Toxins respiratory protection

Immediately dangerous to life or health (IDLH) levels are the ceiling limit for respirators other than SCBAs. However, IDLH levels have not been established for toxins. Therefore, any potential exposure to aerosols of these agents should be regarded with extreme caution and the use of SCBAs for respiratory protection should be considered. 

Drugs Available (No specific anti-toxin) Active immunization and passive antibody prophylaxis are under study, as both are effective in protecting animals from death following exposure by intravenous or respiratory routes. Ricin is not dermally active therefore, respiratory protection is the most critical means of prevention. 

Methods of detection, metabolism, and pathophysiology of the brevetoxins, PbTx-2 and PbTx-3, are summarized. Infrared spectroscopy and innovative chromatographic techniques were examined as methods for detection and structural analysis. Toxicokinetic and metabolic studies for in vivo and in vitro systems demonstrated hepatic metabolism and biliary excretion. An in vivo model of brevetoxin intoxication was developed in conscious tethered rats. Intravenous administration of toxin resulted in a precipitous decrease in body temperature and respiratory rate, as well as signs suggesting central nervous system involvement. A polyclonal antiserum against the brevetoxin polyether backbone was prepared a radioimmunoassay was developed with a sub-nanogram detection limit. This antiserum, when administered prophylactically, protected rats against the toxic effects of brevetoxin. 

This is an acute, non-invasive infectious disease associated with the upper respiratory tract (Chapter 4). The incubation period is fiom 2 to 5 days although the disease remains communicable for up to 4 weeks. A low molecular weight toxin is produced which affects myocardium, nervous and adrenal tissues. Death results in 3-5% of infected children. Diphtheria immunization protects by stimulating the production of an antitoxin. This antitoxin will protect against the disease but not against infection of the respiratory... 

Infants are protected during gestation because the placenta clears most potential toxins. The classical form of the disease therefore does not become clinically manifest until a few days after birth. An initial phase of alternating irritability and lethargy progresses over a period of days to frank coma and respiratory embarrassment. Irreversible brain damage is common in babies who survive, particularly those whose treatment is delayed until after the first week of life. 

An understanding of common mechanisms of death due to poisoning can help prepare the care-giver to treat patients effectively. Many toxins depress the central nervous system (CNS), resulting in obtundation or coma. Comatose patients frequently lose their airway protective reflexes and their respiratory drive. Thus, they may die as a result of airway obstruction by the flaccid tongue, aspiration of gastric contents into the tracheobronchial tree, or respiratory arrest. These are the most common causes of death due to overdoses of narcotics and sedative-hypnotic drugs (eg, barbiturates and alcohol). 

Respiratory, skin, and eye protection is required for personnel working with trichothecenes. There are no specific therapies for trichothecene toxicoses. Neither vaccines nor specific antidotes are readily available. Treatment in people and animals is symptomatic and supportive, and the only known prophylactic measure is avoidance of exposure (Fricke and Poppenga, 1989 National Academy of Science, 1983). T-2 toxin is stable in the environment, and resistant to heat and ultraviolet light. 

Toxins are generally dispersed as aerosols and pose a severe respiratory hazard. However, Toxins are nonvolatile and do not pose an inhalation hazard once the aerosol has settled. Wear appropriate fully encapsulating protective gear with positive pressure self-contained breathing apparatus (SCBA). There is a significant hazard posed by contact of contaminated material with abraded skin or injection of toxins through contact with debris. Appropriate protection to avoid any potential abrasion, laceration or puncture of the skin is essential. 

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