[Subclinical neuropathy in workers occupationally exposed to n-hexane]

N-Hexane is widely used in the production of glues, lacquers, paints, plastics, and rubber products. Consequently, a significant potential for exposure to this toxic solvent exists in industrial settings. This study was undertaken to assess the neurophysiological abnormalities in shoe-makers occupationally exposed to n-hexane and determine whether these abnormalities have any correlation with important occupational parameters. Neurophysiological examinations of upper and lower extremities were made in 27 male-workers, and the results were compared with a sex- and age-matched reference group. In addition, the extent of exposure of individual workers and their urinary concentration of free 2,5-hexanedione were determined. Data were analyzed using the Statistical Package for Social Sciences [version 16.0. for windows]. The time-weighted average exposure to n-hexane and the mean urinary concentration of free 2,5-hexanedione were both lower than the respective TLV-TWA and Biological Exposure Index [BEI] values proposed by ACGIH. Although neurological examinations and nerve conduction velocities were normal, significant negative correlations were observed between the urinary concentration of free 2,5-hexanedione and the sensory nerve action potential [SAP] amplitudes for median [r=-0.67, p<0.001] and sural [r=-0.52, p<0.008] nerves. Reduced SAP amplitude for median and sural nerves appears to be the primary neurotoxic effect of 2,5-hexanedione and can be used as an appropriate indicator for screening subclinical peripheral neuropathy in n-hexane-exposed workers

[Prevalence of musculoskeletal disorders and posture analysis using RULA method in Shiraz general dentists in 2010]

The prevalence of musculoskeletal symptoms in dentists is high although relatively few studies have been conducted in this profession. This study was undertaken to investigate the prevalence of musculoskeletal symptoms [MSDs] and to assess the risk of these symptoms among general dentists in Shiraz, Iran. In this descriptive cross-sectional study the Nordic standard questionnaire and questionnaire pertaining to questions about personal and job characteristics were administered to160 general dentists. Furthermore, the pictures of dentists were taken by camera during dental treatment and the most repetitive postures were selected and assessed by Rapid Upper Limb Assessment [RULA] method. The data were analyzed by SPSS version 16.0 software. A large number of dentists [139 subjects] reported MSDs symptoms in at least one region of their musculoskeletal systems during the past 12 months. The most prevalent MSDs symptoms were neck [105 subjects], shoulders [80 subjects], upper back [76 subjects], wrist/hand [63 subjects], and lower back [55 subjects], respectively. A significant difference was observed between men and women only in the wrist/hand [P>0.05]. The results of posture analysis showed that all dentists' postures fell into corrective second and third action levels. The results of this study revealed that the prevalence of MSDs symptoms in dentists was high and MSDs risk levels were intermediate to high. Therefore, it is recommended that in an appropriate training program be contemplated to improve dentists' awareness regarding MSDs symptoms

[Toxic response of occupational exposure to ethylene oxide, with particular reference to its respiratory effects]

Ethylene oxide is used as a sterilizing agent in health care industries. The present study aimed to assess and recognize the nature of pulmonary reactions, if any, associated with occupational exposure to ethylene oxide and to investigate the prevalence of dermal, visual, neurologic, reproductive, hematologic, hepatic and renal disorders. Forty exposed and 47 unexposed employees were evaluated. Subjects were interviewed and standard respiratory symptom questionnaire as well as a questionnaire pertaining to symptoms of intoxication with this chemical were administered to them. Furthermore, parameters of pulmonary function were measured during exposure and a few days after exposure ceased. Additionally, blood samples were taken for CBC, liver and kidney function tests. moreover, atmospheric concentrations of ethylene oxide were determined by gas detector tubes. Respiratory symptoms such as cough and phlegm as well as dermal, visual and neurologic symptoms in exposed workers were significantly more prevalent p

combined mathematical geophysical model for prediction of pyrite oxidation and pollutant leaching associated with a coal washing waste dump

The waste produced by coal washing process produces many environmental problems. In this study, the pollution problems associated with the waste produced by Alborz Sharghi Coal Washing Plant was investigated by mathematical modeling. The study area is located at 11 km. to Razmjah coal region and 45 km. to Tehran-Mashhad road in the north part od Iran. To achieve the goal, a few samples were taken from different depths at three points on the waste dump in order to investigate pyrite oxidation and pollution generation. The samples were then analysed, using an AA-670 Shimadzu atomic absorption to determine the fraction of pyrite remained within the waste particles. A numerical finite volume model using Phoenics package has been developed to simulate pyrite oxidation and pollution generation from the Alborz Sharghi coal washing waste dump. The pyrite oxidation reaction is described by the shrinking-core model. Gaseous diffusion is the main mechanism for the transport of oxygen through the waste. The results of numerical modelling were compared with the field observations and close agreement was achieved. A simple mathematical model incorporating advection and hydrodynamic dispersion processes was also presented in order to verify the results of geophysical time-laps method showing transportation of the pollutants through the downstream of the waste dump. Both mathematical model and geophysical time-laps method are agreed in the identification of pollutant transport emanated from the waste dump. The results of such investigations can be used for designing an effective environmental management program

Pharmacokinetics of tetracycline hydrochloridein fat-tailed sheep

Tetracycline may be used to treat several types of bacterial diseases in ruminants. In addition, tetracycline is added to food to promote the growth. There are few reports on the pharmacokinetics of tetracycline in sheep. Therefore, the objective of this study was to examine the pharmacokinetic characteristics of the drug in sheep. Ten apparently healthy mixed-breed sheep were administered 20 mg/kg tetracycline orally and intravenously with a time interval of two weeks. Blood samples were collected before and at various time intervals after the administration of the drug. Sera were separated, kept at -20°C, and analysed using fluorescence spectrophotometry. The volume of distribution [V[d]], elimination rate constant [K[el]], half-life [t[1/2], and clearance [C1[b]] of tetracycline after intravenous injection were determined to be 0.21 L/kg, 0.21/hr, 3.3 hr, and 0.73 ml/kg/mm, respectively. When the drug was given orally, these parameters were found to be 0.37 L/kg, 0.12/hr, 5.8 hr, and 0.73 ml/kg/min, respectively. Moreover, the bioavailability of tetracycline after oral administration was around 55%