Frank Jones

Marine waters contaminated with domestic sewage : Nonenteric illnesses associated with bather exposure in the United Kingdom

OBJECTIVES This study identified possible dose-response relationships among bathers exposed to marine waters contaminated with domestic sewage and subsequent risk of nonenteric illness. METHODS Four intervention follow-up studies were conducted within the United Kingdom. Healthy volunteers (n = 1273) were randomized into bather and nonbather groups. Intensive water-quality monitoring was used to assign five bacteriological indices of water quality to individual bathers. Illnesses studied were acute febrile respiratory illness, and eye, ear, and skin ailments. RESULTS Fecal streptococci exposure was predictive of acute febrile respiratory illness, while fecal coliform exposure was predictive of ear ailments. Estimated thresholds of effect occurred at bather exposures above 60 fecal streptococci and 100 fecal coliform per 100 ml of water, respectively. Although no relationship was found between eye ailments and indicator organism exposure, compared with nonbathers, bathers were at higher risk for eye ailments. CONCLUSIONS Nonenteric illness can be transmitted via recreational contact with marine waters contaminated with sewage. These results argue against the use of a single indicator to establish water quality standards.

Order Parameters of Dyes in a Biphenyl/Terphenyl Liquid Crystal Mixturet

Abstract The order parameters of a number of azo- and anthraquinonoid dyes dissolved in a eutectic liquid crystal mixture composed of derivatives of 4-cyanobiphenyl- and 4-cyano-p-terphenyl (Type E7, B.D.H. Chemicals Ltd.) have been determined spectrometrically. Orientation was achieved using rubbed polyvinyl alcohol coated cells. A good correlation was found between order parameter and molecular structure, allowing order parameters to be predicted for other dyes based on the monazo-chromophore. Azo-dyes exhibited a marked red shift relative to the colour of the dye in slightly polar isotropic solvents, whereas anthraquinonoid dyes showed little change. The results are interpreted in terms of charge transfer perturbations arising from dipole-interactions between guest and host molecules.

Naphthoquinone Dyes in Liquid CrystalIine Media

Abstract A number of dyes based on the 1,4-naphthoquinone structure have been synthesised. By ring closure across positions 2– and 3–, naphthimidazoles have been obtained which show improved order parameters and also photo-stabilities comparable with commercial anthraquinonoid dyes. The results are discussed on the basis of comparison with ground state dipole and transition moments as calculated by PPP-MO methods. Solubilities of the dyes in E44 (BDH Chemicals Ltd.) liquid crystal host have also been determined, but little correlation between saturation concentration and solubility parameter has been found.

Photostability of Dyes in Liquid Crystalline Media

Abstract A number of dyes of different types dissolved in a nematic medium have been exposed to ultraviolet and visible radiation under specific test conditions. The results are discussed and factors affecting the differences in photostability of the dyes are considered.

Polymorphism in Anthranilic Acid Crystals—Examination by DTA and DSC

Abstract Crystalline anthranilic acid in modifications I and II has been prepared from aqueous, ethanolic and non-polar solvents, and examined by DTA to determine transition and melting temperatures and by DSC to give associated enthalpy and entropy changes. The transition I → II occurs at 352.2 K at a zero extrapolated heating rate. An additional endotherm occurs with modification II when the acid is obtained from buffered aqueous solutions within a narrow pH range. The low transition enthalpy occurring under these conditions indicates that the modification has a lower degree of lattice order than II obtained under more acid conditions or from ethanolic solution. I and II were confirmed by X-ray powder photographs. The morphology of the forms obtained is discussed briefly.