Cesium-137 Contaminated Roads and Health Problems in Residents: an Epidemiological Investigation in Seoul, 2011

BACKGROUND: In 2011, two roads in a residential area in Seoul were found to be contaminated with the radionuclide cesium-137 (137Cs). In response to public concerns, an epidemiological study was conducted. METHODS: The standardized cancer incidence ratios in the affected and neighboring regions were calculated based on the central cancer registry. Households in the region were sampled using the random stratified sampling technique, and questionnaires were administered to family members, via home visit and via students in elementary to high schools. Information on duration of residency and frequency of use of the roads was applied to calculate cumulative radiation exposure dose from the roads, alongside with the reported 137Cs contamination amounts. Information on past medical history, perceived risk, anxiety and psychological stress was also obtained. Of the 31,053 residents, 8,875 were analyzed. To examine possible associations between radiation exposure and health problems, logistic regression adjusted for covariates were performed with consideration of the sampling design, population weight and stratification. RESULTS: No significant association was found between self-informed diseases, including cancers, and estimated radiation exposure dose. According to an increase of radiation level, a significant increase in anxiety in all and a decline in the psychosocial wellbeing of the adults was noted. The risk perception level was higher in the elderly, females, the less educated, and the highest exposed individuals. CONCLUSION: This study provides a basis for risk communication with residents and community environmental health policy.

Assessment of radiation exposure from cesium-137 contaminated roads for epidemiological studies in Seoul, Korea

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

Assessment of radiation exposure from cesium-137 contaminated roads for epidemiological studies in Seoul, Korea

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

Slot Correction by the Frechet Flaps in Hair Restoration Surgery

PURPOSE: A common side effect of the scalp reduction is a creation of a 'slot' with the hair growing in the opposite directions away from the scar. Overcoming the unnatural appearance of the slot has been a vexing problem in the scalp reduction surgery. None of the conventional corrective surgical techniques provides a complete and satisfactory aesthetic result. The Frechet flap is a triple transposition flap used for the correction of the slot defect secondary to scalp reduction surgery, seldom needing further scar revision. The Frechet technique provides a solution to the problem of the central slot concealment that is unattainable by other means, such as; Z-plasty and mini-graft. METHODS: Authors applied the Frechet technique to Asian patients who had undergone scalp reduction and operated on 4 patients from March, 2000 to January, 2001. Average follow-up period was 13 months. Patients with long scars passing through the temporoparietoccipital zone were excluded. All the undermining was performed in the subgaleal plane, reaching the upper auricular sulcus and stopping just above the nuchal ridge. RESULTS: None of the patients experienced infection, hematoma, nor any permanent hair loss. Transient telogen effluvium at the distal end of flap 2 and 3 was noticeable in one case. CONCLUSION: In conclusion, the results are aesthetically satisfactory without any significant complications.

The Removal of Plates after Craniomaxillofacial Surgery: A Retrospective Study

PURPOSE: Plate systems have been used for osteosynthesis of cranial and oromaxillofacial fracture. However, there is no consensus on the need for routine removal of plate and the question about indications of removal. Therefore, we present the retrospective study to clarify the indications and consensus of removal. METHODS: The medical records of patients who were treated with rigid internal fixation using plates after craniofacial trauma were reviewed. Study variables included age, gender, type of fracture, type of plate, seniority of the operator, causes of removal, and time between insertion and removal. All results amendable to statistics were analyzed using SPSS 10.0 to determine which set of variables might affect the fate of the plates. RESULTS: For a period of 10 years (March 1, 1994 through July 31, 2004), total of 41 plates(6.7%) were removed among 609 plates inserted into 419 patients; 27 plates were removed from 15 patients for infection, which is the most common cause of removal accounting for 65.8%. Mean time between insertion and removal is 35.2 months and mean age is 41.4 years. Most plates were removed from combined fracture(14.92%) and facial fracture(8.47%) and these were statistically significant. The age, gender, seniority of the operator and other variables were not statistically associated with plate removal. CONCLUSION: This retrospective study shows that routine removal does not appear to be clinically indicated due to respectively low removal rate and that the commonest indications for removal were infection.

The Effect of Coating Process of Titanium Plates on the Osteoblast Proliferation and Collagen Synthesis

Titanium plates are becoming widely used as a craniomaxillofacial plating system since they provide rigid fixation. Fairly extensive publications have been reported about the techniques of internal fixation, the evolution of the principles, and facial fracture biomechanics. However, the influence of coating process on bone healing has not been determined yet. The coating process consists of several stages-cleansing, preparation to remove oxidative membrane, coating process by an electric arc and thermodynamic stabilization. Among these, coating process influences chemical property of titanium implants. This study was designed to compare the effect of coating process of titanium plates on the bone healing in vitro using four internationally available titanium plates. Human fetal osteoblast cell line was cultivated. Five thousand osteoblasts per well were incubated in a 96-well culture plate with either one of four titanium plates(Osteomed silver plate(r), Osteomed gold plate(r), Jeil silver plate(r), Jeil gold plate(r)) on top. The medium used in this study was Dulbecco's Modified Eagle's Medium including 5% fetal bovine serum and the titanium plates were cut into squares with 4mm in length. On the 4th day of plating, osteoblast proliferation was determined by MTT method. To measure the production of collagen, the collagen type I carboxy-terminal propeptide enzyme immunoassay was used. Each titanium plate was tested 16 times. There were few differences among control and gold plate groups in osteoblast proliferation and collagen synthesis. However, the silver titanium groups showed less osteoblast survival and collagen synthesis than control and gold titanium groups. Between Osteomed (Addison, TX, U.S.A.) and Jeil Medical(Seoul, Korea) plates, no significant difference was seen in both silver and gold plate groups. These results demonstrated that the coating process of titanium plates could influence the bone healing, and the gold plates were superior to the silver plates on alone culture model.

Comparison of Effect of Polyurethane Foam Dressings on Epithelialization of White Rat

Polyurethane foam dressings are becoming widely used in partial and full thickness skin wounds since they are safe and convenient for both patients and physicians. However, the influence of polyurethane foam dressings on epithelialization has not been fully determined yet. This study was designed to compare 2 internationally available polyurethane foams and 3 locally made polyurethane foams as to their effects on the epithelialization in vivo. Twenty white rats were used. A 5 mm punch was employed to excise skin and subcutaneous tissue in a round fashion at six sites in the back area of 10 rats. After creating 6 open wounds, above mentioned 5 polyurethane foams and gauze dressings were applied. On the 5th day the lengths of the nonepithelialized area were measured under light microscope. In addition, partial thickness wounds were created using carbon dioxide laser at six sites on the back of the another 10 rats. Six dressings were applied on the wounds as same as above. On the 4th day the degree of the epithelialization was measured and compared. In full thickness wound study the best wound closing was also seen in chitin mixed Medifoam-N group. In partial thickness wound study the best epithelialization was seen in chitin mixed Medifoam-N and chitosan mixed Medifoam-N groups. These results demonstrated that polyurethane foam dressings influenced the epithelialization, and chitin mixed Medifoam-N showed the best result.