Phthalate esters (PEs) belong to a class of organic compounds used as plasticisers in plastic materials such as polyvinyl chloride (PVC), polypropylene (PP), polyethylene terephthalate (PET) and so on, including those used in the food packaging industry. Phthalate plasticisers are not chemically bound to plastic materials and hence, migrate into items such as foodstuffs they house. The study aimed at investigating the prevalence of selected phthalate esters from plastic wrappers into food as well as the presence of food and/or pathogenic microorganisms. Plastic-wrapped cheese, vienna sausages and polony samples purchased from commercial stores in the four regions of Pretoria (Tswane), South Africa, were analysed for the presence of plasticisers; di-2-ethylhexyl adipate (DEHA), di-n-butyl phthalate (DnBP), benzyl-butyl phthalate (BBP), di-butyl phthalate (DBP) and dimethyl phthalate (DMP). Soxhlet extraction using hexane with florisil column cleanup was carried out. Analysis of PEs was by Gas Chromatography-Flame Ionization Detection (GC-FID). Microbiological investigations were performed using standard methods. The concentrations of PEs detected in food samples ranged from below detection limit (bdl) to 4.7003 μg/kg. However, DBP, DMP and BBP were predominantly present with more PEs detected in cheese compared to polony and vienna. In polony samples, DBP levels ranged from 0.0412 to 0.611μg/kg, in cheese, ranged from 0.049 to 0.256 μg/kg and in vienna DBP ranged from 0.074 to 0.209 μg/kg. The phthalate DMP ranged from 0.072 to 4.700 μg/kg in cheese, 0.056 to 0.241 μg/kg in polony and 0.092 to 0.816 μg/kg in vienna. The DEHA detected in cheese and polony was 0.120 μg/kg and 0.075 μg/kg respectively and no DEHA was detected in vienna sausages. For microbiological analysis, the total microbial activity (TMA) ranged from 6.8 x 104 to 1.03 x 108 cfu/g; coliforms ranged from no growth to 2.62 x 106 cfu/g; yeast ranged from no growth to 1.49 x 107 cfu/g; and mould ranged from no growth to 9.2 x 104 cfu/g. The results revealed that microbial activity was high in each sample type but revealed the absence of pathogens. Results revealed incidences of PEs in foods wrapped or packaged in plastics, which gave cause for concern and showed the need for proper monitoring and inspection of the levels of organo-microbial entities in the South African food wrapped in plastic wrappers. / Environmental Sciences / M.Sc. (Environmental Science)

Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: South Africa embarked on an ambitious program to rehouse the informally housed poor. These initiatives were formerly called the RDP and later the BNG programmes. This was aimed at improving the living conditions of the urban poor and consequently their health and poverty status. These low-cost houses were quickly augmented by backyard shacks in almost all settlements. The present study is an epidemiological assessment of the health and sanitation status of inhabitants of specific low cost housing communities in the City of Cape Town as contrasted with those occupying ‘backyard dwellings’ on the same premises. The study was undertaken in four low-cost housing communities identified within the City. A health and housing evaluation, together with dwelling inspections were carried out in 336 randomly selected dwellings accommodating 1080 inhabitants from Tafelsig, Masipumelela, Driftsands and Greenfields. In addition, the microbiological pollution of surface run-off water encountered in these settlements was assessed by means of Escherichia coli levels (as found by ColilertTM Defined Substrate Technology) as an indication of environmental health hazards. The study population was classified as ‘young’ - 43% of the study population was aged 20 years or younger. Almost a third of households were headed by a single-parent female. In all four communities combined, 47.3% of households received one or other form of social grant. At the time of inspection 58% of the toilets on the premises were non-operational, while all the houses showed major structural damage - 99% of homeowners reported not being able to afford repairs to their homes. In 32% of dwellings one or more cases of diarrhoea were reported during the two weeks preceding the survey. Five percent of the participants willingly disclosed that they were HIV positive, while 11% reported being TB positive (one of them Multiple Drug Resistant TB). None of the HIV positive or TB positive persons was on any treatment. The E. coli levels of the water on the premises or sidewalks varied from 750 to 1 580 000 000 organisms per 100 ml of water - thus confirming gross faecal pollution of the environment. Improvements in health intended by the re-housing process did not materialise for the recipients of low-cost housing in this study. The health vulnerability of individuals in these communities has considerable implications for the health services. Sanitation failures, infectious disease pressure and environmental pollution in these communities represent a serious public health risk. The densification caused by backyard shacks also has municipal service implications and needs to be better managed. Policies on low-cost housing for the poor need realignment to cope with the realities of backyard densification so that state-funded housing schemes can deliver the improved health that was envisaged at its inception. This is in fact a national problem affecting almost all of the state funded housing communities in South Africa. Public health and urban planning need to bridge the divide between these two disciplines in order to improve the health inequalities facing the urban poor. / AFRIKAANSE OPSOMMING: Suid-Afrika is besig met 'n ambisieuse program om diegene wat in informele behuising woon te hervestig. Hierdie inisiatiewe is voorheen die HOP en tans die “BNG” programme genoem. Hierdie hervestigingsprogramme is gemik daarop om die lewensomstandighede van die stedelike armes en dus hulle gesondheid- en armoedestatus te verbeter. Hierdie laekoste huise is algou in byna alle nedersettings aangevul deur krotwonings in die agterplase. Die huidige studie is 'n epidemiologiese beoordeling van die gesondheid en sanitasiestatus van inwoners van spesifieke laekoste behuisingsgemeenskappe in die Stad Kaapstad in vergelyking met diegene wat krotwonings op dieselfde erwe bewoon. Die studie is onderneem in vier laekoste-behuising gemeenskappe geselekteer in die stadsgebied. 'n Gesondheid- en behuisingevaluasie tesame met 'n inspeksie van elke woning is uitgevoer in 336 ewekansig geselekteerde wonings wat 1080 inwoners gehuisves het. Die woonbuurte was Tafelsig, Masipumelela, Driftsands en Greenfields. Mikrobiologiese besoedelingsvlakke van oppervlak-afloopwater in hierdie gemeenskappe is bepaal deur middel van die bepaling van Escherichia coli vlakke (met behulp van ColilertTM Gedefinieerde Substraat Tegnologie) as aanduiding van gesondheidsgevare in die omgewing. Die studiepopulasie is as ‘jonk’ geklassifiseer - 43% was 20 jaar of jonger. Amper een-derde van die huishoudings het 'n enkelouer-vrou aan die hoof gehad. In al vier gemeenskappe gesamentlik het 47.3% van die huishoudings die een of ander vorm van maatskaplike toelae ontvang. Tydens inspeksie is 58% van die toilette op die erwe as "nie-funksioneel" bevind, terwyl al die huise substansiële strukturele skade getoon het - 99% van die huiseienaars het gerapporteer dat hulle nie herstelwerk aan hulle huise kan bekostig nie. In 32% van die wonings is daar een of meer gevalle van diarree gedurende die voorafgaande twee weke voor die opname gerapporteer. Vyf persent van die deelnemers het vrywillig gerapporteer dat hulle HIV positief was terwyl 11% gerapporteer het dat hulle TB positief was (een was Veelvuldige Middelweerstandige TB). Nie een van die HIV positiewe of TB positiewe persone was op enige behandeling nie. Die E. coli vlakke van die water op die erwe of sypaadjies het gewissel vanaf 750 to 1 580 000 000 organismes per 100 ml water - wat erge fekale besoedeling van die omgewing bevestig het. Die verbetering in gesondheid wat deur die hervestigingsproses voorsien is, het nie gematerialiseer vir die ontvangers van die laekoste-behuising in hierdie studie nie. Die kwesbaarheid van die gesondheid van die individue in hierdie gemeenskappe hou groot implikasies vir gesondheidsdienste in. Sanitasiefalings, infektiewe siektedruk en omgewingsbesoedeling hou groot openbare gesondheidsrisiko in. Die verdigting wat deur agterplaaskrotte meegebring word asook die gevolge vir munisipale dienste benodig beter bestuur. Beleide oor laekoste-behuising vir armes kort herbeplanning om die realiteite wat saamgaan met verdigting deur agterplaaskrotte te kan hanteer sodat die verwagte verbetering in gesondheid kan materialiseer. Hierdie is inderwaarheid 'n nasionale probleem wat omtrent alle staatsbefondste laekoste-behuising gemeenskappe in Suid-Afrika affekteer. Openbare gesondheid en stadsbeplanning behoort die skeiding tussen hierdie twee dissiplines te oorbrug om sodoende die ongelyke gesondheidstatus van die stedelike armes aan te spreek.

published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

Fung, Kit Ching. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 134-144). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Some appendixes in Chinese.

Luo, Weixiang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 90-105). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Lai, Ka Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 231-241). / Abstracts in English and Chinese. / Pages / Abstract --- p.i / 摘要 --- p.iv / Acknowledgment --- p.vii / Contents --- p.viii / List of Figures --- p.xix / List of Table --- p.xxv / Abbreviations --- p.xxx / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Airborne fungi --- p.1 / Chapter 1.2 --- Requirement of water activity for airborne micro-organisms --- p.4 / Chapter 1.3 --- Sampling of airborne fungi --- p.5 / Chapter 1.4 --- Identification of airborne fungi --- p.10 / Chapter 1.5 --- Measurement of diversity of airborne fungi --- p.10 / Chapter 1.6 --- Airborne fungi in different environments --- p.13 / Chapter 1.7 --- Health hazards from airborne fungi and their metabolites --- p.15 / Chapter 1.7.1 --- Health hazards of airborne fungi --- p.15 / Chapter 1.7.2 --- Health hazards of mycotoxins --- p.18 / Chapter 1.7.3 --- "Mycotoxins aflatoxins, deoyxnivalenol, ochratoxins and citrinin" --- p.21 / Chapter 1.8 --- "Aim, objectives and project strategy of this study" --- p.25 / Chapter 1.8.1 --- Aim of study --- p.25 / Chapter 1.8.2 --- Objectives --- p.26 / Chapter 1.8.3 --- Strategy for the study --- p.26 / Chapter 1.9 --- Significance of the study --- p.29 / Chapter Chapter 2 --- Materials and Methods --- p.30 / Chapter 2.1 --- Sampling equipments --- p.30 / Chapter 2.1.1 --- The passive sampling methods --- p.30 / Chapter 2.1.2 --- Operation of the two passive sampling methods --- p.31 / Chapter 2.1.3 --- The active sampling methods --- p.32 / Chapter 2.1.4 --- Operation of the two active sampling methods --- p.34 / Chapter 2.2 --- Identification of airborne fungi --- p.35 / Chapter 2.2.1 --- Identification by morphological markers --- p.35 / Chapter 2.2.2 --- Molecular identification of airborne fungi --- p.36 / Chapter 2.2.2.1 --- Genomic DNA extraction from fungal biomass --- p.36 / Chapter 2.2.2.2 --- Specific polymerase chain reaction (PCR) --- p.37 / Chapter 2.2.2.3 --- Purification of PCR products --- p.38 / Chapter 2.2.2.4 --- Cycle-sequencing --- p.40 / Chapter 2.2.2.5 --- Sequencing --- p.40 / Chapter 2.2.2.6 --- Gel electrophoresis --- p.41 / Chapter 2.3 --- "Determination of viable fungal abundance, species richness, species composition and species diversity" --- p.42 / Chapter 2.3.1 --- Calculation of viable fungal abundance --- p.42 / Chapter 2.3.2 --- "Calculation of species number, relative abundance and species diversity" --- p.44 / Chapter 2.4 --- "Sampling of airborne, soilborne and dustborne fungi" --- p.45 / Chapter 2.4.1 --- Airborne fungal diversity of two storage areas sampled by four methods --- p.45 / Chapter 2.4.1.1 --- Description of the two sampling sites: mushroom house go-down in CUHK and the storage room in Tsing Yi --- p.46 / Chapter 2.4.1.2 --- Sampling conditions of the four sampling methods in the two storage rooms --- p.47 / Chapter 2.4.2 --- Airborne fungal surveys in the two construction workplaces --- p.51 / Chapter 2.4.2.1 --- Description of the construction workplaces in Tsing Yi and Castle Peak Road --- p.52 / Chapter 2.4.2.2 --- Sampling conditions for airborne fungi in the two construction workplaces --- p.58 / Chapter 2.4.2.3 --- "Determination of viable fungal abundance, species richness, species composition and species diversity in the two workplaces" --- p.59 / Chapter 2.4.3 --- Determination of the airborne fungal communities of the contractor site office with a green roof and the neighbouring government office --- p.60 / Chapter 2.4.3.1 --- "Sampling of airborne fungi from a green roof, the indoor environment of the contractor site office with a green roof and the neighboring government office" --- p.62 / Chapter 2.4.3.2 --- Sampling of soilborne fungi and determination of soil properties of the green roof --- p.62 / Chapter 2.4.3.2.1 --- Determination of microbial counts --- p.63 / Chapter 2.4.3.2.2 --- Determination of the aerial biomass of plants --- p.64 / Chapter 2.4.3.2.3 --- "Determination of soil carbon, hydrogen, nitrogen and sulfur (CHNS) contents" --- p.64 / Chapter 2.4.3.2.4 --- Analysis of soil texture --- p.65 / Chapter 2.4.3.2.5 --- Determination of total phosphorus content --- p.66 / Chapter 2.4.3.2.6 --- Determination of available nitrogen and phosphorus contents --- p.67 / Chapter 2.4.3.2.7 --- Determination of potassium content --- p.67 / Chapter 2.4.3.2.8 --- Determination of soil moisture --- p.68 / Chapter 2.4.3.2.9 --- Determination of soil pH and soil electrical conductivity --- p.68 / Chapter 2.4.4 --- Dustborne fungi and the properties of the dusts collected from the air-conditioners of the construction workplaces --- p.69 / Chapter 2.4.4.1 --- Determination of viable dustborne fungal population --- p.69 / Chapter 2.4.4.2 --- Composition analysis and toxicities of the air-conditioner dust samples --- p.70 / Chapter 2.4.4.2.1 --- "Determination of the contents of three mycotoxins by ELISA: aflatoxins, deoxynivalenol and ochratoxins" --- p.71 / Chapter 2.4.4.2.2 --- Determination of mycotoxin citrinin and volatile organic profiles by the gas chromatography-mass spectrometry (GC-MS) --- p.73 / Chapter 2.4.4.2.3 --- Determination of cytotoxicities of the dust samples --- p.75 / Chapter 2.4.4.2.3.1 --- Cell lines and culture conditions --- p.75 / Chapter 2.4.4.2.3.2 --- Growth curves of the cell lines --- p.76 / Chapter 2.4.4.2.3.3 --- Determination of the cytotoxicities of the dust extracts --- p.77 / Chapter Chapter 3 --- Result --- p.78 / Chapter 3.1 --- Airborne fungi in the workplaces --- p.78 / Chapter 3.1.1 --- Biodiversity of airborne fungi in the two storage rooms collected by four sampling methods --- p.78 / Chapter 3.1.1.1 --- Biodiversity of airborne fungi in the two storage rooms collected by the passive sampling methods --- p.78 / Chapter 3.1.1.1.1 --- Abundance of airborne fungi in the two storage rooms collected by the two passive sampling methods --- p.79 / Chapter 3.1.1.1.2 --- Species richness and composition of airborne fungi in the two storage rooms collected by the passive sampling methods --- p.81 / Chapter 3.1.1.1.3 --- Biodiversity indices of the airborne fungal communities in the two storage rooms collected by the passive sampling methods --- p.85 / Chapter 3.1.1.2 --- Biodiversity of airborne fungi in the two storage rooms collected by the active sampling methods --- p.87 / Chapter 3.1.1.2.1 --- Abundance of airborne fungi in the two storage rooms collected by the active sampling methods --- p.87 / Chapter 3.1.1.2.1.1 --- Abundances of airborne fungi in the mushroom house go-down collected by the active sampling methods --- p.88 / Chapter 3.1.1.2.1.2 --- Abundances of airborne fungi in the storage room in Tsing Yi collected by the active sampling methods --- p.94 / Chapter 3.1.1.2.2 --- Species richness in the two storage rooms collected by the active sampling methods --- p.95 / Chapter 3.1.1.2.3 --- Species compositions of airborne fungi in the two storage rooms collected by the active sampling methods --- p.98 / Chapter 3.1.1.2.4 --- Biodiversity indices of airborne fungi in the two storage rooms collected by the active sampling methods --- p.104 / Chapter 3.1.2 --- Airborne fungal surveys in the construction workplaces --- p.106 / Chapter 3.1.2.1 --- Relative humidity and temperature measured in the two construction workplaces --- p.107 / Chapter 3.1.2.2 --- Airborne fungi collected at the two workplaces --- p.108 / Chapter 3.1.2.2.1 --- Abundances of airborne fungi in the four surveys of the two construction workplaces --- p.108 / Chapter 3.1.2.2.2 --- Indoor/ outdoor (I/O) ratios of the airborne fungi in the four surveys of the two construction workplace --- p.113 / Chapter 3.1.2.2.3 --- Species richness of airborne fungi for the four surveys in the two construction workplaces --- p.114 / Chapter 3.1.2.2.4 --- Composition of the airborne fungal communities in the four surveys of the two construction workplaces --- p.116 / Chapter 3.1.2.2.5 --- Biodiversity indices of the airborne fungal communities collected in the four surveys at the two construction workplaces --- p.121 / Chapter 3.1.2.2.6 --- Properties of the identified fungi collected at the two construction workplaces --- p.124 / Chapter 3.1.3 --- The relationship between airborne fungal communities of two neighbouring offices in the Tsing Yi site --- p.125 / Chapter 3.1.3.1 --- Soilborne and airborne fungi of the green roof and their relationship with the indoor airborne fungi of the contractor site office --- p.125 / Chapter 3.1.3.2 --- The relationship between indoor airborne fungi collected from the contractor site office and the neighbouring government office --- p.127 / Chapter 3.2 --- Dusts in air-conditioner filters of the construction workplace --- p.130 / Chapter 3.2.1 --- Microscopic observation of the dust samples --- p.130 / Chapter 3.2.2 --- Viable dustborne fungi of the neighboring site offices --- p.132 / Chapter 3.2.3 --- "Mycotoxin contents, volatile organic profiles and toxicities of the dust samples" --- p.136 / Chapter 3.2.3.1 --- "Mycotoxin aflatoxins, ochratoxins and deoxynivalenol contents of the dust samples" --- p.136 / Chapter 3.2.3.2 --- Mycotoxin citrinin contents and the organic profiles of the dust samples determined by GC-MS --- p.138 / Chapter 3.2.4 --- Cytotoxicities of the dust samples --- p.156 / Chapter 3.2.4.1 --- Population growth curves of the cell lines NCI H1299 and MCF-7 --- p.156 / Chapter 3.2.4.2 --- Toxicities of the dust samples on two cell lines --- p.158 / Chapter Chapter 4 --- Discussion --- p.163 / Chapter 4.1 --- Airborne fungi in the workplace --- p.163 / Chapter 4.1.1 --- Biodiversity of airborne fungi collected in the two storage rooms --- p.163 / Chapter 4.1.1.1 --- Comparison between the airborne fungi in the two storage rooms collected by the two passive sampling methods --- p.164 / Chapter 4.1.1.1.1 --- Abundance of airborne fungi in the two storage rooms collected by the two passive sampling methods --- p.164 / Chapter 4.1.1.1.2 --- Species richness and composition of airborne fungi in the two storage rooms collected by the two passive sampling methods --- p.166 / Chapter 4.1.1.1.3 --- Species diversity of airborne fungi in the two storage rooms collected by the two passive sampling methods --- p.168 / Chapter 4.1.1.2 --- Comparison between the airborne fungi in the two storage rooms collected by the two active sampling methods --- p.170 / Chapter 4.1.1.2.1 --- Abundance of airborne fungi in the two storage rooms collected by the two active sampling methods --- p.170 / Chapter 4.1.1.2.2 --- Species richness and composition of airborne fungi in the two storage rooms collected by the two active sampling methods --- p.174 / Chapter 4.1.1.2.3 --- Species diversity of airborne fungi in the two storage rooms collected by the two active sampling methods --- p.176 / Chapter 4.1.1.3 --- Comparison between the airborne fungi in the two storage rooms collected by the passive and active sampling methods --- p.178 / Chapter 4.1.1.4 --- Conclusion on the study in the two storage rooms --- p.180 / Chapter 4.1.2 --- Airborne fungal surveys in the two construction workplaces --- p.181 / Chapter 4.1.2.1 --- Airborne fungi sampled in the two construction workplaces --- p.182 / Chapter 4.1.2.1.1 --- Relative humidity and temperature recorded in the two construction workplaces --- p.182 / Chapter 4.1.2.1.2 --- Correlation between the two environmental factors and the abundance of airborne fungi collected --- p.183 / Chapter 4.1.2.1.3 --- Airborne viable fungal sampled in the two construction workplaces --- p.184 / Chapter 4.1.2.1.3.1 --- Seasonal change of airborne fungi in the two construction workplaces --- p.184 / Chapter 4.1.2.1.3.2 --- Comparison on the viable airborne fungal abundance collected in the two construction workplaces --- p.186 / Chapter 4.1.2.1.3.3 --- Comparison on the species number and species composition collected in the two construction workplaces --- p.192 / Chapter 4.1.2.1.4 --- Comparison between indoor and outdoor airborne fungi of the two construction workplaces --- p.195 / Chapter 4.1.2.1.4.1 --- Comparison on the viable airborne fungal abundance collected in the indoor and outdoor environments of the two workplaces --- p.195 / Chapter 4.1.2.1.4.2 --- Species number and species composition collected in the indoor and outdoor environments of the two workplaces --- p.197 / Chapter 4.1.2.1.4.3 --- Species diversity collected in the indoor and outdoor environments of the two workplaces --- p.201 / Chapter 4.1.2.1.4.4 --- Properties of the identified fungi collected in the two construction workplaces --- p.202 / Chapter 4.1.2.2 --- Relationship between airborne fungal communities of two neighboring offices in the Tsing Yi site --- p.205 / Chapter 4.1.2.2.1 --- Soilborne and airborne fungi of the green roof and the airborne fungi of the contractor site office --- p.205 / Chapter 4.1.2.2.2 --- Indoor airborne fungi collected from the contractor site office and the neighbouring government site office --- p.206 / Chapter 4.2 --- Dusts from air-conditioners of the workplace --- p.207 / Chapter 4.2.1 --- Comparison of dustborne fungal abundances among different locations --- p.208 / Chapter 4.2.2 --- Comparison of dustborne fungal abundances on different accumulation times --- p.211 / Chapter 4.2.3 --- Comparison of dustborne fungal abundances on the contractor site offices and the government site office in Tsing Yi --- p.212 / Chapter 4.2.4 --- Comparison of species composition among dusts from the contractor site offices and the government site offices --- p.213 / Chapter 4.2.5 --- Mycotoxins in the dust samples --- p.214 / Chapter 4.2.5.1 --- Aflatoxin contents of the dust samples --- p.214 / Chapter 4.2.5.2 --- Deoxynivalenol contents of the dust samples --- p.215 / Chapter 4.2.5.3 --- Ochratoxin contents of the dust samples --- p.216 / Chapter 4.2.5.4 --- Mycotoxin producers in the dust samples --- p.217 / Chapter 4.2.6 --- The volatile organic profiles of the dust samples determined by GC-MS --- p.218 / Chapter 4.2.7 --- Cytotoxicities of the dust samples --- p.221 / Chapter 4.2.8 --- Conclusion on the health hazards from dusts in air-conditioners --- p.223 / Chapter 4.3 --- Sampling strategy --- p.223 / Chapter 4.4 --- Further investigation --- p.227 / Chapter Chapter 5 --- Conclusion --- p.228 / Chapter Chapter 6 --- References --- p.231 / Appendices --- p.242 / Chapter Appendix 1 --- Relative abundance of the airborne fungal species by the passive sampling method in the four surveys of the two construction workplaces --- p.242 / Chapter Appendix 2 --- Images of the most abundance fungal species --- p.246 / Chapter Appendix 3 --- Relative abundance of the airborne fungal species by the active sampling methods in the four surveys of the two construction workplaces --- p.257 / Chapter Appendix 4 --- Details of properties of fungal species identified --- p.260

Graduation date: 2005

NCRP report No.160 states that medical exposure increased to nearly half of the total radiation exposure of the U.S. population from all sources in 2006 (NCRP 2009). Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage, there is an increase in the radionuclide being released into wastewater after the medical procedures. The question then arises: what is the behavior of medical radionuclides and their impurities in the wastewater process? It is important to note that, often, medical radionuclides are not exactly 100% radionuclide pure, but they meet a certain standard of purity. Of particular interest are the longer lived impurities associated with these medical radionuclides. The longer lived impurities have a higher chance of reaching the environment. The goal of this study is to identify the behavior of medical radionuclides and their impurities associated with some of the more common radiopharmaceuticals, including Tc-99m and I-131, and locate and quantify levels of these impurities in municipal wastewater and develop a model that can be used to estimate potential dose and risk to the public. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from May 24, 2012 - May 24, 2014

Acute lymphoblastic leukemia (ALL) encompasses a spectrum of lymphoid progenitors that have undergone malignant transformation and clonal proliferation at various stages of differentiation. Some cases of ALL have been documented to have prenatal origins and in particular neonatal exposure to various environmental pollutants is associated with increased disease risk, including childhood lymphoma and leukemia. Dibenzo[def,p]chrysene (DBC) is a polycyclic aromatic hydrocarbon (PAH) and in our laboratory has been established as a transplacental carcinogen in mice, producing aggressive T-cell lymphoblastic lymphomas, lung, liver, uterine, ovarian, and testicular lesions, depending on timing and dose of exposure. Investigation of the transplacental and translactational transfer of DBC was warranted following a cross-foster experiment demonstrating the greatest tumorigenic response occurred in offspring both gestating in and nursed by an exposed female. [¹⁴C]-DBC (GD17) dosing was utilized to examine time-dependent alterations of [¹⁴C] in maternal and fetal tissues, excreta, and residual levels at weaning. Fetal tissue levels of [¹⁴C]-DBC equivalents were 10-fold lower than maternal tissue, and after weaning the residual body burden was roughly equivalent in offspring exposed only in utero or only via lactation. Certain bioactive food components, including indole-3-carbinol (I3C), 3,3'-diindolylmethane (DIM), and sulforaphane (SFN) from cruciferous vegetables have been shown to target cellular pathways regulating carcinogenesis. In the above mentioned DBC initiated model of carcinogenesis, I3C is an effective transplacental chemopreventive agent. We sought to extend our chemoprevention studies in mice to a human neoplasm in cell culture, analogous to the observed murine T-cell lymphomas. Treatment of the human T-ALL cell line CCRF-CEM (CEM) with I3C reduced cell proliferation and viability only at supraphysiologic concentrations whereas DIM, the primary acid condensation product of I3C, had a marked effect at low micromolar concentrations in vitro and reduced growth of CEM xenografts in vivo. Additional T-ALL lines, selected to represent the heterogeneity of the disease, (CCRF-HSB2, Jurkat, and SUP-T1) responded similarly in vitro, demonstrating a potential therapeutic value of DIM in T-ALL. Given that epigenetic reprograming is especially active during fetal development and that DNA hypermethylation contributes to the etiology of T-ALL we examined genome-wide DNA methylation in CEM. Differential methylation analysis revealed that DIM and I3C alter CpG methylation in unique, yet overlapping, gene targets. DIM treated cells exhibited a dose-dependent decrease in hypermethylation, an observation consistent with an epigenetic mechanism of cancer suppression. Pyroseqencing and RTPCR technologies were utilized to validate changes in DNA methylation and to compare these patterns with a transcriptional response in both novel targets and candidate genes selected from the literature. Collectively, these studies merited returning to the murine transplacental model for further investigation of genetic and epigenetic changes upon maternal dietary intervention with I3C. More importantly we incorporated whole cruciferous vegetable diets (10% broccoli sprouts or 10% Brussels sprouts), SFN diet, or the combination of SFN and I3C, in order to examine matrix and mixture effects. Preliminary analysis suggests a worse prognosis for those animals exposed in utero to SFN or the whole foods, especially males. As this is the first study to administer SFN or whole cruciferous vegetables in a transplacental model of carcinogenesis, our results warrant further study on the concentration dependent influence of these potent phytochemicals during the perinatal window. / Graduation date: 2012

[Truncated abstract] The role of fish consumption and omega-3 polyunsaturated fatty acids (PUFAs) in the prevention of disease has been the subject of much investigation in recent years. A clue that these factors might be of importance was the observation that populations consuming high levels of marine omega-3 PUFAs had lower rates of morbidity and mortality from cardiovascular disease. From there, research in this area has expanded to include a range of chronic diseases and their prevention. An area of particular interest is the role of fish consumption in the prevention of various cancers. In Australia, one in three men and one in four women are expected to be diagnosed with cancer by the age of 75. Identifying preventive factors that can be translated into constructive health promotional messages is of great importance in addressing this group of diseases that has such a large impact on the health and wellbeing of the population. ... Results and conclusions Analysis of the data from the population-based case-control study suggests a protective effect of preserved fish consumption, possibly due to the high oil content of these fish. The developed questionnaire is a valid and reliable tool for measuring fish and seafood consumption as determined by regression analysis with an independent biomarker and reliability analysis using intra-class correlation. Importantly, reliability can be maintained despite asking a high level of detail from participants. For ranking according to overall fish consumption, detailed questioning is probably not necessary, however inclusion of variables representing multiple categories of fish and seafood consumption in a regression model enables us to better account for variation in blood omega-3 PUFA levels than a single variable representing overall consumption. For the purpose of questionnaire validation, plasma phospholipid and erythrocyte membrane levels of EPA and DHA are equivalent biomarkers of fish and seafood consumption. The choice between them by future investigators will be based on more practical aspects such as convenience and the fasting state of subjects. The tangible product of this thesis is additional evidence to support a protective association between fish consumption and prostate and breast cancers, and a valid and reliable questionnaire v for measuring habitual consumption of fish and seafood in a West Australian population, that could also be applied to other populations after minor adjustment for local fish and seafood consumption patterns.