• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.18-29
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• 2019

Objectives: The purpose of this study was to examine the relationship between urinary bisphenol A concentration and allergic diseases in children. Methods: This study was conducted in Seoul, South Korea. We collected urine samples from 231 children from a single elementary school in June 2014. Among these, 69 children with urinary creatinine levels outside the normal range were excluded. Information on allergic diseases was obtained from the parents of the children. Urinary bisphenol A was analyzed using a liquid chromatography tandem mass spectrometer. Logistic regression analysis was used to determine if allergic disease was affected by urinary bisphenol A concentration. Results: Girls had a significantly higher concentration of urinary bisphenol A than did boys (p<0.05). Children of 10-12 years old had a significantly higher concentration of urinary bisphenol A than did children 7-9 years old (p<0.01). Concentration of urinary bisphenol A was increased from underweight to overweight (p<0.05). As the concentration of urinary bisphenol A was increased by $1{\mu}g/L$ or $1{\mu}g/g$ creatinine, the risks of lifetime symptoms of atopic dermatitis in children was 1.22 times (95% CI; 1.05-1.41) or 1.08 times (95% CI; 1.01-1.15). Conclusion: Concentration of urinary bisphenol A was associated with gender, age, body mass index, and allergic disease. Particularly, urinary bisphenol A concentration was associated with lifetime symptoms of atopic dermatitis. The findings of this study could contribute to the management of health effects among sensitive groups such as children.

• Safety and Health at Work
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• v.10 no.1
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• pp.103-108
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• 2019

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.

• Journal of Preventive Medicine and Public Health
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• v.13 no.1
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• pp.27-34
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• 1980

Purpose of this study is to find out proper means of estimating the urinary mercury excretion in the normal individuals. Whole void volume was collected every 2 hours beginning from 6 o'clock in the morning until 6 o'clock next morning. Mercury excretion in each urine specimen was measured by NIOSH recommended dithizone colorimetric method (Method No.: P & CAM 145). Urinary concentration of mercury was adjusted by two means: specific gravity of 1.024 and a gram of creatinine excretion per liter of urine comparing the data with the unadjusted ones. Mercury excretion in 24-hour urine specimen was calculated by adding the amounts measured with the hourly collected specimens of each individual. Statistical analysis of the urinary mercury excretion revealed the following results: 1. Frequency distribution curve of mercury excreted in urine of hourly specimens was best fitted to power function expressed in the form of $y=ax^b$. Adjustment of the urinary mercury concentration by creatinine excretion was shown to be superior($y=1674x^{-1.52},\;r^2=0.95$) over nonadjustment($y=2702x^{-1.57},\;r^2=0.92$) and adjustment by specific gravity of 1.024($y=4535x^{-1.66},\;r^2=0.93$). 2. Both log-transformed mercury excretion in hourly voided specimens and mercury excretion itself in 24 hour specimens showed the normal distributions. 3. The frequency distribution of mercury adjusting the urinary concentration of mercury by creatinine excretion was best fitted to a theoretical normal distribution with the sample means and standard deviation than those unadjusted or adjusted with specific gravity of 1.024. 4. Average urinary mercury excretions in 24-hour urine specimen in an individual were as follows: a) Unadjusted mercury excretion mean and standard deviation : $$18.6{\pm}13.68{\mu}gHg/l$$. median : $$16.0\;{\mu}gHg/l$$. range : $$0.0-55.10\;{\mu}gHg/l$$. b) Adjusted with specific gravity mean : $$20.7{\pm}11.76\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ median : $$20.7\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ range : $$0.0-52.9\;{\mu}gHg/l{\times}\frac{0.024}{S.G-1.000}$$ c) Adjusted with creatinine excretion mean and standard deviation : $$10.5{\pm}6.98\;{\mu}gHg/g$$ creatinine/l median : $$9.4\;{\mu}gHg/g$$ creatinine/l range : $$0.0-26.7\;{\mu}gHg/g$$ creatinine/l 5. No statistically significant differences were found between means calculated from 24-hour urine specimens and those from hourly specimens transformed into logarithmic values. (P<0.05).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.2
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• pp.192-199
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• 1991

Biological exposure indices (BEI) of toluene, perchloroethylene (PCE) and methyl ethyl ketone (MEK) for Korean workers were studied respectively. Environmental exposures in workplace to organic solvent were measured by personal sampling. Blood toluene, blood perchloroethylene, urinary trichloroacetic acid and urinary MEK were determined by headspace gas chromatography. Urinary hippuric acid were determined by HPLC and corrected by creatinine. BEIs for Korean workers were calculated as the levels of determinants which are correspond to permissible exposure limits in Korea. Blood toluene level of 2.2mg/l and urinary hippuric acid level of 1.7g/g creatinine are correspond to an exposure of 100 ppm toluene. Blood PCE concentration of 1.6mg/l and urinary trichloroacetic acid concentration of 2.9mg/l are correspond to an exposure of 50ppm PCE. Urinary MEK concentration of 1.0mg/l is correspond to an exposure of 200ppm of MEK. BEIs for Korean workers determined in this study are very different to ACGIH's BEI as urinary determinants are much lower and blood determinants are much higher than ACGIH's BEI.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.135-144
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• 2001

This study was performed to measure airborne dimethylformamide(DMF), methyl ethyl ketone(MEK) and toluene and their urinary metabolites concentrations and to determine the relationship between airborne and urinary concentration. Airborne samples and their urinary metabolites were measured 98 male workers who work for 8 synthetic leather factories in a portion of Kyoung-In area. Urine samples were collected at end-of-shift to estimate the exposure levels. 1. The concentration of airborne DMF by process was 8.81 ppm for wet-mixing, 15.05 ppm for wet-coating, 6.03 ppm for dry-mixing, 5.58 ppm for dry-coating, 5.37 ppm for printing, and 9.03 ppm for total. There was statistically significant difference by process. Urinary NMF concentrations of wet-mixing, wet-coating, dry-mixing, dry-coating and printing were $90.55mg/{\ell}$, $79.80mg/{\ell}$, $39.86mg/{\ell}$, $25.23mg/{\ell}$, and $38.15mg/{\ell}$, respectively, and total geometric mean was $56.24mg/{\ell}$. There was significant difference by process. 2. The concentration of airborne MEK by process was 1.89 ppm for wet-mixing, 1.96 ppm for wet-coating, 10.33 ppm for dry-mixing, 29.24 ppm for dry-coating, 14.98 ppm for printing, and 4.87 ppm for total. There was statistically significant difference by process. Urinary MEK concentrations of wetmixing, wet-coating, dry-mixing, dry-coating and printing were $0.93mg/{\ell}$, $0.70mg/{\ell}$, $3.29mg/{\ell}$, $3.29mg/{\ell}$, and $1.06mg/{\ell}$, respectively, and total geometric mean was $1.25mg/{\ell}$. There was statistically significant difference by process. Urinary MEK 3. The concentration of airborne toluene by process was 0.35ppm for wet-mixing, 0.42ppm for wet-coating, 2.95ppm for dry-mixing, 11.67ppm for dry-coating, 4.88ppm for printing, 1.24ppm for total. There was statistically significant difference by process. Urinary hippuric acid concentrations of wet-mixing, wet-coating, dry-mixing, dry-coating and printing were 0.24g/g creatinine, 0.21g/g creatinine, 0.34g/g creatinine, 0.52g/g creatinine, and 0.29g/g creatinine, respctively and total geometric mean was 0.28g/g creatinine. There was statistically significant difference by process. 4. No. of exceeded KPEL was 40 workers(40.8%) for DMF(10ppm), 1 worker(1.0%) for MEK(200ppm), and no worker for toluene(100ppm). No. of exceeded KBEI was 62 workers(63.3%) for urinary NMF($40mg/{\ell}$), 29 workers(29.6%) for urinary MEK, 1 worker(1.0%) for urinary hippuric acid. 5. The regression equations were Log(NMF)=0.4094*Log(DMF)+1.3587(r=0.4516) for DMF, Log(MEKU)=0.1859*Log(MEK)-0.0324(r=0.3303) for MEK, Log(HA)=0.2106*Log(Toluene)-0.5685(r=0.4497) for toluene. Synthetic leather factory workers expose to 3 kinds of organic solvents which are DMF, MEK and toluene. Their urinary NMF and MEK levels were higher than their concentration levels through respiratory. It seems that the urinary levels were affected skin absorption for working habit and alcohol intake.

• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.1-7
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• 1996

Mandelic acid is the major metabolite and phenylglyoxylic acid is the minor metabolite of styrene in human. This study was conducted to investigate the correlation between exposure concentrations of styrene and concentration of the metabolites in urine The concentrations of metabolites in urine and exposure concentrations were measured in 60 workers who were occupationally exposed to styrene in FRP industry as well as paint industry and musical instrument manufacturing industry and the concentrations of metabolites in urine ware measured in 90 workers not occupationally exposed to styrene for review the background level in the unexposed population. The results obtained were as follows; 1. The mean exposure concentration is 16.6 $\pm $12.2 ppm (range 0.4-49.9ppm) in the styrene exposed workers. 2. The concentration of mandelic acid in urine collected at the end of shift from worker exposed 8 hours to 50ppm of styrene, based on extrapolation from correlation equations was 578.5 mg/g creatinine and 176.8 mg/g creatinine for next morning urine, the concentration of phenylglyoxylic acid in urine collected at the end of shift was 291.1 mg/g creatinine, 177.9 mg/g creatinine in next morning urine. In the sum of mandelic acid and phenylglyoxylic acid in the urine 870.2 mg/g creatinine in urine sampled at the end of shift corresponds to an exposure of 50ppm of styrene and 366.0 mg/g creatinine for next morning sample corresponds to 50ppm. 3. The correlation of the degree of exposed with sum concentration of mandeliacid and phenylglyoxylic acid in the urine was better(r=0.079 for end of shift, r=0.78 for next morning) than the correlation with single determinant measurement in urine(r=0.75 for mandelic acid at end of shift, r=0.73 for mandelic acid at next morning, r=0.69 for phenylglyoxylic acid at end of shift, r=0.62 for phenylglyoxylic acid at next morning). The monitoring of sum concentration of mandelic acid and phenylglyoxylic acid in urine is a valuable indicator of time weighted average daily exposure ti styrene. And the exposure standard of urinary metabolites produced by styrene should be set, in distinction urine at the end of shift from urine at next morning.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.291-299
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• 2012

Creatinine-adjustment is an important process in the urinary monitoring of the environmental exposure of children and adolescents. The purpose of this study was to investigate the concentrations of urinary creatinine and factors associated with them among Korean children and adolescents. We recruited 1,025 persons from 128 extracted schools. They were from three to 18 years old and supplied urine samples for measuring creatinine. The concentrations of urinary creatinine were 98.18 mg/dl (SD, 67.67) in arithmetic mean and 72.05 mg/dl (GSD 2.49) in geometric mean, were significantly higher among male children/adolescents than females in all age groups, and higher values appeared following increasing ages, heights and BMIs. The rates of the number who were below the lowest limit recommended by WHO (<30 mg/dl) were 25.57% among three to four year olds, 21.77% among five to six year olds, 20.0% among seven to eight year olds and 14.69% among nine to ten year olds, respectively. The rates of those above the highest limit (>300 mg/dl) were 0.0% among three to twelve year olds. The coefficient of determination R-square of the fitted regression model for urinary creatinine was 27.4% with general characteristic variables of sex, age, BMI and height. The significant variables among these were height (standardized beta = 0.372) and age (standardized beta = 0.129). Another coefficient of determination R-square was 15.3% with dietary habit variables of smoking, drinking, dining area, number of meals and snacks, and intake of milk food, cup-noodles, canned foods, popcorn, nachos, and hamburgers. In conclusion, the concentration of urinary creatinine was significantly lower in children than in adults, and was very significantly associated with the height of children. Therefore, children need the recommended concentrations for urinary creatinine, as distinguished from adults.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.493-505
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• 2015

Objectives: The purpose of this study was to evaluate the relevance of adjusting a urinary sample for urine hippuric correction value and its effects. Urinary biological monitoring data are typically adjusted to a constant creatinine and specific gravity concentration to correct for variable dilutions among spot samples. This study was conducted to evaluate the suitability of adjusting the urinary concentrations of urine creatinine and specific gravity(SG). Methods: We measured the concentrations of hippuric acid, in spot urine samples collected from control(119), case(120) individuals. The value of hippuric acid was adjusted by SG and urinary creatinine(HPLC & Jaffe). Results: The major results were as follows. The concentrations of urinary creatinine and SG for the control group were 1.84 g/L(SD 0.99) for arithmetic mean and 1.56 g/L(GSD 1.86) for geometric mean by HPLC method, 1.57 g/L (SD, 0.82) for arithmetic mean and 1.33 g/L(GSD 1.85) for geometric mean by Jaffe method, 1.028(SD 0.09) for arithmetic mean and 1.02(GSD 1.06) for geometric mean by refractometer. Hippuric acid levels were 0.40 g/L(SD 0.51) by arithmetic mean and 0.20 g/L(GSD 3.59). In that case the exposed group was 1.40 g/L(SD 0.58) for arithmetic mean and 1.28 g/L(GSD 1.55) for geometric mean by HPLC method, 1.27 g/L(SD 0.56) for arithmetic mean and 1.14 g/L(GSD 1.62) for geometric mean by Jaffe method, 1.045 L(SD 0.27) for arithmetic mean and 1.02(GSD 1.13) for geometric mean by refractometer(P<0.05). Hippuric acid levels were 0.67 g/L(SD 0.79) for arithmetic mean and 0.39 g/L(GSD 2.94)(p<0.05). The urine creatinine concentrations were affected by gender(p < 0.01) but SG levels were not affected by gender or age(p>0.05). After adjustment, urine hippuric acid was correlated with creatinine(HPLC & Jaffe)(r=0.723, P<0.05, r=0.708, P<0.05) and SG(r=0.936, P<0.05) and the control group shows significantly higher than the case group. In the case group for adjusted urine hippuric acid was correlated with creatinine(HPLC & Jaffe), (r=0.736, P<0.05), r=0.549, P<0.05), SG(r=0.549, P<0.05). After adjusting urine hippuric acid by urine creatinine(HPLC and Jaffe method) and specific gravity, significant associations were found between the control group and case group, respectively(r=0.832, P<0.05, r=0.845, P<0.05) and (r=0.841, P<0.05, r=0.849, P<0.05). Specific gravity adjustment appears to be more appropriate for variations in the urine creatinine method. Conclusion: we found that urinary creatinine concentrations were significantly affected by gender, and other factors and that care should therefore be exercised when correcting urinary metabolites according to the urinary creatinine concentration in spot urine. It is determined that additional study is needed for biological monitoring.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.190-195
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• 2015

The objective of this study is to estimate the relationship between amalgam removal and urinary mercury levels. To measure urinary mercury concentration, urine of participants was collected at baseline, immediately, 24 hours and 48 hours after removal of amalgam restorations. The statistical analysis was performed using IBM SPSS Statistics ver. 20.0. The overall mean urinary mercury concentration at baseline, immediately, 24 hours and 48 hours after removal of amalgam restorations was 2.77, 2.75, 2.95 and $4.00{\mu}g/g$ creatinine, respectively. Logistic regression model shows that the gender leads to increased odds of high urinary mercury concentration in children (odds ratio, OR=1.99), even after adjusting for high amalgam surfaces (OR=1.23) and fish consumption (OR=1.26) at the baseline. Our findings suggest that mercury exposure from dental amalgam adversely impact health and therefore are a health risk.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.52-58
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• 2014

Objectives: Using laborers participating in the petrochemical factory turnaround process as subjects, this study aims to identify exposure to benzene in the air and examine the relationship between exposure and the excretion of urinary metabolites by measuring concentrations of urinary trans, trans-muconic acid (t,t-MA). Methods: A passive sampler was used to measure the level of benzene in the air. In order to analyze urinary metabolites, the urine of laborers participating in the turnaround process was collected twice daily, both before and after work. In addition, a survey was conducted on work factors and lifestyle habits as factors affecting the concentration of urinary metabolites. Results: During the survey period, benzene was detected in the samples from all workers, and its average concentration was $0.16{\pm}0.22ppm$. The average concentration of t,t-MA after work was $1.20{\pm}1.86mg/g$ creatinine, and the results of analyzing urinary metabolites concentration before and after work showed statistically significant differences(p=0.003). There was also a statistically significant correlation (r=0.52, p=0.002) between benzene in the air and the concentration of after-work urinary t,t-MA. Conclusions: During the turnaround process, the average benzene concentration in workers was $0.16{\pm}0.22ppm$, which was below the exposure limit. However, their average t,t-MA concentration was $1.20{\pm}1.86mg/g$ creatinine, which exceeded the exposure limit of 1mg/g creatinine. The characteristics of turnaround process work require considerations such as underestimating the passive sampler being used and the skin absorption of benzene, and there needs to be a simultaneous assessment of working environment measurements and biological monitoring.