Accidental exposures

Toxicity. Sulfur tetrafluoride has an inhalation toxicity comparable to phosgene. The current OSHA standard maximum allowable concentration for human exposure in air is 0.4 mg/m (TWA) (54). On exposure to moisture, eg, on the surface of skin, sulfur tetrafluoride Hberates hydrofluoric acid and care must be taken to avoid bums. One case of accidental exposure of electrical workers to decomposed SF gas containing SF has been cited (108). 

In experimental work, some accidental exposures, or in the administration of medicine, the dose may be a certain quantity of the chemical administered at one time, such as in a pill, an injection, or an accidentally swallowed poison. In industry, time is a factor in most exposures, and the dose is the result of both the concentration of the toxic agent and the duration of the exposure. 

Developmental Effects. Adverse effects of methyl parathion on hirman fetal development have not been reported. Based on studies in animals, such effects appear to be possible if pregnant women were exposed during the first trimester to high concentrations of methyl parathion that resulted in significant depression of cholinesterase levels, particularly if concomitant signs and symptoms of organophosphate intoxication occur. Such an exposure scenario may occur with occupational exposure, exposure in homes or offices illegally sprayed with methyl parathion, or accidental exposure to methyl parathion, but is less likely as a result of low-level exposure. 

The theoretieal baekground whieh underlies immunity to infection has been discussed in detail in Chapter 14. Immunity to infeetion may be passively acquired through the receipt of preformed, proteetive antibodies or it may be aetively acquired through an immune response following deliberate or accidental exposure to microorganisms or their eomponent parts. Aetive aequired immunity might involve either or both humoral and cell-mediated responses. 

Water-sensitive papers are readily available in most countries and provide a convenient system for visually assessing spray drift performance. These papers are coated with bromoethyl blue, which turns from yellow to blue when contacted with water. " However, since any water can cause this change in color, care needs to be taken to prevent accidental exposure to sources of water other than the pesticide. Such cards do not work well under humid conditions, and are not appropriate for sampling droplets with diameter below 15 qm. Quantitative estimates of droplet size distributions must take account of the exponential increase in droplet volume as the droplet diameter increases. As droplets strike the paper, the liquid spreads over the surface and leaves a stain with a size that is dependent on the volume of the droplet. The apparent droplet size will be greater for large droplets than for small droplets, and the size determination must be corrected to avoid bias. 

M usculoskeletal Effects. Accidental exposure of a worker to 241 Am resulted in histological signs of fibrosis, bone cell depletion, and bone marrow atrophy. Degenerative changes in bone have also been observed in animals acutely exposed to 241 Am via inhalation and intravenous administration. 

No reports were located regarding death in humans that could be associated with acute-, intermediate,- or chronic-duration dermal exposure to americium. An explosion and accidental exposure of a 64-year-old man to 1-5 Ci (37-185 GBq) of241 Am was followed by immediate treatment to reduce contamination to approximately 6 mCi (222 MBq) and to 1 mCi (37 MBq) after the first day (Thompson 1983 Toohey and Kathren 1995). Survival was likely the result of intense and long-term chelation therapy, such as with diethylenetriaminepentaacetic acid (DTPA). The patient lived until natural death 11 years after the accident (see Section 3.2.3.2 for more detailed information regarding this accidental exposure and subsequent treatment and follow-up). 

Section 3.2.3.2 Hematological Effects for a more detailed account of this accidental exposure to americium). 

Several cases of accidental exposure to americium as a result of wound penetrations have been reported (Thompson 1983). These exposures have resulted in241 Am burdens in the liver and skeleton, indicating absorption and distribution from the wound site (Mclnroy et al. 1989). 

Information on the excretion of americium after dermal exposure in humans or animals is extremely limited. Some qualitative information is available from an accidental exposure in which a worker received facial wounds from projectile debris and nitric acid during an explosion of a vessel containing 241 Am (McMurray 1983). The subject also inhaled 241Am released to the air as dust and nitric acid aerosols, which was evident from external chest measurements of internal radioactivity thus, excretion estimates reflect combined inhalation, dermal, and wound penetration exposures (Palmer et al. 1983). Measurements of cumulative fecal and urinary excretion of241 Am during the first years after the accident, and periodic measurements made from day 10 to 11 years post accident indicated a fecal urine excretion ratio of approximately 0.2-0.3, although the ratio was approximately 1 on day 3 post accident (Breitenstein and... 

Hematological Effects. The cyanosis that has been reported in a number of cases of accidental exposure to hydrogen sulfide is believed to result from respiratory distress (Arnold et al. 1985 Burnett et al. 1977 Deng and Chang 1987 Peters 1981 Ravizza et al. 1982 Stine et al. 1976 Tvedt et al. 1991a, 1991b). 

Hydrogen sulfide is primarily absorbed through the lungs. It can also be absorbed through the gastrointestinal tract and the skin. Hydrogen sulfide is widely distributed in the body after inhalation exposure. Based on analyses of tissues from humans who died after accidental exposure, sulfides have... 

Respiratory Effects. In most case reports of acute accidental exposure to hydrogen sulfide and occupational studies, exposure concentrations and duration were not reported. However, acute inhalation exposure to >500 ppm hydrogen sulfide is considered to result in respiratory failure. Death is often the result of respiratory depression as a result of the action of hydrogen sulfide on the respiratory center in the brain. Respiratory distress was reported in 2 workers exposed to >40 ppm hydrogen sulfide for... 

No accidental inhalation exposures to aniline in which concentrations were known were identified in the available literature. However, methemoglobin levels were measured after accidental exposures to liquid aniline or aromatic... 

Data on acute exposures of humans to both isomers of dimethylhydrazine are limited to case reports of accidental exposures. Signs and symptoms of exposure include respiratory irritation, pulmonary edema, nausea, vomiting, and neurologic effects. However, definitive exposure data (concentration and duration) were unavailable for these accidents. The limited data in humans suggest that the nonlethal toxic response to acute inhalation of dimethylhydrazine is qualitatively similar to that observed in animals. No information was available regarding lethal responses in humans. In the absence of quantitative data in humans, the use of animal data is considered a credible approach for developing AEGL values. 

In 1954, a proprietary formulation, Stalinon , was marketed in France for oral administration of boils. The formulation was primarily linoleic acid but was contaminated with triethyltin (TET)iodide (LD50 in rats, ca 0.7 mg/kg1) and may have contained the mono-, di- and tetraethyltin compounds. The formulation led to the death of 102 people and the intoxication of more than 200 others. The TET caused altopic cerebral edema of the white matter of the brain. Since the Stalinon Affair , a great deal of control has been exerted in the manufacture and marketing of organotins and few deaths have occurred11. The accidental exposure of six industrial workers to TMT led to one death and to two seriously... 

PCDD/PCDFs are today found in almost all compartments of the global ecosystem in at least trace amounts. They are ubiquitous in soil, sediments and air. Excluding occupational or accidental exposures, most human background exposure to dioxins and PCBs occurs through the diet, with food of animal origin being the major source, as they are persistent in the environment and accumulate in animal fat. 

In March of 2000, a microbiologist working with infectious diseases in a Biosafety Level 3 facility at USAMRIID contacted glanders due to accidental exposure. Between 1987 and 1990, two other workers acquired infectious diseases at the same facility. 

Is there a risk of accidental exposure to persons involved in the production of smallpox vaccine ... 

Private residences or other nonhospital facilities that are used to isolate confirmed or suspected smallpox patients should have nonshared ventilation, heating, and air-conditioning systems. Access to those facilities should be limited to recently vaccinated persons with a demonstrated immune response. If suspected smallpox patients are placed in the same isolation facility, they should be vaccinated to guard against accidental exposure caused by misclassification as someone with smallpox. 

---