This study was conducted to investigate of water qualities in the upper and middle reaches of the Han River. For this purpose, water was sampled at Kwangjin and 1st Han-River Bridges of the Han River in Seoul and analysed from August, 1988 to September, 1989. The results are summarized as follows: 1. Water quality at 1st Han-River Bridge was more polluted than that at Kwangjin Bridge. 2. Except biological oxygen demand (BOD), turbidity, suspended solid (SS), dissolved oxygen (DO), DO saturation (DOS), ammonia nitrogen (NH3-N), nitrite nitrogen (NO2-N) and chloride ion (Cl-) at Kwangjin and 1st Han-River Bridges were lower as compared with the previous data before redevelopment of the Han River. 3. SS, DO and pH at Kwangjin and 1st Han-River Bridges could be classified to the 1st grade in environmental water quality standard. DOS at Kwangjin Bridge was over 100% and that at 1st Han-River Bridge was below 100% in the Han River. BOD at Kwangjin Bridge could be classified to 2nd grade and that at 1st Han-River Bridge to 3rd grade in environmental water quality standard. 4. The higher the level of water was, the lower the levels of turbidity and SS, and NH3-N was decreased with increasing water level at 1st Han-River Bridge. DO was decreased as water temperature went up but DOS was increased with DO. BOD was positively correlated with nitrite-nitrogens. 5. Turbidity and SS at the both sites and Chloride ion (Cl-) at Kwangjin Bridge were increased in July and August. And DO at the both sites and NH3-N at 1st Han-River Bridge were decreased in at July and August.
Ammonia ; Biological Oxygen Demand Analysis ; Hydrogen-Ion Concentration ; Nitrogen ; Oxygen ; Rivers ; Seasons* ; Seoul ; Water Quality ; Water*

Adult ; Female ; Humans ; Hyperthyroidism ; drug therapy ; metabolism ; Iodine Radioisotopes ; pharmacokinetics ; therapeutic use ; urine ; Male ; Middle Aged ; Models, Biological ; Radiation Dosage ; Radiation Monitoring ; Radiopharmaceuticals ; pharmacokinetics ; therapeutic use ; urine ; Radiotherapy Dosage ; Young Adult

Animals ; Cells, Cultured ; Environmental Monitoring ; methods ; Humans ; Models, Animal ; Models, Biological ; Population Surveillance ; methods

Electromagnetic Fields ; adverse effects ; Environmental Exposure ; adverse effects ; Humans ; Occupational Exposure ; adverse effects ; Radiation Monitoring ; methods ; Risk Assessment

OBJECTIVETo measure the endocrine disrupting chemicals (EDCs) in wastewater and evaluate the EDCs removal efficiencies in the municipal wastewater treatment plants (WWTP).

METHODSA battery of in vitro recombinant yeast bioassays incorporated with exogenous metabolic activation system (rat liver preparation, S9 mix) was conducted to assess the estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR), and thyroid receptor (TR) ant/agonistic activities of effluents collected from Datansha WWTP.

RESULTSThe indirect estrogenic, anti-androgenic, anti-progesteronic, and anti-thyroidic activities were observed in the influent. The removal efficiencies of EDCs were above 74%, suggesting that the present wastewater treatment processes were good enough to remove most of these indirect endocrine disrupting chemicals.

CONCLUSIONThe incorporation of exogenous metabolic capacity into the test system was valid for the study of indirect effects on ER, AR, PR, and TR.

Biological Assay ; methods ; Endocrine Disruptors ; chemistry ; toxicity ; Environmental Exposure ; Environmental Monitoring ; methods ; Saccharomyces cerevisiae ; genetics ; metabolism ; Waste Disposal, Fluid ; methods ; Water ; chemistry ; Water Pollutants, Chemical ; toxicity ; Water Purification ; standards

OBJECTIVETo investigate the annual effective doses from indoor radon received by academic staff in the Faculty building.

METHODSMeasurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylül University for two surveys of about 1 month duration respectively using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building: classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon.

RESULTSThe arithmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose.

CONCLUSIONReported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.

Air Pollution, Indoor ; analysis ; Environmental Monitoring ; Faculty ; Housing ; statistics & numerical data ; Humans ; Radiation Dosage ; Radon ; analysis ; Risk Assessment ; Turkey ; Universities ; statistics & numerical data

OBJECTIVESTo investigate intensity of extremely low frequency magnetic field (ELFMF) emitted from cathode-ray tubes (CRT) of monitors in various directions and to find ways to avoid its influence.

METHODSTwo hundred CRT monitors and 10 monitors with liquid-crystal display (LCD) were selected. Their ELFMF was detected for three times in front of the monitor at an interval of every 5 cm from 0 cm to 50 cm, as well as at various directions from the monitor.

RESULTSIntensity of ELFMF significantly attenuated at regular operating position (30 - 40 cm) from 0 cm to 50 cm in front of both 38 cm and 43 cm CRT monitors (P < 0.05). Intensity exceeded 0.4 microT both within 15 cm and 10 cm in front of 38 cm and 43 cm monitors. The highest intensity was found at the upright top position of both kinds of monitors, 9.54 microT for 38 cm monitor and 6.38 microT for 43 cm one, respectively.

CONCLUSIONSIt is suggested to keep away from monitor screen as possible when operating a computer, to reduce unnecessary operation in front of a monitor screen, and to shorten operating time. To avoid more hazards from interactive interference between computers, it is necessary to increase distance between monitors.

Computers ; Electromagnetic Fields ; adverse effects ; Environmental Exposure ; adverse effects ; Equipment Safety ; Humans ; Occupational Exposure ; adverse effects ; Radiation Monitoring ; methods ; Risk Assessment

OBJECTIVEThis work explores the diurnal variation of Solar ultraviolet radiation (UVR) and total solar radiation (TSR) in northeast China, using daily observations of UVR and TSR in Shenyang.

METHODSUVR and TSR measurements were carried out from March 1st, 2006 to December 31st, 2009 in Shenyang, Liaoning province, China (41°51' N, 123°27' E).

RESULTSBoth TSR and UVR showed seasonal variation, reaching the highest levels in summer and the lowest in winter. They showed the greatest fluctuation in summer and autumn. The irradiance of TSR and UVR on clear days around the equinoxes and solstices increased substantially compared with the mean seasonal irradiance, especially in autumn. The whole day accumulated dose of UVR in winter was far less than that during the middle part of a summer day (i.e. between 10:00 and 14:00). It was also less than the accumulated summer dose of morning and afternoon (i.e. between 8:00 and 10:00 and 14:00 and 16:00).

CONCLUSIONThe instant irradiance and daily accumulated amount of UVR are low in Shenyang, especially in autumn and winter. Thus concern about the health effects arising because shortage of UVR in northeast China is warranted.

China ; Radiation Monitoring ; Seasons ; Sunlight ; Ultraviolet Rays

The paper is focused on a kind of portable monitor that is widely used in military hospitals. In order to study the electromagnetic radiation immunity of the monitor, the experiments of electromagnetic radiation caused by radio frequency continuous wave in reverberation chamber and by ultra wide band (UWB) electromagnetic pulse have been done. The study results show that UWB electromagnetic pulse interferes observably the operating state of the monitor. It should be paid high attention to take protective measures. The monitor tested has some electromagnetic immunity ability for radio frequency continuous wave radiation. The frequent abnormal phenomena are baseline drift and waveform distortion. The electromagnetic sensitivity of the monitor is related to the frequency of interference source. The monitor tested is most sensitive to the frequency of 390 MHz.
Electromagnetic Fields ; Electromagnetic Radiation ; Monitoring, Physiologic ; instrumentation

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.
Clothing ; Gamma Rays* ; Isotopes ; Radiation Monitoring ; Semiconductors