•Higher concentrations of PFRs were found in dust from schools than houses.•Higher TBOEP were detected in dust and floor polisher/wax products.•TBOEP intake of children through dust ingestion was 1.9 ...times higher than its RfD.
To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270000ngg−1 dry weight (3700–5500000ngg−1 dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•The method is applicable and well-prepared for large-scale study.•12 urine samples (100μL each) are extracted within 30min.•The LLOQ for cortisol and cortisone was 2.5ng/mL (injection volume: ...10μL).•Minimal degradation of urine samples at room temperature during first 24h.•The extracted urine samples are quantifiable for up to 5days after extraction.
Levels of urinary glucocorticoids and their concentration ratios have been analyzed as potential markers for various pathological statuses. Large-scale studies may possibly accelerate the investigations; however, a suitable method needs to be established. Analytical conditions for measurement of urinary glucocorticoids with LCMS were examined. Electrospray ionization in the positive ion mode was applied for detection of cortisol (precursor>product ion: 363.3>121.0), cortisol-d4 (internal standard, IS, 367.4>121.1), and cortisone (361.2>163.2). To maximize ionization, acetic acid-ammonium acetate buffer (18mM) at pH 5.3 was employed as eluent A. A C18 column (100mm×2.1mm, 2.7μm) at 50°C was used for the 9.5min binary gradient separation starting with 60% eluent A with methanol being eluent B. Linear correlations were observed between the concentrations and the peak areas in the concentration range of 1–300ng/mL with correlation coefficients (r) of 0.998 and 0.997 for cortisol and cortisone, respectively, without IS adjustment, and 0.999 with IS adjustment for both cortisol and cortisone. Solid-phase extraction (SPE) using a 2mL centrifuge column was performed for the urine samples, with the original and final volumes being 100μL. The SPE of 12 urine specimens could be performed within 30min. The effect of the sample matrix on the quantification of endogenous compounds present in the urine extract was limited (coefficient of variation (CV) of IS-adjusted matrix factor: 4.4–8.1%; urine extracts of 8 individuals); however, substantial peak reduction of cortisol was observed at low concentrations. Exogenous contaminants originating from the SPE centrifuge column seemed to be a main cause for this phenomenon because the pure-water extract showed similar peak reduction. A recovery of ∼50% was obtained for both cortisol and cortisone. Adjustment with the IS improved the apparent recovery, with ∼100% being obtained for both cortisol and cortisone. The recovery rate decreased when the urine samples were concentrated in the SPE step; the reduction was greater for cortisol than for cortisone. The lower limit of quantification (LLOQ) was set at 2.5ng/mL when the injection volume was 10μL, based on the reproducibility of the standards which were measured (CV of 12 repetitions: 10.1% for 0.5ng/mL cortisol and 19.6% for 1ng/mL cortisone), the matrix effect (−55% at 2ng/mL concentrations of cortisol), and the recovery rate (∼50%). Furthermore an alternative approach for preparation of the cortisol standards was required for low concentration range (2.5–20ng/mL) because of the effect of the matrix. Degradation of original urine specimens at room temperature was minimal during the first 24h. The extracted urine samples degraded over time; however, their concentrations were corrected with the IS, allowing for analysis up to 5days after extraction. In conclusion, an analytical method for urinary glucocorticoids was established, which is fast, sensitive, and well suited for practical application to large-scale study.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Objectives
We assessed dermal exposure to N,N‐dimethylacetamide (DMAC) in a spray worker by utilizing a combination of personal exposure monitoring, biological monitoring, and glove permeation ...monitoring. We also determined the protective effects of chemical protective gloves (CPGs).
Methods
Surveys with and without CPG usage were performed on different days. In the survey with CPG usage, the worker had worn leather gloves over the CPG. Personal exposure monitoring and glove permeation monitoring were performed using 3M Organic Vapor Monitor 3500 and PERMEA‐TEC Pads respectively. Urinary concentration of DMAC and its metabolites (N‐methylacetamide NMAC, N‐hydroxymethyl‐N‐methylacetamide DMAC‐OH, S‐(acetamidomethyl) mercapturic acid AMMA) were measured in the before‐shift and end‐of‐shift samples collected from the worker.
Results
Personal exposure DMAC concentration in the survey with CPG usage (0.32 ppm) was twice that in the survey without CPG usage (0.15 ppm). However, urinary concentrations of DMAC‐OH and AMMA in the end‐of‐shift samples in the survey with CPG usage (DMAC‐OH, 0.74 mg/g creatinine; AMMA, 0.10 mg/g creatinine) were lower than those in the survey without CPG usage (DMAC‐OH, 1.27 mg/g creatinine; AMMA, 0.24 mg/g creatinine). Urinary concentrations of DMAC and NMAC were below the limit of detection in all samples. DMAC concentrations in PERMEA‐TEC Pads that were used in the surveys with and without CPG usage were in the range of 0.3‐2.1 µg/sample and 16.4‐1985.2 µg/sample respectively.
Conclusions
The combination of CPG usage and leather gloves was effective in preventing dermal exposure to DMAC.
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CEKLJ, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Objectives
The purpose of this research was to develop and validate an analytical method for rapid determination of the exposure of workers to ortho‐phthalaldehyde (OPA) at the ceiling threshold ...concentration.
Methods
A 2,4‐dinitrophenylhydrazine (DNPH)‐silica cartridge was chosen as a sampler. OPA collected by the DNPH‐silica cartridge was subsequently extracted with 5 mL of acetonitrile. A 50‐µL aliquot of phosphoric acid/acetonitrile solution (2%, v/v) was added to 950 µL of the extraction solution and allowed to stand for 30 minutes at room temperature. This solution was then analyzed by high‐performance liquid chromatography tandem mass spectrometry. The basic characteristics of the proposed method, such as recovery, repeatability, limit of quantification, and storage stability of the samples, were examined.
Results
The overall recoveries of OPA from OPA‐spiked DNPH‐silica cartridges were 93.6%‐100.1% with relative standard deviations, representing the repeatability, of 1.5%‐10.8%. The limit of quantification was 0.165 ng/sample. The recovery of OPA from DNPH‐silica cartridges after 5 days of storage in a refrigerator exceeded 95%.
Conclusions
The proposed method enabled the determination of the OPA concentration corresponding to the Threshold Limit Value‐Ceiling of 0.1 ppb recommended by the American Conference of Governmental Industrial Hygienists, with a minimum sampling time of 18 seconds (corresponding to a sampling volume of 300 mL at 25°C and 1 atm). Thus, this method will be useful for estimating worker exposures to OPA.
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CEKLJ, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract : Objectives : N,N-Dimethylacetamide (DMAC) is widely used in industry as a solvent. It can be absorbed through human skin. Therefore, it is necessary to determine exposure to DMAC via ...biological monitoring. However, the precision of traditional gas chromatography (GC) is low due to the thermal decomposition of metabolites in the high-temperature GC injection port. To overcome this problem, we have developed a new method for the simultaneous separation and quantification of urinary DMAC metabolites using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods : Urine samples were diluted 10-fold in formic acid, and 1-μl aliquots were injected into the LC-MS/MS equipment. A C18 reverse-phase Octa Decyl Silyl (ODS) column was used as the analytical column, and the mobile phase consisted of a mixture of methanol and aqueous formic acid solution. Results : Urinary concentrations of DMAC and its known metabolites (N-hydroxymethyl-N-methylacetamide (DMAC-OH), N-methylacetamide (NMAC), and S-(acetamidomethyl) mercapturic acid (AMMA)) were determined in a single run. The dynamic ranges of the calibration curves were 0.05-5 mg/l (r>_0.999) for all four compounds. The limits of detection for DMAC, DMAC-OH, NMAC, and AMMA in urine were 0.04, 0.02, 0.05, and 0.02 mg/l, respectively. Within-run accuracies were 96.5%-109.6% with relative standard deviations of precision being 3.43%-10.31%. Conclusions : The results demonstrated that the proposed method could successfully quantify low concentrations of DMAC and its metabolites with high precision. Hence, this method is useful for evaluating DMAC exposure. In addition, this method can be used to examine metabolite behaviors in human bodies after exposure and to select appropriate biomarkers.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Purpose
Polycyclic aromatic hydrocarbons (PAHs) are multiple compounds that include many carcinogens. We conducted a cross-sectional study in steel plant workers in Anshan, China, to identify ...biomarkers that reflect the carcinogenicity of PAHs.
Methods
Subjects were 57 workers and 20 controls. Level of personal exposure to PAHs was measured using GC–MS. In accordance with the assessment methods defined by the United States Environmental Protection Agency (US EPA), 15 PAHs were selected for the analysis. For the measurement of urinary metabolites, urine samples were treated with β-glucuronidase and analyzed using HPLC with a fluorescence detector.
Results
The mean range of personal exposure to 15 PAHs (total PAHs) was 178.85, 47.08–1,329.45 (geometric mean, 5th and 95th percentile) μg/m
3
. Ten known urinary metabolites (1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 3-hydroxyphenanthrene, 9-hydroxyphenanthrene, 1-hydroxypyrene, 3-hydroxybenzaanthracene, 6-hydroxychrysene, and 3-hydroxybenzoapyrene) and four unknown peaks were detected. The highest correlation was between total PAHs and urinary 2-hydroxynaphthalene (Spearman
r
= 0.716,
P
< 0.01). Among the detected urinary metabolites, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene were found to correlate significantly with the “Σ carcinogenic potency of PAHs” (sum of seven carcinogenic PAHs calculated from the levels of personal PAHs and relative potency factors), and with the greatest correlation found for 1-hydroxypyrene (Spearman
r
= 0.630,
P
< 0.01).
Conclusions
The analysis of personal exposure to 15 PAHs and 10 urinary metabolites, and calculation of Σ carcinogenic potency, indicated that urinary 1-hydroxypyrene was the most comprehensive carcinogenic biomarker of exposure to PAHs.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Objectives
The present study aimed to develop a method for measuring the ceiling level of ortho‐phthalaldehyde (OPA) exposure and evaluate the ceiling levels of OPA exposure among health care workers ...who handle disinfectant solutions containing OPA for the disinfection of endoscopes.
Methods
The study consisted of a preliminary survey and main survey. In the preliminary survey, processes involving high‐concentration exposure to OPA were identified by video‐exposure monitoring (VEM). In the main survey, the ceiling levels of OPA exposure for high‐concentration exposure processes identified from the results of the preliminary survey were determined using a measuring method combining sampling using a 2,4‐dinitrophenylhydrazine‐silica cartridge and analysis by high‐performance liquid chromatography tandem mass spectrometry.
Results
In the preliminary survey, seven processes involving high‐concentration exposure to OPA were identified by VEM. The duration of each process was short, lasting from 20 seconds to a few minutes. In the main survey, the OPA concentrations for the identified high‐concentration exposure processes ranged from 1.18 to 4.49 ppb, which markedly exceeded the threshold limit value ceiling (TLV‐C) of 0.1 ppb recommended by the American Conference of Governmental Industrial Hygienists.
Conclusions
The method for measuring the ceiling level of OPA exposure was established using VEM and the highly sensitive method of chemical analysis; and we successfully evaluated the ceiling levels of OPA exposure among health care workers engaged in endoscope disinfection. This approach can also be applied to other chemical substances with recommended TLV‐Cs, and important information for reducing exposure can thus be obtained.
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CEKLJ, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Purpose To study the effect that limbering up of the muscles attached to the pelvis has on muscle strength of the trunk and upper and lower extremities, which are not being exercised, and to ...investigate the possibilities for clinical application. Subjects and Methods A total of 152 healthy adult men. Sthenometry was conducted using a handheld dynamometer to assess the effect of limbering up of the upper gluteus maximus, hamstrings, and internal abdominal oblique muscles attached to thoracolumbar fascia on the trunk and upper and lower extremities. The exercises were slowly performed 20 repetitions. Subjects were divided into AB group (n=49) measuring abdominal and back muscle strength, K group (n=42) measuring knee flexor and extensor strength, and S group (n=61) measuring shoulder flexor and external rotator strength and compared to non-exercising controls. Results In the exercise groups, exercising either gluteus maximus or hamstrings significantly increased the strength of abdominal and back muscles; exercising gluteus maximus increased knee extensor strength, and exercising the abdominal internal oblique muscle significantly increased knee flexor strength; and shoulder flexor strength significantly increased after exercising gluteus maximus versus controls. Conclusion This may be useful in rehabilitation of injuries to the trunk and upper and lower extremities.
Purpose To assess the influence of plantar sensory input and task guidance produced by a protrusion on lower limb joint dynamics during gait by changes in muscle activity and two-dimensional motion ...analysis. The protrusion seals on the soles of the feet, named “Perceptual Stimulus Protrusion” were used in this study. Participants and Methods In this study, 40 and 42 healthy adults were recruited for muscle activity and two-dimensional analysis, respectively. In addition to walking without perceptual stimulus protrusion (“Control” condition), the testing conditions included attachment of the protrusion to the heel (“Heel Condition”) and the hallucal (“Hallucal Condition”). As task guidance, participants were orally instructed how to walk for each conditions. The muscle activities of the rectus femoris, vastus medialis, tibialis anterior, and medial head of the gastrocnemius were measured. The two-dimensional analysis was compared with the angle of ankle dorsiflexion and plantarflexion, the toe height during the swing phase between the test conditions, respectively. Results In the Heel Condition, the tibialis anterior and vastus medialis activity in the stance and swing phases, toe height, and angle of ankle dorsiflexion and plantarflexion increased. In the Hallucal Condition, tibialis anterior activity during the stance and swing phases, gastrocnemius activity during the stance phase, toe height, and angle of ankle plantarflexion increased. Conclusion Plantar sensory input and task guidance using perceptual stimulus protrusion influences active motion control. Therefore, the application of this procedure can be expected to support motion guidance, such as gait and load practice.
Abstract A genetic polymorphism of the aldehyde dehydrogenase 2 ( ALDH2 ) gene, ALDH 2*2 , encodes an enzymatically defective ALDH2 protein. Recent epidemiological studies suggest that possessing ...ALDH 2*2 is a protective factor for liver tissue in healthy individuals, although these studies lack a mechanistic explanation. Our animal studies have shown the same trend: levels of serum alanine transaminase (ALT), hepatic malondialdehyde (MDA), and hepatic tumor necrosis factor alpha (TNF-α) were lower in Aldh2 knockout ( Aldh2 −/− ) mice than in wild-type ( Aldh2 +/+ ) mice after ethanol administration. To propose a mechanistic hypothesis, residual liver specimens from the previous experiment were analyzed. An anti-oxidative protein, heme oxygenase 1 (HO-1), and an oxidative stress-producing protein, cytochrome P450 2E1 (CYP2E1), were detected at higher levels in Aldh2 −/− mice than in Aldh2 +/+ mice, regardless of ethanol treatment. Other oxidative stress-related proteins and inflammatory cytokines did not show such a significant difference. To conclude, we propose a protective role of HO-1 in individuals with A LDH 2*2 . Our continued studies support the epidemiological finding that possession of A LDH 2*2 is a protective factor in the liver of the healthy individual.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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