A determination method for methyl iodide in the work place has been developed, using a diffusive sampler and a capillary gas chromatogrph with a thermal desorption cold trap injector and an FID. The sampler consists of a glass tube (6 mm o.d., 4 mm i.d., 16 cm length) packed with porous polymer beads. The diffusion path of the sampler is made of a 3 mm i.d., 52 mm length poly (terafluoroethylene) tube inserted in the glass tube. The sampling rate of the sampler for methyl iodide was 4.6 ml/h, and variations caused by temperature, relative humidity, and wind speed were found to be small and negligible. The sample could be stored for at least two weeks without significant loss. A time-weighted average concentration of methyl iodide in the range of sub ppm to ppm for two to six hours can be measured by this method. The average concentration of methyl iodide for a period of a few seconds can also be measured by grab sampling, i.e., injecting 20 ml of air directly into the sampler.
Using a fluorometric HPLC method, we determined δ-aminolevulinic acid (ALA) in sera and urine samples from 16 lead workers with blood lead levels ranging from 19 to 107 μG/100 ml. The concentration of ALA in serum correlated highly with the urinary ALA concentration (γ=0.957 for ALA mg/1, γ=0.967 for ALA mg/g creatinine). The ALA concentrations in the serum of lead workers ranged from 11 to 151 μg/1 with a mean of 51 μg/1. In addition, the concentrations of urinary ALA (mg/g creatinine) and serum ALA μg/1) had a strong correlation with blood lead concentrations (γ=0.838 and 0.892, respectively). These data indicate that the measurement of serum ALA, as well as urinary ALA, is very useful for the biological monitoring of occupational lead exposure.
Tetramethylthiuram disulphide (Thiram), a dithiocarbamate fungicide was ad-ministered to male rats through gavage at dose 5, 10 and 25 mg/kg/day for 30, 60 and 90 days. A significant increase in relative testes weight (GSI) was observed at dose (25 mg/ kg/d) after 90 days exposure, associated with mild pathomorphological changes. This included degeneration of seminiferous tubules with sloughing of germinal cells and accu-mulation of oedamatous fluid in tubular lumen. The activity of testicular enzymes such as lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glucose 6-phosphate dehydrogen-ase (G-6-PDH) were increased significantly in dose dependent manner. The activities of succinate dehydrogenase (SDH) and acid phosphatase (ACP) decreased significantly while serum cholesterol and testicular free sialic acid were increased at all dose levels. The alterations in the activity of testicular enzymes associated with marked increase in GSI and pathomorphological changes suggest that thiram induces testicular dysfunctions in rats.
In order to assist in the analysis of working postures which might cause lumbago in the field of industrial health, a system was developed for the synchronous recording and analyzing of postures, work content and physiological data. The system is composed of a portable unit for recording 3 channels of goniometers, 1 channel of inclinometer and 1 channel of surface electromyogram, a video camera for recording work content, a host computer and some peripheral devices for analyzing the data from the portable unit and video camera. In this system, postures are automatically classified from data on joint angles and upper body inclination angle by using a discriminant function. The joint angles are measured by the goniometers using rubber optical fibers. The angle of upper body inclination is obtained by the inclinometer using a magnetic resistance sensor. In addition to the work content and video images, the postures and the electromyogram can be analyzed and confirmed by simultaneous display of the data on the host computer screen. Based on the trial use of this system in a work model of manual baggage handling, it was proved useful for evaluating in detail the workload caused by working postures.