Purpose: The substantial impact of indoor air quality and environmental hazards in the home on one’s health has long been recognized in the field of public health. This cross-sectional study investigates the risk between home based hazards, specifically lead, and respiratory health in children. The objective of this study is to examine the extent to which children testing positive for blood lead exposure are at an increased risk for having poor respiratory health. Methods: A nationally representative sample of 977 children ages 1- 6 years was obtained from the 2005-2006 National Health and Nutrition Examination Survey (NHANES). Information from the demographic, blood lead level, and respiratory health questionnaire databases were combined to assess the impact of lead exposure on respiratory health. Blood lead exposure (BLL) was assessed at the following cut-off values: 1, 2, 3, 4, 5 and 10ug/dL. Respiratory health status was dichotomized as good and poor respiratory health based on the study participant’s answers to the questionnaire. Logistic regression was used to determine the relationship between blood lead levels and respiratory health status while controlling for the following potential confounders: race, age, sex, and annual family income. Results: This study was unable to establish a relationship between lead exposure and poor respiratory health in children ages 1-6 years, and the lack of relationship held for increasing levels of lead exposure. However, this study did reveal the significant impact of low level lead exposure in children with approximately 77% exposed at BLL ≥ 1ug/dL and 39% at BLL ≥ 2ug/dL. It is important to note that this is only a snapshot of the amount of lead exposure within this population; it is very likely that the levels fluctuate. Conclusion: While the percentage of study population decreases as the lead exposure increases, it is still alarming at the number of children exposed to low levels of lead. A large and growing body of literature documents the adverse health effects associated with low levels of lead exposure in children. This finding further supports the need for continuing research in examining the true impact of low level lead exposure and in determining a threshold dose level. In addition, a stronger study with a larger sample size and a more clearly defined respiratory health variable would allow for the relationship to be more closely examined before a definitive “no association” result can be made.

<div>In this experiment, swirl injectors were designed and tested to validate their use in spraying liquid </div><div>lead into a Barton pot combustion chamber to produce lead oxide at a smaller particle size than </div><div>the current stream injection. Testing was done with water and air to determine the best design for </div><div>atomization results, and then the injector was fabricated for liquid lead testing. Thermochemistry </div><div>calculations showed that due to lead oxidation being a surface reaction, the combustion process </div><div>was diffusion controlled. These conditions were used to determine residence time inside a Barton </div><div>pot combustion chamber for predicted droplet sizes. Results of the liquid lead testing showed that </div><div>final lead oxide particle size and residence time was reduced when using a swirl atomizer in place </div><div>of a steady feed stream. Further calculations were done to create a model for a standard combustion </div><div>chamber and injection system for lead oxide production.</div>

Chan Kai Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 109-119). / Abstracts in English and Chinese. / Title --- p.i / Thesis committee --- p.ii / Statement --- p.iii / Acknowledgement --- p.iv / Abbreviations --- p.v / Abstract (English) --- p.vii / Abstract (Chinese) --- p.ix / Table of contents --- p.xi / List of Figures --- p.xvi / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1 --- Human Hemoglobin --- p.1 / Chapter 1.2 --- Hemoglobinopathies --- p.4 / Chapter 1.3 --- Hereditary Persistence of Fetal Hemoglobin (HPFH) and β - Thalassemias --- p.6 / Chapter 1.4 --- Globin Genes Switching --- p.7 / Chapter 1.5 --- Pharmaceutical Agents for γ-Globin Gene Reactivation --- p.9 / Chapter 1.6 --- Discovery of LC978: A Novel Fetal Hemoglobin Inducing Agent --- p.10 / Chapter 1.7 --- Aim of Study --- p.11 / Chapter Chapter 2: --- Specific Induction of Gamma Globin Gene Transcription in K562 Leukemia Cell Line by Lead Compound LC978 --- p.12 / Chapter 2.1 --- K562 Cell Line as a Model for Gamma Globin Gene Induction Studies --- p.12 / Chapter 2.2 --- LC978-Induced Fetal Hemoglobin Expression in K562 Cell Line --- p.12 / Chapter 2.3 --- Materials --- p.14 / Chapter 2.3.1 --- "Chemicals, Kits and Reagents" --- p.14 / Chapter 2.3.2 --- Buffers and Solutions --- p.15 / Chapter 2.3.3 --- Cell Line --- p.16 / Chapter 2.3.4 --- Instruments and Equipments --- p.16 / Chapter 2.3.5 --- Enzymes --- p.16 / Chapter 2.3.6 --- Nucleic Acids --- p.17 / Chapter 2.3.7 --- Oligo Primers --- p.17 / Chapter 2.4 --- Methods --- p.17 / Chapter 2.4.1 --- In vitro Bioassay for Total Hemoglobin Production --- p.17 / Chapter (a) --- Preparation of Treatment Cell Culture Plates --- p.17 / Chapter (b) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (c) --- Signal Development --- p.18 / Chapter 2.4.2 --- Detection of Fetal Hemoglobin Production by HbF Sandwich ELISA --- p.18 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (b) --- Preparation of Capture Antibody-Coated and BSA-Blocked ELISA Plate --- p.19 / Chapter (c) --- Preparation of K562 Cell Lysates --- p.19 / Chapter (d) --- Antigen Capture and Signal Development --- p.19 / Chapter 2.4.3 --- Detection of Gamma Globin mRNA Level by Real-time RT-PCR --- p.20 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.20 / Chapter (b) --- Preparation of K562 Cell Lysate in Guanidium Thiocyanate (GT) Solution --- p.20 / Chapter (c) --- Isolation of Total RNA from LC978-treated K562 Cells --- p.21 / Chapter (d) --- cDNA Synthesis from mRNA by Reverse Transcriptase (RT) --- p.22 / Chapter (e) --- Real-Time Quantitative Polymerase Chain Reaction (PCR) --- p.23 / Chapter 2.5 --- Results --- p.24 / Chapter (a) --- In vitro Bioassay for Total Hemoglobin Production --- p.24 / Chapter (b) --- Fetal Hemoglobin Sandwich ELISA --- p.24 / Chapter (c) --- LC978-Induced Gamma Globin mRNA Accumulation --- p.25 / Chapter 2.6 --- Discussion --- p.31 / Chapter Chapter 3: --- Construction of Promoter-Reporter Plasmid Constructs --- p.33 / Chapter 3.1 --- The Human Gamma Globin Gene Promoter --- p.33 / Chapter 3.2 --- SEAP as a Reporter Gene for Promoter Deletion Study --- p.34 / Chapter 3.3 --- Materials --- p.35 / Chapter 3.3.1 --- "Chemicals, Kits and Reagents" --- p.35 / Chapter 3.3.2 --- Buffers and Solutions --- p.35 / Chapter 3.3.3 --- Bacterial Strain --- p.36 / Chapter 3.3.4 --- Cell Line --- p.36 / Chapter 3.3.5 --- Enzymes --- p.37 / Chapter 3.3.6 --- Nucleic Acids --- p.37 / Chapter 3.3.7 --- Oligo Primers --- p.37 / Chapter 3.4 --- Methods --- p.38 / Chapter 3.4.1 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pBlueScript II SK (-) --- p.38 / Chapter (a) --- Design and Synthesis of Oligo Primers --- p.38 / Chapter (b) --- Isolation of Genomic DNA from K562 Cells --- p.39 / Chapter (c) --- PCR Amplification of Gamma Globin Gene Promoter and 3' Enhancer --- p.40 / Chapter (d) --- Ligation of PCR Fragments into EcoR V-cut pBlueScript II SK (-) --- p.41 / Chapter (e) --- Preparation of E coli DH5a Competent Cells --- p.43 / Chapter (f) --- Heat-Shock Transformation of E. coli DH5a Competent Cells --- p.44 / Chapter (g) --- PCR Screening and Plasmid Purification of Putative pBlu2SKM-γAP and pBlu2SKM-γAE --- p.44 / Chapter (h) --- Isolation of Putative pBlu2SKM-γAP and pBlu2SKM-γAE Plasmid DNA --- p.45 / Chapter (j) --- Nucleotide Sequencing of Putative pBlu2SKM-yAP and pBlu2SKM-γAE --- p.47 / Chapter (j) --- Graphical Summary of Section 3.6.1 Sub-cloning Procedures --- p.49 / Chapter 3.4.2 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pSEAP2-Enhancer --- p.51 / Chapter (a) --- Sub-cloning of Promoter Fragment into pSEAP2-Enhancer --- p.51 / Chapter (b) --- Sub-cloning of 3' Enhancer Fragment into p 1224γAP-SEAP2 --- p.52 / Chapter (c) --- Graphical Summary of Section 3.6.2 Sub-cloning Procedures --- p.54 / Chapter 3.4.3 --- Construction of p 1224γAP-SEAP2-γAE Promoter Deletions Constructs --- p.56 / Chapter (a) --- Restriction Digestion at 5' End of A-Gamma Promoter Deletions --- p.56 / Chapter (b) --- Restriction Digestion at 3' Ends of A-Gamma Promoter Deletions --- p.56 / Chapter (c) --- Blunting 5'-overhangs and Self-Ligation of Linearized Plasmid Constructs --- p.57 / Chapter (d) --- Graphical Summary of Section 3.6.3 5，Deletions Procedures --- p.58 / Chapter 3.5 --- Results --- p.59 / Chapter (a) --- Nucleotide Sequence Confirmed by Cycle Sequencing --- p.60 / Chapter (b) --- "Resulting Plasmid Constructs p 1224γAP-SEAP2-yAE, p754yAP-SEAP2-yAE and p205yAP-SEAP2-γAE" --- p.64 / Chapter 3.6 --- Discussion --- p.67 / Chapter Chapter 4: --- Mapping of LC978-Responsive Elements on Human A-Gamma Globin Gene Promoter --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.2 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.69 / Chapter 4.3 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.70 / Chapter 4.4 --- Materials --- p.72 / Chapter 4.4.1 --- "Chemicals, Kits and Reagents" --- p.72 / Chapter 4.4.2 --- Buffers and Solutions --- p.73 / Chapter 4.4.3 --- Cell Line --- p.74 / Chapter 4.4.4 --- Nucleic Acids --- p.74 / Chapter 4.4.5 --- Instruments and Equipments --- p.74 / Chapter 4.5 --- Methods --- p.74 / Chapter 4.5.1 --- Determination of Optimal Dose of Transfection Reagent for --- p.74 / Chapter (a) --- Sterilization of Plasmid DNA for Transfection --- p.74 / Chapter (b) --- Transient Transfection of K562 Cells by pEGFP-N 1 --- p.75 / Chapter (c) --- Examination of EGFP Expression Level --- p.76 / Chapter 4.5.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.76 / Chapter (a) --- Transient Transfection of K562 Cells by pSV-β-Gal --- p.76 / Chapter (b) --- Determination of β-Galactosidase Expression Level --- p.76 / Chapter 4.5.3 --- Mapping of LC978-Responsive Elements on Human Gamma Globin Gene Promoter --- p.77 / Chapter (a) --- Co-Transfection of K562 Cells by p1224/754/205γAP-SEAP2 -γAE and pSV-β-Gal --- p.77 / Chapter (b) --- Treatment of Co-Transfected K562 Cells by LC978 --- p.77 / Chapter (c) --- Determination of β-Galactosidase Expression Level --- p.78 / Chapter (d) --- Determination of Secreted Alkaline Phosphatase (SEAP) Expression Level --- p.78 / Chapter (e) --- Determination of Fetal Hemoglobin Expression Level --- p.79 / Chapter 4.5.4 --- Mapping of Hydroxyurea-Responsive Elements on Human Gammm Globin Gene Promoter --- p.80 / Chapter (a) --- Determination of Optimal Biological Dose (OBD) of Hydroxyurea --- p.80 / Chapter (b) --- Co-Transfection of K562 Cells and Subsequent Treatment by Hydroxyurea --- p.80 / Chapter (c) --- "Assay for β-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.81 / Chapter 4.5.5 --- Sodium Butyrate-Induced SEAP Expression --- p.81 / Chapter (a) --- Determination of Optimal Biological Dose (OB(d) of Sodium Butyrate --- p.81 / Chapter (b) --- Co-Transfection of K562 Cells and Treatment by Sodium Butyrate --- p.82 / Chapter (c) --- "Assay for p-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.83 / Chapter 4.5.6 --- Data Analysis --- p.83 / Chapter (a) --- "Data Processing, Normalization and Graphing" --- p.83 / Chapter (b) --- Statistical Analysis --- p.83 / Chapter 4.6 --- Results --- p.84 / Chapter 4.6.1 --- Optimal Dose of Transfection Reagent for K562 --- p.84 / Chapter 4.6.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.84 / Chapter 4.6.3 --- LC978 Induction on Co-Transfected K562 Cells --- p.84 / Chapter 4.6.4 --- Hydroxyurea Induction on Co-Transfected K562 Cells --- p.85 / Chapter 4.6.5 --- Sodium Butyrate Induction on Co-Transfected K562 Cells --- p.86 / Chapter 4.7 --- Discussion --- p.98 / Chapter 4.7.1 --- Theme Question to be Answered --- p.98 / Chapter 4.7.2 --- Optimal Dose of DMRIE-C Transfection Reagent on K562 Cell Line --- p.98 / Chapter 4.7.3 --- pSV-β-gal as an Internal Normalization Control --- p.99 / Chapter 4.7.4 --- Responsive Element Mapping --- p.99 / Chapter (a) --- LC978-Induced Response --- p.100 / Chapter (b) --- Hydroxyurea-Induced Response --- p.100 / Chapter (c) --- Sodium Butyrate-Induced Response --- p.101 / Chapter 4.7.5 --- LCR-Dependent Gamma Globin Gene Reactivation --- p.101 / Chapter 4.7.6 --- Induction of Gamma Globin by Histone Deacetylase Inhibitor --- p.104 / Chapter 4.7.7 --- Basal SEAP Expression Levels of the Promoter-Reporter Constructs --- p.105 / Chapter 4.7.8 --- Summary --- p.105 / Chapter Chapter 5: --- General Discussion --- p.106 / References Cited --- p.109

Although competitive today, traditional PbA (<1500 cycles) and advanced lead-acid batteries (ALAB) (>4000 cycles) will not be able to compete with lithium and flow batteries by 2020. To compete with novel zinc, lithium and flow batteries, the PbA chemistry needs to achieve significant performance improvements, primarily through sustainable increases to specific energy (Wh/kg), while not negatively impacting cycle life. Inverse charging has been examined for its potential in improving PbA cycle life as a battery maintenance procedure, and as a potential technique for improving electrode specific capacity (mAh/kg) during battery manufacturing and formation. A thorough levelized cost of energy (LCOE) shows that for traditional PbA batteries with cycle lives <2000, inverse charging as a maintenance strategy (to increase cycle life) improves battery economics. Inverse charging to increase cycle life for ALAB systems (>4000 cycle life) was proven to worsen battery economics, as additional costs of capital and maintenance fail to outweigh savings achieved through reductions in replacement cost. On the other hand, inverse charging employed as a manufacturing practice to increase specific energy dramatically reduces the cost of the PbA and ALAB systems, ensuring future cost competitiveness. Inverse charging as a maintenance strategy should be restricted to devices with <2000 cycles and to projects with long project lives (20 years) that require frequent replacement. Inverse charging as a manufacturing strategy (to increase specific energy) is highly preferable in all instances. When successful, inverse charging increases the specific capacity and active material utilization of studied battery electrodes significantly. Successful inverse charging of battery electrodes and pure lead rods show improvements in discharge capacities over a range of discharge rates with negligible impact to coulombic and energy efficiency values. The extent of success, however, depends on several important variables. Thorough examination of inverse charging on Pb rods and porous battery electrodes illustrates the importance of the degree of prior electrode sulfation and obstruction of transport of H₂SO₄. Other important factors include the composition of electrode grid alloys, the peak oxidation voltage applied to the negative electrode during inverse charging, initial particle sizes, and electrolyte additives. Significant challenges to inverse charging exist. For heavily sulfated batteries and lead metals, impeded electrolyte transport results in excessive internal pore pH increases, creating semipermeable membranes through an electrode hydration mechanism, resulting in dramatic inverse charging failure. Additionally, impedance, voltage, x-ray and BET data hint that post-inverse charging, agglomeration of finely divided Pb and PbSO₄ particles occurs, coupled with negative electrode conductive pathway destruction. As such, the influence of expander materials and nucleation additives should be investigated to better prevent sulfation failure, and to better control the nucleation and growth of lead and lead sulfate structures during inverse charging. Cycle life studies on flooded lead antimony batteries subjected to periodic inverse charging illustrate that inverse charging is highly successful on all batteries independent of states-of-health. Batteries with poor states-of-health (discharge capacities <15% of initial values) experienced almost perfect discharge capacity restoration post-inverse charging. Traditional methods of extending cycle life (i.e. prolonged overcharging techniques) were demonstrated to be inadequate at appreciably regenerating battery capacities, providing only marginal increases. The benefits of inverse charging, however, are met with significant challenges to battery redesign. Temporary antimony poisoning effects lead to declines in round-trip-efficiency for batteries with antimony-based positive plates. Tin dissolution results in diminished grid to active material conductivity and reduced capacity for batteries with tin-based positives. For the negative electrode, Brunauer–Emmett–Teller (BET) surface area and x-ray measurements indicate that although large PbSO₄ crystals are oxidized during inverse charging, creating extensive micropore networks during conversion from Pb to PbO₂, surface area and capacity gains are lost during reconversion back to sponge lead due to uncontrolled nucleation and particle fusion. Additionally, active material shedding of the positive and negative electrodes is observed to spike during and after inverse charging. Negative electrode active material suffers excessive degradation and loss of cohesion, particularly for electrodes with small initial particle feature sizes, resulting in a loss of structure upon completion of the technique. Positive electrode composition changes to weakly interconnected b-PbO₂, dramatically increasing electrode capacity while simultaneously accelerating electrode failure through shedding. Loss of particle cohesion in both electrodes promotes excessive shedding and sludging, creating intra-cellular short-circuits. In addition, inverse charging aggravates grid growth, promoting inter-cellular short-circuiting by creating pathways for cell-to-cell electrolyte contact upon seal destruction in current monoblock designs.

Made available in DSpace on 2014-06-11T19:31:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-06Bitstream added on 2014-06-13T19:01:17Z : No. of bitstreams: 1 chaconsanhueza_ae_dr_bauru_prot.pdf: 7689915 bytes, checksum: 8ebb39720ca5e37b27ba08b395d4278d (MD5) / Este trabalho apresenta o desenvolvimento de dois métodos alternativos para recuperar chumbo. Fusão Alcalina e Eletrohidrometalúrgico. Ambos oferencem a possibilidade de recuperação de outros elementos químicos normalmente perdidos nas escórias. Partindo-se de matérias primas como sucata de baterias chumbo-ácido, resíduos e outras fontes contendo chumbo, a taxa de recuperação foi de 92% a 99% em chumbo com pureza de 99,74%, quando utilizado o método da Fusão Alkalina. Esta taxa foi de 94% em chumbo de 99,99% de pureza, quando empregado o processo Eletrohidrometalúrgico. Cumpre ressaltar que os resíduos gerados por estes métodos são da ordem de 6% a 10% e estão em uma forma química que permite a recuperação de outros metais. Pelo processo convencional (pirometalúrgico), a taxa de recuperação foi de 90% em chumbo com pureza de 98,5% com quantidade de resíduo que chega a 25% do chumbo total produzido e cuja composição obriga o descarte em aterros classe 1. Este trabalho também desenvolve um método para a obtenção de um aditivo que assegura a formação de massas ativas eficientes para placas de baterias chumbo-ácido. O aditivo, à base de sulfato tetrabásico de chumbo (4BS), proporcionou maior reversibilidade ao longo dos dois ciclos, sendo que o tempo de vida útil da bateria dobrou e a quantidade de baterias rejeitadas diminuiu 10% para menos do que 0,5%. Estes índices vêm sendo mantidos durante dois anos em uma empresa do estado de São Paulo, que produz 1000 baterias por mês. Além disso, foi desenvolvido um lacre à base de chumbo que ao ser utilizado nos vasos das baterias durante a sua formação, suprimiu em 97,5% o arraste do ácido sulfúrico para a atmosfera. Finalmente, foi elaborado um processo para tratamento de efluentes liquidos que gera gesso como subproduto e possibilita a reutilização... / This work presents the development of two alternative methods to recycle lead. Alkaline Fuson and Electrohydrometallurgic. Both also offer the possibility to recover other chemical elements that normally are lost as waste. From raw materials such as scrap lead-acid batteries, waste and other sources containing lead, the Alkaline Fusion method yields 92% to 99% of recovering of lead having a purity of 99.74%. Using the Electrohydrometallurgic process, the recovery is 94% of lead of 99.99% purity. It must be emphasized that the generated wastes by these methods are around 6% to 10% and they are in a chemical form, which allows further recycling of other metals. By the conventional process, the pirometallurgic one, it was obtained 90% of recovering of lead of 98.5% purity. Furthermore, the waste amount is around 25% of the total produced lead, whose composition requires an expensive discarding system (Type 1 system). This work also develops a method for obtaining an additive that ensures the efficient active mass formation for lead-acid batteries plates. The additive, constituted by tetrabasic lead sulphate (4BS), provid higher reversibility for charging/discharging cycles being that the battery lifetine increased two folds and the amount of rejected batteries diminished from 10% to less than 0.5%. Such indices are being held for two years in a company of the São Paulo State, Which produces one thousand batteries in a month. In addition, it was developed a lead based sealing device that, when utilized in battery vessel during its formation suppresses the sulfuric acid released to the atmosphere in 97.5%. Finally, it was advanced a process for liquid effluent treatment that produces plaster, a by-product, and allows the reuse of water, since it contains a low metal content. The utilization of the developed methods by a company in... (Complete abstract click electronic access below)

Lead is a global health hazard and reducing environmental exposures to lead is becoming increasingly important as negative health impacts are documented at lower levels of exposure. Soils, an important source of lead exposure in children, represent a largely untested reservoir of accumulated past and present lead contamination retained in the surface. Concentrations of soil lead are very spatially heterogeneous, however, and testing is required to identify whether site-specific soils present a hazard. In this dissertation I outline the several ways to increase testing and awareness about soil-lead contamination to provide individuals with the information needed to prevent exposure to soil lead. Chapter one presents a new field procedure for use by the general public to screen soils for hazardous levels of lead that is based on determining bioaccessible lead. Chapter two describes the delineation of soil-lead hotspots in four mining-impacted towns in Peru and reveals that parents using the field procedure identified a hotspot missed by previous testing. In this study, we find child blood lead information is associated with parent cleanliness, which may represent a pathway for child exposure to dust and soil lead, although no associations are seen directly with soil lead concentrations. In chapter three, Peruvian high school students use the field procedure in their science classes to identify hotspots of soil lead and share this information with their community. Finally, chapter four highlights that extremely elevated concentrations of soil lead are not limited to far-off mining communities but are also present locally in New York City. Soil core data collected does not reveal a single source or blanket atmospheric inputs, but rather highlights the variability of deposition that requires widespread testing.

Les jeunes enfants sont les plus exposés au plomb et les plus sensibles à ses effets sur la santé, notamment sur le développement. Une enquête d’imprégnation sur 3831 enfants vivant en France a permis d’établir la moyenne géométrique des expositions au plomb à 14,9 (+/- 0,5) µg/L de sang avec 76000 enfants au-delà du seuil d’intervention obligatoire de 50µg/L. Les critères actuels de dépistage se sont avérés peu aptes à repérer ces enfants surexposés et de nouveaux critères sont proposés. En complément, une enquête environnementale avec mesures de plomb dans le logement a été réalisée dans 484 logements. Les poussières au sol des habitations et l’eau du robinet sont des facteurs important de surexposition, ainsi que l’utilisation de vaisselle et cosmétiques traditionnels. Les politiques de prévention doivent être poursuivies compte tenu de la persistance de sources d’exposition et de la toxicité même à faible dose. / Young children are most exposed to lead and the most susceptible to its health effects, notably on development. A nationwide representative survey on 3831 children in France has established the geometric mean of lead exposures at 14.9 (+/- 0.5) µg/L of blood with 76000 children beyond the mandatory action level of 50μg / L. The current screening criteria have proved insufficient to identify these overexposed children and new ones are proposed. In addition, an environmental investigation with lead measurements in housing was performed in 484 homes. Household floor dust and tap water are major factors of overexposure, and also the use of traditional dishes and cosmetics. Prevention policies must be pursued in light of the continuing sources of exposure and toxicity even at low doses.

Arsenic is a well-known lung carcinogen in humans. In 2006, IARC upgraded inorganic lead as a possible human carcinogen (2A). The aim of this thesis has been to evaluate the lung cancer mortality and incidence in long-term exposed primary lead smelter workers and also to estimate present exposures to arsenic and lead in relation to those occurring in the past. The basic cohort (N=3832 workers; hired before 1967 and followed up from 1950-1981; SMR comparisons with general and local reference populations) showed an excess of deaths for total mortality, malignant neoplasms (e.g. lung and stomach cancer), ischaemic heart diseases, and cerebrovascular diseases compared to the general population. In a subcohort of lead workers (N=437; regular blood lead sampling since 1950) only the raised SMR for lung cancer (162) was sustained. In a follow-up study of the basic cohort (N=3979), a subcohort of lead exposed workers (N=1992) was formed. The expected mortality in 1955-1987 and cancer incidence in 1958-1987 were calculated relative to county rates. A cumulative blood lead index (CBLI) was used for dose-response analyses. The lung cancer incidence was raised in the total cohort (SIR 2.8; 95 % CI 2.1 3.8). A higher lung cancer risk was observed in workers hired before 1950 (SIR 3.6; 95 % CI 2.6-5.0). The increased lung cancer risks were further elevated in the subcohort of lead exposed workers, especially in the highest exposed subgroup (SIR 5.1; 95 % 2.0-10.5; latency period of 15 y). No excesses of other malignancies were observed. The increased relative risks for lung cancer may have been caused by interactions between inorganic lead and other substances at the smelter, e.g. arsenic. To further analyze the effects from inorganic lead, two subcohorts of workers at the lead departments were formed from the original cohort (N=3979), one of 710 workers and the other of 383 workers. The lung cancer incidence was raised in both subcohorts (Lead subcohort 1; SIR 2.4; 95 % CI 1.2-4.5; Lead subcohort 2; SIR 3.6; 95 % CI 1.2-8.3). Among the 10 workers that had developed lung cancer in lead subcohort 1 all but one had a considerable exposure also to arsenic. Thus, a possible interaction effect between lead and arsenic may explain the increased lung cancer risks. To further elucidate the impact from lead and arsenic a case control study was undertaken. In the basic cohort (N=3979), 46 male workers had contracted respiratory malignancies. They were compared with 141 agematched male referents from the primary smelter by conditional logistic regression analysis using smoking habits, cumulative blood lead and air arsenic exposure as predictor variables. The lung cancer cases showed a significantly higher smoking rate than referents (Odds ratio, OR = 4.0; 95 % CI 1.6-10.1; p=0.003). When restricted to smokers, the cumulative arsenic air exposure index, but not the lead exposure indices, were significantly higher among the cases (OR=1.07; 95 % CI 1.02-1.11; p = 0.005). Accordingly, cumulative arsenic exposure and smoking were identified as significant risk factors for the development of lung cancer in the final analyses, while lead exposure was not a significant risk factor. However, inorganic lead still may play a minor role in the multifactorial genesis of lung cancer. These studies describe risks from exposures occurring from time periods before 1950 up to 1981. Because of the long latency period for lung cancer, exposures after 1970 probably have had limited impact on the reported results. Compared to the levels in the early 1970´s present exposures to arsenic are lower by a factor of ten or more and risks probably correspondingly lower.

The lead-cooled fast reactor (LFR) is one of the concepts of the Generation IV reactorsystems. There are some issues that have to be solved before a research orcommercial LFR can be built. The objective of this thesis was to identify these keyissues and analyse them by studying results from previous research: choice of fuel,corrosion on structural materials and corrosion/erosion on pumps.The major fuel candidates for the LFR are MOX fuel (Mixed OXide fuel), metallic fuel,nitride fuel and carbide fuel. Nitride fuel has desirable properties but its production ismore difficult than for MOX fuel.Most of today’s commercial steels are not corrosion resistant at higher temperaturesbut they could possibly be used for an LFR test demonstrator with an operatingtemperature lower than 450 ºC. A new type of steel called oxide dispersionstrengthened (ODS) steel and a new ceramic material MAXTHAL both showpromising corrosion resistance even at higher temperatures.By controlling the oxygen concentration a protective oxide film is produced. Flowingliquid coolant causes erosion and wears down the oxide film. Pumps are exposed tocoolant velocities of 10-15 m/s causing both erosion and corrosion. There is nosolution today, but MAXTHAL shows promising results in tests with liquid lead of lowvelocity. There are also other issues unsolved, such as irradiation damage onstructural materials, thus more research is needed.Economic and political aspects were not covered in this study. This thesis work wasperformed at Vattenfall Research and Development AB.

Title from PDF of title page. / Document formatted into pages; contains 161 pages. / Thesis (M.S.C.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Driving piles constitute a large portion of the high-capacity foundations used today. They transfer structural loads to deep bearing strata when adequate surficial soils are not available. The mechanisms required to install these piles generally consist of a hammer, hammer lead, a crane, and various support rigging. This study focused on lead sections, specifically, one which was manufactured by Berminghammer Foundation Equipment, Inc. The dimensions and strength of a lead section must be capable of supporting both the pile driving hammer and the longest anticipated pile for a given site. The strength of the section must be capable of withstanding hundreds of tons in compression and bending. If the lead is operated in a batter, (tilted forward, backward, or sideways) the weight of the hammer and pile causes much more bending than the vertical orientation. / ABSTRACT: The cross-section details for these long steel sections vary from design to design but usually incorporate some form of bolt group, pins, and steel alignment dowels. This thesis focuses on the design, modeling, and testing of such a connection. The motivation of the study stems from a company-wide incentive to standardize the connections used to splice the Berminghammer C15-series lead section. In an effort to verify a proposed connection design, Berminghammer Foundation Engineering solicited the University of South Florida to test a full-sized lead section to failure, while monitoring the splice-connection performance. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.