+<unk>  poisoning at in the dry in 36 subjects in order of performance Exposure (mins.) Num. of subjects Symptoms 96 1 Prolonged dazzle; severe spasmodic vomiting 60–69 3 Severe lip-twitching; Euphoria; Nausea and vertigo; arm twitch 50–55 4 Severe lip-twitching; Dazzle; Blubbering of lips; fell asleep; Dazed 31–35 4 Nausea, vertigo, lip-twitching; Convulsed 21–30 6 Convulsed; Drowsiness; Severe lip-twitching; epigastric aura; twitch L arm; amnesia 16–20 8 Convulsed; Vertigo and severe lip twitching; epigastric aura; spasmodic respiration; 11–15 4 Inspiratory predominance; lip-twitching and syncope; Nausea and confusion 6–10 6 Dazed and lip-twitching; paraesthesiae; vertigo; "Diaphragmatic spasm"; Severe nausea Central nervous system Central nervous system<unk>  manifests as symptoms such as visual changes (especially tunnel vision), ringing in the ears (tinnitus), nausea, twitching (especially of the face), behavioural changes (irritability, anxiety, confusion), and dizziness. This may be followed by a tonic–clonic seizure consisting of two phases: intense muscle contraction occurs for several seconds (tonic phase); followed by rapid spasms of alternate muscle relaxation and contraction producing convulsive jerking (clonic phase). The seizure ends with a period of unconsciousness (the postictal state). The onset of seizure depends upon the partial pressure of<unk>  in the breathing gas and exposure duration. However, exposure time before onset is unpredictable, as tests have shown a wide variation, both amongst individuals, and in the same individual from day to day. In addition, many external factors, such as underwater immersion, exposure to cold, and exercise will decrease the time to onset of central nervous system symptoms. Decrease of tolerance is closely linked to retention of carbon dioxide. Other factors, such as darkness and caffeine, increase tolerance in test animals, but these effects have not been proven in humans. Lungs Pulmonary<unk>  symptoms result from an inflammation that starts in the airways leading to the lungs and then spreads into the lungs (tracheobronchial tree). The symptoms appear in the upper chest region (substernal and carinal regions). This begins as a mild tickle on inhalation and progresses to frequent coughing. If breathing increased partial pressures of<unk>  continues, patients experience a mild burning on inhalation along with uncontrollable coughing and occasional shortness of breath (dyspnea). Physical findings related to pulmonary<unk>  have included bubbling sounds heard through a stethoscope (bubbling rales), fever, and increased blood flow to the lining of the nose (hyperaemia of the nasal mucosa). X-rays of the lungs show little change in the short term, but extended exposure leads to increasing diffuse shadowing throughout both lungs. Pulmonary function measurements are reduced, as noted by a reduction in the amount of air that the lungs can hold (vital capacity) and changes in expiratory function and lung elasticity. Tests in animals have indicated a variation in tolerance similar to that found in central nervous system<unk> , as well as significant variations between species. When the exposure to<unk>  above is intermittent, it permits the lungs to recover and delays the onset of<unk> . Eyes In premature babies, signs of damage to the eye (retinopathy of prematurity, or ROP) are observed via an ophthalmoscope as a demarcation between the vascularised and non-vascularised regions of an infant's retina. The degree of this demarcation is used to designate four stages: (I) the demarcation is a line; (II) the demarcation becomes a ridge; (III) growth of new blood vessels occurs around the ridge; (IV) the retina begins to detach from the inner wall of the eye (choroid).
Oxygen toxicity
Cerebral hypoxia
Nitrogen dioxide poisoning
Chromium toxicity
Histotoxic hypoxia
Fluoride toxicity
Chlorine gas poisoning
Silent hypoxia