Risk assessment of di(2-ethylhexyl) phthalate in the workplace

OBJECTIVES: A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. METHODS: Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor (“Survey on the work environment”) and by the Ministry of Environment (“Survey on the circulation amount of chemicals”). Risk was determined according to exposure in workplaces and chemical hazard. RESULTS: In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be 0.990 mg/m³, as compared to the threshold exposure level of 5 mg/m³. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. CONCLUSIONS: DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below 5 mg/m³ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

Oxidative DNA Damage from Nanoparticle Exposure and Its Application to Workers' Health: A Literature Review

The use of nanoparticles (NPs) in industry is increasing, bringing with it a number of adverse health effects on workers. Like other chemical carcinogens, NPs can cause cancer via oxidative DNA damage. Of all the molecules vulnerable to oxidative modification by NPs, DNA has received the greatest attention, and biomarkers of exposure and effect are nearing validation. This review concentrates on studies published between 2000 and 2012 that attempted to detect oxidative DNA damage in humans, laboratory animals, and cell lines. It is important to review these studies to improve the current understanding of the oxidative DNA damage caused by NP exposure in the workplace. In addition to examining studies on oxidative damage, this review briefly describes NPs, giving some examples of their adverse effects, and reviews occupational exposure assessments and approaches to minimizing exposure (e.g., personal protective equipment and engineering controls such as fume hoods). Current recommendations to minimize exposure are largely based on common sense, analogy to ultrafine material toxicity, and general health and safety recommendations.

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.

Toxicity of Methylcyclohexane and Its Effect on the Reproductive System in SD Rats

OBJECTIVES: There is limited data regarding the toxicity of methylcyclohexane, despite its wide use in rubber adhesives, paint diluents, and cleansing agents. This study aimed to verify the toxicity and influence on the reproductive system of methylcyclohexane after its repeated injection in Sprague Dawley (SD) rats. METHODS: Methylcyclohexane was injected subcutaneously into male and female SD rats once a day, five times a week, for 13 weeks at different doses (0, 10, 100, and 1,000 mg/kg/day) for each group. The toxicity of testing material was verified by observing the change in body and organ weight, hematological change, pathological findings, and effect on the reproductive system at each different concentration. RESULTS: In the 1,000 mg/kg/day group, there were cases of animal deaths. In animals that survived, hematological changes, including a decrease in the red blood cell count, were observed. A considerable weight gain or loss and pathological abnormalities in the liver, kidney, and other organs were found. However, the 10 and 100 mg/kg/day groups did not cause deaths or other specific abnormalities. In terms of reproductive toxicity, there were changes in hormone levels, including a significant decrease in hormones such as estradiol and progesterone (p < 0.001) in male animals. Menstrual cycle change for female animals did not show concentration dependency. CONCLUSION: When injected repeatedly for 13 weeks, methylcyclohexane proved to be toxic for the liver, heart, and kidney at a high dose. The absolute toxic dose was 1,000 mg/kg/day, while the no observed adverse effect level was less than 100 mg/kg/day. The substance exerted little influence on the reproductive system.

Acute and Subchronic Inhalation Toxicity of n-Octane in Rats

OBJECTIVES: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. METHODS: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). RESULTS: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. CONCLUSION: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.

Appendiceal Mucocele

Appendiceal mucocele is a cystic dilatation of the appendiceal lumen with mucus, which may be caused by either benign or malignant diseases. In this report, five cases of appendiceal mucocele are reported, three of which had a preoperative diagnosis of mucocele, whereas the others were found incidentally during the operation under the diagnosis of intussusception and periappendiceal abscess. All five patients underwent surgical resections, including one ileocecal resection and four right hemicolectomies. Histopathology revealed a mucinous cystadenoma in four cases, and a mucinous cystadenocarcinoma in one. There was no disease-related death during 18 months of follow-up.

Effects of Biophysical Index, Knowledge, and Self Management Compliance of Patients with Primary Hypertension by a Self Management Compliance Promotion Program / 간호학회지

PURPOSE: This study was to develop and prove the effects of aself management compliance promotion program for primary hypertension patients who reside in rural communities. METHOD: The content of the self management compliance promotion program developed by this study was as follows: A leader trains patients as a group or individually, in walking, education and green tea therapy from the first to twelfth week. From the thirteenth to twenty fourth week, the patients should perform walking and green tea therapy by themselves. One hundred twenty subjects volunteered to participate in the study, who were among those registered as hypertension patients in the 14 community health clinics located in Chungcheongbuk-do. RESULT: Systolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, triglyceride, step width, and degree of obesity decreased significantly. High-density lipoprotein cholesterol, step length, knowledge of hypertension, and self management compliance significantly increased. CONCLUSION: A self management compliance promotion program for primary hypertensive patients enhances biophysical index and knowledge on hypertension, thus ultimately suggesting a nursing intervention for promoting self management compliance.

Inhalation effect of 1,1-dichloro-1-fluoroethane (HCFC-141b) on the respiratory system / 천식및알레르기

BACKGROUND: 1,1-dichloro-1-fluoroethane (HCFC-141b) has been known to be relatively safe except irritation of the skin and upper airway, and pulmonary disease directly associated with HCFC-141b exposure has not been reported yet. OBJECTIVE: We report a highly suspicious case of HCFC-141b-related occupational asthma, which was assessed by workplace challenge, but not confirmed by specific inhalation test. We also performed animal experiment to evaluate whether long-term exposure to HCFC-141b could cause inflammation of the airway and parenchymal lung tissue. METHOD: Forty Sprague-Dawley rats were divided into 4 groups. HCFC-141b exposure for each group was carried out under the condition of 6 hours a day, 5 days a week for 13 weeks by inhalation with different concentration of HCFC-141b; Group A-control: Group B-low concentration, 1500 ppm: Group C-moderate concentration, 3000 ppm: and Group D-high concentration, 6000 ppm. Bronchoalveolar lavage (BAL) and histopathological examination of lung tissue was undertaken after HCFC-141b exposure. RESULTS: HCFC-141b did not induce any abnormal change in the clinical and behavioral signs during and at the termination of the inhalation exposure. Compared with control rat, significantly abnormal findings in the microscopic examination of BAL and tissue preparations was not noted in HCFC-141b exposed rats. CONCLUSION: We report a suspicious case of occupational asthma due to HCFC-141b exposure. Animal experiment, however, revealed that HCFC-141b has no toxic or side effect on the respiratory system regardless of its concentration.

Effects of Exposure to Hexavalent Chromium on the Level of 8-Hydroxydeoxyguanosine and the Activities of Superoxide Dismutase and 8-Hydroxyguanine Endonuclease in Rat Lung / 예방의학회지

OBJECTIVES: To determine the effects of exposure to hexavalent chromium, 93 male Sprague-Dawley rats were exposed to hexavalent chromium solution. METHODS: Rats were divided into 4 groups and exposed to 0.1 ml of 0 mM, 0.4 mM, 2.0 mM, and 10.0 mM potassium chromate in the first experiment, and to 0.1 ml of 0 mM, 20 mM, 40 mM, and 80 mM in the second for consecutive 3 days by tracheal instillation. Three and 10 rats were the controls for the first and the second experiments, respectively. Lung tissues were then removed to measure the 8-hydroxydeoxyguanosine (8-OH-dG) level using the HPLC-ECD method, superoxide dismutase (SOD) activity using the cytochrome C method, and 8-hydroxyguanine endonuclease activity using the oligonucleotide nicking assay. RESULTS: The results showed no significant linear relationship between chromium exposure level and 8-OH-dG level or 8-hydroxyguanine endonuclease activity. In the first experiment, 8-OH-dG level and 8-hydroxyguanine endonuclease activity increased in 0.4 mM group, and then decreased in 2.0 mM and 10.0 mM groups. The correlation coefficients between 8-OH-dG level and 8-hydroxyguanine endonuclease activity was statistically significant (P<0.01), and total SOD activity was elevated by chromium exposure in a dose-dependent manner (P<0.05). In contrast, there was no significant dose-response pattern or correlation in the second experiment. CONCLUSIONS: Based on the fact that there was no linear relationship between chromium dose and 8-OH-dG level or activity of the repair enzyme, it seems unlikely that 8-OH-dG formation is the major mechanism of chromium carcinogenesis.