China
Africa
Explore chapters and articles related to this topic
Recent Advances In Otoacoustic Emissions
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
Hearing damage due to environmental toxins in the workplace is another application of OAEs. In workers exposed to styrene and noise, DPOAE levels are significantly lower and are correlated with high levels of oxidative damage biomarkers in the exposed workers (Sisto et al., 2016). OAEs have shown promise in recent human trials of otoprotectant drugs that may prevent hearing loss due to ototoxicity or noise exposure. However, there are issues concerning the most appropriate OAE protocols to use and what constitutes a “significant” OAE response change. Guidelines to help standardize protocols are crucial and an excellent review was provided recently (Konrad-Martin et al., 2016). As reviewed in this report, measurement system capabilities are ever-expanding and test efficacy varies across systems and patient populations. Standardizing minimal measurement criteria and reporting of results is needed, including documentation of test-retest variability so that useful comparisons can be made across trials. It is also important that protocols are theoretically based on known patterns of damage, generate valid results in most individuals tested, are accurate, repeatable, and involve minimal time. Although behavioral audiometry remains the gold standard for clinical trials, OAEs should be included in clinical trials when measurement conditions and time permit.
Methods in Physiologically Based Pharmacokinetic Modeling
Published in Francis N. Marzulli, Howard I. Maibach, Dermatotoxicology Methods: The Laboratory Worker’s Vade Mecum, 2019
Figure 1 is a schematic representation of the classical two-compartment pharmacokinetic model having a body compartment connected with the plasma. The first order transfer rates (K12, K21, K10) are descriptive of a particular situation (see Gibaldi and Perrier, 1982) but do not allow extrapolation to other exposure conditions or species because their physiological basis is obscure. PB-PK models are better suited for extrapolation because their physiological basis is well defined. It has been shown that a PB-PK model for the inhalation of styrene in rats can be predictive of blood and exhaled air concentrations of styrene in humans after scaling-up the physiological and metabolic constants (Ramsey and Andersen, 1984). Extrapolation with a PB-PK model is only limited by the ability of the modeler to quantitatively describe the species differences in the pharmacokinetic and physiological processes involved.
Organic Chemicals
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
Styrene is used as a solvent for synthetic rubber resins and is an intermediate in the chemical synthesis and manufacture of polymerized synthetic materials. Along with irritation of mucosal membranes and dermatitis it is also associated with chromosomal damage. It can cause abnormal CNS function. Twenty-two percent of 500 chemically sensitive patients surveyed at the EHC-Dallas had styrene in their blood. It is the easiest chemical to be removed from the blood. In our series, we were able to remove 100% styrene out of our patients.247 However, others have speculated that styrene may not be removed. It may, instead, convert to another toxic substance and subsequently remain undetected in the body. Although this scenario is possible, it seems unlikely since patients continue to improve after analytical evidence of clearing occurs (Tables 5.37 and 5.38).
Carcinogenic and health risk assessment of respiratory exposure to acrylonitrile, 1,3-butadiene and styrene in the petrochemical industry using the US Environmental Protection Agency method
Published in International Journal of Occupational Safety and Ergonomics, 2022
Vahid Ahmadi-Moshiran, Ali Asghar Sajedian, Ahmad Soltanzadeh, Fatemeh Seifi, Rozhin Koobasi, Neda Nikbakht, Mohsen Sadeghi-Yarandi
Another VOC produced in the petrochemical industry is styrene. Styrene is widely used in the manufacture of acrylonitrile, 1,3-butadiene and styrene (ABS) copolymer, plastics, rubber, polyester resin, fiberglass, toys, home appliances, etc. [13–15]. Styrene, with the chemical formula C6H5CH=CH2 or C8H8, is a benzene-derived aromatic hydrocarbon with a sweet smell that is colorless and vaporizes quickly [16,17]. Exposure to styrene causes toxic effects, including changes in the peripheral and central nervous system (such as drowsiness, headache, imbalance), skin and respiratory system irritation and mild liver damage [18]. Significant correlations have been found between exposure to styrene and impaired color recognition (as the most apparent sign of styrene neurotoxicity), hearing loss and neurocognitive disorder [19]. The IARC has designated group 2B (probable carcinogen) for this substance [15,20]. Previous studies have shown that exposure to styrene is a risk factor for benign respiratory diseases [19].
The exposure to BTEX/Styrene and their health risk in the tire manufacturing
Published in Toxin Reviews, 2022
Mehran Nazarparvar-Noshadi, Mehrdad Yadegari, Yousef Mohammadian, Yadolah Fakhri
Acute myelogenous leukemia and blood diseases, immune system damage, menstrual disorders, and changes are the adverse health effects of exposure to benzene (Boogaard and Van Sittert 1995, Lynge et al. 1997). Exposure to toluene can lead to multiple complications, including changes in the central nervous system, such as fatigue, dizziness, lack of coordination, delay in response time, and perceived person’s speed (Wexler 1998). ethylbenzene and xylene also cause respiratory and nervous problems (Substances and Registry 2010, Rajan and Malathi 2014). The health impacts of styrene are acute and chronic effects on the central and peripheral nervous system, decreased consciousness, changes in mental functioning, cognition, and emotions (Rebert and Hall 1994, Morgan et al. 1997, Sumner et al. 1997).
Effects of concomitant exposure to styrene and intense noise on rats’ whole lung tissues. Biochemical and histopathological studies
Published in Drug and Chemical Toxicology, 2022
Mojtaba Haghighat, Abdolamir Allameh, Mohammad Fereidan, Ali Khavanin, Zahrasadat Ghasemi
Styrene (ST) is a widely used industrial organic solvent. A considerable portion of exposures to ST is believed to occur occupationally among workers of the reinforced plastics industry such as boat and automobile manufacturing, plastic packaging, and rubber and resin production (Cohen et al.2002, McCague et al.2015). It is well-documented that excessive exposure to ST may contribute to hypersensitivity pneumonitis, asthma, obliterative bronchiolitis (OB), diffuse cell damage involving the tracheal, bronchiolar and alveolar epithelium, together with ototoxicity, genotoxicity and carcinogenicity (IARC Group 2B) (Coccini et al.1997, Lataye et al.2000). ST has also been shown to be hepatotoxic, pneumotoxic and ototoxic in rodents. Previous studies have established that organic solvents exert their toxicity through oxidative stress as a result of excessive reactive oxygen species (ROS) formation (Mattia et al.1993, Rababa’h et al.2016). These unstable molecules can damage cellular lipids, proteins and nucleic acids in DNA.