Exposure Estimates to Disinfection By-products of Chlorinated Drinking Water

Weisel.Clifford P 강원대학교 환경연구소 1999 環境硏究 Vol.16 No.-

Chloroform Body Burden From Swimming In Indoor Swimming Pools

Jo, Wan Kuen,Weisel, C. P. 한국환경과학회 1995 한국환경과학회지 Vol.4 No.4

The use of chlorinated water in swimming pools produces elevated chloroform levels in the water and air of the pools which can cause chloroform body burden of swimming individuals. Present study confirmed the chloroform body burdens from a 40-min swimming and evaluated the decay of chloroform breath concentration after the cessation of a 60-min swimming. Air and water concentrations were measured in the pools. The water and air chloroform concentrations ranged from 18.1 to 25.3 ㎍/ℓ and from 30.9 to 60.7 ㎍/㎥ for the confirmation study, respectively. The breath level after 40-min swimming was about 64 to 266 folds higher than the corresponding background breath. The breath concentration after the 40-min swimming ranged from 10.5 to 21.3 ㎍/㎥, while that prior to the corresponding swimming ranged from 0.07 to 0.19 ㎍/㎥. In addition, the post-exposure breath level varied with the subjects who swam in the pool on the same visiting day. Breath concentration increased gradually during 60-min swimming, then decreased rapidly within 5 minutes after the cessation of exposure, after that, decreased slowly, and finally approached to a background breath level at 1-2 hr after exposure.

DERMAL ABSORPTION OF DICHLORO : AND TRICHLOROACETIC ACIDS FROM CHLORINATED WATER

KIM, HEKAP,CLIFFORD P. WEISEL 江原大學校 附設 環境硏究所 1999 環境硏究 Vol.16 No.-

Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) are major nonvolatile disinfection by-products of water chlorination. These compounds are currently being considered for regulation because of potential adverse health effects. In the current study, DCAA and TCAA dermal exposures were investigated in four human subjects during a thirty minute walk or swim in a pool by measuring the pool water concentrations and urinary excretion rates of DCAA and TCAA. These two compounds were eliminated in urine within approximately 3 hours of the exposure, with the dermal DCAA dose being ~6 ㎍ from pool water containing 600 ㎍/L. The amount of water ingested by each subject during a 30 minute swim was estimated to be between 12 and 45 mL. The DCAA permeability coefficient at pH 7 was calculated to be between 1 and 8×10^(-3) ㎝/h, when assuming that only 3% of the dermal dose, as was observed for ingestion, was excreted and between 2 and 9×10^(-5) ㎝/h, assuming that 48% of the dermal dose, an upper limit, was excreted. Exposure estimates indicate that ingestion is the major route of exposure and that the dermal contribution during typical household uses is a minor contributor to the total exposure of these compounds from chlorinated drinking water.

Parameters Affecting Indoor Air Exposure to Volatile Organic Compounds

Jo, W. K.,Weisel, C. P. 한국환경과학회 1992 한국환경과학회지 Vol.1 No.1

Volatile organic compounds(VOC_s) present in the VOCs-contaminated water are released to air while showering and their air concentrations depend on the shower parameters, resulting in the variation of the VOCs breath concentration. The present study evaluated the key shower parameters(water temperature and inhalation duration) that affect the inhalation exposure to air chloroform while showering, by determining chloroform breath concentration. The chloroform breath concentrations increased with water temperature and inhalation duration increase. The two inhalation exposure conditions which resulted in the greatest chloroform breath concentration difference were a 5 min-inhalation exposure with warm water and a 15 min-inhalation exposure with hot water. The chloroform breath concentration was almost three times higher after later exposure. The mathematical model analyzing the relationship between two key shower parameters and breath concentration normalized to water concentration fits quite well with the experimental data at a probability of p = 0.0001.

Daratumumab plus bortezomib and dexamethasone <i>versus</i> bortezomib and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of CASTOR

Spencer, Andrew,Lentzsch, Suzanne,Weisel, Katja,Avet-Loiseau, Hervé,Mark, Tomer M.,Spicka, Ivan,Masszi, Tamas,Lauri, Birgitta,Levin, Mark-David,Bosi, Alberto,Hungria, Vania,Cavo, Michele,Lee, Je Ferrata Storti Foundation 2018 Haematologica/The Hematology Journal Vol.103 No.12

<P>Daratumumab, a CD38 human monoclonal antibody, demonstrated significant clinical activity in combination with bortezomib and dexamethasone <I>versus</I> bortezomib and dexamethasone alone in the primary analysis of CASTOR, a phase 3 study in relapsed and/or refractory multiple myeloma. A <I>post hoc</I> analysis based on treatment history and longer follow up is presented. After 19.4 (range: 0–27.7) months of median follow up, daratumumab plus bortezomib and dexamethasone prolonged progression-free survival (median: 16.7 <I>versus</I> 7.1 months; hazard ratio, 0.31; 95% confidence interval, 0.24-0.39; <I>P</I><0.0001) and improved the overall response rate (83.8% <I>versus</I> 63.2%; <I>P</I><0.0001) compared with bortezomib and dexamethasone alone. The progression-free survival benefit of daratumumab plus bortezomib and dexamethasone was most apparent in patients with 1 prior line of therapy (median: not reached <I>versus</I> 7.9 months; hazard ratio, 0.19; 95% confidence interval, 0.12-0.29; <I>P</I><0.0001). Daratumumab plus bortezomib and dexamethasone was also superior to bortezomib and dexamethasone alone in subgroups based on prior treatment exposure (bortezomib, thalidomide, or lenalidomide), lenalidomide-refractory status, time since last therapy (≤12, >12, ≤6, or >6 months), or cytogenetic risk. Minimal residual disease–negative rates were >2.5-fold higher with daratumumab across subgroups. The safety profile of daratumumab plus bortezomib and dexamethasone remained consistent with longer follow up. Daratumumab plus bortezomib and dexamethasone demonstrated significant clinical activity across clinically relevant subgroups and provided the greatest benefit to patients treated at first relapse. Trial registration: <I>clinicaltrials.gov identifier: 02136134</I>.</P>

Source Proximity and Meteorological Effects on Residential Ambient Concentrations of PM_2.5, Organic Carbon, Elemental Carbon, and p-PAHs in Houston and Los Angeles, USA

( Jaymin Kwon ),( Clifford P. Weisel ),( Maria T. Morandi ),( Thomas H. Stock ),( Barbara Turpin ) 한국환경과학회 2016 한국환경과학회지 Vol.25 No.10

Concentrations of fine particulate matter (PM_2.5) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. PM_2.5 mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the PM_2.5 constituents` regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven PM_2.5 constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the PM_2.5 constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to PM_2.5 mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.

Smooth Muscle Cells Transplantation is better than Heart Cells Transplantation for Improvement of Heart Function in Dilated Cardiomyopathy

유경종,Ren-Ke Li,Richard D. Weisel,Donald A.G. Mickle,Shinji Tomita,Nobu Ohno,Takeshiro Fujii 연세대학교의과대학 2002 Yonsei medical journal Vol.43 No.3

Muscle cell transplantation may delay or prevent cardiac dilation in dilated cardiomyopathy. The present study was designed to compare the effects of the heart function of smooth muscle cell (SMCs) auto-transplantation and heart cell (CMs) allo-transplantation in dilated cardiomyopathic hamsters, and to determine which cells are better for cell transplantation. CMs and SMCs were isolated from BIO 53.58 hamsters, and cultured for transplantation. CMs, SMCs (4×106 cells each) or culture medium were transplanted into 17 weeks old BIO 53.58 hamsters to achieve CM transplantation (CMTx), SMC transplantation (SMCTx), and controls (Con) (N=10 each). Cyclosporine (5mg/Kg) was administered subcutaneously to CMTx. Healthy hamsters (sham, N=6) were used to compare heart functions. Four weeks after transplantation, heart function was evaluated in all groups using a Langendorff perfusion apparatus. Histology demonstrated severe focal myocardial necrosis in the dilated cardiomyopathic hearts. CMTx and SMCTx formed huge muscle tissue in the dilated myocardium. Sham, SMCTx, and CMTx had a better heart function than Con (p<0.01), and SMCTx had a better peak systolic pressure (p<0.05) and developed pressure (p<0.05) than CMTx at any balloon volume. However, sham and SMCTx were not statistically different. SMCTx and CMTx formed muscle tissue and produced better heart function in the cardiomyopathic hearts, and SMCTx showed better systolic and developed pressures than CMTx, even though they were similar in other functions. Significantly, SMCTx had heart functions, which were similar to those of healthy hamster's hearts.

Evaluation of Biomarkers of Environmental Exposures : Urinary Haloacetic Acids Associated with lngestion of Chlorinated Drinking Water

Kim, Hekap,Patricia Haltmeier,Judith B. Klotz,Clifford P. Weisel 江原大學校 附設 環境硏究所 1999 環境硏究 Vol.16 No.-

A study wss conducted to determine if DCAA and TCAA urinary excretion rates are valid biomarkers of chronic ingestion exposure to these disinfection by-products of chlorination of drinking water. Entire first morning urine voids, time-of-visit urine samples, and tap water samples were collected from 47 female subjects. In addition, a 48-h recall questionnaire was administered to determine the amounts and types of liquids ingested by each subject as well as other exposures that could lead to DCAA and TCAA urinary excretion. The TCAA excretion rate for the first morning urine samples was significantly correlated with estimated 48-h TCAA ingestion exposure for 25 subjects whose ingestion exposures primarily occurred at home, while the DCAA excretion rate was not correlated with the DCAA ingestion exposure. Thus, urinary TCAA appears to be a valid biomarker of chronic ingestion exposure to TCAA from chlorinated water, while urinary DCAA is not. It is proposed that the difference in the biological half-lives between these two compounds is the rationale for this finding. The bilogical half-life of TCAA is longer than successive exposure intervals; thus TCAA accumulates until it reaches a steady state. The halflife of DCAA is shorter than successive exposure intervalsl; thus DCAA is almost coplectely metabolized following an exposure and is eliminated from the bodly. This study suggests that biological half-life, exposure interval, and sample collection interval should be considered in selecting biomarkers and designing studies to validate them.

Exposure Estimates to Disinfection By-products of Chlorinated Drinking Water

Hekap Kim,Patricia Haltmeier,Judith B. Klotz,Clifford P. Weisel 강원대학교 환경연구소 1999 環境硏究 Vol.16 No.-

Microwave Heating and Pre-sintering of Copper Powder Metal Compacts in Separated Electric and Magnetic Fields

Zimmerman Darin T.,Johnson Earnie J.,Ma JunKun,Miskovsky Nicholas M.,Weisel Gary J.,Weiss Brock L. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

We present a systematic study of the heating and pre-sintering behavior of porous copper powder metal compacts. We employ a TE102 single mode microwave system to position the samples in the separated electric field (E) or magnetic field (H) anti-node of the cavity. We observe significant differences in the heating, pre-sintering, and microstructure evolution of the samples due to the individual fields. We note that sample history (whether heated first in the E-field or H-field) greatly effects a difference in heating trends and subsequent heating behavior and does not appear to be solely a thermal process.