No description available.

No description available.

Atmospheric aerosol samples from coastal and open ocean environments in the North Atlantic were analysed for the atmophile elements arsenic and antimony, and for the marine tracers sodium and magnesium. The aerosol concentrations of sodium and magnesium were similar in both environments, about 2000 ng Na (SCM)ˉ¹ and 320 ng Mg (SCM)ˉ¹. The atmophiles were more concentrated in the coastal aerosol, 0.67 ng As(SCM)ˉ¹ and 0.32 ng Sb (SCM)ˉ¹, than in the open ocean aerosol, 0.07 ng As (SCM)ˉ¹ and 0.086 ng Sb (SCM)ˉ¹, and as continental particles were only observed in the coastal aerosol, this indicates that arsenic and antimony in the marine aerosol are of continental origin. Total deposition fluxes to the North Atlantic were about 1.4 kt yrˉ¹for arsenic and antimony, and about 12 t As yrˉ¹ and 5 t Sb yrˉ¹to the dissolved phase of the English Channel. Coastal deposition was higher than the dissolved element fluxes from the River Tamar. From the above data, steady state models of the arsenic cycle were developed, and an anthropogenic perturbation rate was calibrated for kinetic analysis, to define the most sensitive areas of the geochemical cycle. Air-sea exchange exerts a major control on the atmospheric transport of pollutant arsenic to the sea, variations in river flow exert a minor influence. The major unknown factor in the biogeochemistry of arsenic is the size of the reservoir for low temperature anthropogenic mobilisation, as this has a larger long term effect than industrial pollutant input. Low temperature mobilisation may lead to a serious increase in the atmospheric arsenic burden. The modelling technique was extended to quantify a novel tentative model for antimony, which was subject to limited examination by kinetic analysis. Again, air-sea exchange exerts a major influence on the atmospheric transport of pollutant antimony to the oceans, although river flow exerts a larger influence than for arsenic. Low temperature mobilisation may be even more significant for antimony than for arsenic.

No description available.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves 118-123. / vii, 123 l graphs, tables

Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [63]-64).

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 93-94)

Thesis--Massachusetts Institute of Technology. / Includes bibliographies.

Analytical methods were developed and validated for the determination of the total concentration of trace elements (Se, Fe, Cu, Zn, Mg, Ca, Mn, Mo, I, Cd and Pb) and the various organic and inorganic selenium species present in human body fluids. Total elemental analysis involved the use of inductively coupled plasma mass spectrometry (ICP-MS). Speciation analysis utilised ion-pair high performance liquid chromatography (HPLC) coupled on-line to a hexapole collision cell ICP-MS. The methods that were developed were then applied to three separate studies. The effect of psychological stress on human fertility was determined by comparing the trace element levels in blood serum from 47 infertile women undergoing in-vitro fertilisation (IVF) treatment. Elemental data was compared with stress-hormone (plasma prolactin and serum cortisol) levels and Spielberger stress questionnaires. Statistical analysis showed no relationship between stress-hormones and blood serum trace element levels and that stress-hormones do not have an adverse effect on human fertility. A further study examined the total trace element levels of blood serum, follicular fluid, endometrial fluid and scalp hair from a study population of 97 women aged between 24 - 44 years undergoing IVF treatment. Selenium levels in blood serum were significantly lower in IVF patients in contrast to 18 (age and gender matched) control cases (P = 0.001, 35 degrees of freedom). This was in agreement with a previous study with infertile women, aged < 35 years. Zinc and manganese were determined in endometrial fluid, both showing a high degree of correlation (P = 0.001, 17 degrees of freedom) in the IVF population (no control samples were available for analysis). The levels of each element measured in scalp hair showed no correlation with the levels determined in any other matrix. A major contribution of this research involved speciation analysis of selenium in blood serum, seminal plasma and urine. Commercial selenium supplements were consumed over 28 days and the effect that this had on selenium levels (total and species) within the human body fluids was investigated. Consumption caused an increase in the levels of selenium within all human body fluids and in general, the total level of selenium was found to be higher than the sum of the species present. An in-vitro bioavailability procedure was performed on the supplements and showed that two selenium yeast commercial products contained different selenium species. Some selenium species were identified and the implications of this are discussed.