• Journal of Radiation Protection and Research
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• v.31 no.3
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• pp.135-140
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• 2006

Intakes of radionuclides through both inhalation and ingestion pathways may occur particularly in an incident involving unsealed radionuclides. If one assume only one intake path in this case, which is usual in routine monitoring, a significant error in the evaluated committed effective dose($E_{50}$) may result. In order to demonstrate the potential errors, variations of the resulting committed effective doses were analyzed for different fractions of the inhaled activities to the total intake of $^{241}Am$. Simulated bioassav measurements for the lungs, urine and feces were generated based on the biokinetic model and data of the radionuclide, 5 ${\mu}m$ AMAD and absorption type M for inhalation, for various inhalation fractions. The potential errors in $E_{50}$ due to the assumption of one intake path were in the range from -100% to as large as +34,000% when the bioassays were made 3 days after the intakes. Larger errors are expected when only the feces assay is applied while inhalation intake exists. A strategy which employs two types of bioassay was proposed to reduce the error caused by a misjudgement of the intake path.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.84-89
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• 2023

Background: Food consumption is one of the most important routes for radionuclide intake for the public; therefore, there is the need to have a comprehensive understanding of the amount of radioactivity in food products. Consumption of radionuclide-contaminated food could increase potential health risks associated with exposure to radiation such as cancers. The present study aims to determine radioactivity levels in some food products (milk, rice, sugar, and wheat flour) consumed in Mali and to evaluate the radiological effect on the public health from these radionuclides. Materials and Methods: The health impact due to ingestion of radionuclides from these foods was evaluated by the determination of activity concentration of radionuclides ²³⁸U, ²³²Th, ⁴⁰K, and ¹³⁷Cs using gamma spectrometry system with high-purity germanium detector and radiological hazards index in 16 samples collected in some markets, mall, and shops of Bamako-Mali. Results and Discussion: The average activity concentrations were 9.8±0.6 Bq/kg for ²³⁸U, 8.7±0.5 Bq/kg for ²³²Th, 162.9±7.9 Bq/kg for ⁴⁰K, and 0.0035±0.0005 Bq/kg for ¹³⁷Cs. The mean values of radiological hazard parameters such as annual committed effective dose, internal hazard index, and risk assessment from this work were within the dose criteria limits given by international organizations (International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation) and national standards. Conclusion: The results show low public exposure to radioactivity and associated radiological impact on public health. Nevertheless, this study stipulates vital data for future research and regulatory authorities in Mali.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.12-27
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• 2004

The contamination pattern of indoor air was simulated when groundwater dissolving benzene was used for household activities. Indoor exposure scenario consisted of inhalation, ingestion, and dermal absorption. Physiologically based pharmacokinetic (PBPK) model was used to analyze how benzene exposed to human body was distributed in internal organs. Main exposure pathways contributing total internal dose were inhalation and ingestion while the contribution of dermal absorption was very small. Man showed higher exposure rate than woman due to his higher breath rate. For a short-term exposure, benzene concentration in venous blood of SPT, RPT and liver changed rapidly while slowly did in venous blood of adipose tissue at a low concentration. For a long-term exposure, woman accumulated about 2.1 times higher than man. Most of benzene exposed to human body was removed by exhalation and metabolism at lung and liver, respectively. For inhalation and ingestion, the benzene removals by exhalation were 69.8 and 48.4%, respectively. Relative importance of removal mechanism was different according to the inflow displacement of benzene. The results obtained from this study would help understand exposure, distribution, and removal phenomena and make plans for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.31-41
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• 1997

Public concerns about hazardous health effect from the exposure to organic by-products of the chlorination have been increased. There are numerous studies reporting that chlorination of drinking water produces numerous chlorinated organic by-products including THMs, HAAs, HANs. Some of these products are known to be animal carcinogens. The purpose of this study was to estimate health risk of DBPs by chlorinated drinking water ingestion in Seoul based on methodologies that have been developed for conducting risk assessment of complex-chemical-mixture. The drinking water sample was collected seperately at six water treatment plant in Seoul at March, April, 1996. In tap water of households in Seoul, DBPs were measured wilfh the mean value of 36.6 $\mu$g/L. Risk assessment processes,. which include processes for the estimation of human cancer potency using animal bioassay data and calculation of human exposure, entail uncertainties. In the exposure assessment process, exposure scenarios with various assumptions could affect the exposure amount and excess cancer risk. The reference dose of haloacetonitriles was estimated to be 0.0023 mg/kg/day by applying dibromoacetonitrile NOAEL and uncertainty factor to the mean concentration. In the first case, human excess cancer risk was estimated by the US EPA method used to set the MCL (maximum contaminant level). In the second and third case, the risk was estimated for multi-route exposure with and without adopting Monte-Carlo simulation, respectively. In the second case, exposure input parameters and cancer potencies used probability distributions, and in the third case, those values used point estimates (mean, and maximum or 95% upper-bound value). As a result, while the excess cancer risk estimated by US EPA method considering only direct ingestion tended to be underestimated, the risk which was estimated by considering multi-route exposure without Monte-Carlo simulation and then using the maximum or 95% upper-bound value as input parameters tended to be overestimated. In risk assessment for Trihalomethanes, considering multi-route exposure with adopting Monte-Carlo analysis seems to provide the most reasonable estimations.

• Journal of Yeungnam Medical Science
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• v.29 no.2
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• pp.121-124
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• 2012

Valaciclovir is metabolized to acyclovir after ingestion and thereafter exerts its antiviral activity. Because of its superior pharmacokinetic profile, it has quickly replaced acyclovir in the treatment of herpesvirus infection. Neurotoxicity caused by valaciclovir has been reported, however, among patients with pre-existing impaired renal function. This paper reports a case of neurotoxicity of valaciclovir in a patient with end-stage renal disease who was undergoing continuous ambulatory peritoneal dialysis (CAPD). A 67-year-old female on CAPD took 500 mg of valaciclovir twice for herpes zoster. After she took her second dose orally, she developed confusion and disorientation, along with involuntary movements. Her mental confusion progressed to a coma. Discontinuation of valaciclovir showed no rapid improvement. There- fore, hemodialysis was started. After two sessions of hemodialysis, the patient became alert; and after four sessions of hemodialysis, her neurological abnormalities were completely reversed. In conclusion, valaciclovir can induce life-threatening neurotoxicity, especially in CAPD patients, even with appropriate dose reduction, which can be effectively managed by hemodialysis.

• Applied Microscopy
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• v.36 no.1
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• pp.17-23
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• 2006

The pregnant rats were given a drinking water administration of the sodium fluoride and normal saline for control animals. The sodium fluoride produced cellular changes of odontoblast with consistent response. Compare to control group, the odontoblasts that were administrated by sodium fluoride, showed significantly ultrastructural differences including large number of free ribosomes and swelled mitochondria in dose-dependent manner (300 ppm). From fine structural and morphological investigations of the changes in odontoblast, there were three distinctive structural changes: (1) destruction of the endoplasmic reticulum, (2) swelling of the mitochondria, and (3) severe cellular derangement of the endoplasmic reticulum and mitochondria. From this consecutive structural change, we observed that sodium fluoride temporarily affects the cell organelles in odontoblasts (100, 200 ppm), suggesting it is important that optimal concentration of the sodium fluoride in developing fetus of the rat.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.3046-3053
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• 2023

Radon is a naturally occurring carcinogenic agent, poses a serious health hazard when inhaled or ingested in significant amounts. The water of the Padma river will be used as a tertiary coolant for the soon-to-be-commissioned 'Rooppur Nuclear Power Plant'. Hence, it is important to assess the radiological status of the river prior to the commission of this power plant. Therefore, for the first time, 25 samples of water were collected from various locations of the Padma River and analyzed for radon concentration using the RAD H₂O (DURRIDGE) radon monitoring device. The radon concentrations were found in the range from 0.077 ± 0.036 to 0.494 ± 0.211 Bq/L with a mean of 0.250 ± 0.093 Bq/L. All the concentrations were found to be below the recommended limits of WHO (100 Bq/L) and USEPA (11.1 Bq/L). The mean annual effective dose due to the radon exposure via inhalation and ingestion pathways were 0.638 µSv/y and 0.629 µSv/y, respectively, which were all well below the annual effective dose recommended by WHO (0.1 mSv/y). Since Bangladesh lacks a national safety limit of radon in water, this pioneering study provides baseline data on radon levels for the environment around Rooppur Nuclear Power Plant.

• Parasites, Hosts and Diseases
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• v.55 no.1
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• pp.61-64
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• 2017

We described a human case of zoonotic dog tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), rarely occurring in China. The mother of a 17 month-old boy noted the appearance of small white and active worms over a month period in her son's feces, but the boy was asymptomatic except mild diarrhea. We observed 3 tapeworm proglottids resembling cucumber seeds in his stool sample. Microscopically, each proglottid had 2 genital pores, 1 on each lateral edge, and numerous egg capsules in the uterus. The patient was successfully treated with a single oral dose of praziquantel. Adult worms were recovered in the diarrheic stool after praziquantel treatment and purgation. His family had household pet dogs for several years, and he might have acquired the infection by ingestion of infected fleas of his pet dogs. A history of dog or cat pets and flea bites may be important clues to diagnosis of D. caninum infection. The infected pets should also be treated.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.1
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• pp.1-10
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• 2020

Pharmaceutical agents are the most common causes of poisoning in Korea. Calcium channel blockers (CCBs) are commonly used in Korea for the management of hypertension and other cardiovascular diseases, but are associated with a risk of mortality due to overdose. Due to the frequent fatalities associated with CCB overdose, it is essential that the emergency physician is capable of identifying CCB intoxication, and has the knowledge to manage CCB overdose. This article reviews the existing clinical guidelines, retrospective studies, and systematic reviews on the emergency management of CCB overdose. The following are the varied treatments of CCB overdose currently administered. 1) For asymptomatic patients: observation with enough time and decontamination, if indicated. 2) For symptomatic patients: infusion of calcium salt, high dose insulin therapy, and vasopressor (norepinephrine) or atropine for bradycardia. 3) For patients refractory to the first line therapy or with refractory shock or impending arrest: lipid emulsion therapy and extracorporeal membrane oxygenation. 4) As adjunct therapy: phosphodiesterase inhibitors, glucagon, methylene blue, pacemaker for AV block. Small CCB ingestion is known to be fatal for pediatric patients. Hence, close observation for sufficient time is required.

• Journal of Yeungnam Medical Science
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• v.32 no.1
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• pp.17-21
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• 2015

Amlodipine, a calcium channel blocker of the dihydropyridine group, is commonly used in management of hypertension, angina, and myocardial infarction. Amlodipine overdose, characterized by severe hypotension, arrythmias, and pulmonary edema, has seldom been reported in Korean literature. We report on a fatal case of amlodipine intoxication with complications including rhabdomyolysis and oliguric acute kidney injury. A 70-year-old woman with a medical history of hypertension was presented at the author's hospital 6 hours after ingestion of 50 amlodipine (norvasc) tablets (total dosage 250 mg) in an attempted suicide. Her laboratory tests showed a serum creatinine level of 2.5 mg/dL, with elevated serum creatine phosphokinase and myoglobin. The patient was initially treated with fluids, alkali, calcium gluconate, glucagon, and vasopressors without a hemodynamic effect. High-dose insulin therapy was also started with a bolus injection of regular insulin (RI), followed by continuous infusion of RI and 50% dextrose with water. Despite intensive treatment including insulin therapy, inotropics, mechanical ventilation, and continuous venovenous hemodiafiltration, the patient died of refractory shock and cardiac arrest with no signs of renal recovery 116 hours after her hospital admission.