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Thesis (Ph. D.)--University of Adelaide, 1984. / Appendix 7, (3 leaves) in pocket. Includes bibliographical references.

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Chlorpyrifos, an organophosphate pesticide moderately toxic to humans via inhalation and dermal absorption (LD50 oral, rat = 226 mg kg-1, LD50 skin, rabbits = 1265 mg kg-1), is widely used to eradicate termites in Australia. A series of 28 surveys totaling 32 separate assessments, or 10% of all professional users in Perth, Western Australia, comprised biological monitoring, exposure assessment techniques, a health symptoms and work practices questionnaire. Chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol and alkyl phosphates were extracted from urine, and serum cholinesterase (SChE) and erythrocyte acetylcholinesterase from blood. Chlorpyrifos was extracted from 24 patches removed from a supplied cotton overall, cotton gloves worn under protective gloves, 7 absorbent patches placed on the skin and an organic vapour collection tube. Surface wipes were collected in the workers vehicle and on the workers forehead. Chlorpyrifos was applied in either 0.5% (n=2) or 1% (n=26) concentration of active ingredient in water solution. Surveys took place at pre-construction sites (n=5) where pesticide was sprayed onto a prepared site, existing buildings with concrete foundations (n=17) where pesticide was injected under pressure around the perimeter of the building and existing buildings with suspended floors requiring the worker to spray under floor (n=6). Combined left and right glove deposition was 9 mg hour- 1 (SD = 18 mg.hour-1). Mean deposition on overalls was 14 mg.hour-1 (SD = 12 mg.hour-1), on skin patches was 0.2 ƒÝg.cm-1.hour-1, on vehicle gear-stick was 3 ƒÝg (SD = 8 ƒÝg) and, on steering wheels¡¦ was 3 ƒÝg (SD = 3 ƒÝg). The mean protection 4 factor of overalls, a ratio of outer layer and inner levels, was 75 (SD = 411). Mean air concentration of chlorpyrifos during an application was 30 ƒÝg m-3, and 17 ƒÝg m-3 8 hour TWA (SD = 40 ƒÝg m-3 8 hour TWA), and in one group of 17 workers correlated (p<0.05) with ambient air temperature (15 to 38 oC). Urinary metabolites and SChE activity were effective indicators of exposure. The health symptoms questionnaire did not highlight significant health effects. A discrepancy between operators¡¦ perception of risk and their actual exposure requires addressing, for example the measured high deposition rate to hands was ineffectively controlled, as 48% or workers wore inappropriate or no gloves and only 26% washed their hands after completing their tasks. All workers indicated in the questionnaire they would wash their hands after completing their tasks. The questionnaire also highlighted a high incidence of poor work practices, 58% spilt the concentrate at least once a week, 74% had recently spilt/splashed diluted chlorpyrifos in their eyes and 90% on their boots, and 52% believed they would benefit from more education concerning chlorpyrifos. Observations concluded that workers unnecessarily increased their exposure by poor work practice. Recommendations include modification to pesticide worker education, licencing and health surveillance systems; an improvement in the understanding of the benefits of a health and safety management systems for employers, and pesticide suppliers taking a stewardship role in the usage of their products.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted.

Young children are particularly sensitive to environmental pollutants. They can directly ingest soil by putting dirty hands and objects in their mouths. The reliance on animal derived models for human health risk and exposure assessment has several limitations. In this investigation, a tool-kit was developed and optimised to facilitate more accurate, reliable and representative predictions of soil contaminants that might pose a significant hazard to young children. The tool-kit was developed and optimised using an in vitro human digestion bioassay. This procedure was followed by the optimisation of several mutagenicity bioassays to link to the bioaccessible fraction which quantified by the in vitro bioassay. The application of novel and sensitive environmental-based biosensors requires them to work in parallel with effective and proven extraction techniques. In this study, chemical analysis was used to quantify the bioaccessible (human assimilated portion) of pollutants in soils. Acute toxicity was measured using constitutively marked bioluminescent bacterial biosensors and these were indicative of the total contaminant burden. A range of mutagenic assays were applied and optimised. In the Ames assay, any compound exhibiting a greater than two-fold increase in the number of revertants colonies over the number of spontaneous revertants was considered as a mutagen. Mutagenic-responsive SOS-lux based microbial biosensors were compared to the Ames assay. Mutagenicity assessment of a broad range of environmental pollutants (i.e. B[a]P, DiB(a,h)A, B[a]A, Ni and Cu), was performed using four SOS-lux microbial biosensors; E. coli DPD1718, E. coli K12C600, S. aureus pAmiUmuC and S. aureus pAmiRecA. The results substantiated that the four biosensors were unable to be induced by these pollutants. Nevertheless, E. coli DPD1718 and E. coli K12C600 were successfully induced by Mitomycin C (MMC) in a dose response manner. The Ames assay was performed for the above pollutants in the absence and the presence of the metabolic activation S9 mix. The standard plate incorporation assay and a modification protocol for the Ames assay were applied. Results reported from the Ames assay confirmed mutagenicity responses of the tested pollutants except Cu and Ni. MMC was selected and introduced into soil samples as a case study to assess the performance of the developed tool-kit. Soils amended with MMC were extracted by the in vitro human digestion bioassay, and the mutagenicity of the bioaccessible fraction was measured using the Ames assay and the biosensors. A comparison was made between the permissible concentrations of MMC obtained from the developed tool-kit and RISC4 derived concentrations. The four microbial biosensors applied in this study were incapable to detect the mutagenicity of the tested pollutants. On the other hand, the Ames assay was more robust and sensitive to a broad range of environmental pollutants. The in vitro human digestion bioassay enabled the quantification of the human bioaccessible fraction of the tested pollutants. This fraction posed a concern due to its estimation of the doses that would reach the blood circulation and cause harm to human. While the permissible concentration of MMC measured by the developed tool-kit was less than 10 μg MMC/g, the RISC4 model calculated that it should be 40 μg MMC/g. This revealed that, in this situation, risk assessment model was less conservative than empirical study for human health risk assessment. This study enabled the assessment of the permissible concentrations of environmental pollutants that could remain in a soil and pose permissible harm to humans. This approach also enabled a comparison of modelled and empirical data to allow a measure of sensitivity to be judged. There is a need to develop bioassay techniques more able to assess the potency of hydrophobic compounds both in isolation and combination.

Este trabalho tem por objetivo uma revisão analítica da determinação de cobalto no sangue e/ou urina para fins de monitorização biológica. A proposta de alternativas viáveis para tal metodologia está fundamentada num estudo crítico dos métodos estudados, associados a um Sistema da Qualidade. Os efeitos tóxicos observados nas exposições a diferentes compostos de cobalto, a relação dose-efeito e dose-resposta, bem como os valores de referência para a população sadia e não ocupacionalmente exposta, levou a ACGIH (American Conference of Governmental Industrial Hygienists) dos Estados Unidos a propor desde 1995 a utilização de um BEI (Biological Exposure Indice) para este tipo de exposição. Apesar de o Brasil ainda não ter incluído o cobalto no Programa de Controle Médico de Saúde Ocupacional da Norma Regulamentadora-7, a utilização de um indicador biológico pode constituir-se numa necessidade devido a estudos toxicológicos e analíticos revistos e relatados na literatura. / This work has the purpose of an analytical review of blood and urine\'s cobalt quantification in order to be used in biological monitoring. A proposal of alternatives and feasible methodologies that habe been found are based upon the crutical study associated with a Quality system. The toxic effects observed in exposure to different cobalt compounds, the dose-effect relationship and dose-response, and the reference values in health and non-exposed population, have brought ACGIH (American Conference of Governmental Industrial Hygienists) of the United States to propose since 1995 a BEI (Biological Exposure Indice) to this kind of exposure. Although Brazil has not included cobalt in the PCMSO (Programa de Controle Médico de Saúde Ocupacional), the use of biological indicator can become a necessity due to toxicological and analytical studies here reviewed and reported in the literature

Appendix 7, (3 leaves) in pocket. Includes bibliography.

Hydrogen cyanide gas (HCN{g)) is formed during the process of extracting gold from ore and may pose a risk to the health of the workers at the gold refinery (Mill/plant), especially the risk of detrimental effects on the central nervous system and the cardiovascular system. The measurement of the personal airborne HCN(g) exposure of a worker using sorbent tubes, provides the concentration of the chemical that the worker breaths in. The measurement of the urinary thiocyanate (SCN~) concentration provides the total HCN exposure experience by the worker through all possible routes of exposure. The study's aim was to determine if the workers were exposed to HCN(g) concentrations that was higher than the occupational exposure limit (OEL) , which would mean that the workers are exposed to excessive and possibly harmful levels of HCN. The monitored workers were divided into three homogenous exposure groups or HEGs, according to the their potential level of exposure. The results were compared between the three HEGs and between three work description groups, namely the Mill/plant workers, SGS laboratory assistants and members of the environmental department. The study found that all the workers were exposed to personal airborne HCN(9) concentrations below the OEL. A statistical significant difference was found the personal airborne exposure experienced by the three HEGs and between the Mill/plant workers and the members of the environmental department. No statistical significant difference was found between the urinary SCN" concentration found in the three HEGs or the between the three work description groups. Confounding factors such as smoking, the consumption of cassava, the exposure to fire smoke and the amount of time worked at the mine did not influence the urinary SCN~ concentration. The implementation of a biological monitoring program would enable the identification of any worker that is exposed to excessive levels of HCN. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2009.