910 resultados para Human Health Risk
Resumo:
Research has identified a number of putative risk factors that places adolescents at incrementally higher risk for involvement in alcohol and other drug (AOD) use and sexual risk behaviors (SRBs). Such factors include personality characteristics such as sensation-seeking, cognitive factors such as positive expectancies and inhibition conflict as well as peer norm processes. The current study was guided by a conceptual perspective that support the notion that an integrative framework that includes multi-level factors has significant explanatory value for understanding processes associated with the co-occurrence of AOD use and sexual risk behavior outcomes. This study evaluated simultaneously the mediating role of AOD-sex related expectancies and inhibition conflict on antecedents of AOD use and SRBs including sexual sensation-seeking and peer norms for condom use.^ The sample was drawn from the Enhancing My Personal Options While Evaluating Risk (EMPOWER: Jonathan Tubman, PI), data set (N = 396; aged 12-18 years). Measures used in the study included Sexual Sensation-Seeking Scale, Inhibition Conflict for Condom Use, Risky Sex Scale. All relevant measures had well-documented psychometric properties. A global assessment of alcohol, drug use and sexual risk behaviors was used.^ Results demonstrated that AOD-sex related expectancies mediated the influence of sexual sensation-seeking on the co-occurrence of alcohol and other drug use and sexual risk behaviors. The evaluation of the integrative model also revealed that sexual sensation-seeking was positively associated with peer norms for condom use. Also, peer norms predicted inhibition conflict among this sample of multi-problem youth. ^ This dissertation research identified mechanisms of risk and protection associated with the co-occurrence of AOD use and SRBs among a multi-problem sample of adolescents receiving treatment for alcohol or drug use and related problems. This study is informative for adolescent-serving programs that address those individual and contextual characteristics that enhance treatment efficacy and effectiveness among adolescents receiving substance use and related problems services.^
Resumo:
Adolescents engage in a range of risk behaviors during their transition from childhood to adulthood. Identifying and understanding interpersonal and socio-environmental factors that may influence risk-taking is imperative in order to meet the Healthy People 2020 goals of reducing the incidence of unintended pregnancies, HIV, and other sexually transmitted infections among youth. The purpose of this study was to investigate gender differences in the predictors of HIV risk behaviors among South Florida youth. More specifically, this study examined how protective factors, risk factors, and health risk behaviors, derived from a guiding framework using the Theory of Problem Behavior and Theory of Gender and Power, were associated with HIV risk behavior. A secondary analysis of 2009 Youth Risk Behavior Survey data sets from Miami-Dade, Broward, and Palm Beach school districts tested hypotheses for factors associated with HIV risk behaviors. The sample consisted of 5,869 high school students (mean age 16.1 years), with 69% identifying as Black or Hispanic. Logistic regression analyses revealed gender differences in the predictors of HIV risk behavior. An increase in the health risk behaviors was related to an increase in the odds that a student would engage in HIV risk behavior. An increase in risk factors was also found to significantly predict an increase in the odds of HIV risk behavior, but only in females. Also, the probability of participation in HIV risk behavior increased with grade level. Post-hoc analyses identified recent sexual activity (past 3 months) as the strongest predictor of condom nonuse and having four or more sexual partners for both genders. The strongest predictors of having sex under the influence of drugs/alcohol were alcohol use in both genders, marijuana use in females, and physical fighting in males. Gender differences in the predictors of unprotected sex, multiple sexual partners, and having sex under the influence were also found. Additional studies are warranted to understand the gender differences in predictors of HIV risk behavior among youth in order to better inform prevention programming and policy, as well as meet the national Healthy People 2020 goals.
Resumo:
Research has identified a number of putative risk factors that places adolescents at incrementally higher risk for involvement in alcohol and other drug (AOD) use and sexual risk behaviors (SRBs). Such factors include personality characteristics such as sensation-seeking, cognitive factors such as positive expectancies and inhibition conflict as well as peer norm processes. The current study was guided by a conceptual perspective that support the notion that an integrative framework that includes multi-level factors has significant explanatory value for understanding processes associated with the co-occurrence of AOD use and sexual risk behavior outcomes. This study evaluated simultaneously the mediating role of AOD-sex related expectancies and inhibition conflict on antecedents of AOD use and SRBs including sexual sensation-seeking and peer norms for condom use. The sample was drawn from the Enhancing My Personal Options While Evaluating Risk (EMPOWER: Jonathan Tubman, PI), data set (N = 396; aged 12-18 years). Measures used in the study included Sexual Sensation-Seeking Scale, Inhibition Conflict for Condom Use, Risky Sex Scale. All relevant measures had well-documented psychometric properties. A global assessment of alcohol, drug use and sexual risk behaviors was used. Results demonstrated that AOD-sex related expectancies mediated the influence of sexual sensation-seeking on the co-occurrence of alcohol and other drug use and sexual risk behaviors. The evaluation of the integrative model also revealed that sexual sensation-seeking was positively associated with peer norms for condom use. Also, peer norms predicted inhibition conflict among this sample of multi-problem youth. This dissertation research identified mechanisms of risk and protection associated with the co-occurrence of AOD use and SRBs among a multi-problem sample of adolescents receiving treatment for alcohol or drug use and related problems. This study is informative for adolescent-serving programs that address those individual and contextual characteristics that enhance treatment efficacy and effectiveness among adolescents receiving substance use and related problems services.
Resumo:
People, animals and the environment can be exposed to multiple chemicals at once from a variety of sources, but current risk assessment is usually carried out based on one chemical substance at a time. In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, a wide group of fungal secondary metabolites that are known to potentially cause toxicity and carcinogenic outcomes. Mycotoxins are commonly found in a variety of foods including those intended for consumption by infants and young children and have been found in processed cereal-based foods available in the Portuguese market. The use of mathematical models, including probabilistic approaches using Monte Carlo simulations, constitutes a prominent issue in human health risk assessment in general and in mycotoxins exposure assessment in particular. The present study aims to characterize, for the first time, the risk associated with the exposure of Portuguese children to single and multiple mycotoxins present in processed cereal-based foods (CBF). Portuguese children (0-3 years old) food consumption data (n=103) were collected using a 3 days food diary. Contamination data concerned the quantification of 12 mycotoxins (aflatoxins, ochratoxin A, fumonisins and trichothecenes) were evaluated in 20 CBF samples marketed in 2014 and 2015 in Lisbon; samples were analyzed by HPLC-FLD, LC-MS/MS and GC-MS. Daily exposure of children to mycotoxins was performed using deterministic and probabilistic approaches. Different strategies were used to treat the left censored data. For aflatoxins, as carcinogenic compounds, the margin of exposure (MoE) was calculated as a ratio of BMDL (benchmark dose lower confidence limit) to the aflatoxin exposure. The magnitude of the MoE gives an indication of the risk level. For the remaining mycotoxins, the output of exposure was compared to the dose reference values (TDI) in order to calculate the hazard quotients (ratio between exposure and a reference dose, HQ). For the cumulative risk assessment of multiple mycotoxins, the concentration addition (CA) concept was used. The combined margin of exposure (MoET) and the hazard index (HI) were calculated for aflatoxins and the remaining mycotoxins, respectively. 71% of CBF analyzed samples were contaminated with mycotoxins (with values below the legal limits) and approximately 56% of the studied children consumed CBF at least once in these 3 days. Preliminary results showed that children exposure to single mycotoxins present in CBF were below the TDI. Aflatoxins MoE and MoET revealed a reduced potential risk by exposure through consumption of CBF (with values around 10000 or more). HQ and HI values for the remaining mycotoxins were below 1. Children are a particularly vulnerable population group to food contaminants and the present results point out an urgent need to establish legal limits and control strategies regarding the presence of multiple mycotoxins in children foods in order to protect their health. The development of packaging materials with antifungal properties is a possible solution to control the growth of moulds and consequently to reduce mycotoxin production, contributing to guarantee the quality and safety of foods intended for children consumption.
Resumo:
Receiving personalised feedback on body mass index and other health risk indicators may prompt behaviour change. Few studies have investigated men’s reactions to receiving objective feedback on such measures and detailed information on physical activity and sedentary time. The aim of my research was to understand the meanings different forms of objective feedback have for overweight/obese men, and to explore whether these varied between groups. Participants took part in Football Fans in Training, a gender-sensitised, weight loss programme delivered via Scottish Professional Football Clubs. Semi-structured interviews were conducted with 28 men, purposively sampled from four clubs to investigate the experiences of men who achieved and did not achieve their 5% weight loss target. Data were analysed using the principles of thematic analysis and interpreted through Self-Determination Theory and sociological understandings of masculinity. Several factors were vital in supporting a ‘motivational climate’ in which men could feel ‘at ease’ and adopt self-regulation strategies: the ‘place’ was described as motivating, whereas the ‘people’ (other men ‘like them’; fieldwork staff; community coaches) provided supportive and facilitative roles. Men who achieved greater weight loss were more likely to describe being motivated as a consequence of receiving information on their objective health risk indicators. They continued using self-monitoring technologies after the programme as it was enjoyable; or they had redefined themselves by integrating new-found activities into their lives and no longer relied on external technologies/feedback. They were more likely to see post-programme feedback as confirmation of success, so long as they could fully interpret the information. Men who did not achieve their 5% weight loss reported no longer being motivated to continue their activity levels or self-monitor them with a pedometer. Social support within the programme appeared more important. These men were also less positive about objective post-programme feedback which confirmed their lack of success and had less utility as a motivational tool. Providing different forms of objective feedback to men within an environment that has intrinsic value (e.g. football club setting) and congruent with common cultural constructions of masculinity, appears more conducive to health behaviour change.
Resumo:
The project goal was to determine plant operations and maintenance worker’s level of exposure to mercury during routine and non-routine (i.e. turnarounds and inspections) maintenance events in eight gas processing plants. The project team prepared sampling and analysis plans designed to each plant’s process design and scheduled maintenance events. Occupational exposure sampling and monitoring efforts were focused on the measurement of mercury vapor concentration in worker breathing zone air during specific maintenance events including: pipe scrapping, process filter replacement, and process vessel inspection. Similar exposure groups were identified and worker breathing zone and ambient air samples were collected and analyzed for total mercury. Occupational exposure measurement techniques included portable field monitoring instruments, standard passive and active monitoring methods and an emerging passive absorption technology. Process sampling campaigns were focused on inlet gas streams, mercury removal unit outlets, treated gas, acid gas and sales gas. The results were used to identify process areas with increased potential for mercury exposure during maintenance events. Sampling methods used for the determination of total mercury in gas phase streams were based on the USEPA Methods 30B and EPA 1631 and EPA 1669. The results of four six-week long sampling campaigns have been evaluated and some conclusions and recommendations have been made. The author’s role in this project included the direction of all field phases of the project and the development and implementation of the sampling strategy. Additionally, the author participated in the development and implementation of the Quality Assurance Project Plan, Data Quality Objectives, and Similar Exposure Groups identification. All field generated data was reviewed by the author along with laboratory reports in order to generate conclusions and recommendations.
Resumo:
Adolescents engage in a range of risk behaviors during their transition from childhood to adulthood. Identifying and understanding interpersonal and socio-environmental factors that may influence risk-taking is imperative in order to meet the Healthy People 2020 goals of reducing the incidence of unintended pregnancies, HIV, and other sexually transmitted infections among youth. The purpose of this study was to investigate gender differences in the predictors of HIV risk behaviors among South Florida youth. More specifically, this study examined how protective factors, risk factors, and health risk behaviors, derived from a guiding framework using the Theory of Problem Behavior and Theory of Gender and Power, were associated with HIV risk behavior. A secondary analysis of 2009 Youth Risk Behavior Survey data sets from Miami-Dade, Broward, and Palm Beach school districts tested hypotheses for factors associated with HIV risk behaviors. The sample consisted of 5,869 high school students (mean age 16.1 years), with 69% identifying as Black or Hispanic. Logistic regression analyses revealed gender differences in the predictors of HIV risk behavior. An increase in the health risk behaviors was related to an increase in the odds that a student would engage in HIV risk behavior. An increase in risk factors was also found to significantly predict an increase in the odds of HIV risk behavior, but only in females. Also, the probability of participation in HIV risk behavior increased with grade level. Post-hoc analyses identified recent sexual activity (past 3 months) as the strongest predictor of condom nonuse and having four or more sexual partners for both genders. The strongest predictors of having sex under the influence of drugs/alcohol were alcohol use in both genders, marijuana use in females, and physical fighting in males. Gender differences in the predictors of unprotected sex, multiple sexual partners, and having sex under the influence were also found. Additional studies are warranted to understand the gender differences in predictors of HIV risk behavior among youth in order to better inform prevention programming and policy, as well as meet the national Healthy People 2020 goals.
Resumo:
This thesis describes a study of various methods to produce bioactive peptides. Initially, the generation of anti-Cronobacter spp. peptides by fermentation of milk protein is described. Lactobacillus johnsonii DPC6026 was used to generate two previously described antimicrobial peptides. Phenotypic analysis indicated unsatisfactory casein hydrolysis. The genome of the strain was sequenced and annotated. Results showed a number of unique features present, most notably a large symmetrical inversion of approximately 750kb in comparison with the human isolate L. johnsonii NCC 533. The data suggest significant genetic diversity and intra-species genomic rearrangements within the L. johnsonii spp.. Cronobacter spp. have emerged as pathogens of concern to the powdered infant formula industry. Chapters 3 and 4 of this thesis describe novel methods to generate two antimicrobial peptides, Caseicin A and B. In Chapter 3 a bank of Bacillus strains was generated and investigated for caseicin production. Following casein hydrolysis by specific B. cereus and B. thuringiensis strains the peptides of interest were generated. Chapter 4 describes a sterile enzymatic method to generate peptides from casein. Bioinformatic tools were used to predict enzymes capable of liberating caseicin peptides from casein. Hydrolysates were generated using suitable enzymes, examined and some were found to produce peptides with activity against Cronobacter spp.. This study establishes a potential industrial-grade method to generate antimicrobial peptides. Administration of GLP-1 leads to improved glycaemic control in diabetes patients. Generation of a recombinant lactic acid bacteria capable of producing a GLP-1 analogue is described in Chapter 5. In-vivo analysis confirmed insulinotropic activity. The results illustrate a method using bacteriocin producing cellular machinery to generate bioactive peptides. This thesis describes the generation of bioactive peptides by bacterial fermentation, tailored enzymatic hydrolysis and recombinant bacterial methods. The techniques described contribute to bioactive peptide research with regards novel methods of production and industrial scale-up.
Resumo:
Agriculture and livestock are key sectors of the Brazilian economy, which are essential for the country?s economic growth and for the equality between the domestic currency?s supply and demand. Agribusiness answered for about 23% of the gross domestic product (GDP) in 2015, according to Confederação Nacional da Agricultura (CNA), and reached 50.3% of total exports in February 2016, according to Secretaria de Relações Internacionais do Agronegócio (SRI) of Ministério da Agricultura, Pecuária e Abastecimento (Mapa) (Brasil, 2016). Currently, this sector is recognized as the most competitive and efficient in Brazil, considering the global scenario.
Resumo:
Contaminants of emerging concern are increasingly detected in the water cycle, with endocrine-disrupting chemicals (EDCs) receiving attention due to their potential to cause adverse health effects even at low concentrations. Although the EU has recently introduced some EDCs into drinking water legislation, most drinking water treatment plants (DWTPs) are not designed to remove EDCs, making their detection and removal in DWTPs an important challenge. The aim of this doctoral project was to investigate hormones and phenolic compounds as suspected EDCs in drinking waters across the Romagna area (Italy). The main objectives were to assess the occurrence of considered contaminants in source and drinking water from three DWTPs, characterize the effectiveness of removal by different water treatment processes, and evaluate the potential biological impact on drinking water and human health. Specifically, a complementary approach of target chemical analysis and effect-based methods was adopted to explore drinking water quality, treatment efficacy, and biological potential. This study found that nonylphenol (NP) was prevalent in all samples, followed by BPA. Sporadic contamination of hormones was found only in source waters. Although the measured EDC concentrations in drinking water did not exceed threshold guideline values, the potential role of DWTPs as an additional source of EDC contamination should be considered. Significant increases in BPA and NP levels were observed during water treatment steps, which were also reflected in estrogenic and mutagenic responses in water samples after the ultrafiltration. This highlights the need to monitor water quality during various treatment processes to improve the efficiency of DWTPs. Biological assessments on finished water did not reveal any bioactivity, except for few treated water samples that exhibited estrogenic responses. Overall, the data emphasize the high quality of produced drinking water and the value of applying integrated chemical analysis and in vitro bioassays for water quality assessment.
Resumo:
Este artigo versa sobre contribuições da teoria social a um estudo sobre o risco à saúde humana e ao ambiente, desenvolvido entre 2003 e 2005 em área urbana contaminada, localizada no bairro Vila Carioca, no sudeste do município de São Paulo, Brasil. Resíduos perigosos provenientes de processo produtivo do setor químico, dispostos inadequadamente na localidade ao longo do tempo, resultaram em contaminação ambiental, cujos efeitos representam riscos à saúde da população local. A investigação foi realizada com o objetivo de identificar interpretações sociais sobre o conceito de situação de risco, condizentes com concepções incorporadoras da dimensão social do risco e voltadas à melhoria das condições de saúde ambiental. Utilizou-se metodologia qualitativa de pesquisa, alicerçada na teoria social, e instrumentos variados de coleta de dados. Os resultados apontaram interpretações sociais diferenciadas sobre o conceito de situação de risco, sugerindo diversidade de concepções entre a população pesquisada a respeito dos problemas ambientais e de saúde que os atingiam. Neste artigo, apresentam-se fundamentos do enfoque do risco, na teoria social e na obra de Ulrick Beck sobre sociedade de risco, a fim de conferir suporte teórico à interpretação dos dados coletados em campo. Tais contribuições da teoria social, em contraponto com abordagens multidisciplinares e ecossistêmicas em saúde e ambiente, são discutidas como forma de incorporar a diversidade de interpretações sociais expressadas pela população, no sentido de favorecer a inter-relação entre portadores de risco e decisões políticas locais sobre a questão do risco, ampliar o escopo dos fenômenos observados e propiciar a busca de melhores condições de saúde dos indivíduos e da qualidade do seu ambiente
Resumo:
The present study was designed to explore the correlation between the frequency of micronuclei in Trad-MN, measured across 28 biomonitoring stations during the period comprised between 11 of May and 2 of October, 2006, and adjusted mortality rates due to cardiovascular, respiratory diseases and cancer in Sao Jose dos Campos, Brazil, an area with different sources of air pollution. For controlling purposes, mortality rate due to gastrointestinal diseases (an event less prone to be affected by air pollution) was also considered in the analysis. Spatial distribution of micronuclei frequency was determined using average interpolation. The association between health estimators and micronuclei frequency was determined by measures of Pearson`s correlation. Higher frequencies of micronuclei were detected in areas with high traffic and close to a petrochemical pole. Significant associations were detected between micronuclei frequency and adjusted mortality rate due to cardiovascular diseases (r = 0.841, p = 0.036) and cancer (r = 0.890, p = 0.018). The association between mortality due to chronic obstructive pulmonary diseases was positive but did not reach statistical significance (r = 0.640, p = 0.172), probably because of the small number of events. Gastrointestinal mortality did not exhibit significant association with micronuclei frequency. Because the small number of observations and the nature of an ecological study, the present findings must be considered with caution and considered as preliminary. Further studies, performed in different conditions of contamination and climate should be done before considering Trad-MN in the evaluation of human health risk imposed by air pollutants. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
This work was focused on a multi-purpose estuarine environment (river Sado estuary, SW Portugal) around which a number of activities (e.g., fishing, farming, heavy industry, tourism and recreational activities) coexist with urban centres with a total of about 200 000 inhabitants. Based on previous knowledge of the hazardous chemicals within the ecosystem and their potential toxicity to benthic species, this project intended to evaluate the impact of estuarine contaminants on the human and ecosystem health. An integrative methodology based on epidemiological, analytical and biological data and comprising several lines of evidence, namely, human contamination pathways, human health effects, consumption of local produce, estuarine sediments, wells and soils contamination, effects on commercial benthic organisms, and genotoxic potential of sediments, was used. The epidemiological survey confirmed the occurrence of direct and indirect (through food chain) exposure of the local population to estuarine contaminants. Furthermore, the complex mixture of contaminants (e.g., metals, pesticides, polycyclic aromatic hydrocarbons) trapped in the estuary sediments was toxic to human liver cells exposed in vitro, causing cell death, oxidative stress and genotoxic effects that might constitute a risk factor for the development of chronic-degenerative diseases, on the long term. Finally, the integration of data from several endpoints indicated that the estuary is moderately impacted by toxicants that affect also the aquatic biota. Nevertheless, the human health risk can only be correctly assessed through a biomonitoring study including the quantification of contaminants (or metabolites) in biological fluids as well as biomarkers of early biological effects (e.g., biochemical, genetic and omics-based endpoints) and genetic susceptibility in the target population. Data should be supported by a detailed survey to assess the impact of the contaminated seafood and local farm products consumption on human health and, particularly, on metabolic diseases or cancer development.
Resumo:
Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk.
Resumo:
Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.