Short-Term Effectiveness of Oral Nirmatrelvir/Ritonavir Against the SARS-CoV-2 Omicron Variant and Culture-Positive Viral Shedding

Background@#Information on the effectiveness of nirmatrelvir/ritonavir against the omicron is limited. The clinical response and viral kinetics to therapy in the real world need to be evaluated. @*Methods@#Mild to moderate coronavirus disease 2019 (COVID-19) patients with risk factors for severe illness were prospectively enrolled as a treatment group with nirmatrelvir/ritonavir therapy versus a control group with supportive care. Serial viral load and culture from the upper respiratory tract were evaluated for seven days, and clinical responses and adverse reactions were evaluated for 28 days. @*Results@#A total of 51 patients were analyzed including 40 in the treatment group and 11 in the control group. Faster symptom resolution during hospitalization (P= 0.048) was observed in the treatment group. Only minor adverse reactions were reported in 27.5% of patients. The viral load on Day 7 was lower in the treatment group (P = 0.002). The viral culture showed a positivity of 67.6% (25/37) vs. 100% (6/6) on Day 1, 0% (0/37) vs. 16.7 (1/6) on Day 5, and 0% (0/16) vs. 50.0% (2/4) on Day 7 in the treatment and control groups, respectively. @*Conclusions@#Nirmatrelvir/ritonavir against the omicron was safe and resulted in negative viral culture conversion after Day 5 of treatment with better symptomatic resolution.

Seroprevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) in public health workers responding to a MERS outbreak in Seoul, Republic of Korea, in 2015

@#The first case of Middle East respiratory syndrome coronavirus (MERS-CoV) in the Republic of Korea was confirmed in May 2015 after a traveller returned from the Middle East. There were 186 cases, including 38 deaths, within two months. The potential of a single MERS-confirmed patient to result in such a large MERS outbreak constitutes a serious global health concern.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES@#The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.@*METHODS@#Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.@*RESULTS@#The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.@*CONCLUSIONS@#The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Subchronic Inhalation Toxicity Study of n-pentane in Rats

OBJECTIVES: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. METHODS: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. RESULTS: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. CONCLUSION: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

Effect of Agglomeration on the Toxicity of Nano-sized Carbon Black in Sprague-Dawley Rats

OBJECTIVES: Recent studies have shown that nano-sized carbon black is more toxic than large respirable carbon black because of its higher surface area. However, it is not clear if carbon black made larger by agglomeration demonstrates decreased toxicity. The purpose of this study was to verify if agglomeration affects the toxicity of carbon black using three differently prepared nano-sized carbon black aerosols in nose-only inhalation chambers for 13 weeks. METHODS: Printex 90 was selected as a representative nano-sized carbon black. To generate aerosols of three different types of agglomerates, Printex 90 was dispersed in distilled water by three different methods: vortex, vortex+sonication, and vortex+sonication with dispersion in a stabilizer. Then, the three differently prepared solutions were aerosolized through venturi nozzles. Male Sprague-Dawley rats were exposed to Printex 90 aerosols in a nose-only exposure chamber for 6 h/d, 5 d/wk for 13 weeks at a concentration of approximately 9 mg/m3. RESULTS: Numbers of total cells in the bronchoalveolar lavage (BAL) fluid, macrophages, and polymorphonuclear leukocytes were increased and carbon black masses were clearly seen in BAL cells and lung tissues of rats exposed to Printex 90. However, few differences were found between the three differently agglomerated aerosols. In addition, there were no significant differences in other parameters, such as body weight, lung function or cytokine levels in BAL fluid following carbon black exposure. CONCLUSIONS: Only mild to moderate respiratory effects were found in rats exposed to nano-sized carbon black at 9 mg/m3 for 13 weeks. Agglomeration did not affect the toxicity of nano-sized carbon particles.

External Quality Assessment Scheme for Biological Monitoring of Occupational Exposure to Toxic Chemicals

OBJECTIVES: In this study, we summarized the External Quality Assessment Scheme (EQAS) for the biological monitoring of occupational exposure to toxic chemicals which started in 1995 and continued until a 31st round robin in the spring of 2010. The program was performed twice per year until 2009, and this was changed to once a year since 2010. The objective of the program is to ensure the reliability of the data related to biological monitoring from analytical laboratories. METHODS: One hundred and eighteen laboratories participated in the 31st round robin. The program offers 5 items for inorganic analysis: lead in blood, cadmium in blood, manganese in blood, cadmium in urine, and mercury in urine. It also offers 10 items for organic analysis, including hippuric acid, methylhippuric acid, mandelic acid, phenylglyoxylic acid, N-methylformamide, N-methylacetamide, trichloroacetic acid, total trichloro-compounds, trans,trans-muconic acid, and 2,5-hexanedione in urine. Target values were determined by statistical analysis using consensus values. All the data, such as chromatograms and calibration curves, were reviewed by the committee. RESULTS: The proficiency rate was below 70% prior to the first round robin and improved to over 90% for common items, such as PbB and HA, while those for other items still remained in the range of 60-90% and need to be improved up to 90%. CONCLUSION: The EQAS has taken a primary role in improving the reliability of analytical data. A total quality assurance scheme is suggested, including the validation of technical documentation for the whole analytical procedure.

Effect of Nano-sized Carbon Black Particles on Lung and Circulatory System by Inhalation Exposure in Rats

OBJECTIVES: We sought to establish a novel method to generate nano-sized carbon black particles (nano-CBPs) with an average size smaller than 100 nm for examining the inhalation exposure risks of experimental rats. We also tested the effect of nano-CBPs on the pulmonary and circulatory systems. METHODS: We used chemical vapor deposition (CVD) without the addition of any additives to generate nano-CBPs with a particle size (electrical mobility diameter) of less than 100nm to examine the effects of inhalation exposure. Nano-CBPs were applied to a nose-only inhalation chamber system for studying the inhalation toxicity in rats. The effect on the lungs and circulatory system was determined according to the degree of inflammation as quantified by bronchoalveolar lavage fluid (BALF). The functional alteration of the hemostatic and vasomotor activities was measured by plasma coagulation, platelet activity, contraction and relaxation of blood vessels. RESULTS: Nano-CBPs were generated in the range of 83.3-87.9 nm. Rats were exposed for 4 hour/day, 5 days/week for 4 weeks to 4.2 x 10(6), 6.2 x 10(5), and 1.3 x 10(5) particles/cm3. Exposure of nano-CBPs by inhalation resulted in minimal pulmonary inflammation and did not appear to damage the lung tissue. In addition, there was no significant effect on blood functions, such as plasma coagulation and platelet aggregation, or on vasomotor function. CONCLUSION: We successfully generated nano-CBPs in the range of 83.3-87.9 nm at a maximum concentration of 4.2 x 10(6) particles/cm3 in a nose-only inhalation chamber system. This reliable method can be useful to investigate the biological and toxicological effects of inhalation exposure to nano-CBPs on experimental rats.

Evaluation of the Genetic Toxicity of Cyclopentane and Ammonium Nitrate: In vitro Mammalian Chromosomal Aberration Assay in Chinese Hamster Ovary Cells

OBJECTIVES: In this study, the in vitro mammalian chromosomal aberration (CA) assay was conducted to gain additional information concerning the hazards associated with the use of cyclopentane and ammonium nitrate. While these two chemicals had already been tested by many methods, they had not been studied in the CA test. METHODS: The assay was performed using the ovarian infantile cell (CHO-K1 cell), by the direct method (-S9) and by the metabolic activated method (+S9 mix). RESULTS: Using the direct method, the 7 dosages in a 48 hour treatment group did not show that the frequency of CA is proportion to the dosage addition. The frequency of CA is not proportion to the dosage addition for a 6 hour treatment using the metabolic activated method. CONCLUSION: From these findings, it was decided that the 2 chemicals do not induce chromosomal aberrations under the tested conditions.

A Study of Micronucleus Induction with Methyl Formate and 2-Methylbutane in Bone Marrow Cells of Male ICR Mice

OBJECTIVES: We investigated the genotoxicity of two chemicals, methyl formate and 2-methylbutane, using male ICR mice bone marrow cells for the screening of micronucleus induction. Although these two chemicals have already been tested numerous times, a micronucleus test has not been conducted and the amounts used have recently been increased. METHODS: 7 week male ICR mice were tested at dosages of 250, 500, and 1,000 mg/kg for methyl formate and 500, 1,000, and 2,000 mg/kg for 2-methlybutane, respectively. After 24 hours of oral administration with the two chemicals, the mice were sacrificed and their bone marrow cells were prepared for smearing slides. RESULTS: As a result of counting the micronucleated polychromatic erythrocyte (MNPCE) of 2,000 polychromatic erythrocytes, all treated groups expressed no statistically significant increase of MNPCE compared to the negative control group. There were no clinical signs related with the oral exposure of these two chemicals. CONCLUSION: It was concluded that the two chemicals did not induce micronucleus in the bone marrow cells of ICR mice, and there was no direct proportion with dosage. These results indicate that the two chemicals have no mutagenic potential under each study condition.

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.

Comparison of an enzyme-linked immunosorbent assay with serum neutralization test for serodiagnosis of porcine epidemic diarrhea virus infection

An indirect porcine epidemic diarrhea (PED) virus (PEDV) enzyme-linked immunosorbent assay (ELISA) was compared with the serum neutralization (SN) test by testing 46 samples from experimentally infected sows, 73 samples from naive sows, and 1, 024 field sow samples from 48 commercial swine farms of undefined PED status. The SN test and the ELISA were performed using PEDV, KPEDV-9 strain. Viral proteins as a coating antigen of PEDV ELISA were extracted from the cytoplasm of PEDV-infected Vero cells using a non-ionic detergent, Triton X-100, and a simple protocol of PEDV ELISA was followed. The presence of antibodies in these experimental samples was confirmed by SN and ELISA in which the sensitivity of the ELISA was 89.1%, and the corresponding specificity was 94.5%. On testing 1, 024 field samples, an overall agreement of 84.2% was generated between the SN and ELISA. This study demonstrates that the PEDV ELISA is a useful serodiagnostic screening test at herd level for detecting swine antibodies against PEDV.

Effect of soluble porcine aminopeptidase N on antibody production against porcine epidemic diarrhea virus

A few members of coronavirus group I which includes porcine epidemic diarrhea virus (PEDV) use porcine aminopeptidase N (pAPN) as a cellular receptor. Cellular receptors play an important role in virus attachment and entry. However, the low permissiveness of PEDV to APN-expressing porcine cell lines has made it difficult to elucidate the role of pAPN in vitro. The purpose of this study was to prove whether the treatment of soluble pAPN could enhance the antibody production against PEDV in guinea pigs, rabbits and sows. The animals (20 guinea pigs, 8 rabbits and 20 sows) were divided into 4 groups. Group A was injected intramuscularly (IM) with soluble pAPN at one hour before intramuscular infection of PEDV on the same site, group B for IM simultaneous injection of pAPN and PEDV, and group C for IM injection of PEDV only. Group D served as a control of pAPN treatment or PEDV infection. Antibody production against PEDV was compared among groups at regular intervals. The results suggested that pAPN could enhance the antibody production against PEDV in guinea pigs and rabbits which are free of pAPN, however, the effect of pAPN treatment in sows was not clearly elucidated.

Analysis of Claimed Cases as an Occupational Disease at Korea Occupational Safety and Health Agency from 1992 to 1999 / 대한산업의학회지

OBJECTIVES: Pneumoconisis and noise-induced hearing loss(NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardiocerebrovascular accident(CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). METHODS: The local office of the Korea Labor Welfare Corporation(KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. RESULTS: Male was 80. 7 % of the requested cases. Their mean age was 42 years old and 75. 5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50. 7 %. The majority of requested cases were respiratory diseases(22.4 %), cancers(18.5 %), Neuropsychiatric problems (14. 5 %), and musculoskeletal problems (13. 5 %). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73. 6 % of them were caused by chemical agents, especially 28. 5 % were by organic solvents. 67 % of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. CONCLUSIONS: A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

Analysis of Korean Analytical Quality Assurance Program for the Special Health Examination from 1995 to 1999 / 대한산업의학회지

OBJECTIVE: The accuracy of analytical results of blood and urine heavy metals came out to the main issue on occupational health from late eighties. The discrepancy of the results for same samples from different laboratories made the diagnosis for occupational diseases be unreliable. Therefore, a quality control program for analysis of samples taken from workplace had been introduced in Korea since 1992. This study aims to show the quality control program f'or analysis of blood and urine samples and its proficient rates from 1992 to 1999 and to know how they have been being used in occupational health. METHODS: The quality control program runs twice a year with mandatory items of blood lead and urine hippuvic acid and voluntary items of blood cadmium and manganese and urine mandellic acid and methyl hippuric acid. Participant laboratories are receiving three levels for each items and two out of three samples have to be qualified for being a proficient laboratory for the item. The acceptable range of blood lead and urine hippuric acid is +/-15% and that of the others is within 3 SD(standard deviation) from the reference values. RESULTS: The proficient rates of blood lead and urine hippuric acid was 89%, 90%, repectively, however those of the other voluntary items have been from 51% to 62%. The proficient rates of urine mercury and urine N-methylformamide(NMF), which are introduced since 1999, were very poor. Urine hippuric acid and blood lead were analyzed frequently for the purpose of biological monitoring conducting by special health examination organizations. Urine and blood manganese and urine metabolites of trichloroethylene, urine phenol, methylhippuric acid and cadmium were followed. CONCLUSIONS: In conclusion, the quality control program for biological monitoring has dramatically improve the ability of analysing blood and urine samples and eventually contributes to diagnose occupational diseases and to prevent occupational poisoning. However, some biological monitoring data, such as urine manganese, mercury and NMF, have been still reported from laboratories that were not accepted as a proficient laboratory.

Factors Associated with Psychoneurobehavjral Outcomes in Workers Exposed to Manganese / 대한산업의학회지

The risk posed to human health by environmental manganese (Mn) exposure is unknown. The purpose of this study is to establish if subclinical effects related to Mn exposure and examine the factors influencing psychoneurobehaviral outcomes of Mn exposed workers. This study involved 121 male workers of welding, alloy furnace, and manufacturing of welding stick. Study investigations include: a questionnaire covering demographic characteristics, job and exposure history and medical symptoms and conditions, monitoring workplace air for personal exposure to respirable and inhalable manganese, analysis of blood and urine samples. psychoneurobehaviral test(neurobehaviral core test battery (NCTB), signal change on magnetic resonance imaging (MRJ) scans, minimental state and neurological examination). The main results of this study were as follows: 1. Preliminary results showed that, with increasing manganese exposure, neurobehaviral performance was poorer and signal change on MRI scans increased. 2. The results of examination revealed significant relations on psychoneurobehaviral out-comes (neurobehaviral performance, signal change on MRI scans, and neurological features). 3. In multiple regression, age and educational status as demographic variables and exposure level were significantly related to 4neurobehaviral test. Also exposure level and serum Mn concentrations were positively relatel to signal change on MRI scans and neurological features affected by Mn on the brain (signal change). 4. Psychoneurobehaviral outcomes from Mn exposure were related to neurobehaviral performance, signal change on MRJ scans, neurological features and profile of mood states (POMS), and influnced positively with age, alcohol and smoking history, and duration of Mn exposure, negatively with educational status. Serum Mn concentrations in combination with brain MRI scans, and perhaps a battery of neurobehaviral tests, appear to be the best way to monitor excessive exposure to Mn. These results are consistent with our knowledge on Mn action on the brain and are similar to the type of neurobehaviral dysfunction. They suggest that there may be age, educational status, and life style (alcohol and drinking history) differences with chronic environmental exposure. These findings suggest further evaluation, particularly on relationships between Mn exposure, aging, and susceptibility factors.

Polyneuropathy by Occupational Exposure to Acrylamide / 대한산업의학회지

Authors report a first Korean case of polyneuropathy in an acrylamide producing factory together with an environmental and epidemiologic survey for the ten workers of the same workplace and 46 workers in the production and manufacturing acrylamide in Ulsan, Korea. The case is 30 years old man who worked in the prcduction of the acrylamide for two years. In August, 1997, he had a weakness of the lower extremity with loss of body weight of 15 Kg which progressed to paresthesia of the limbs, the loss of vibration sense, difficulty in walking, speech disturbance, dysuria, constipation, difficulty in erection and swallowing difficulty. Neurologic examination showed a complete loss of vibration and position sense, and loss of deep tendon reflex in all the limbs. There was a contact dermatitis-like skin lesion on the feet. Electrodiagnostic test showed a generalized polyneuropathy of moderate degree involving motor and sensory component of peripheral and cranial nerves. After 8 months' cessation from exposure and supportive care, his symptoms were completely resolved, but abnormality in electrodiagnostic test and vibrotactile perception threshold still persisted, although much improved than before. There were 11 workers in the same workplace of the case, producing acrylamide by microorganism as a catalyst. Environmental monitoring of the workplace revealed air-borne concentration of the acrylamide to be from 0.05 to 0.23 mg/m(3) by personal sampling and from 7.65 to 11.65 mg/m(3) by area sampling during filter exchanging process, which far exceeds TLV-TWA of 0.03 mg/m(3). However acrylamide was not detected from the plasma of the workers. Symptom questionnaire showed a markedly higher complain of neurologic symptoms, compared to the workers of the other acrylamide producing companies. Electrodiagnostic test showed a several workers are in the lower normal range without definite abnormality. Vibrotactile perception threshold by Vibratron II showed a significantly increased threshold in the workers of the same workplace compared to the other acrylamide workers and significantly decreased test score of color vision compared to normal controls. After improvement of the production process and strict wearing of the protective device, most workers reported the improvement of clinical symptoms, but vibrotactile perception threshold was not improved. These result suggests the need for the effective environmental monitoring together with a periodic biological monitoring. Development of effective screening test is urgently needed to control and assess the skin absorption of acrylamide.

Assessment of Cadmium in Blood and Urine of Occupationally Exposed Workers and Renal Dysfunction by Cumulative Exposure Estimate / 대한산업의학회지

88 workers exposed to cadmium were examined at the 12 factories using or producing cadmium in order to know the present state of cadmium exposure and renal dysfunction in 1992. Cadmium in blood and in urine were measured and compared by the 3 exposure level of cadmium in air. Cadmium in blood of low, moderate and high exposure group were 2.5, 3,8 and 7.6 microgram/L, respectively. Cadmium in urine were 1.8(1.3), 3.8(2,6) and 7.9 microgram/L(6.1 microgram/g creatinine) , resrectively. However, there was no relationship between Urinary cadmium and beta(2)-microglobulin. Cumulative exposure estimate (CEE) was calculated by multiplying the mean ambient cadmium level of the factory and working duration. CEE has a high correlation with cadmium in blood and urine, but no relation to beta(2)-microglobulin. Because working durations were relatively shorter than European workers', the highest CEE was just 300 microgram. year/m(3), which was not enough to induce renal tubular dysfunction. This study, however, suggested the possibility that renal tubular dysfunction caused by cadmium could be happened in Korea in the near future.

Styrene in Air and Blood and Mandelic acid in Urine in the Workers exposed to Styrene / 대한산업의학회지

The concentration of styrene in air and in blood and mandelic acid in urine were checked for the 60 workers with normal liver function, exposed to styrene. Styrene in air were sampled with personal air sampler at least 4 hours and analyzed by gas chromatography. Blood and spot urine were collected at the end of shift with a vacuum tube and a plyethylene bottle and analyzed by has chromatography and high performance liquid chromatography. Means of air and blood styrene and urine mandelic acid were 8.16 ppm (geometric mean), 0.199 mg/L, and 0.519 g/g creatinine, respectively. The concentration of styrene in air and mandelic acid in urine were high in the FRP factories and low in polymerization factory. Styrene in blood showed large difference by the working process. Styrene in air showed a good correlation with mandelic acid in urine(r=0.6369) and styrene in blood(r=0.6371). The mandelic acid in urine and styrene in blood corresponded to exposure of 50 ppm styrene were 0.890 g/g creatinine and 0.434 mg/L. However, hippuric acid in urine did not show any correlation with styrene in air. Urine mandelic acid excretion expected ratio showed a tendency to decrease according to obesity index and to increase with alcohol consumption.