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CF(3)I is being considered by the U.S. Air Force as a replacement for Halon 1301 for fire-extinguishing requirements in unoccupied spaces. The purpose of this study was to determine and evaluate the potential for CF(3)I to produce reproductive toxicity and to provide additional information on the effect of CF(3)I exposure on the thyroid. Groups of 16 male and 16 female rats were exposed (6 h/day) to CF(3)I vapor at concentrations of 0 (control), 0.2, 0.7, and 2.0% using whole-body inhalation chambers. Prior to mating, rats were exposed to CF(3)I for 4 wk (5 days/wk). Exposures were 7 days/wk during the periods of mating (2 wk), gestation (3 wk), and lactation (3 wk). First-generation pups were not exposed to CF(3)I vapor. In parental animals, there were no clinical signs of toxicity except for a minimal decrease in mean body weight in female rats at 2.0% CF(3)I. At necropsy, gross findings, mean serum chemistry levels, mean hematology values, mean bone marrow micronuclei scores, and mean organ weights were similar for all exposure groups, including the air control group. Statistically significant differences did not show a pattern and/or were considered incidental. There were no treatment-related microscopic tissue findings, including the thyroid organ. Analysis of reproductive indices and parameters indicates CF(3)I is not a reproductive toxicant. Results of serum thyroid hormone levels (e.g., T(3), T(4), rT(3), and TSH), showed concentration-related increases in TSH, T(4), and rT(3). T(3) levels were decreased. First-generation pup survival and mean body weights were similar in all exposure groups, including the control. Exposure of 2.0% CF(3)I vapor for approximately 14 wk produced minimal general toxicity and no reproductive toxicity in Sprague-Dawley rats. On the basis of reproductive indices and parameters, the NOAEL for this study is 2.0% CF(3)I.

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Fischer 344 rats (250-300 g) were exposed to the resulting aerosols from the pyrolysis of Spectrex Fire Extinguishant (SFE) Formulation A, a pyrotechnically generated aerosol fire suppressant, at a loading equivalent of 50 or 80 g m(-3) air for 15 or 60 min. Exposures were conducted in a 700-1 whole-body inhalation chamber under static conditions. The chamber atmosphere was analyzed for mass aerosol concentration and size distribution. Clinical observations were taken throughout the exposure. Animals were euthanized at 1 h, 6 h, 24 h, 7 days or 14 days post-exposure and underwent histopathological examination, enzyme analyses and wet/dry lung weight determination. No deaths occurred during the study. Animals exhibited signs of dyspnea, coughing, lack of coordination and lethargy during each exposure. These signs became more pronounced as the load and exposure length increased. No lesions were noted in the trachea, lung, heart or abdominal organs upon gross examination. A reversible pulmonary edema and olfactory necrosis were observed only in those animals exposed to an SFE loading equivalent to 80 g m(-3) for 60 min. Protein concentrations increased in the bronchoalveolar lavage but no changes in enzyme levels were observed. There was no significant difference between the control groups and the exposure groups for wet/dry lung weight determination.

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Trifluoroiodomethane (CF3I) is being considered as a replacement compound for halon fire suppressants. Its structure is similar to that of Halon 1301 (CF3Br), but it has very low ozone depletion potential compared to CF3Br. As part of the process of developing environmental and health effects criteria, acute, 2-week, and 13-week nose-only inhalation toxicity studies were conducted in Fischer 344 rats. In the acute study, three groups of 30 male rats each were exposed to 0 (control), 0.5, or 1.0% (v/v) CF3I for 4 hr and euthanized immediately following exposure, 3 days postexposure, or 14 days postexposure. There were no deaths and no clinical signs of toxicity throughout the study. Histopathologic examination of select tissues showed no lesions of pathologic significance. In the 2-week study, four groups of 5 male rats each were exposed for 2 hr/day, 5 days/week to 0, 3, 6, or 12% CF3I. No deaths were observed, though lethargy and slight incoordination were noted in rats of the 6 and 12% groups at the conclusion of each daily exposure. Mean body weight gains were depressed in rats of the 6 and 12% groups. Serum thyroglobulin and reverse T3 (rT3) values were increased at all exposure levels. At necropsy, no gross lesions or differences in absolute or relative organ weights were noted. Histopathologic examination of the thyroid and parathyroid glands indicated no morphological abnormalities in the CF3I-exposed rats. In the 13-week study, four groups of 15 male and 15 female rats were exposed to 0, 2, 4, or 8% CF3I 2 hr/day, 5 days/week for 13 weeks. Rats exposed to 4 or 8% CF3I had lower mean body weights than the controls. Deaths observed in the 2 and 8% groups were attributed to accidents resulting from the restraint system employed. Hematologic alterations were minimal and considered insignificant. Increases in the frequency of micronucleated bone marrow polychromatic erythrocytes were observed in rats of all three CF3I groups. Serum chemistry alterations observed in rats of all CF3I exposure groups included decreases in T3 and increases in thyroglobulin, rT3, T4, and TSH. Relative organ weight increases (8% CF3I group) occurred in the brain, liver, and thyroid glands; decreases were observed in the thymus and testes. A decrease in relative thymus weights and an increase in relative thyroid weights were observed also in rats of the 2 and 4% groups. Histopathological findings included a mild inflammation in the nasal turbinates of rats exposed to 4 or 8% CF3I, mild atrophy and degeneration of the testes (4 and 8% CF3I groups), and a mild increase in thyroid follicular colloid content in rats of all CF3I exposure groups. Though NOAELs were observed for select target organs (e.g., nasal turbinates, testes), NOAELs were not apparent in all target organs examined (e.g., thyroid glands, bone marrow).

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We investigate scaling with the cross-sectional area of energy and speed for optical devices and of optical design, speed, and thermal dissipation for device arrays. Theory and experiments clearly point to lower energy and faster speed for smaller devices and to simpler optical design, smaller propagation time delays, and higher thermal dissipation capability for smaller array sizes. We conclude that the development of high speed digital optical processors will depend on small devices interconnected by microoptic systems.

RESUMEN

Using a 6 X 6 array of integrated quantum-well self-electro-optic-effect devices, we demonstrate an optically addressed spatial light modulator able to convert a visible, incoherent image into coherent infrared (IR) light. Depending on the IR wavelength used, the output is either a positive, binary-thresholded version of the input (bistable mode) or its linear, negative (self-linearized) mode. This device can also function as a dynamic bistable memory that can retain its internal state without power for times as long as 30 sec.