Central nervous system chronic effects

Neurological Effects. Neurological effects in hrnnans after acute inhalation exposure to chloroform are well documented because chloroform has been used as an anesthetic for surgery. Inhaled chloroform acts as a depressant on the central nervous system. Chronic inhalation exposure to chloroform resulted in exhaustion, lack of concentration, depression, and irritability in occupationally exposed people (Challen et al. 1958). In a case study, chloroform inhalation for 12 years resulted in psychotic episodes, hallucinations, and convulsions (Heilbmnn et al. 1945). Central nervous system toxicity was observed in humans after oral exposure to chloroform, which suggests that the effects of inhalation and oral exposure are similar. In case reports of patients who intentionally or accidentally ingested several ounces of chloroform, deep coma with abolished reflexes occurred within a few minutes (Piersol et al. 1933 Schroeder 1965 Storms 1973). 

Chronic exposure results in eye damage, kidney degeneration, and central nervous system (CNS) effects. It is a carcinogen to nasal passages, pharynx, and respiratory tract. A dose-response relationship exists between exposure and damage to the reproductive system. Age or stage of sexual development also mediated damage. 

CHRONIC HEALTH RISKS depressed levels of cholinesterase activity in the semm and erythrocytes anorexia cardiovascular system effects effects on the central nervous system chronic skin disorders. 

Symptoms of acute solvent poisoning include dizziness, drowsiness, headache, loss of consciousness, and narcotic effects which are attributed to disturbances of the central nervous system. Chronic poisoning is initially undetectable, but subsequently causes damage to organs that are specific for each solvent [14.107]-[14.11oj. 

Health and Safety Factors. Carbonyl sulfide is dangerously poisonous, more so because it is practically odorless when pure. It is lethal to rats at 2900 ppm. Studies show an LD q (rat, ip) of 22.5 mg/kg. The mechanism of toxic action appears to iavolve breakdowa to hydrogea sulfide (36). It acts principally on the central nervous system with death resulting mainly from respiratory paralysis. Little is known regarding the health effects of subacute or chronic exposure to carbonyl sulfide a 400-p.g/m max level has been suggested until more data are available (37). Carbon oxysulfide has a reported inhalation toxicity in mice LD q (mouse) = 2900 ppm (37). 

Inhalation is the most common means by which ethers enter the body. The effects of various ethers may include narcosis, irritation of the nose, throat, and mucous membranes, and chronic or acute poisoning. In general, ethers are central nervous system depressants, eg, ethyl ether and vinyl ether are used as general anesthetics. 

Air-poUutant effects on neural and sensory functions in humans vary widely. Odorous pollutants cause only minor annoyance yet, if persistent, they can lead to irritation, emotional upset, anorexia, and mental depression. Carbon monoxide can cause death secondary to the depression of the respiratory centers of the central nervous system. Short of death, repeated and prolonged exposure to carbon monoxide can alter sensory protection, temporal perception, and higher mental functions. Lipid-soluble aerosols can enter the body and be absorbed in the lipids of the central nervous system. Once there, their effects may persist long after the initial contact has been removed. Examples of agents of long-term chronic effects are organic phosphate pesticides and aerosols carrying the metals lead, mercury, and cadmium. 

Dille JR, Smith WS. 1964. Central nervous system effects of chronic exposure to organophosphate insecticides. Aerospace Medicine May 475-478. 

Some of the severe central nervous system effects described above have not been described in some intermediate or chronic ingestion studies of endosulfan in experimental animals (FMC 1959a, 1965,... 

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