Accidental exposure to/toxicity

Workers exposed to an airborne fluoride concentration of 5mg/m complained of eye and respiratory tract irritation and nausea. The lethal oral dose of sodium fluoride for humans has been estimated to be 32-65 mg F/kg of body weight. Effects from ingestion are diffuse abdominal pain, diarrhea, and vomiting excessive salivation, thirst, and perspiration painful spasms of the limbs and sometimes albuminuria." Gastrointestinal effects produced after the acute ingestion of toxic amounts of fluoride likely arise from the corrosive action of hydrofluoric acid, which is produced within the acidic environment of the stomach. Cardiac arrest after accidental exposure to high levels of fluoride has been attributed to the development of hypocalcemia and/or hyperkalemia. ... 

Of three chemical workers who were observed after accidental exposures to perchloromethyl mercaptan, two survived episodes of pulmonary edema, and the third died after 36 hours. The fatality resulted from a spill of the liquid on the clothing and floor with exposure to the vapor. At autopsy, there was necrotizing tracheitis, massive hemorrhagic pulmonary edema, marked toxic nephrosis, and vacuolization of centrilobular hepatic cells. 

Paraquat and the related chemical diquat are nonselective herbicides that are also toxic to mammals. Occupational or accidental exposure to paraquat can be from oral ingestion, dermal exposure, or inhalation, all of which can cause serious illness or death. While seldom used in the United States, paraquat is still widely used in developing countries. At one time it was used to kill marijuana plants, but a number of fatalities were observed when marijuana contaminated with paraquat was inhaled. 

Exposure to toxicants can vary, producing what is known as acute or chronic poisoning. Poisoning can also be classified according to the intent of use. Poisoning can either be suicidal (non-accidental) or accidental in nature. Recreational poisoning, such as substance abuse, can be a source of harmful intoxication and, in some cases, can lead to addiction and withdrawal symptoms. Intentional harm is observed when there is criminal doping with sedative-hypnotic medicines, often associated with robberies. 

Because of accidental exposure to insecticides by children or by agricultural workers, an appreciation of the toxicities of insecticide anticholinesterase inhibitors is medically relevant. 

Toxic effects observed after accidental exposure to dichloroacetylene were mainly neurological disorders that persisted for periods ranging from several days to years (lARC, 1986). 

The climate in which the questionnaire was used might raise concern about interpretation of the results. For example, subjects who wished (for whatever reason) to misrepresent the nature and severity of their problems could distort the results (and hence their interpretation), especially if their chemical-test group was fairly small. In addition, as in any cohort study, there was no control of the subjects environments after discharge from the service, so even legitimate complaints associated with exposure to toxic substances could have been due to occupational or accidental exposure to chemical agents, rather than to exposure at Edgewood. 

TABLE 2-5 Human Toxicity Data, Accidental Exposure to Ammonia... 

Much of the evidence for the adverse reproductive effects of selected toxicants will be based on cases involving wildlife exposures to environmental contaminants or on the experimental results of research exposing laboratory animals to large, pharmacological doses of potential toxicants. When available, data will be presented from accidental or intentional human and domestic animal exposures to toxicants associated with riot control and chemical warfare or with environmental catastrophes where incidences of infertility, abortion, and teratogenesis have been traced over the course of a number of years. 

In humans, the mechanism of toxicity following accidental exposure to veterinary products is poorly understood but may include the penetration of ivermectin into the central nervous system (CNS). Humans undergoing treatment with ivermectin may suffer from anaphylactic-type reactions as microfilaria die off. Toxicity in animals is usually associated with extreme overdosing. Purebred and mixed breed Collies and Australian Shepherds exhibit greater distribution of ivermectin into the CNS resulting in ataxia, tremor, and often death. Use of ivermectin should be avoided in these animals. 

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