Toxicity, epidemiologic studies

Polyalphaolefin Hydraulic Fluids. No human studies for polyalphaolefin hydraulic fluids were located. Polyalphaolefin hydraulic fluids are used in U.S. military aircraft hydraulic systems thus, there is a potential for occupational exposure. Animal studies were insufficient for determining the primary targets of toxicity. Epidemiology studies examining a number of end points would be useful for identifying targets of toxicity. 

Exposure assessment to reveal the exposure of different groups of people, and to compare their exposure levels to the doses that cause harmful effects in humans as shown in epidemiological studies, or to doses that cause toxic effects in experimental animals... 

Case-Control Study—A t5q)e of epidemiological study which examines the relationship between a particular outcome (disease or condition) and a variety of potential causative agents (such as toxic chemicals). In a case-controlled study, a group of people with a specified and well-defined outcome is identified and compared to a similar group of people without outcome. 

Acute poisoning of humans by freshwater cyanobacteria as occurs with paralytic shellfish poisoning, while reported, has never been confirmed. Humans are probably just as susceptible as pets, livestock, or wildlife but people naturally avoid contact with heavy waterblooms of cyanobacteria. In addition, there are no known vectors, like shellfish, to concentrate toxins from cyanobacteria into the human food chain. Susceptibility of humans to cyanobacteria toxins is supported mostly by indirect evidence. In many of these cases, however, if a more thorough epidemiological study had been possible these cases probably would have shown direct evidence for toxicity. 

Assessment of whether a chemical has the potential to cause adverse effects in humans arises usually from direct observation of an effect in animals or humans, such as the acute poisoning episodes that have occurred when potatoes contain high levels of glycoalkaloids. Epidemiological studies have also been used to infer a possible relationship between intake of a particular type of food, or constituent of that food, and the potential to cause an adverse effect. Such observations led to the characterisation of the aflatoxins as human carcinogens. However, natural toxic substances that occur in plant foods have often been identified through observations in animals, particularly farm animals. It was observations of adverse effects in farm animals that led to the further characterisation of the phytoestrogens and the mycotoxins. In other instances, the concern arises from the chemical similarity to other known toxins. 

Hu H, Rabinowitz M, Smith D. 1998. Bone lead as a biological marker in epidemiologic studies of chronic toxicity conceptual paradigms. Environmental Health Perspectives 106(1) 1-8. 

Human studies including case reports, epidemiological studies, and, in some cases, direct human studies (with volunteers). The advantages of these studies are that toxic effects are evaluated in humans and no interspecies extrapolation is... 

Knowing the results of epidemiology studies on the association between diesel exhaust exposure and lung cancer, and animal studies on the toxicity of two types of soot, what can we conclude concerning the toxicity to humans of soot associated with fires Combustion processes produce small, respirable size soot particles. The composition of the soot from fires can vary widely with the condi-... 

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