Inhalation arsenic

Arsenic causes both skin and lung cancer. Skin cancer was observed over 100 years ago in patients treated with arsenical compounds, and lung cancer was seen in smelter workers who chronically inhaled arsenic dust. Although arsenic is an established human carcinogen, it has been difficult to confirm and study in animal models. Arsenic readily crosses the placenta, but there appears to be increased methylation of arsenic to its organic form, which reduces its toxicity to the fetus. 

Minimal data are available from typical inhalation studies in laboratory animals to allow evaluation of extent or dose-dependency in inhaled arsenic absorption. Beck, Slayton and Farr (2002) reported a study in which rabbits were exposed to 0.05, 0.1, 0.22, or 1.1 mg m-3 of arsenic trioxide 8 hours/day, seven days/week for eight weeks. The particle size (mass median aerodynamic diameter, MMAD) ranged from 3.2 to 4.1pm. On the basis of minimal elevation of inorganic arsenic in plasma until exposure levels were at or above 0.22 mg m-3, the authors concluded that systemic uptake of arsenic trioxide following inhalation exposure was low and did not contribute significantly to body burden until relatively high levels of exposure were achieved. 

According to the US EPA, the estimated average national exposure in the USA is about 6 ng As m h Assuming that about 20 m of air is inhaled per person per day, this leads to a total daily inhaled arsenic... 

The toxicity of ingested or inhaled arsenic is dealt with by Hall (1990). Fowler s solution, used orally in the treatment of psoriasis, contains arsenic. Arsenical keratoses and malignancies are well-recognized longterm reactions to this. However, Von Roemeling et al. (1979) reported multifocal malignancies of the bowel and bladder in a psoriatic patient treated 20 years previously with topical Fowler s solution. 

Compare the inhalation risk for tlie emission of 100 pg/m of arsenic willt unit risk of 3.30. x 10 (pg/nv ) ) and dio.xin/dibenz.ofunm willi unit risk of 3.80x10 (pg/m ) ). Also how much arsenic is equivalent to 100 lb of dioxin/dibciizofuran from an inhalation risk perspective ... 

Arsenic may be absorbed by ingestion, inhalation, or through permeation of the skin or mucous membranes. 

Aranyi, C., J.N. Bradof, W.J. O Shea, J.A. Graham, and F.J. Miller. 1985. Effects of arsenic trioxide inhalation exposure on pulmonary antibacterial defenses in mice. Jour. Toxicol. Environ. Health 15 163-172. 

Arsenic and arsenic compounds Asbestos (when inhaled)... 

Unfortunately, the referenced tables were not included with the report. Dr. Abramson told us that he had concluded that the inhalation route was approximately one-third as effective as the oral route. Abramson s ability to arrive at the same conclusion as we did almost ten years later is remarkable, considering that he did not have the benefit of the sophisticated delivery system, including controlled breathing, as we did in our later studies at Edgewood Arsenal. 

Assessment of EA 1729 and EA 3528 by the Inhalation Route. Edgewood Arsenal, MD Chemical Research and Development Laboratory 1964. CRDL Technical Report 3226. 

Most of the compounds of arsenic are toxic when in contact with the skin, when inhaled, or when ingested. As with arsenics cousin phosphorus above it in group 15 of the periodic table, care must be taken when using arsenic. The compound arsenic trioxide (As O ), an excellent weed-killer, is also carcinogenic. Copper acetoarsenite, known as Paris green, is used to spray cotton for boll weevils. A poisonous dose of arsenic as small as 60 miUigrams can be detected within the body by using the Marsh test. 

Ytterbium dust and powder can explode and may be toxic if inhaled. The compound, ytterbium arsenate is a poison. 

Acute inhalation exposures have resulted in irritation of the upper respiratory tract, even leading to nasal perforations. Occupational exposure to arsenic compounds results in hyperpigmentation of the skin and hyperkeratoses of palmar and plantar surfaces, as well as dermatitis of both primary irritation and sensitization types. Impairment of peripheral circulation and Raynaud phenomenon have been reported with long-term exposure. ... 

Arsenic trichloride is a vesicant and can cause severe damage to the respiratory system on inhalation it is rapidly absorbed through the skin, and a fatal case after a spill on the skin has been reported. The vapor of arsenic trichloride is highly irritating to the eyes. Some organic arsenicals, such as arsanilates, have a selective effect on the optic nerve and can cause blindness. 

Arsine is the most acutely toxic form of arsenic. It binds with oxidized hemoglobin, causing profound hemolysis of sudden onset. Inhalation of 250ppm may be fatal within 30 minutes, whereas 10-50 ppm may cause anemia and death with more prolonged exposure. Human experience has indicated that there is usually a delay of 2-24 hours after exposure before the onset of headache, malaise, weakness, dizziness, and dyspnea, with abdominal pain, nausea, and vomiting. Dark red urine is frequently noted 4—6 hours after exposure. This often progresses to brown urine, with jaundice appearing at 24-48 hours after exposure. 

Inhaled arsine is oxidized to form elemental trivalent arsenic (As ) and arsenous oxide (AS2O3), two human carcinogens. Excess cancers from trivalent arsenic and arsenic trioxide have been associated with cumulative lifetime arsenic exposure. Exposure to arsine above 0.004ppm is associated with increased urinary arsenic excretion, indicating exposure to arsenic. Current exposure limits may not prevent potential chronic toxicity. ... 

Toxicology. Lead arsenate may cause lead and/or arsenic intoxication arsenic symptoms likely predominate in acute intoxication, whereas prolonged inhalation of lead arsenate may induce the symptoms of lead intoxication. ... 

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