BACKGROUND: Respirator fit testing is a method to assess if the respirator provides an adequate face seal for the worker. METHODS: Workers from four Norwegian smelters were invited to participate in the study, and 701 respirator fit tests were performed on 127 workers. Fourteen respirator models were included: one FFABE1P3 and 11 FFP3 respirator models produced in one size and two silicone half masks with P3 filters available in three sizes. The workers performed a quantitative fit test according to Health and Safety Executive 282/28 with 5–6 different respirator models, and they rated the respirators based on comfort. Predictors of overall fit factors were explored. RESULTS: The pass rate for all fit tests was 62%, 56% for women, and 63% for men. The silicone respirators had the highest percentage of passed tests (92–100%). The pass rate for the FFP3 models varied from 19–89%, whereas the FFABE1P3 respirator had a pass rate of 36%. Five workers did not pass with any respirators, and 14 passed with all the respirators tested. Only 63% passed the test with the respirator they normally used. The mean comfort score on the scale from 1 to 5 was 3.2. The respirator model was the strongest predictor of the overall fit factor. The other predictors (age, sex, and comfort score) did not improve the fit of the model. CONCLUSION: There were large differences in how well the different respirator models fitted the Norwegian smelter workers. The results can be useful when choosing which respirators to include in respirator fit testing programs in similar populations.
Female ; Humans ; Male ; Masks ; Methods ; Osmeriformes ; Silicon ; Silicones ; Ventilators, Mechanical

The efficacy of using a bacteriophage (phage) to control Flavobacterium psychrophilum (F. psychrophilum) infection of ayu (Plecoglossus altivelis altivelis) was evaluated in this study. Intramuscular challenge failed to induce sufficient infection levels; therefore, a newly designed net-scratch challenge method was also used to induce bacterial infection. Administration of phage PFpW-3 in F. psychrophilum-infected ayu showed notable protective effects, increased survival rates and mean times to death. Additionally, the fate of inoculated bacteria and phage in ayu were investigated. Our results suggest that the phage PFpW-3 could be considered an alternative biocontrol agent against F. psychrophilum infections in ayu culture.
Bacteria ; Bacterial Infections ; Bacteriophages ; Flavobacterium ; Methods ; Osmeriformes ; Survival Rate

BACKGROUND: Lead and cadmium are harmful heavy metals that are used for a variety of occupational purposes. Considering their potentially hazardous effects on health, studies on the association between exposure to these two heavy metals and health disorders have been actively conducted. This study aimed to determine the association between blood lead and cadmium levels and blood pressure in workers exposed to lead and cadmium in a smelter. METHODS: Nine hundred and sixty-three male workers who worked in a smelter, and underwent medical examinations at the Ulsan University Hospital between January 1 and December 31, 2014, were selected as participants. Among them, 310 subjects whose data on height, weight, blood pressure, fasting blood glucose, lipid profile, and blood lead and cadmium levels were available and who answered the questionnaire were selected as the final participants. We investigated the drinking habit, smoking status, exercise adequacy, and family history of hypertension of these workers using formal questionnaires. A statistical analysis was conducted using Student's t-test, analysis of variance, and linear or logistic regression. RESULTS: The association between blood lead and cadmium levels and blood pressure was analyzed through statistical adjustment of the risk factors of hypertension. Results showed an association between blood cadmium level and blood pressure elevation. However, blood lead level was found to be not correlated with blood pressure elevation. CONCLUSIONS: This study shows the association between blood cadmium level and systolic blood pressure (SBP) and diastolic blood pressure (DBP) elevation. TRIAL REGISTRATION: IRB No. 2017–03-037. Retrospectively Registered 30 March 2017.
Blood Glucose ; Blood Pressure* ; Cadmium* ; Cross-Sectional Studies* ; Drinking ; Ethics Committees, Research ; Fasting ; Humans ; Hypertension ; Logistic Models ; Male ; Metals, Heavy ; Osmeriformes* ; Retrospective Studies ; Risk Factors ; Smoke ; Smoking ; Ulsan

Metagonimus yokogawai (Katsurada, 1912) Katsurada, 1912 (Trematoda: Heterophyidae) is parasitic in the small intestine of mammals including man and birds in Far Eastern Russia, Korea, Japan, China, and Taiwan. In the present study, the metacercariae and adults of M. yokogawai were redescribed to designate a neotype of this fluke together with reviews of previous studies including study histories from the first discovery to now. We particularly, attempted to review the study histories and morphological descriptions of M. yokogawai for the species validity, and compared with the morphological characteristics and life cycles of the closely related species, Metagonimus takahashii and Metagonimus miyatai. Finally, we proposed a differential key for the 8 known Metagonimus species distributed in East Asia. Metacercariae were obtained from the body muscles of sweetfish (Plecoglossus altivelis) collected in the Asahi River at Takebe-cho, Kita-ku, Okayama City, Okayama Prefecture, Japan. Adults were recovered from the small intestine of Syrian golden hamsters, to which the metacercariae had been fed 14 days before. A neotype was selected out of the present adult specimens. The Asahi River at Takebo-cho became the type locality of M. yokogawai. In conclusion, the present review shows that M. yokogawai, M. takahashii, and M. miyatai are valid and discriminated by means of morphological characteristics.
Animals ; Fish Diseases/parasitology ; Helminthiasis ; Heterophyidae/*anatomy & histology/*classification/isolation & purification ; Intestinal Diseases, Parasitic/veterinary ; Japan ; *Life Cycle Stages ; Mesocricetus/parasitology ; Microscopy ; Osmeriformes/parasitology ; Rodent Diseases/parasitology

Almost all heavy metals are serious toxicants as carcinogens. However, due to their chemical and physiological properties, heavy metals are useful in industrial areas including alloy, smelting and production of commercial products. Such applications increase the opportunity for heavy metal exposure. Waste from industrial processes is also a major source of environmental contamination and accumulation in the human body. Arsenic, cadmium, chromium, and nickel are classified as group 1 carcinogens by the International Agency for Research on Cancer, and are utilized commercially. In this review, we used molecular pathway analysis to understand the toxicity and carcinogenic mechanisms of these metals. Our analyzed data showed that above-mentioned metallic substances induce oxidative stress, DNA damage, and cell death processes, resulting in increase the risk of cancer and cancer-related diseases. Thus, we might think phytochelatin molecules and antioxidative phytochemical substances are helpful for prevention of heavy metal-induced cancer.
Alloys ; Arsenic ; Cadmium ; Carcinogens ; Cell Death ; Chromium ; DNA Damage ; Human Body ; International Agencies ; Metals ; Metals, Heavy ; Nickel ; Osmeriformes ; Oxidative Stress ; Phytochelatins

The present study was performed to determine the current infecion status of Metagonimus yokogawai metacercariae in sweetfish, Plecoglossus altivelis, collected from several streams in eastern and southern coastal areas of Korea. The sweetfish collected were artificially digested with pepsin-HCl solution and examined under a stereomicroscope in August and September, 2007. Out of 145 sweetfish collected from 10 streams in eastern coasts (Gangwon-do and Gye-ongsangbuk-do), 88 (60.7%) were infected with Metagonimus metacercariae. The average metacercarial density was 61 per infected fish. Among 141 sweetfish collected from 10 streams in southern coasts (Gyeongsangnam-do, Ulsan Metropolitan city, and Jeollanam-do), 140 (99.3%) were infected with Metagonimus metacercariae, and their average density was 949 per infected fish. The present study confirmed that M. yokogawai metacercariae are still prevalent in the sweetfish from several eastern and southern coastal localities. The prevalence and metacercarial density were much higher in the sweetfish from streams of southern coasts than in those of eastern coasts. Therefore, attention should be paid to this small fluke infection, and consumption of raw sweetfish naturally produced in these areas should be prohibited.
Animals ; Fish Diseases/*epidemiology/parasitology ; Heterophyidae/*isolation & purification ; Korea/epidemiology ; Metacercariae/isolation & purification ; Microscopy ; Osmeriformes/*parasitology ; Prevalence ; Trematode Infections/epidemiology/parasitology/*veterinary

In order to evaluate the genetic variability of the causative agent of cold water disease (CWD), plasmid profiling was used to characterize Flavobacterium (F.) psychrophilum isolates (n = 169). Size analysis of plasmids in F. psychrophilum isolates (n = 128) from several fish species demonstrated that six kinds of plasmids were harbored, and ayu isolates had different profiles compared to other isolates. Moreover, multiple isolates (n = 41) from CWD outbreaks in 2002 to 2003 at a single ayu farm were examined to determine differences between isolates from successive outbreaks and showed different profiles by the sources of seedlings.
Animals ; DNA, Bacterial/genetics ; Disease Outbreaks/*veterinary ; Electrophoresis, Agar Gel/veterinary ; Fish Diseases/genetics/*microbiology ; Flavobacteriaceae Infections/microbiology/*veterinary ; Flavobacterium/genetics/*isolation & purification ; Genetic Variation/*genetics ; Japan ; *Osmeriformes ; Plasmids/genetics

In order to determine the current infection status of pond smelts, Hypomesus olidus, and other freshwater fishes with trematode metacercariae, a total of 4,861 pond smelts and 18 other freshwater fishes, collected from the Soyang and Uiam Lakes in Gangwon-do, the Unam Lake in Jeollabuk-do, the Jangseong Lake in Jeollanam-do, the Uirim-ji (lake) in Chungcheongbuk-do, and the Andong Lake in Gyeongsangbuk-do, were individually digested with 1% pepsin-HCl and examined under a dissecting microscope. In all pond smelts caught from the 6 lakes, we were unable to detect any known human infectious trematode metacercariae in Korea. However, in other freshwater fishes, such as, Squalidus japonicus coreanus (Unam Lake), and Zacco platypus (Jangseong Lake) and Opsariichthys uncirostris amurensis (Jangseong Lake), metacercariae of human-infecting trematodes, i.e., Clonorchis sinensis and Metagonimus sp. were detected, respectively.
Trematode Infections/*veterinary ; Osmeriformes/*parasitology ; Korea ; Humans ; Fresh Water ; Fish Diseases/*parasitology ; Animals

The pond smelt Hypomesus olidus and minnow Zacco platypus were collected from the Soyang and Daechung Lakes in January 2003, and their metacercarial infections was examined by the muscle compression and artificial digestion techniques. In the Soyang Lake, 161 metacercariae of Clonorchis sinensis (0.35 per fish) were harvested from 459 pond smelts examined. Also, 13 metacercariae of C. sinensis (0.43 per fish), 1 of Metagonimus sp., 4 of Echinostoma sp., 148 of Centrocestus armatus and 44 unidentified species were collected from 30 minnows. In the Daechung Lake, 369 metacercariae of C. sinensis (3.69 per fish) and 51 unidentified species were recovered from 100 pond smelts. The metacercariae of C. sinensis were fed to experimental rats, in which the adult flukes were identified. The pond smelts and minnows collected from the Soyang and Daechung Lakes were verified to be the second intermediate hosts and the sources of human C. sinensis infection.
Animals ; Clonorchiasis/parasitology/*veterinary ; Clonorchis sinensis/growth & development/*isolation & purification ; Cyprinidae/*parasitology ; Fish Diseases/parasitology ; Fresh Water ; Host-Parasite Relations ; Korea ; Osmeriformes/*parasitology ; Rats ; Rats, Sprague-Dawley

OBJECTIVES: This study was performed to evaluate the relationship between biological markers of lead exposure and level of sex hormones in men occupationally exposed to lead. METHODS: In this study, 33 male workers who employed at smelting and battery factories were compared with 33 male workers who were not exposed to lead. As biological markers of lead exposure, hemoglobin, ZPP, blood lead and urine lead were measured. As sex hormones, FSH, LH, testosterone, SHBG and FTI were determined. RESULTS: Hemoglobin level was significantly lower in exposed than in nonexposed group. Level of ZPP, blood lead, and urine lead were significantly higher in exposed than in nonexposed group. There was a trend that level of FSH, testosterone, SHBG, and FTI was lower in exposed than in nonexposed group respectively, but there were no statistical significance. In exposed group, FSH level was correlated with age, ZPP, and blood lead; testosterone level was correlated with hemoglobin, blood lead, urine lead, and SHBG; and FTI level was correlated with age. CONCLUSIONS: Level of some sex hormones were lower in exposed than in nonexposed group but there were no statistical significance between the exposed and the nonexposed group. But level of sex hormones were correlated with several biological markers of lead in exposed group. It suggests that occupational lead exposure might affect sex hormones.
Biological Markers ; Gonadal Steroid Hormones* ; Humans ; Male* ; Occupations ; Osmeriformes ; Testosterone