Lead exposure in adult males in urban Transvaal Province, South Africa during the apartheid era

Human exposure to lead is a substantial public health hazard worldwide and is particularly problematic in the Republic of South Africa given the country’s late cessation of leaded petrol. Lead exposure is associated with a number of serious health issues and diseases including developmental and cognitive deficiency, hypertension and heart disease. Understanding the distribution of lifetime lead burden within a given population is critical for reducing exposure rates. Femoral bone from 101 deceased adult males living in urban Transvaal Province (now Gauteng Province), South Africa between 1960 and 1998 were analyzed for lead concentration by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Of the 72 black and 29 white individuals sampled, chronic lead exposure was apparent in nearly all individuals. White males showed significantly higher median bone lead concentration (ME = 10.04 µg·g−1), than black males (ME = 3.80 µg·g−1) despite higher socioeconomic status. Bone lead concentration covaries significantly, though weakly, with individual age. There was no significant temporal trend in bone lead concentration. These results indicate that long-term low to moderate lead exposure is the historical norm among South African males. Unexpectedly, this research indicates that white males in the sample population were more highly exposed to lead

Inter-individual variations of human mercury exposure biomarkers: a cross-sectional assessment

BACKGROUND: Biomarkers for mercury (Hg) exposure have frequently been used to assess exposure and risk in various groups of the general population. We have evaluated the most frequently used biomarkers and the physiology on which they are based, to explore the inter-individual variations and their suitability for exposure assessment. METHODS: Concentrations of total Hg (THg), inorganic Hg (IHg) and organic Hg (OHg, assumed to be methylmercury; MeHg) were determined in whole blood, red blood cells, plasma, hair and urine from Swedish men and women. An automated multiple injection cold vapour atomic fluorescence spectrophotometry analytical system for Hg analysis was developed, which provided high sensitivity, accuracy, and precision. The distribution of the various mercury forms in the different biological media was explored. RESULTS: About 90% of the mercury found in the red blood cells was in the form of MeHg with small inter-individual variations, and part of the IHg found in the red blood cells could be attributed to demethylated MeHg. THg in plasma was associated with both IHg and MeHg, with large inter-individual variations in the distribution between red blood cells and plasma. THg in hair reflects MeHg exposure at all exposure levels, and not IHg exposure. The small fraction of IHg in hair is most probably emanating from demethylated MeHg. The inter-individual variation in the blood to hair ratio was very large. The variability seemed to decrease with increasing OHg in blood, most probably due to more frequent fish consumption and thereby blood concentrations approaching steady state. THg in urine reflected IHg exposure, also at very low IHg exposure levels. CONCLUSION: The use of THg concentration in whole blood as a proxy for MeHg exposure will give rise to an overestimation of the MeHg exposure depending on the degree of IHg exposure, why speciation of mercury forms is needed. THg in RBC and hair are suitable proxies for MeHg exposure. Using THg concentration in plasma as a measure of IHg exposure can lead to significant exposure misclassification. THg in urine is a suitable proxy for IHg exposure

Quality of life, psychological morbidity and family stress in elderly residing in the community

Este estudo procurou investigar as relações existentes entre morbilidade psicológica, stress familiar e qualidade de vida (QV) da pessoa idosa. A amostra foi constituída por 126 idosos. Os instrumentos utilizados foram: The Lawton Instrumental Activities of Daily Living (IADL), Quality of Life (WHOQOL-Bref), Geriatric Anxiety Inventory (GSI), Geriatric Depression Scale (GDS); e Index of Family Relations (IFR). Os resultados revelaram a importância da idade, estado civil, escolaridade e número de patologias assim como o género na capacidade funcional, morbilidade, stress familiar e QV. Ao nível dos preditores, a depressão foi a variável que mais contribuiu para a QV. Não foram encontradas variáveis moderadoras no modelo. A discussão e implicações dos resultados são abordadas bem como a intervenção psicológica nesta população.This study sought to understand the relationships among psychological morbidity, family stress and quality of life (QL) of elderly. The sample consisted of 126 elderly. The following instruments were used: the Lawton Instrumental Activities of Daily Living (IADL); Quality of Life (WHOQOL-Bref), Geriatric Anxiety Inventory (GSI), Geriatric Depression Scale (GDS), and the Index of Family Relations (IFR). Results revealed the importance of age, marital status, education and number of pathologies as well as gender on functional capacity, morbidity, family stress and QV. In terms of predictors, depression was the variable that contributed the most to QL. There were no moderating variables in the model. Discussion and implications of results are addressed as well as psychological interventions.(undefined

Influence of Socioeconomic Status Trajectories on Innate Immune Responsiveness in Children

Lower socioeconomic status (SES) is consistently associated with poor health, yet little is known about the biological mechanisms underlying this inequality. In children, we examined the impact of early-life SES trajectories on the intensity of global innate immune activation, recognizing that excessive activation can be a precursor to inflammation and chronic disease.Stimulated interleukin-6 production, a measure of immune responsiveness, was analyzed ex vivo for 267 Canadian schoolchildren from a 1995 birth cohort in Manitoba, Canada. Childhood SES trajectories were determined from parent-reported housing data using a longitudinal latent-class modeling technique. Multivariate regression was conducted with adjustment for potential confounders.SES was inversely associated with innate immune responsiveness (p=0.003), with persistently low-SES children exhibiting responses more than twice as intense as their high-SES counterparts. Despite initially lower SES, responses from children experiencing increasing SES trajectories throughout childhood were indistinguishable from high-SES children. Low-SES effects were strongest among overweight children (p<0.01). Independent of SES trajectories, immune responsiveness was increased in First Nations children (p<0.05) and urban children with atopic asthma (p<0.01).These results implicate differential immune activation in the association between SES and clinical outcomes, and broadly imply that SES interventions during childhood could limit or reverse the damaging biological effects of exposure to poverty during the preschool years

Comprehensive Analysis of 5-Aminolevulinic Acid Dehydrogenase (ALAD) Variants and Renal Cell Carcinoma Risk among Individuals Exposed to Lead

BACKGROUND: Epidemiologic studies are reporting associations between lead exposure and human cancers. A polymorphism in the 5-aminolevulinic acid dehydratase (ALAD) gene affects lead toxicokinetics and may modify the adverse effects of lead. METHODS: The objective of this study was to evaluate single-nucleotide polymorphisms (SNPs) tagging the ALAD region among renal cancer cases and controls to determine whether genetic variation alters the relationship between lead and renal cancer. Occupational exposure to lead and risk of cancer was examined in a case-control study of renal cell carcinoma (RCC). Comprehensive analysis of variation across the ALAD gene was assessed using a tagging SNP approach among 987 cases and 1298 controls. Occupational lead exposure was estimated using questionnaire-based exposure assessment and expert review. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression. RESULTS: The adjusted risk associated with the ALAD variant rs8177796(CT/TT) was increased (OR = 1.35, 95%CI = 1.05-1.73, p-value = 0.02) when compared to the major allele, regardless of lead exposure. Joint effects of lead and ALAD rs2761016 suggest an increased RCC risk for the homozygous wild-type and heterozygous alleles ((GG)OR = 2.68, 95%CI = 1.17-6.12, p = 0.01; (GA)OR = 1.79, 95%CI = 1.06-3.04 with an interaction approaching significance (p(int) = 0.06). No significant modification in RCC risk was observed for the functional variant rs1800435(K68N). Haplotype analysis identified a region associated with risk supporting tagging SNP results. CONCLUSION: A common genetic variation in ALAD may alter the risk of RCC overall, and among individuals occupationally exposed to lead. Further work in larger exposed populations is warranted to determine if ALAD modifies RCC risk associated with lead exposure

Design of a randomized controlled trial of physical training and cancer (Phys-Can) – the impact of exercise intensity on cancer related fatigue, quality of life and disease outcome

Background: Cancer-related fatigue is a common problem in persons with cancer, influencing health-related quality of life and causing a considerable challenge to society. Current evidence supports the beneficial effects of physical exercise in reducing fatigue, but the results across studies are not consistent, especially in terms of exercise intensity. It is also unclear whether use of behaviour change techniques can further increase exercise adherence and maintain physical activity behaviour. This study will investigate whether exercise intensity affects fatigue and health related quality of life in persons undergoing adjuvant cancer treatment. In addition, to examine effects of exercise intensity on mood disturbance, adherence to oncological treatment, adverse effects from treatment, activities of daily living after treatment completion and return to work, and behaviour change techniques effect on exercise adherence. We will also investigate whether exercise intensity influences inflammatory markers and cytokines, and whether gene expressions following training serve as mediators for the effects of exercise on fatigue and health related quality of life. Methods/design: Six hundred newly diagnosed persons with breast, colorectal or prostate cancer undergoing adjuvant therapy will be randomized in a 2 × 2 factorial design to following conditions; A) individually tailored low-to-moderate intensity exercise with or without behaviour change techniques or B) individually tailored high intensity exercise with or without behaviour change techniques. The training consists of both resistance and endurance exercise sessions under the guidance of trained coaches. The primary outcomes, fatigue and health related quality of life, are measured by self-reports. Secondary outcomes include fitness, mood disturbance, adherence to the cancer treatment, adverse effects, return to activities of daily living after completed treatment, return to work as well as inflammatory markers, cytokines and gene expression. Discussion: The study will contribute to our understanding of the value of exercise and exercise intensity in reducing fatigue and improving health related quality of life and, potentially, clinical outcomes. The value of behaviour change techniques in terms of adherence to and maintenance of physical exercise behaviour in persons with cancer will be evaluated