Polychromatic exposures

Action Spectra Derived from Polychromatic Exposure... 

An action spectrum shows the relationship between the effectiveness of a particular photoprocess and the wavelength of irradiation. They can be conveniently generated from the measurement of photodamage resulting from exposure of samples to near-monochromatic radiation of known irradiance. Action spectra can also be calculated firom source-specific activation spectra, provided the irradiance distribution used in generating the data is accurately known. Accordingly, action spectra have been derived from polychromatic exposure data obtained using a series of cut-on filters [20]. (While no activation... 

Determination of Activation Spectra From Polychromatic Exposure Experiments... 

Determination of Action Spectra from Polychromatic Exposures... 

Glocker and Frohnmayer determined the characteristic constant c for nine elements (Reference 2, Table 4) ranging in atomic numbers from 42 (molybdenum) to 90 (thorium). They proved that identical results could be obtained with the sample in the primary (polychromatic) or in the diffracted (monochromatic) beam. The method was applied with good results to the determination of barium in glass of antimony in a silicate of hafnium in the mineral alvite and of molybdenum, antimony, barium, and lanthanum in a solution of their salts—for example, 5.45% barium was found on 90-minute exposure by the x-ray method for a glass that yielded 5.8% on being analyzed chemically. 

Polycyclic Aromatic Hydrocarbon Physiologically Based Pharmacodynamic Physiologically Based Pharmacokinetic polychromatic erythrocytes permissible exposure limit photo ionization detector picogram picomole... 

Animals, usually rodents, are exposed to the test substance by an appropriate route, usually by gavage or by intraperitoneal injection. Each treated and control group must include at least five animals per sex. Positive controls should produce micronuclei in vivo at exposure levels expected to give a detectable increase over background. No standard treatment schedule (i.e., 1, 2, or more treatments at 24-h intervals) has been recommended. Three dose levels are generally used these should cover a range from the maximum to little or no toxicity. The erythrocytes are sampled from the bone marrow and/or peripheral blood of the animals. If bone marrow is used, the animals are sacrificed at appropriate times after treatment, the bone marrow extracted, and preparations made and stained. When peripheral blood is used, the blood is collected at appropriate times after treatment and smear preparations are made and stained. Preparations are analyzed for the presence of micronuclei. An increase in the frequency of micronucleated polychromatic erythrocytes in treated animals is an indication of induced chromosome damage. 

Genotoxicity. No studies were found on the genotoxic effects of chlorobenzene in humans by any route of exposure. Results of animal assays were mixed. Chlorobenzene induced statistically significant increases in polychromatic erythrocytes containing micronuclei in mice following... 

---