0.15 +/- 0.05)%, (0.13 +/- 0.05)% and (0.20 +/- 0.11)% in workers exposed to benzene series, and (0.10 +/- 0.04)%, (0.10 +/- 0.04)% and (0.13 +/- 0.06)% in control workers. There was statistical difference in disomic frequency of X sperm and overall disomic frequency between the benzene series-exposed workers (0.15% and 0.48%, respectively) and the control workers (0.10% and 0.33%, respectively). CONCLUSION: Exposed to benzene at higher concentration may induce increase in aneuploidy frequency of sperm sex chromosome in exposed workers.

Adult↗

[Detection of the frequencies of numerical and structural chromosome aberrations in sperm of benzene series-exposed workers by multi-color fluorescence in situ hybridization].

To study the frequencies of numerical and structural aberrations for chromosome in sperm of benzene exposed workers, the multi-color FISH was used. Four DNA probes(one for chromosome 1 centromere and one for 1 p terminal, and two for chromosome 18 centromere) were hybridized with interphase sperms, and the frequencies of numerical aberrations for chromosome 1, 18 and structural aberrations of chromosome 1 were detected simultaneously. The time weighted average concentration (TWA) of benzene in workplace (42.29 mg/m3) was higher than that of our national maximum allowable concentration (6 mg/m3). The geometric concentration of urinary trans, trans-muconic acid(tt-MA) in exposed group was significantly higher than that of control group. A total of 144,282 sperm of 15 benzene-exposed workers and 135,937 sperm in 14 controls were scored. The frequency of hybridization efficiency was 99.85%. The mean frequencies of disomic sperms for chromosome 1 and 18 in exposed group(0.088% +/- 0.041%, and 0.087% +/- 0.049%, respectively) were statistically increased over that of the control group(0.045% +/- 0.024%, and 0.035% +/- 0.028%), and the mean frequencies of nullisomic sperms for chromosome 1 and 18(0.11% +/- 0.059%, 0.075% +/- 0.035%) in exposed group were statistically increased over that of control group too (0.048% +/- 0.018%; 0.045% +/- 0.024%). The frequencies of diploidy sperm were no difference in both exposed and control groups. The mean frequencies of terminal duplication and terminal deletion for chromosome 1 p(0.16% +/- 0.037%; 0.14% +/- 0.053%, respectively) were significantly increased over that of control group(0.082% +/- 0.023%; 0.069% +/- 0.028%, respectively). The mean frequencies of centromeric duplication and centromeric deletion for chromosome 1(0.10% +/- 0.035%; 0.10% +/- 0.041%, respectively) were significantly increased over that of control group(0.075% +/- 0.023%; 0.060% +/- 0.029%). Our experiments showed that exposed to benzene at higher concentration(42.29 mg/m3) may induce increases in frequencies not only of numerical aberrations for chromosome 1 and 18, but also of structural aberrations for chromosome 1 of sperms in exposed workers.

Adult↗

Impaired respiratory muscle function in chemical plant workers producing chlorfenvinphos.

All employees of a chemical plant division producing chlorfenvinphos were studied, i.e. 35 males aged 25-57 years (mean 42.1); their employment period ranged from 1-15 years (mean 9.0). Chronic bronchitis was diagnosed in 13 workers (37.1%). Mean air chlorfenvinphos concentrations in the work environment estimated with gas-liquid chromatography were from 0.0008-0.0018 mg/m3 (maximum allowable concentration according to Polish standards is 0. 01 mg/m3). The activity of erythrocyte acetylcholinesterase was similar to that observed in people who were not exposed to chemicals, however, a slightly lowered activity of plasma cholinesterase in the studied population was evidently the result of mild liver impairment. Spirometric investigations performed in the studied workers revealed slight alterations manifested by increased intrathoracic gas volume (ITGV) (the value of the index was 138.6% of the mean value, 24 workers with an abnormally high index), as well as by decreased specific airway conductance (sGaw); its mean value in the studied group was 58.5% of the mean standard (11 people showed an abnormal index). Substantial functional changes were found in the respiratory muscles. Maximal inspiratory pressures (MIP = 97. 2 +/- 28.3 cm H2O) as well as maximal expiratory pressures (MEP = 113.9 +/- 44.2 cm H2O) in the studied group were significantly lower (p < 0.01) as compared to those observed in the control group (MIP = 120.7 +/- 31.7; MEP = 154.4 +/- 40.2 cm H2O) of 22 males having similar cigarette smoking habit, without occupational exposure to chemicals. It was also found that the people who had worked for more than 10 years under conditions of exposure to chlorfenvinphos showed significantly lower (p < 0.05) values of maximal inspiratory pressure (87.2 +/- 28.06 cm H2O, n = 17) compared to the workers whose period of employment was shorter than 10 years (106.6 +/- 26.8 cm H2O, n = 18). The two groups were comparable with regard to age and smoking habits. The values of maximal expiratory pressures were similar in both groups. No essential disturbances in neuro-muscular transmission were observed; only in 3 workers (8.5%) the electrostimulating myasthenic test showed some disturbances in neuro-muscular transmission. It seems that respiratory muscles impairment in humans exposed to chlorfenvinphos results from changes in the metabolism and structure of muscles, and partly from lung hyperinflation.

Acetylcholinesterase↗

A study on the dose-response relationship between asbestos exposure level and asbestosis among workers in a Chinese chrysotile product factory.

The dose-response relationship for asbestos exposure in a chrysotile product factory was studied. The past gravimetric dust concentration values, obtained from different worksites, were converted into fiber concentration values according to conversion factors that were worked out by simultaneous sampling in this study. The conversions were made so that exposure could be expressed in fiber-years (f-yr). Asbestosis was diagnosed on the basis of chest radiographs and occupational histories. Cumulative dust exposure (f-yr) was calculated up to the date of diagnosis for asbestosis patients, and up to September 1982 for the remaining workers. A dose-response relationship expressed as fiber-years exposed vs cumulative prevalence of asbestosis was established by the life table method on the basis of these data. Predicted 3 and 1% prevalence of asbestosis corresponded to 43 and 22 f-yr exposure, respectively. Considering that a worker can work for 35 years, these doses are commensurate with dust concentrations of 1.22 and 0.63 f/ml, respectively. It is recommended that 1 f/ml be taken as the maximum allowable concentration of airborne asbestos dust for the workplace with an anticipated prevalence of about 2% asbestosis after 35 years of exposure.

Air Pollutants, Occupational↗

Teratogenesis induced by short- and long-term exposure of Xenopus laevis progeny to lead.

Short-term (96-h) tests on Xenopus laevis embryos are advocated for rapid screening of teratogens, as an alternative to the use of mammals. The objective of the present investigation was to determine whether extending the short-term tests beyond 96 h would detect the teratogenicity of chemicals that would otherwise be missed by the short-term tests. Lead teratogenicity was examined in Xenopus, using lead concentrations of 0.02, 0.05, 0.1, 0.5, 1.0, and 3.0 mg/L, which bracket the U.S. Environmental Protection Agency (EPA) maximum allowable concentration of 0.05 mg/L in water. Short-term exposure times were 72 or 96 h, starting on d 1, 2, or 3 postfertilization, while long-term exposure covered d 1 through metamorphosis. Short-term exposure resulted in neural tube defects (when exposure included d 1 and/or d 2) and tail curvatures, but only at the higher lead concentrations (1 and 3 mg/L). Lower lead concentrations produced no malformations upon short-term exposure, and this corresponded with the absence of tissue lead uptake. On the other hand, long-term exposure to lead (> 3 wk) resulted in the delayed appearance of lordoscoliosis at low lead concentrations (0.02-0.1 mg/L). The delayed appearance of lordoscoliosis corresponded roughly with the attainment of stable lead tissue levels, and this malformation persisted after metamorphosis. Thus, short-term observation tests alone may fail to detect the teratogenicity of low concentrations of environmental chemicals, and may result in the setting of inappropriately liberal exposure standards.

Animals↗

Toxicity of propoxur to rats by subacute inhalation.

Male and female rats were exposed to propoxur (2-isopropoxyphenyl-N-methyl-carbamate) aerosol, concentrations averaging 5.7, 18.7 and 31.7 mg/m3 air, for 6 hours daily on five days in a week over a period of 12 weeks. The effects were depressions of plasma by 20 to 30%, and of erythrocyte and brain cholinesterase activities which were caused by the highest air concentration of 31.7 mg/m3. On the basis of the physical, biochemical, phamacokinetic and metabolic behaviors of propoxur, a maximum allowable concentration of 2.5 mg/m3 air is suggested.

Aerosols↗

[Detection of numerical chromosome aberrations in sperm of workers exposed to benzene series by two-color fluorescence in situ hybridization].

To study the frequency of numerical chromosome aberrations in sperm of workers exposed to benzene series, the aneuploidy frequencies of 9 and 18 chromosomes were detected in sperm of workers by two color fluorescence in situ hybridization with digoxingenin labeled 9 chromosome probe (D9z1) and biotin labelled 18 chromosome probe (D18z1). The timeweight average air concentration (TWA) of benzene in the workplace was 86.49 mg/m3, it was two fold higher than the national maximum allowable concentration. The concentration of urinary trans, transmuconic acid (ttMA) in exposed group was significantly higher than that of control group. The sperms counted in 14 exposed workers and 16 control workers were 136,401 and 156,955 respectively. The results showed that the disomy frequencies of sperm for chromosome 9 and 18 (0.168% +/- 0.063% and 0.055% +/- 0.031% respectively) and the frequency of diploidy sperm (0.073% +/- 0.045%) were statistically increased over that of the control group (0.050% +/- 0.030%; 0.033% +/- 0.025% and 0.040% +/- 0.036%, respectively). The nullisomic frequencies of 9 and 18 chromosome in the exposed group (0.206% +/- 0.047%, 0.068% +/- 0.044%) were statistically increased over that of the control group too (0.067% +/- 0.037%, 0.048% +/- 0.034%). The frequency of overall numerical chromosome aberrations in the exposed group was 0.570% +/- 0.144%, when this value was compared with that of control (0.218% +/- 0.071%), a statistically significance was presented. Our experiments showed that exposed to benzene at higher concentration may induce increase in aneuploidy frequency of sperm autosomal chromosome in exposed workers.

Benzene↗

Pentachlorophenol and the peripheral nervous system: a longitudinal study in exposed workers.

A longitudinal study was performed to examine whether chronic occupational exposure to pentachlorophenol (PCP) or its compounds causes measurable alterations in the conduction velocity in peripheral nerves as an "adverse effect." In total, the results of nerve conduction velocity (NCV) determinations in 1980 and 1984 in 10 subjects (7 men, 3 women) who had been exposed for an average of 16 years (range 4-24) were available. The concentrations of PCP in the air at the workplace varied between 0.3 and 180 micrograms/m3 and were thus below the maximum allowed concentration (MAK value) of 500 micrograms/m3. The biological monitoring carried out showed the following results: PCP in the serum: 38-1270 micrograms/l; PCP in the urine: 8-1224 micrograms/l. Compared with the upper normal limits (PCP in the serum 150 micrograms/l, PCP in the urine 60 micrograms/l), distinct internal exposure to PCP has resulted in some of the employees. Determinations of the NCV of motor and sensory nerve fibres (ulnar, median, peroneal, and sural nerve) were always in the normal range. A significant difference in the NCV for the period 1980-4 could not be detected. In addition, the correlation analyses did not show any hints of "dose-effect relations." It is concluded that occupational exposure to PCP over several years in the concentrations observed probably do not lead to any adverse effects on the peripheral nervous system.

Adult↗

Chloride extraction for quality improvement of municipal solid waste incinerator ash for the concrete industry.

Coal ash from power stations has long been used successfully in the cement industry as binders in several Portland formulations. This is not the case for municipal solid waste (MSW) ash as chloride concentrations, ranging from 10 to 200 g kg(-1) dry weight in the bottom and fly ash, respectively, exceed the maximum allowable concentration in most cement mixtures. To reduce chloride content in MSW bottom ash, a laboratory investigation was carried out based on the exhaustive washing in tap water. The influence of operative parameters such as temperature, granulometric properties and solid/liquid ratio of extraction was evaluated. In addition to optimization of the mentioned operative parameters for full-scale application, the paper gives preliminary indications on mechanistic aspects of the washing operation.

Carbon↗

[Detection of numerical aberrations of chromosomes 7 and 8 in sperms of workers exposed to benzene series by two-color fluorescence in situ hybridization].

OBJECTIVE: To investigate the frequency of numerical aberrations for chromosomes 7 and 8 in the sperms of workers exposed to benzene series. METHODS: Numerical aberrations in the sperms of workers were detected by two-color fluorescence in situ hybridization with biotin labeled chromosome 7 probe (D7Z1) and digoxingenin labeled chromosome 8 probe (D8Z1). RESULTS: The time-weight average air concentration (TWA) of benzene in the workshop was 42.29 mg/m(3), which was significantly higher than that of the national maximum allowable concentration [6 mg/m(3)]. The concentration of urinary trans,trans-muconic acid(ttMA) in the exposed group was also higher than that of the control group. In all, 155721 sperm nuclei from 15 workers in the exposed group and 123771 sperm nuclei from 12 individuals in the control group were examined. The results showed that the frequency of diploidy sperms and the frequencies of disomic sperm for chromosomes 7 and 8 in the exposed group (0.129%, 0.170%, 0.078%) were significantly higher than those of the control group (0.055%, 0.053%, 0.033%), respectively. The frequencies of nullisomic sperm for chromosomes 7 and 8 in the exposed group (0.165%, 0.088%) were also significantly increased, compared with those of the control group (0.056%, 0.029%). A statistically significant difference in the frequency of overall numerical chromosome aberrations was seen between the exposed group (0.745%) and the control group (0.289%). CONCLUSION: The results suggested that higher concentration of benzene may induce higher frequencies of numerical aberrations in the sperms of workers exposed to benzene series.

Adult↗

Heavy metals content and microbiological quality of carp (Cyprinus carpio, L.) muscle from two Southwestern Slovak fish farms.

The purpose of this study was to assess concentration and correlation of selected heavy metals and level of some microbiological indicators (total bacteria count-TBC, mesophilic anaerobic sporulating bacteria-MASB) in the muscle of common carp (Cyprinus carpio). Fish were collected by seine net within the frame of pondfishing, in October (pond Horné Obdokovce--pond A) and December (pond Budmerice--pond B) 2003. Concentrations of selected metals were measured using an atomic absorption spectrophotometer Pye Unicam SP9. The concentrations of metals (mg/kg wet weight basis) ranged as follows: Fe 3.47-15.15; Mn 0.14-0.42; Zn 3.47-9.52; Cu 0.24-1.32; Co 0.05-0.17; Ni 0.07-0.42; Cr 0.08-0.19; Pb 0.11-0.30; and Cd 0.01-0.05. The count of MASB and TCB (in CFU/g) varied as follow: 1.12-7.76 x 10(3) and 0.03-7.59 x 10(6), respectively. Significant differences (P < 0.05) for Cu, Ni, and Cr bioaccumulation, as well as for count of MASB between ponds were recorded. An opposite trend of bioaccumulation was found in only 12 of 36 cases. Positive correlations between counts of MASB and accumulated heavy metals, except Ni and negative correlations between TBC and accumulated heavy metals, except Cr, were recorded, (P < 0.05) for TBC-Mn and TBC-Cd relationship. Lead concentrations exceeded the maximum values allowed concentration in Slovakia by Codex Alimentarius (0.2 mg/kg) by 60% for pond-A and 40% for pond-B. The level of MASB count exceeded the maximum allowed concentration in 100% by both ponds. On average, the order of metal concentrations in the fish muscle was: (Pond-A) Fe > Zn > Cu > Mn > Pb > Cr > Ni > Co > Cd; (Pond-B) Fe > Zn > Cu > Mn > Pb > Ni > Cr > Co > Cd.

Animals↗

Chromosome and sister-chromatid exchange analysis in peripheral lymphocytes, and mutagenicity of urine in anesthesiology personnel.

Genotoxic effects of occupational exposure to anesthetic gases (halothane and nitrous oxide) were studied in 24 persons working at departments of anesthesiology and resuscitation (14 anesthesiologists and 10 anesthesiologic nurses). Frequencies of chromosomal aberrations were determined in 48-h cultures, and sister-chromatid exchanges (SCEs) in 72-h cultures of peripheral lymphocytes. In parallel, the mutagenetic potential of urine was tested using Ames tester Salmonella typhimurium strains TA98 and TA100 in both the presence and the absence of a metabolic activation system. The control group consisted of 30 healthy blood donors from the Clinic of Hematology and Blood Transfusion. Halothane concentrations in the working environment of operating rooms were determined using gas-liquid chromatography. Halothane exposure levels were far above the maximum allowable concentration in most countries, ranging between 9 and 490 mg.m-3. Cytogenetic analysis of peripheral lymphocytes revealed significantly increased frequencies of aberrant cells (ABCs) and SCEs in the exposed group as compared with the controls (3.84% vs 1.87% ABCs, 8.69 +/- 1.30 vs 7.86 +/- 1.07 SCEs per cell). Results of the urine mutagenicity test were negative.

Adult↗

Advanced analytical determination of volatile organic compounds (VOC) and other major contaminants in water samples using GC-ion trap MS.

The GC-Ion Trap MS is recently one of the most efficient instrumental analysis recommended for understanding the chemistry of volatile organic compounds, not only in water but even in the food chain and other environmental media (air and soil). Results of the experiment conducted on water samples from Kuguri and Yatsutani sampling stations showed considerably higher levels of organic enrichment (COD = 10 mg/L and 11 mg/L respectively). Total concentrations of Pb (0.072 mg/L and 0.093 mg/L) and Cd (0.004 mg/L and 0.011 mg/L) on the other hand, invariably exceeded the maximum allowable concentrations for human health and the living environment (Pb = 0.005 mg/L; Cd = 0.001 mg/L respectively). And the toxicity levels for these contaminants at LC50 showed critical impact on rainbow trout (hypersensitive species) at 0.14 mg/L for Pb and 0.007 mg/L for Cd in 96 hours respectively. Although these major contaminants including phenol and 3-, 4-cresol, showed relatively higher toxicity impact in the experimental media, it would remain contentious to justify any associated potential dangers without regular routine water monitoring, at least for a period of one year. Nevertheless, the data could serve as a benchmark through which other phenomena can easily be investigated.

Animals↗

European isolation and confinement study. Additional experiments.

Microbiological Experiments. The ISEMSI microbiological contamination experiments confirmed known hypotheses, such as: the trend toward uniformity of skin microbial flora across a group of individuals enclosed together; the rather fast "colonization" of the environment by microorganisms shed by human inhabitants; and the heavy growth of microorganisms in poorly accessible and wet areas (toilets, air conditioning). In addition, possible disturbances of skin defense mechanisms against colonization by potentially pathogenic microbes were noted, as well as a difficulty in monitoring the microbial contents of the atmosphere (significant random variations occur between samples taken at different times and locations). Sensors for Atmospheric Contaminants. Several different prototypes of "array sensors" for the monitoring of trace gas contaminants in the atmosphere were evaluated during ISEMSI. Their performance was promising when compared with results achieved with a more conventional (and more complex) gas chromatograph/mass spectrometer device, also used during ISEMSI. An overall picture of the most important chemical contaminants to be found in enclosed, manned habitats (including contaminants produced by man himself) was obtained via the use of Tenax gas-adsorption traps. This permitted monitoring the fluctuation of contaminants on a daily basis, as well as during the complete 4-week period. Results will provide a valuable input for designing systems to monitor and control atmospheric contamination in future spacecraft. Particular attention was devoted to the monitoring of carbon monoxide in the chamber. Results showing the correlation between its concentration in the atmosphere and the percentage of carboxyhemoglobin in the EMSInauts' blood will allow the evaluation of the correctness of the presently specified maximum allowable concentration for spacecraft. Telemedicine Experiment. The telemedicine experiment confirmed the feasibility and importance of applying to a space station scenario many aspects of remote health care already widely used in the maritime environment. ISEMSI successfully evaluated telemedical consultation procedures and training protocols for the crew. EMSInauts, trained as paramedical assistants, had to interview a "patient" (another EMSInaut, trained to feign illness symptoms), prepare an anamnesis, carry out a medical examination, assess the severity of the case, and administer effective medical care under remote medical advice. An expert system was used to provide step-by-step guidance to the paramedical assistant. ISEMSI demonstrated the great importance of practicing and rehearsing emergency procedures; it confirmed that simulation of medical emergencies during an actual long-duration space mission will be required to provide "refresher training" to astronauts trained as paramedical assistants.(ABSTRACT TRUNCATED AT 400 WORDS)

Aerospace Medicine↗

Trace elements in bottled and soft drinks in Nigeria--a preliminary study.

The levels of Co, Cu, Zn, Cd, Pb, Cr, Se and Ni were determined in bottled waters and soft drinks in Nigeria. The mean levels of the elements ranged between 0.52 microgram/l for Co and 14.8 micrograms/l for Mn in the bottled waters and 3.10 micrograms/l for Co and 82.4 micrograms/l for Mn in the soft drinks, respectively. Comparison of the elemental concentrations in the water samples with WHO limits showed the mean levels of all the elements investigated in all the samples were below the WHO maximum allowable concentrations for drinking waters.

Carbonated Beverages↗

Cytogenetic analysis and occupational health in the Czech Republic.

This paper summarizes the experiences of the Czech Hygiene Service since the middle 1970s until the present time, using cytogenetic analysis as a biomarker of exposure. We have included a review of all the available scientific literature in Czech as well as in English, and have described the most important milestones in the history of the use of cytogenetic analysis in the Czech Republic. Details on the levels of occupational exposure and the corresponding observed frequencies of aberrant cells are provided. Furthermore, we discuss the interpretation of the cytogenetic findings in the context of occupational health and give several examples when the results of cytogenetic analysis provided the chief argument used to enforce improved working conditions and to establish safer maximum allowable concentrations.

Antineoplastic Agents↗