Effects of nitrosation on the chemical composition and epidermal carcinogenicity of the nitrogen-rich fraction of a high-boiling coal liquid

Spectroscopic properties of some derivatives of polycyclic aromatic hydrocarbons

The aim of this paper is to provide a general picture of the spectral characteristics of some polycyclic aromatic hydrocarbon (PAH) derivatives. A great deal of data concerning PAHs has been reported in the literature, but there is lack of comprehensiveness about important parameters in the same experimental conditions for their nitro (NO(2)) and amino (NH(2)) derivatives such as absorption and emission characteristics. Thus, important parameters such as the molar extinction coefficient, absorption maxima, fluorescence maxima, and fluorescence quantum yield are reported here. The efficiencies of the reduction of NO(2)-PAHs to their corresponding amino compounds were also verified by means of high-performance liquid chromatography (HPLC). This class of derivatives represents one of the most toxic groups of carcinogenic substances and therefore the data reported here should be useful for toxicological research.

Toxicology of coal liquefaction products: an overview

Repeated exposure to coal liquefaction products produces a broad range of systemic effects. Among these, growth suppression, anaemia, leucocytosis and other haematological disorders are most prominent. Bone marrow, liver and kidney are the target organs affected by treatment. The effects are more severe with heavy distillates and male rats are more sensitive than females. Other changes included increased serum transaminases, alkaline phosphatase and cholesterol. Depending on the route of administration, the skin or lung may also be affected. Inhalation exposure produces the most severe changes, and oral exposure the least. Distillates containing N-PAHs and sulphur-containing PAHs are also more biologically active. Teratological effects were only observed if animals were exposed to the heavy distillate. Similarly, heavy distillates have mutagenic or carcinogenic properties. Teratological effects, as well as mutagenicity and carcinogenicity, of the coal liquefaction distillates seem to be linked to their PAH content, especially the N-PAHs. From the data presented in this review, it should become evident that the potential effects of coal liquefaction products on human health could be severe, especially with long-term exposure. Limited information exists on the occupational effects to coal liquefaction materials because most of the work to date has been with pilot plants. Careful and good judgement is required in order to extrapolate data from pilot plants to commercial-scale production. Experience in health effects of workers in the petroleum industry and coke-oven operations can serve as a guide for the implementation of industrial hygiene programmes for coal liquefaction operations. These programmes include engineering controls, health education, personal monitoring and hygienic practices, medical surveillance and long-term epidemiology studies, and they should be implemented to make coal liquefaction a healthy and environmentally sustainable industry.

Complex mixture effects on the dermal absorption of benzo[a]pyrene and other polycyclic aromatic hydrocarbons from mouse skin

To study the dermal penetration of benzo[a]pyrene (BAP) in relation to other polycyclic aromatic hydrocarbons (PAHs), a complex mixture of PAHs was applied to the backs of CD-1 mice, and the dermal residence times of BAP and eleven other PAHs were determined using gas chromatography. The dermal penetration of BAP was found to be representative of the other PAHs studied, with a dermal half-life of 6.7 h. Half-lives of the other eleven PAHs ranged from 5.0 to 8.8 h. The dermal half-life of BAP applied in a volatile organic solvent, rather than a PAH mixture, was 3.0 h. The effects of five complex organic mixtures, with boiling points ranging from 300-700 degrees F to greater than 850 degrees F, on the dermal residence time of BAP was studied by adding radiolabeled BAP to the mixtures, and applying them to the backs of mice. All of the mixtures studied increased the dermal residence time of BAP by amounts ranging from 1.8-fold to 6.9-fold.