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Trifluoroacetic Acid from CFC Replacements: An Atmospheric Toxicant Becomes a Terrestrial Problem
Published in James N. Seiber, Thomas M. Cahill, Pesticides, Organic Contaminants, and Pathogens in Air, 2022
James N. Seiber, Thomas M. Cahill
Inhaled anesthetics represent another source of halocarbons that can form TFA when they are released to the environment. The anesthetic halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) is still used in developing countries although it has been mostly replaced by other chemicals. In 2014, it was estimated that 250 t/yr of halothane was being used (Vollmer et al., 2015) even though its ozone-depleting potential (ODP) is 1.56, which is greater than that of CFC-11. Its high ODP is largely due to the presence of a bromine atom that is even more efficient at catalyzing ozone destruction than chlorine atoms. Most developed countries have switched over to fluorinated compounds such as isoflurane, sevoflurane, and desflurane (Vollmer et al., 2015). In 2014, the emissions of isoflurane, sevoflurane, and desflurane were estimated to be 880, 1,200, and 960 t/yr, respectively. These compounds combined represent approximately 1% of the abundance of HFC-134a consumed each year, so they are minor compared to the HCF refrigerants. Unfortunately, all of these anesthetics, along with halothane, have the potential to form TFA (Andersen et al., 2012; Hankins and Kharasch, 1997; Wallington et al., 2002). In contrast to refrigerants that tend to leak out of products slowly, the anesthetics are completely released during each usage. No significant efforts to recapture these compounds after use have been made. There are alternatives to these inhaled anesthetics, such as injected anesthetics, xenon (Xe) and nitrous oxide (N2O), but they have their own limitations.
General Concepts
Published in Dag K. Brune, Christer Edling, Occupational Hazards in the Health Professions, 2020
Halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) is used as an anesthetic gas, usually together with other halogenated anesthetic gases or nitrous oxide. The introduction of the 1986–1987 ACGIH TLV Booklet26 states: “Threshold limit values refer to airborn concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Because of wide variation in individual susceptibility, however, a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit”. The time-weighted average exposure limit in the ACGIH 1986–1987 TLV booklet26 for halothane is given the value of 50 ppm (400 mg/m3). Halothane is placed in the list under “Notice of Intended Changes”, where it has been since the 1984–1985 list. It means that it is not yet adopted, but is considered as a trial limit. The documentation behind this trial limit has not been published. It should be noticed in this context that the lists given by the ACGIH are used in many countries as the basis for their own national exposure limit levels.
Two Co(II)-based coordination polymers: structural diversity and treatment effect on the cardiac arrest induced by anesthesia by regulating Sirt1 expression
Published in Inorganic and Nano-Metal Chemistry, 2020
Ya-Ming Jiang, Rong Li, Hong-Jun Zheng, Gang Liu
In the past decades, the local anesthetics have been widely used in clinic, but the relationship between the local anesthetics and cardiovascular effects has also reported in the past years.[1] More and more researchers indicated that the local anesthetics injection could induce a variety of cardiovascular inhibition, such as electrocardiographic abnormalities, acute hypertension, arrhythmia, and acute myocardial infarction) through multifactorial mechanisms.[2,3] The Copeland SE also reported that the halothane/O2 anesthesia has significant induction activity on the cardiovascular and central nervous system (CNS) toxic responses.[4] With the development of the researches, number of new and different anesthesia was developed, but they all couldn’t avoid the severe cardiotoxicity during clinical treatment. Respiratory cardiac arrest is regarded as the most serious complication caused by anesthesia, which could lead to irreparable damage of patients and hospitals, and should be highly regarded by medical workers.[5] Thus, in the present study, we aimed to reveal the specific mechanism of the cardiovascular inhibition and development new candidates for the local anesthetics.
Work environment and occupational risk assessment for small animal Portuguese veterinary activities
Published in Journal of Occupational and Environmental Hygiene, 2018
Angela C. Macedo, Vânia T. Mota, João M. Tavares, Osvaldo L. Machado, Francisco X. Malcata, Marinela P. Cristo, Olga N. Mayan
Chemical risk results mainly from the use of drugs (especially antineoplastic and antiparasitic agents), detergents, disinfectants, and gaseous anesthetics.[4] Bleach has been the most commonly used chemical agent for environmental disinfection of infectious body fluids;[10] however, it has been substituted by quaternary ammonium compounds in recent times. Halothane, isoflurane, and sevoflurane are the most common types of inhalation anesthetic gases;[11] therefore, a large number of workers may be exposed in their workplace. Some anesthetic agents can enter the operating room atmosphere, thus exposing veterinary workers to potential risks, ranging from chronic exposure to acute inhalation of anesthetic gas.[12]
Genetic toxicity assessment using liver cell models: past, present, and future
Published in Journal of Toxicology and Environmental Health, Part B, 2020
Xiaoqing Guo, Ji-Eun Seo, Xilin Li, Nan Mei
Following a 3-d treatment, the combined administration of anesthetic sevoflurane (2.4% for 2 hr, daily) or halothane (1.5% for 2 hr, daily) and the antineoplastic drug cisplatin (5 mg/kg/d) exhibited a marked synergistic genotoxic effect in liver cells of healthy male Swiss albino mice (Brozovic et al. 2011, 2008). In contrast, the co-treatment of halothane and cisplatin showed the most potent antagonistic effect on liver cells of Ehrlich ascites tumor-bearing mice as compared to those of kidney cells and PBLs (Brozovic et al. 2008). Concomitant intake of ∆9-tetrahydrocannabinol (THC) did not markedly affect the levels of conventional anticancer drug irinotecan (IRI)-induced genotoxicity following 1-, 3-, and 7-d exposures (Lucić Vrdoljak et al. 2018).