DEVELOPMENT OF UNSTEADY INDOOR CONTAMINANT CONCENTRATION DISTRIBUTIONS FOR RISK ASSESSMENT OF HIGH CONCENTRATION AND SHORT-TERM EXPOSURE (PART 1): FUNDAMENTAL EXPERIMENTS USING SMALL GLASS CHAMBER AND VALIDATION OF PREDICTION ACCURACY

2020 ◽  
Vol 85 (778) ◽  
pp. 985-992
Author(s):  
Eisaku SUMIYOSHI ◽  
Hiroshi HARASHIMA ◽  
Kazuhide ITO
Keyword(s):  
Risk Assessment ◽  
Prediction Accuracy ◽  
Contaminant Concentration ◽  
High Concentration ◽  
Short Term ◽  
Small Glass ◽  
Glass Chamber ◽  
Short Term Exposure

scholarly journals Morpho-Functional Alterations in the Gills of a Seawater Teleost, the Ornate Wrasse (Thalassoma pavo L.), after Short-Term Exposure to Chlorpyrifos

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Rachele Macirella ◽  
Vittoria Curcio ◽  
Elvira Brunelli
Keyword(s):  
Goblet Cells ◽  
High Concentration ◽  
Short Term ◽  
Cell Degeneration ◽  
Widespread Species ◽  
Pillar Cell ◽  
Secondary Lamellae ◽  
Short Term Exposure ◽  
First Time ◽  
Sublethal Concentrations

Chlorpyrifos (CPF) is an organophosphorus insecticide commonly used for domestic and agricultural purposes. The risk posed by environmental contamination from CPF is well acknowledged, and it has been detected worldwide in aquatic habitats and coastal areas. In addition, due to its slower degradation in seawater compared to freshwater, CPF is of particular concern for marine environments. Here, we investigated for the first time the morpho-functional alterations induced by CPF on the gills of Thalassoma pavo, a widespread species in the Mediterranean Sea. We tested the effects of two sublethal concentrations (4 and 8 µg/L) after 48 and 96 h. Our study demonstrates that the alterations induced by CPF are dose and time-dependent and highlight the harmful properties of this insecticide. After exposure to the low tested concentration, the more frequent alteration is an intense proliferation of the primary epithelium, whereas after exposure to the high concentration, the primary epithelium proliferation is less extensive, and the most evident effects are the thinning of secondary lamellae and the ectopia of chloride and goblet cells. CPF also modulated the expression of Na+/K+-ATPase. Dilation of lamellar apical tips, pillar cell degeneration, and appearance of aneurysms are often observed.

scholarly journals Acute Effects of High-Level PM 2.5 Exposure on Central Blood Pressure

Hypertension ◽  
2019 ◽  
Vol 74 (6) ◽  
pp. 1349-1356 ◽  
Author(s):  
Fangfang Fan ◽  
Shixuan Wang ◽  
Yi Zhang ◽  
Dandan Xu ◽  
Jia Jia ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Particulate Matter ◽  
Pollution Monitoring ◽  
Chinese Community ◽  
Cardiovascular Risks ◽  
High Concentration ◽  
Short Term ◽  
Community Based ◽  
Air Pollution Monitoring ◽  
Short Term Exposure

Central aortic blood pressure (BP) has been increasingly recognized as having a closer relationship with cardiovascular risks than peripheral BP. However, the effects of particulate matter pollution on central aortic BP have not been clearly demonstrated. In this study, we assessed the association between short-term ambient fine particulate matter (with an aerodynamic diameter ≤2.5 μm; PM 2.5 ) exposure and central aortic BP in a Chinese community-based population. A total of 4715 visits were in our final analysis, including 2151 visits at the baseline and 2564 visits at the follow-up. Central aortic systolic BP (cSBP) was measured noninvasively using the method of radial artery tonometry with Omron HEM-9000AI machine. Data from air pollution monitoring stations were used to estimate daily PM 2.5 exposure. Generalized additive mixed models with clinical and meteorologic covariates adjusted were used to examine the association between PM 2.5 exposure and cSBP. The relationships between PM 2.5 exposure and cSBP were nonlinear, and significant increments of cSBP were observed when the PM 2.5 exposure concentration was above 100 μg/cm 3 . An interquartile range increase (80.25 μg/m 3 ) in daily PM 2.5 on the day of cSBP measurement (lag 0 day) was associated with 2.54 mm Hg (95% CI, 0.92–4.16) elevation in cSBP. The associations of PM 2.5 with cSBP were not modified by age, sex, body mass index, medications, and comorbid diseases except for cardiovascular disease. Our findings demonstrated that short-term exposure to high concentration of ambient PM 2.5 above 100 μg/cm 3 was associated with significant increases in central aortic BP in a Chinese community-based population.

scholarly journals Exposure Characterization of Haloacetic Acids in Humans for Exposure and Risk Assessment Applications: An Exploratory Study

2019 ◽  
Vol 16 (3) ◽  
pp. 471 ◽  
Author(s):  
Shahid Parvez ◽  
Jeffrey L. Ashby ◽  
Susana Y. Kimura ◽  
Susan D. Richardson
Keyword(s):  
Risk Assessment ◽  
Interindividual Variability ◽  
Individual Variability ◽  
Haloacetic Acids ◽  
Short Term ◽  
Cross Sectional ◽  
Exposure Biomarker ◽  
Short Term Exposure

Disinfected water is the major source of haloacetic acids (HAAs) in humans, but their inter- and intra-individual variability for exposure and risk assessment applications is under-researched. Thus, we measured HAAs in cross-sectional and longitudinal urine and water specimens from 17 individuals. Five regulated HAAs—mono, di, and trichloroacetic acid (MCAA, DCAA, and TCAA) and mono- and dibromoacetic acid (MBAA and DBAA)—and one unregulated HAA—bromochloroacetic acid (BCAA)—were measured. Urinary DCAA, MBAA, DBAA, and BCAA levels were always below the limits of detection (LOD). Measured levels and interindividual variability of urinary MCAA were higher than urinary TCAA. Longitudinal urinary specimens showed MCAA levels peaked in after-shower specimens, while TCAA levels remain unchanged. Correlation between urinary MCAA and TCAA was moderate but statistically significant. The prevalence of MCAA and TCAA in urine suggest they can be considered as biomarkers of HAA. Peak urinary MCAA in post-shower specimens suggest MCAA captures short-term exposure via dermal and/or inhalation, while urinary TCAA captures long-term exposure via ingestion. However, further research is warranted in a large pool of participants to test the reliability of MCAA as exposure biomarker.

scholarly journals Risk Analysis of Cellulose Nanomaterials by Inhalation: Current State of Science

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 337 ◽  
Author(s):  
James Ede ◽  
Kimberly Ong ◽  
Michael Goergen ◽  
Alan Rudie ◽  
Cassidy Pomeroy-Carter ◽  
...  
Keyword(s):  
Risk Assessment ◽  
In Vivo Studies ◽  
Weight Of Evidence ◽  
Short Term ◽  
Multiwalled Carbon ◽  
Potential Health ◽  
Short Term Exposure ◽  
Cellulose Nanomaterials

Cellulose nanomaterials (CNs) are emerging advanced materials with many unique properties and growing commercial significance. A life-cycle risk assessment and environmental health and safety roadmap identified potential risks from inhalation of powdered CNs in the workplace as a key gap in our understanding of safety and recommended addressing this data gap to advance the safe and successful commercialization of these materials. Here, we (i) summarize the currently available published literature for its contribution to our current understanding of CN inhalation hazard and (ii) evaluate the quality of the studies for risk assessment purposes using published study evaluation tools for nanomaterials to assess the weight of evidence provided. Our analysis found that the quality of the available studies is generally inadequate for risk assessment purposes but is improving over time. There have been some advances in knowledge about the effects of short-term inhalation exposures of CN. The most recent in vivo studies suggest that short-term exposure to CNs results in transient inflammation, similarly to other poorly soluble, low toxicity dusts such as conventional cellulose, but is markedly different from fibers with known toxicity such as certain types of multiwalled carbon nanotubes or asbestos. However, several data gaps remain, and there is still a lack of understanding of the effects from long-term, low-dose exposures that represent realistic workplace conditions, essential for a quantitative assessment of potential health risk. Therefore, taking precautions when handling dry forms of CNs to avoid dust inhalation exposure is warranted.

scholarly journals Cerium oxide nanoparticles induced physio-biochemical, neurochemical, and morphological responses in Cirrhinus mrigala during short term exposure

2021 ◽  
pp. 51-61
Author(s):  
Kalpesh Swamy ◽  
Naveenkumar Chandrashekar ◽  
Raghunandhakumar Subramanian ◽  
Sandya Sukumaran ◽  
Sharath Chandra
Keyword(s):  
Oxidative Stress ◽  
Cerium Oxide ◽  
Biological Effects ◽  
Hematological Parameters ◽  
High Concentration ◽  
Control Groups ◽  
Short Term ◽  
Cirrhinus Mrigala ◽  
Short Term Exposure ◽  
Different Doses

Cerium oxide nanoparticle (CeO2NPs) has wide applications in pharmaceutical, biomedical and chemical industries. Albeit of their uses, bioavailability followed by toxicity of CeO2NPs in fresh water fishes, are yet to be understood in detail. In this evaluation, we have synthesized, characterized and assessed the biological effects (hematology, ionoregulatory, oxidative stress, histological and glutamate indices) of CeO2NPs at different doses (2.5mg/L and 25mg/L based on 1/10th LC50) on freshwater carps Cirrhinus mrigala, for short term exposure of 96 h. Impact of CeO2NPs at low concentration (2.5mg/L) confirmed a significant decrease in hematological parameters and also affecting serum Na+, Cl-, K+ levels along with gill Na+/K+-ATPase activity. The indicated variations oxidative stress enzymes superoxide dismutase, Catalase, glutathione peroxidase with relative elevation in lipid peroxidation (LPO) (22.47±0.198) compared to control groups. CeO2NPs at high concentration (25mg/L) revealed the alterations in neurotransmitter glutamate levels compared to control groups. Rise in glucose and decrease in plasma protein levels in response to both the concentrations was noted. Microscopic observations confirmed the tissue damages and alterations in gill architecture. By integrating all results obtained by short term exposure of juvenile carps to CeO2NPs at different doses, we reported nanoparticles have considerable deleterious effects on physiological and morphological condition of fishes.

scholarly journals Mixture toxicity analysis in zebrafish embryo: a time and concentration resolved study on mixture effect predictivity

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Gianina Jakobs ◽  
Janet Krüger ◽  
Andreas Schüttler ◽  
Rolf Altenburger ◽  
Wibke Busch
Keyword(s):  
Exposure Duration ◽  
Prediction Accuracy ◽  
Mixture Toxicity ◽  
Concentration Addition ◽  
Short Term ◽  
Response Curves ◽  
Low Concentrations ◽  
Short Term Exposure ◽  
Deviation Factor ◽  
Ca Model

Abstract Background Humans and wildlife are continuously exposed to chemical mixtures. These mixtures vary in composition but typically contain hundreds of micropollutants at low concentrations. As it is not feasible to measure the toxicity of all possibly occurring mixtures, there is a need to predict mixture toxicity. Two models, Concentration Addition (CA) and Independent Action (IA), have been applied to estimate mixture toxicity. Here, we compared measured with predicted toxicity of nine mixtures designed from 15 environmentally relevant substances in zebrafish embryos to investigate the usability of these models for predicting phenotypic effects in a whole organism short term acute assay. Results In total, we compared 177 toxicity values derived from 31 exposure scenarios with their predicted counterparts. Our results show that mixture toxicity was either correctly estimated (86%) by the prediction window, the concentration-effect space that is spanned between both models, or was underestimated with both models (14%). The CA model correctly predicted the measured mixture toxicity in 100% of cases when a prediction deviation factor of 2.5 was allowed. However, prediction accuracy of mixture toxicity prediction was dependent on exposure duration and mixture potency. The CA model showed highest prediction quality for long-term exposure with highly potent mixtures, respectively, whereas IA proved to be more accurate for short-term exposure with less potent mixtures. Obtained mixture concentration–response curves were steep and indicated the occurrence of remarkable combined effects as mixture constituents were applied at concentrations below their respective individual effect threshold in 90% of all investigated cases. Conclusions Experimental factors, such as exposure duration or mixture potency, influence the prediction accuracy of both inspected models. The CA model showed highest prediction accuracy even for a set of diverse mixtures and various exposure conditions. However, the prediction window served as the most robust predicator to estimate mixture toxicity. Overall, our results demonstrate the importance of considering mixture toxicity in risk assessment schemes and give guidance for future experiment design regarding mixture toxicity investigations.

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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