Incapacitating Agents and Technologies: A Review *
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
n-Butyl mercaptan is also known as 1-butanethiol. It is a colorless flammable liquid having a strong and obnoxious garlic-like odor. It has a high vapor pressure (83 mm Hg at 388°C; MSDS, 2005a). The odor threshold is 0.1–1 ppb, and it is stated to have a “readily noticeable” odor at concentrations between 0.1 and 1 ppm. The American Conference of Governmental Industrial Hygienists (ACGIH) time-weighted average (TWA)8 threshold limit value (TLV) is 0.5 ppm based on irritation, CNS effects, and reproductive toxicity (ACGIH, 2006). Oral LD50 values (rat) are cited as 1500 and 1800 mg kg−1, and the rat i.p. LD50 is 399 mg kg−1 (Fairchild and Stokinger, 1958; MSDS, 2005a).
Epidemiology in occupational health policy
Sol Levine, Abraham M. Lilienfeld in Epidemiology and Health Policy, 1987
A threshold limit value or maximal allowable concentration may need to be reduced as more knowledge becomes available. The more recent history of the acceptable concentration of asbestos in the work-place is illustrative. In 1968, some thirty years after the publication of the US Public Health Service, monograph already mentioned, the British Occupational Hygiene Society (BOHS) reconsidered the evidence on exposure to asbestos and the risk of asbestosis. The experience of a textile factory in the north of England provided the data from which a dose/response curve (Figure 5.1) was derived. During the 1960s, the method which was used to measure the concentration of asbestos in the work-place was changed and the result was no longer expressed in mp/ft3, but instead fibers per cubic centimeter (fb/cm3), or in fibers per milliliter (fb/ml). The average lifetime working-shift concentration was combined with the number of years of exposure to obtain an estimate for each worker of the lifetime dosage of asbestos received. The result was expressed as fiber-years per ml (fb-yrs/ml) by multiplying the mean fibers/ml by the number of years of exposure. Figure 5.1 indicates that 1% of the employees might be expected to have developed the earliest signs of asbestosis after exposure to 112 fb-yrs/ml of asbestos. This is equivalent to an exposure of 2.2 fb/ml each work-shift for fifty years or 4.4 fb/ml each work-shift for twenty-five years. On the basis of this evidence, a Threshold Limit Value – Time Weighted Average (TLV TWA) – the average concentration for a normal eight hour work day and forty hour work week, to which nearly all workers may be repeatedly exposed, day after day, without adverse health effect – was set at 2 fb/ml. This is the basis for the current asbestos standard in the United States. Again, the results of epidemiology clearly affected public health policy.
Employment Law and Occupational Health and Safety
Julie Dickinson, Anne Meyer, Karen J. Huff, Deborah A. Wipf, Elizabeth K. Zorn, Kathy G. Ferrell, Lisa Mancuso, Marjorie Berg Pugatch, Joanne Walker, Karen Wilkinson in Legal Nurse Consulting Principles and Practices, 2019
When engineering and administrative noise controls are not possible, employers must provide personal protective equipment (PPE); this includes ear plugs, ear muffs, and canal caps. All employees must wear hearing protection if exposed to eight-hour TWA noise levels of 85 dB or above for six months with no baseline hearing test; have incurred a standard threshold shift; or are working in an area where noise levels are 90 dB or above.
Total wrist fusion versus total wrist prosthesis: a comparative study
Published in Journal of Plastic Surgery and Hand Surgery, 2023
Luis Rodríguez-Nogué, Gregorio Martínez-Villén
For decades, total wrist fusion (TWF) has been the treatment of choice for advanced radiocarpal joint degeneration of any aetiology, providing satisfactory results with predictable cost-effectiveness and low failure rates [1]. Various methods of fixation have been developed for TWF with the contoured plate being the most common to date [2,3]. Due to the high number of supplementary operations, the lack of complete improvement of functional results and the absence of universal return to work, it has been argued that TWF is not the ultimate solution to complex wrist problems [4]. Moreover, the disability caused by the loss of movement after a TWF has led to the development of numerous implants in the last 40 years. The fourth-generation total wrist prosthesis (TWP) is currently an alternative that aim to preserve pain-free movement in a stable wrist [5–8]. There has been much controversy concerning the advantages and disadvantages of TWP compared with TWA for a given indication. However, there are very few original studies comparing both procedures [9,10] and the few systematic reviews that have been conducted are compromised by bias [11,12]. The aim of the study was to compare the functional results, complications and subjective satisfaction of patients undergoing TWF or fourth-generation TWP.
Joseph L.A. Ghesquiere (Halle, Belgium, November 30, 1925 – Archennes, Belgium, January 26, 2021)
Published in Annals of Human Biology, 2021
Michael A. Little, Robert M. Malina
As Regional Director of IRSAC, Joseph supervised the agronomic research centre in the tropical forest in the Bikoro Territory, south of Mbandaka, the Équateur Province capital. Bantu farmers (Oto) lived in close proximity to Pygmies (Twa) in the region around the agronomic field station, and they were the subjects of numerous studies of physical development, exercise capacity, and temperature regulation carried out by Joseph and colleagues. One of us (MAL) had the good fortune to visit Joseph and his family in Kinshasa for two weeks during the fall of 1972. At that time, we flew to the IRSAC field station to visit a U.S. student whom Joseph was supervising while the student was visiting Zaïre to conduct heat stress studies of Twa Pygmies (Austin et al. 1976; Austin and Ghesquiere 1979). During that period, Joseph was an active participant in the Human Adaptability component of the International Biological Programme because of his work with the human biology of Congolese Bantu and Pygmies (Ghesquiere 1971; Ghesquiere and Hiernaux 1981). Some of his other work included studies of exercise capacity (Lange Andersen and Ghesquiere 1972; Ghesquiere and Lange Andersen 1973); growth and development (Ghesquiere 1979; Ghesquiere and D’Hulst, 1988); fitness and motor performance of children (Ghesquiere and Eeckels 1984); and anthropometrics (Ghesquiere and Karvonen 1981).
Investigating the role of internal layout of magnetic field-generating equipment on workers’ exposure at power substations
Published in International Journal of Occupational Safety and Ergonomics, 2021
Monireh Hosseini, Laleh Farhang Matin, Mohammad Reza Monazzam, Hossein Khosroabadi
McCurdy et al. [14] in their study estimated the exposure level of 273 women in different occupational groups from 25 counties of North Carolina, USA. The highest geometric mean TWA value was 0.27 μT, which falls within the range of 0.05–3.43 μT belonging to women working in industrial manufacturing factories. The minimum geometric mean values of this parameter were 0.13 μT in the range of 0.03–0.29 μT, belonging to health technicians and nurses, and 0.09 μT in the range of 0.03–0.67 μT, belonging to teachers and school managers [14]. In Italy, Gobba et al. [15] calculated the TWA values for 150 workers (84 men and 66 women) in 28 different occupational groups. In their study, the highest average TWA value was 1.12 μT belonging to the workers at high-voltage substations of the power plant. The lowest exposure level also belonged to kindergarten teachers [15].
Related Knowledge Centers
- Threshold Limit Value
- Parts-Per Notation
- Short-Term Exposure Limit
- Administrative Controls
- Occupational Exposure Banding