ABSTRACT
BACKGROUND: This study was designed to provide logical backgrounds for the revision of biological exposure indices (BEIs) for styrene exposure in Korea. In order to investigate the correlation between airborne styrene and biological exposure indices, we measured urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) in workers exposed to styrene occupationally, as well as airborne styrene at workplaces. METHODS: Surveys were conducted for 56 subjects. The concentrations of airborne styrene and urinary metabolites of styrene were measured in 36 workers who were occupationally exposed to styrene, and in 20 controls. Air samples were collected using personal air samplers and analyzed by gas chromatography. Urine samples were collected at the end of the shift and analyzed by high performance liquid chromatography. RESULTS: The geometric mean concentration of airborne styrene was 9.6 ppm. The concentrations of urinary MA, PGA, and MA+PGA in the exposure group were 267.7, 143.3, and 416.8 mg/g creatinine, respectively. The correlation coefficients for correlation between airborne styrene and MA, PGA, and MA+PGA were 0.714, 0.604, and 0.769, respectively. The sum of urinary MA and PGA corresponding to an exposure of 20 ppm styrene was 603 mg/g creatinine. CONCLUSION: The correlation of the sum of urinary MA and PGA with airborne styrene was better than the correlation of each individual urinary determinant. It is considered appropriate to amend the concentration of urinary MA+PGA to 600 mg/g creatinine as a BEI, which corresponds to an airborne styrene concentration of 20 ppm in Korea.
Subject(s)
Humans , Chromatography, Gas , Chromatography, Liquid , Creatinine , Korea , Logic , Occupations , StyreneABSTRACT
Objective@#To revise the standard method for the determination of phenylglyoxylic acid(PGA)and mandelic acid(MA) in urine by ultra-performance liquid chromatography.@*Methods@#The original standard method was evaluated by experiment, and the chromatographic column, the detection limit,quantitation limit and stabilityof the method were studied.@*Results@#The samples were separated by BEH Phenyl(50mm×2.1mm×1.7μm)column and the internal standard working curve method was used. The regression equations were y=3.660 7x+0.066 3 and y=5.161 2x-0.007 3 for MA and PGA respectively. Linear correlation coefficients were 0.999 3 and 0.999 1. Linearity ranges were 0.10-1.00 mg/ml,0.04-0.40 mg/ml. The recoveries of PGA and MA were 91.6%-97.1% and 84.3%-99.0%,the precision were 0.9%-4.6% and 0.5%-1.9%. The detection limit and quantitation limit of the method were 1.1 mg/L and 3.7 mg/L for PGA, 5.4 mg/L and 17.9 mg/L for MA.@*Conclusion@#The method uses the phenyh modified chromatographic column, determines the detection limit. The method can improve quantitation limit, the detection accuracy and meet the detection of occupational population samples.
ABSTRACT
OBJECTIVE: Until now,no effective screening tools have been available for evaluating the neurotoxicity of organic solvents and metals. The aim of this study was to evaluate the usefulness of posturography as a screening tool for the chronic neurotoxicity of organic solvents. METHOD: 36 workers in 4 septic tank manufacturers,who were exposed to styrene over a period of 1 year (exposed group),and 15 hospital volunteer manual workers were examined by posturography.The subjects' physical,medical,and occupational characteristics were obtained by means of a physical examination and a questionnaire. We excluded from both groups those persons who had psychiatric problems, diabetes, neurologic symptoms, gait disturbance,or a history of stroke.The sway area of the exposed group was compared to that of the non-exposed group using bivariate and multiple regression analysis. We controlled a number of variables including age, alcohol consumption,smoking, weight, height, and body mass index. RESULT: The sway area of the exposed group was found to be higher than that of the non-exposed group after taking into consideration the effects of other characteristics by means of multiple regression analysis. CONCLUSION: We concluded the posturography would be an effective tool for the screening of chronic neurotoxicity in workers exposed to styrene.
Subject(s)
Humans , Body Mass Index , Gait , Hospital Volunteers , Mass Screening , Metals , Neurologic Manifestations , Physical Examination , Surveys and Questionnaires , Solvents , StyreneABSTRACT
In order to prepare the fundamental data for the health promotion by assessing the exposure level of styrene, the author determined the concentration of mandelic acid and phenylglyoxylic acid in urine of 42 workers who were exposed to styrene by high performance liquid chromatography and surveyed 16 symptoms, by questionnaire and also tested neurobehavioral test(digit symbol, benton visual retention) in 2 FRP plants of Kyung Nam area from July to September, 1995. Control was sampled by age sex matching method. The concentration of styrene in air was determined by gas chromatography. The results were as follows; 1. Geometric mean concentration of styrene in air was 17.4ppm, geometric mean concentration of mandelic acid(MA) in urine were 404.3mg/g creatinine for exposure group, 46.4mg/g creatinine for control group, geometric mean concentration of phenylglyoxylic acid(PGA) in urine were 57.5mg/g creatinine for exposure group, 9.5mg/g creatinine for control group. Mean concentration of MA and PGA showed statistically significant difference between exposure group and control group(p<0.01). 2. Number of symptom were 2.9 for exposure group, 3.3 for control group, number of digit symbol were 24.1 for exposure group, 32.5 for control group, number of Benton visual retention test were 6.1 for exposure group, 6.0 for control group, respectively. As result of adjusting the education year, number of Benton visual retention test showed statistically significant difference between exposure group and control group(p<0.05). 3. Excellent correlation were observed between environmental styrene exposure and urinary MA(r=0.80), PGA(r=0.73), and MA+PGA(r=0.81).