scholarly journals Metodología para evaluar la exposición ocupacional a contaminantes químicos en altitud

2021 ◽  
Vol 24 (4) ◽  
pp. 404-409
Author(s):  
Margarita Zamora Saa ◽  
Jilberto Zamora-Saa
Keyword(s):  
Threshold Limit Value ◽  
Limit Value ◽  
Threshold Limit

Este artículo examina el actual método para evaluar la exposición a contaminantes químicos en altitud usando los Threshold Limit Value (TLV). Estos valores son establecidos para trabajos a nivel del mar en jornadas de 8 horas diarias y 40 horas semanales. Se analiza este problema aplicándolo a un grupo específico de mineros chilenos que trabaja sobre los 3000 m con jornadas excepcionales de 12 horas diarias. Se comparan dos alternativas para evaluar la exposición a contaminantes químicos: ajustes al TLV en altitud, y el cálculo de la dosis inhalada. Puesto que la ventilación por minuto es el parámetro fisiológico que cambia en altitud se propone y fundamenta como método de evaluación el cálculo de la dosis inhalada del contaminante químico.

EXPERIMENTAL SUBSTANTIATION OF THE MAXIMUM ALLOWABLE CONCENTRATION OF DIOCTYL TEREPHTHALATE IN THE AIR OF THE WORKING AREA

2020 ◽  
pp. 34-38
Author(s):  
A. S. Radilov ◽  
S. A. Solntseva ◽  
I. E. Shkaeva ◽  
S. A. Dulov ◽  
E. V. Vivulanets ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional State ◽  
Hematological Parameters ◽  
Inhalation Exposure ◽  
Threshold Limit Value ◽  
Maximum Allowable Concentration ◽  
Limit Value ◽  
Threshold Limit ◽  
The Central Nervous System

Toxicity and hazard assessment of dioctyl terephthalate (DOTP) was performed in acute, subacute, and chronic experiments, and its principal toxicometry parameters were determined.It was found that on single exposure DOTP exhibits low toxicity and hazard. No resorptive and irritant effects on skin and mucous membrane of eyes were detected in animal experiments. The single inhalation exposure threshold limit value was set at 300 mg/m3, based on the results of monitoring of the functional state of the central nervous system and myocardium and hematological parameters.Thirty-day subacute experiments (oral administration, inhalation exposure, and skin applications) revealed no accumulation of the compound.Four-month chronic exposure to DOTP aerosols (concentration 96,8 mg/m3) caused disorder of the functional state of the central nervous system and myocardium, changes in the hematological and biochemical parameters, gas and acid-base status of the blood, and morphological changes in the lungs and heart. Embryotoxic, genotoxic and gonadotoxic effects were not detected.The chronic inhalation exposure threshold limit value for DOTP (Limch) was set at 18,6 mg/m3, and the concentration of 3,4 mg/m3 was found to be ineffective.The maximum allowable concentration of DOTP in the air of the working area was set at 3,0 mg/m3, hazard class 3.

Metallic Mercury Contamination of the Dental Operatory

1975 ◽  
Vol 17 (4) ◽  
pp. 346-355 ◽  
Author(s):  
Richard G. Domey
Keyword(s):  
San Antonio ◽  
Threshold Limit Value ◽  
Mercury Contamination ◽  
Metallic Mercury ◽  
General Lack ◽  
Limit Value ◽  
Threshold Limit ◽  
Routine Monitoring ◽  
Cleaning Methods

The American Conference of Governmental Industrial Hygienists 1971 standard threshold limit value (TLV) of 0.55 mgHg/m of air was found to be exceeded frequently in a sample of 60 dental operatories in San Antonio, Texas. Significant differences in contamination among laboratories were found, among sites within operatories, and among times of day, correlated with kilograms of mercury used, average number of amalgams inserted per day, age of operatories, height of carpeting pile, cleaning methods, frequency of cleaning, and general lack of routine monitoring and use of bioassays. Recommendations for control of metallic mercury contamination in dental operatories are offered.

scholarly journals Modeling the Effect of the 2018 Revised ACGIH® Hand Activity Threshold Limit Value® (TLV) at Reducing Risk for Carpal Tunnel Syndrome

2019 ◽  
Vol 16 (9) ◽  
pp. 628-633 ◽  
Author(s):  
Marcus Yung ◽  
Ann Marie Dale ◽  
Jay Kapellusch ◽  
Stephen Bao ◽  
Carisa Harris-Adamson ◽  
...  
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Threshold Limit Value ◽  
Limit Value ◽  
Threshold Limit ◽  
Tunnel Syndrome

scholarly journals Prediction of hydrogen sulfide emission from an energy dissipation chamber and assessment of its distribution in the ambient air

2019 ◽  
Vol 140 ◽  
pp. 06001
Author(s):  
Anna Telyatnikova ◽  
Sviatoslav Fedorov ◽  
Iurii Stolbikhin ◽  
Elena Korneeva
Keyword(s):  
Hydrogen Sulfide ◽  
Energy Dissipation ◽  
Ambient Air ◽  
Threshold Limit Value ◽  
Internal Space ◽  
Sulfide Concentration ◽  
Limit Value ◽  
Threshold Limit ◽  
The Impact ◽  
Flow Velocities

Wastewater transport in sewer networks contributes to the formation and emission of fetid and toxic sewage gases into the environment, one of which is hydrogen sulfide. The emission of gases can have a significant impact on the environment and health of maintenance workers and city residents. The object of the research is the study of the process of hydrogen sulfide emission in the energy dissipation chamber (EDC). The method of two-stage mathematical modeling in the program of finite element analysis ANSYS CFX is applied for the research. Two models have been created, the first one simulates the internal space of the EDC structure itself, and the second one simulates the EDC manhole and the volume of the surrounding air next to it. Mathematical dependences of hydrogen sulfide concentration change at three sections inside the structure are obtained for incoming wastewater flow velocities V = 1 m/s, 1.5 m/s and 2 m/s. The critical flow velocities at which the maximum single threshold limit value will exceed 1 m/s and the threshold limit value of the working area will exceed 1.52 m/s are determined. The methodology for solving the problem of assessing the impact of the EDC object on the environment is formed. The results of the study can be applied in the design of structures for a preliminary assessment and prediction of the impact of a wastewater facility, as well as the selection of the most favorable hydraulic regime.

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