Individual occupation

Equation 13 has an important implication a clathrate behaves as an ideally dilute solution insofar as the chemical potential of the solvent is independent of the nature of the solutes and is uniquely determined by the total solute concentrations 2K yK1.. . 2x yKn in the different types of cavities. For a clathrate with one type of cavity the reverse is also true for a given value of fjiq (e.g. given concentration of Q in a liquid solution from which the clathrate is being crystallized) the fraction of cavities occupied 2kVk s uniquely determined by Eq. 13. When there are several types of cavities, however, this is no longer so since the individual occupation numbers 2k2/ki . ..,2k yKn, and hence the total solute concentration... 

Hepatic Effects. Jaundice and abnormal liver function tests including increases in serum transaminase levels have been reported in individuals occupationally exposed to trichloroethylene by both dermal and inhalation exposure (Bauer and Rabens 1974 Phoon et al. 1984). 

Neurological examinations of humans with M-hexanc-induced peripheral neuropathy have not shown clinical signs of central nervous system toxicity (Herskowitz et al. 1971 Yamamura 1969). There have been reports of altered evoked potentials recorded in the brain (increased latency, decreased amplitude) in humans occupationally exposed to -hexane (Mutti et al. 1982c Seppalainen et al. 1979). There has been one report of an individual occupationally exposed to -hexane for 38 years who developed Parkinsonism (Pezzoli et al. 1995), although the etiology of this case is complicated by the fact that the patient had a sister who was probably affected by Parkinsonism. Further studies, particularly prospective... 

However, reliable quantitative exposure levels that lead to these effects are lacking. Additional quantitative exposure data obtained from individuals occupationally exposed to low levels of endrin would be useful in evaluating potential risk to people living near hazardous waste sites. 

It has become customary among cancer epidemiologists to talk about certain lifestyle factors as important contributors to cancer risk. Lifestyle factors (smoking, dietary patterns, alcohol consumption) are assumed to be largely under the control of individuals. These are distinguishable from factors that are less directly in the control of individuals (occupation, medicines, consumer products), and those over which individuals have little or no control (food additives, pesticides, environmental pollutants). Just how much control individuals have over the various lifestyle factors is of course much debated. 

Bencko V, Wagner V, Wagnerova M, et al. 1983. Immuno-biochemical findings in groups of individuals occupationally and nonoccupationally exposed to emissions containing nickel and cobalt. J Hyg Epidemiol Microbiol Immunol 27 387-394. 

Individuals occupationally exposed to coal tars or the naphtha fraction of coal-tar distillate have potentially high exposure to 2,3-benzofuran. Persons living near industrial sources or hazardous waste sites contaminated with 2,3-benzofuran may be exposed to 2,3-benzofuran. There are insufficient data to identify any other populations with potentially high exposure to this compound. 

Ott MG, Zober A, Germann C. 1994. Laboratory results for selected target organs in 138 individuals occupationally exposed to TCDD. Chemosphere 29 9-11. 

Chapters 21 through 34 address individual occupancies. Chapter 60 addresses hazardous materials, and all subsequent chapters address some specific hazardous materials, including aerosols, compressed gases, corrosives, explosives, fireworks, flammable and combustible liquids, flammable solids, and toxics. Much of the old misleading information about some of these hazardous materials has been taken out of recent editions. 

Acute inhalation and oral exposures of humans to high concentrations of benzene have caused death (Cronin 1924 Greenburg 1926 Tauber 1970 Thienes and Haley 1972). These exposures are also associated with central nervous system depression (Flury 1928 Greenburg 1926). Chronic low-level exposures have been associated with peripheral nervous system effects (Baslo and Aksoy 1982). Abnormalities in motor conduction velocity were noted in 4 of 6 pancytopenic individuals occupationally exposed to adhesives containing benzene. 

Townsend JC, Ott MG, Fishbeck WA. 1978. Health exam findings among individuals occupationally... 

Autopsy data from individuals occupationally exposed to uranium indicates that bone is the primary site of long term retention of absorbed uranium (ICRP 1995). Inhalation exposure may also result in some retention of insoluble uranium particles in the lungs. An evaluation of the postmortem data from a uranium worker who had inhaled a total of 220 mg (147 pCi) uranium over a 3-year period found 11 pg (7 pCi) uranium in the lungs 13 years after the end of exposure. The total calculated dose equivalent from the inhaled uranium was 35 rem (0.35 Sv) (Keane and Polednak 1983). 

Rom WN, Travis WD. 1992. Lymphocyte-macrophage alveolitis in nonsmoking individuals occupationally exposed to asbestos. Chest 101(3) 779-786. 

In connection with the development of an analytical method (13) for the determination of organophosphorus pesticides in human blood and urine, mass spectral confirmation of a series of methylated and ethylated derivatives of the hydrolytic and metabolic products of these insecticides was required. The urine of an individual occupationally exposed to parathion was extracted with a 1 1 (v/v) solvent mixture of acetonitrile and diethyl ether. Simultaneously, the intact organophosphorus insecticides were hydrolyzed by adding a portion of 5N hydrochloric acid to... 

Chronic inhalation or oral exposure to low levels of vinyl chloride may cause liver damage in humans. Some individuals occupationally exposed to high levels of vinyl chloride develop a specific syndrome termed vinyl chloride disease . This is characterized by dizziness, numbness, earache, headache, blurred vision, fatigue, nausea, shortness of breath, Raynaud s phenomenon, loss of weight, changes in bone structure at the ends of the fingers, joint, and muscle pain, and scleroderma-type changes in the skin. 

Thrasher JD, Broughton A, Micevich P. 1988b. Antibodies and immune profiles of individuals occupationally exposed to formaldehyde six case reports. Am J Ind Med 14 479-488. 

Human exposure to PAHs can be monitored through analytical determination of PAHs and metabolites (e.g., 1-hydroxypyrene) in the urine of exposed individuals (Jongeneelen et al. 1985, 1987 Tolos et al. 1991 Weston et al. 1994). For example, Clonfero et al. (1990) detected increased levels of PAH metabolites in the urine of individuals occupationally (i.e., aluminum plant workers) and therapeutically (i.e., psoriatic patients) exposed to coal tar, as compared to unexposed subjects. Weston et al. (1994) reported similar results for coal-tar treated psoriasis patients. Tolos et al. 

A number of experiments performed thereafter were supportive for the immune-based etiology of zimeldine-induced adverse effects (Kristofferson Nilsson, 1989). Three individuals occupationally exposed to zimeldine developed allergy to the compound and showed positive patch and skin prick tests and positive response to zimeldine in the lymphocyte transformation test. Patients with a history of zimeldine-induced disease showed marked lymphocyte transformation test responses to zimeldine as well as two metabolites (norzimeldine and CPP200). These findings indicate that zimeldine may be immunogenic indeed, zimeldine has been shown to be positive in the popliteal lymph node assay, based on cell numbers and including germinal centre formation and production of IgM and IgG antibodies (Thomas et al., 1989). 

Different travel distances are established for unsprinklered and sprin-klered buildings with the exception of certain occupancies classified as Hazardous Uses. Maximum allowable travel distances for individual occupancies should be determined by reference to the applicable code. 

However, more extensive study of individuals occupationally exposed would be useful, and would hopefully clarify the equivocal reports of previous studies. 

Individuals occupationally exposed to plutonium in the past are continually monitored in programs across the country. For example, whole body counting studies are currently conducted at Los Alamos National Laboratory in New Mexico. Animal studies conducted at the Lawrence Berkeley Laboratory, University of California, Berkeley, by P. Durbin are evaluating the behavior and movement of plutonium inhaled into the lungs. Models used to estimate body burden based on urinary excretion data and other biological measurements of plutonium (Leggett and Eckerman 1987) are under continual revision. 

Fluctuations of individual occupations around the industry average should affect the variance of the risk measures but not the best estimate of their values. 

A.26. Records of occupational radiation doses. Inspection personnel should selectively review records of individual occupational doses, including internal and external doses. Activities should be observed to ensure that procedural and management controls are effective. This includes controls for radiation areas and contamination areas as well as inspection of activities for internal and external dosimetry. Exposures of personnel that result in the operator s reference levels for effective doses or intakes being exceeded should be noted. Records of radiation protection training and retraining should be assessed. 

A competing concept of documenting medically (dermatologically) relevant descriptors, i.e., exposures and their duration and intensity, would be to classify not the individual occupation of the patient, but the type of industry in which he or she works. Examples of such classifications and some of their applications, e.g., employers liability insurance or governmental labor statistics, are listed below. A classification system provided by the United Nations (UN) for this purpose is the international standard industrial classification (ISIC) (United Nations 1990), as shown below. 

In a study of 66 occupational groups (and 170 individual occupations) in Sweden (Hellgren 1976), lichen planus was found to be more prevalent in agriculture and forestry workers than in the total population, an observation that was ascribed to the dirty nature of these occupations where skin became contaminated with soil, etc. 

Often, it is almost impossible to determine the individual occupational exposure of leather-industry workers. The biocides to which they are exposed by handling semi-processed leather are unknown to the... 

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