All the following methods use an active sampling technique with personal air pumps to draw air through a sampling medium. Occupational histories were extracted from personnel files. Odds ratios with and without adjustment for smoking and coal tar were comparable. Such agents include PAHs, naphthalene, benzo[ a ]pyrene and aldehydes. Relative risks were estimated in an internal analysis using Poisson regression.
In place of new mineral aggregates and bitumens, reclaimed asphalt pavement is commonly added to asphalt mix for use in highway pavements and other applications.
Advances in Materials Science and Engineering
Small numbers reduced precision in analyses of some combinations of cancer site and exposure, and this combined with the unusually large number of comparisons made it likely that some associations occurred by chance. Similarly, PAH concentrations were significantly higher in smokers than in non-smokers. Geometric mean concentrations of 0. Until the s, bitumen specifications in both Europe and the USA relied primarily on mechanical tests of hardness and viscosity. In an update of the original Finnish report was published in English Pukkala, Solvent-precipitated asphalts, which are harder and less resistant to temperature changes than other bitumens, have a higher content of asphaltenes than the vacuum residues from which they are produced, but a lower content of saturates than would be obtained by distillation of the vacuum residue IARC,