Cytotoxicity and genotoxicity in vitro and irritation potency in vivo of two red phosphorus-based pyrotechnic smokes.

Two red phosphorus (RP)-based smokes (P60 and RPB), differing from each other mainly in RP content and in type of additive, were evaluated for in vitro cytotoxicity (cell viability by the trypan-blue exclusion method) and genotoxicity (comet assay) by exposing BEAS 2B human bronchial epithelial cells to the smokes in a laboratory-scale chamber for 5 min. The irritation potency of RPB smoke was studied in mice. A hexachloroethane-based smoke (HC/Zn/TNT) was used as a reference in the studies.

In vivo and in vitro evaluation of the acute toxicity, the genotoxicity, and the irritation potency of two hexachloroethane-based pyrotechnic smokes.

The two hexachloroethane (HC)-based smoke formulations studied consisted of HC/Zn/2,4,6-trinitrotoluene (TNT) and HC/Zn. In the in vitro tests, human bronchial epithelial cells were exposed to the smokes at various concentrations. The responses studied were acute toxicity (viability of cells, trypan blue exclusion method) and genotoxicity (DNA single-strand breaks, COMET assay).

Aerosol extinction models based on measurements at two sites in Sweden.

Two aerosol extinction models have been developed using statistical analysis of long-term optical transmission measurements in Sweden performed at two locations from July 1977 to June 1982. The aerosol volume extinction coefficient for infrared (IR) radiation is calculated by the models with visibility, temperature, and air pressure as input parameters. As in the MODTRAN model, the IR extinction coefficient is proportional to the coefficient at 550 nm, which depends on the visibility.