Exposure, dose, and toxicokinetics of metals

2022 ◽  
pp. 55-86
Author(s):  
Alison Elder ◽  
Gunnar F. Nordberg, ◽  
Michael Kleinman
Keyword(s):  
Exposure Dose

PHYTOTOXICITY OF WASTEWATER CONTAINING CADMIUM (Cd) USING OLEANDER

2020 ◽  
Vol 51 (4) ◽  
pp. 1231-1238
Author(s):  
Zeki & Ridha
Keyword(s):  
Translocation Factor ◽  
Preliminary Test ◽  
Dry Weight ◽  
Exposure Dose ◽  
Test Duration ◽  
Plant Analysis ◽  
Wet Weight ◽  
Simulated Wastewater ◽  
Almost All ◽  
Plant Shoots

This study was aimed to investigate the ability of N.oleander to remove Cadmium (Cd) from wastewater. A prolonged toxicity test was performed in a single exposure and run for 65 days with various concentrations of Cd. Plants were grown in sand medium and irrigated with simulated wastewater contaminated with Cd, using different concentrations (0, 10, 25, 50, 75 mg/L), which were chosen based on previous preliminary test. The results of physical observation of the plants didn’t show any withering symptoms. The Cd concentration in plants increased, while in water decreased. The results of plant analysis showed that Cd concentration in plant shoots (stems and leaves) was higher than that in roots for almost all exposure doses along the test duration. The concentration of Cd in water decreased significantly from the first week of the test and become (0 mg/l) on day-35 for 10 and 25 mg/l exposure doses, while exceeded the permissible limits for 50 and 75 mg/l exposure doses and were 0.14 and 0.91 mg/l, respectively. Wet weight and dry weight of Oleander decreased with increasing Cd concentration level except for 10 mg/l exposure dose where the plant wet weight and dry weight increased at the end of the test. Bioaccumulation factor (BAF) and Translocation Factor (TF) was found to be greater than 1, indicating that Oleander is a successful hyperaccumulator for Cd.

scholarly journals A systematic assessment of the association between frequently prescribed medicines and the risk of common cancers: a series of nested case-control studies

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
R. D. McDowell ◽  
C. Hughes ◽  
P. Murchie ◽  
C. Cardwell
Keyword(s):  
Cancer Risk ◽  
Conditional Logistic Regression ◽  
Exposure Dose ◽  
Case Control ◽  
Case Control Studies ◽  
Systematic Assessment ◽  
Exposure Response ◽  
Prescribed Medicines ◽  
Nested Case Control ◽  
Novel Associations

Abstract Background Studies systematically screening medications have successfully identified prescription medicines associated with cancer risk. However, adjustment for confounding factors in these studies has been limited. We therefore investigated the association between frequently prescribed medicines and the risk of common cancers adjusting for a range of confounders. Methods A series of nested case-control studies were undertaken using the Primary Care Clinical Informatics Unit Research (PCCIUR) database containing general practice (GP) records from Scotland. Cancer cases at 22 cancer sites, diagnosed between 1999 and 2011, were identified from GP records and matched with up to five controls (based on age, gender, GP practice and date of registration). Odds ratios (OR) and 95% confidence intervals (CI) comparing any versus no prescriptions for each of the most commonly prescribed medicines, identified from prescription records, were calculated using conditional logistic regression, adjusting for comorbidities. Additional analyses adjusted for smoking use. An association was considered a signal based upon the magnitude of its adjusted OR, p-value and evidence of an exposure-response relationship. Supplementary analyses were undertaken comparing 6 or more prescriptions versus less than 6 for each medicine. Results Overall, 62,109 cases and 276,580 controls were included in the analyses and a total of 5622 medication-cancer associations were studied across the 22 cancer sites. After adjusting for comorbidities 2060 medicine-cancer associations for any prescription had adjusted ORs greater than 1.25 (or less than 0.8), 214 had a corresponding p-value less than or equal to 0.01 and 118 had evidence of an exposure-dose relationship hence meeting the criteria for a signal. Seventy-seven signals were identified after additionally adjusting for smoking. Based upon an exposure of 6 or more prescriptions, there were 118 signals after adjusting for comorbidities and 82 after additionally adjusting for smoking. Conclusions In this study a number of novel associations between medicine and cancer were identified which require further clinical and epidemiological investigation. The majority of medicines were not associated with an altered cancer risk and many identified signals reflected known associations between medicine and cancer.

Evaluation of Velopharyngeal Closure Function With 4-Dimensional Computed Tomography and Assessment of Radiation Exposure in Pediatric Patients: A Cross-Sectional Study

2021 ◽  
pp. 105566562110017
Author(s):  
Yoshikazu Kobayashi ◽  
Masanao Kobayashi ◽  
Daisuke Kanamori ◽  
Naoko Fujii ◽  
Yumi Kataoka ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Exposure ◽  
Exposure Dose ◽  
Velopharyngeal Insufficiency ◽  
Radiation Doses ◽  
Secondary Surgery ◽  
Cross Sectional ◽  
Computed Tomography Images ◽  
Velopharyngeal Closure ◽  
Closure Function

Objective: Some patients with cleft palate (CP) need secondary surgery to improve functionality. Although 4-dimensional assessment of velopharyngeal closure function (VPF) in patients with CP using computed tomography (CT) has been existed, the knowledge about quantitative evaluation and radiation exposure dose is limited. We performed a qualitative and quantitative assessment of VPF using CT and estimated the exposure doses. Design: Cross-sectional. Setting: Computed tomography images from 5 preoperative patients with submucous CP (SMCP) and 10 postoperative patients with a history of CP (8 boys and 7 girls, aged 4-7 years) were evaluated. Patients: Five patients had undergone primary surgery for SMCP; 10 received secondary surgery for hypernasality. Main Outcome Measures: The presence of velopharyngeal insufficiency (VPI), patterns of velopharyngeal closure (VPC), and cross-sectional area (CSA) of VPI was evaluated via CT findings. Organ-absorbed radiation doses were estimated in 5 of 15 patients. The differences between cleft type and VPI, VPC patterns, and CSA of VPI were evaluated. Results: All patients had VPI. The VPC patterns (SMCP/CP) were evaluated as coronal (1/4), sagittal (0/1), circular (1/2), and circular with Passavant’s ridge (2/2); 2 patients (1/1) were unevaluable because of poor VPF. The CSA of VPI was statistically larger in the SMCP group ( P = .0027). The organ-absorbed radiation doses were relatively lower than those previously reported. Conclusions: Four-dimensional CT can provide the detailed findings of VPF that are not possible with conventional CT, and the exposure dose was considered medically acceptable.

scholarly journals Radiation exposure dose of fluoroscopy-guided gastrointestinal procedures: A single-center retrospective study

2020 ◽  
Vol 08 (12) ◽  
pp. E1872-E1877
Author(s):  
Shiro Hayashi ◽  
Tsutomu Nishida ◽  
Shinji Kuriki ◽  
Li-sa Chang ◽  
Kazuki Aochi ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Balloon Dilatation ◽  
Exposure Dose ◽  
Sigmoid Volvulus ◽  
Tube Placement ◽  
Injection Sclerotherapy ◽  
Single Center ◽  
Endoscopic Injection ◽  
Dose Area Product ◽  
Esophageal Balloon

Abstract Background and study aims Fluoroscopy-guided gastrointestinal procedures (FGPs) are increasingly common. However, the radiation exposure (RE) to patients undergoing FGPs is still unclear. We examined the actual RE of FGPs. Patients and methods This retrospective, single-center cohort study included consecutive FGPs, including endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasound (EUS), enteral stenting, balloon-assisted enteroscopy, tube placement, endoscopic injection sclerotherapy (EIS), esophageal balloon dilatation and repositioning for sigmoid volvulus, from September 2012 to June 2019. We measured the air kerma (AK, mGy), dose area product (DAP, Gycm2), and fluoroscopy time (FT, min) for each procedure. Results In total, 3831 patients were enrolled. Overall, 2778 ERCPs were performed. The median AK, DAP, and FT were as follows: ERCP: 109 mGy, 13.3 Gycm2 and 10.0 min; self-expandable enteral stenting (SEMS): 62 mGy, 12.4 Gycm2 and 10.4 min; tube placement: 40 mGy, 13.8 Gycm2 and 11.1 min; balloon-assisted enteroscopy: 43 mGy, 22.4 Gycm2 and 18.2 min; EUS cyst drainage (EUS-CD): 96 mGy, 18.3 Gycm2 and 10.4 min; EIS: 36 mGy, 8.1 Gycm2 and 4.4 min; esophageal balloon dilatation: 9 mGy, 2.2 Gycm2 and 1.8 min; and repositioning for sigmoid volvulus: 7 mGy, 4.7 Gycm2 and 1.6 min. Conclusion This large series reporting actual RE doses of various FGPs could serve as a reference for future prospective studies.

Exposure (dose) tables for hematoporphyrin derivative photoradiation therapy

1984 ◽  
Vol 4 (1) ◽  
pp. 107-131 ◽  
Author(s):  
Michael W. Berns ◽  
Gregory S. Berns ◽  
Joan Coffey ◽  
Alan G. Wile
Keyword(s):  
Exposure Dose ◽  
Hematoporphyrin Derivative
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