945 resultados para exposure risk
Resumo:
Background. An abnormally high incidence (44%) of bronchopulmonary dysplasia with variations in rates among cities was observed in Colombia among premature infants. Objective. To identify risk factors that could explain the observed high incidence and regional variations of bronchopulmonary dysplasia. Study Design. A case-control study was designed for testing the hypothesis that differences in the disease rates were not explained by differences in city-of-birth specific population characteristics or by differences in respiratory management practices in the first 7 days of life, among cities. Results. Multivariate analysis showed that premature rupture of membranes, exposure to mechanical ventilation after received nasal CPAP, no surfactant exposure, use of rescue surfactant (instead of early surfactant), PDA, sepsis and the median daily FIO2, were associated with a higher risk of dysplasia. Significant differences between cases and controls were found among cities. Models exploring for associations between city of birth and dysplasia showed that being born in the highest altitude city (Bogotá) was associated with a higher risk of dysplasia (OR 1.82 95% CI 1.31–2.53). Conclusions. Bronchopulmonary dysplasia was manly explained by traditional risk factors. Findings suggest that altitude may play an important role in the development of this disease. Prenatal steroids did not appear to be protective at high altitude.
Resumo:
The overall objective of the research presented in this dissertation was to assess exposure to endocrine disrupting chemicals (EDCs), polychlorinated biphenyls (PCBs), phthalates, and bisphenol A (BPA) in the general population and evaluate their associations with adverse reproductive health effects, including cancers, in women. Given the proven contribution of unopposed estrogens to the risk for endometrial neoplasia or breast cancer, renewed health concerns have aroused about estrogen mimicking EDCs found in food, personal care products or as environmental contaminants. Our meta-analysis showed that exposure to estrogen mimicking PCBs increased summary risk of breast cancer and endometriosis. We further evaluated the relationship between endometriosis and breast cancer, and EDCs using a bioinformatics method. Our bioinformatics approach was able to identify genes with the potential to be involved in interaction with PCB, phthalates and BPA that may be important to the development of breast cancer and endometriosis. Therefore, we hypothesized that exposure to EDCs such as PCBs, phthalates, and BPA, results in adverse reproductive health effects in women. Using subject data and biomarkers available from the Center for Disease Controls National Health and Nutrition Examination Survey database we conducted a cross-sectional study of EDCs in relation to self-reported history of endometriosis, uterine leiomyomas, breast cancer, cervical cancer, ovarian cancer, and uterine cancer. Significantly higher body burdens of PCBs were found in women diagnosed with breast cancer, ovarian cancer, and uterine cancer compared to women without cancer. PCB 138 was significantly associated with breast cancer, cervical cancer, and uterine cancer, while PCBs 74 and 118 were significantly associated with ovarian cancer. The sum of dioxin-like PCBs were significantly associated with ovarian cancer (OR of 2.02, 95% CI: 1.06-3.85) and the sum of non-dioxin-like PCBs were significantly associated with uterine cancer (OR of 1.12, 95%CI: 1.03-1.23). Significantly higher body burdens of PCBs were also found in women diagnosed with endometriosis and uterine leiomyomas. Documenting the exposure to EDCs among the general U.S. population, and identifying agents associated with reproductive toxicity have the potential to fill research gaps and facilitate our understanding of the complex role environmental chemicals play in producing toxicity in reproductive organs.^
Resumo:
Multi-problem youth undergoing treatment for substance use problems are at high behavioral risk for exposure to sexually transmitted infections (STIs), including human immunodeficiency virus (HIV). Specific risk factors include childhood adversities such as maltreatment experiences and subsequent forms of psychopathology. The current study used a person-centered analytical approach to examine how childhood maltreatment experiences were related to patterns of psychiatric symptoms and HIV/STI risk behaviors in a sample of adolescents (N = 408) receiving treatment services. Data were collected in face-to-face interviews at two community-based facilities. Descriptive statistics and Latent Profile Analysis (LPA) were used to (a) classify adolescents into groups based on past year psychiatric symptoms, and (b) examine relations between class membership and forms of childhood maltreatment experiences, as well as past year sexual risk behavior (SRB). LPA results indicated significant heterogeneity in psychiatric symptoms among the participants. The three classes generated via the optimal LPA solution included: (a) a low psychiatric symptoms class, (b) a high alcohol symptoms class and (c) a high internalizing symptoms class. Class membership was associated significantly with adolescents’ self-reported scores for childhood sexual abuse and emotional neglect. ANOVAs documented significant differences in mean scores for multiple indices of SRB indices by class membership, demonstrating differential risk for HIV/STI exposure across classes. The two classes characterized by elevated psychiatric symptom profiles and more severe maltreatment histories were at increased behavioral risk for HIV/STI exposure, compared to the low psychiatric symptoms class. The high internalizing symptoms class reported the highest scores for most of the indices of SRB assessed. The heterogeneity of psychiatric symptom patterns documented in the current study has important implications for HIV/STI prevention programs implemented with multi-problem youth. The results highlight complex relations between childhood maltreatment experiences, psychopathology and multiple forms of health risk behavior among adolescents. The results underscore the importance of further integration between substance abuse treatment and HIV/STI risk reduction efforts to improve morbidity and mortality among vulnerable youth.
Resumo:
Patient awareness and concern regarding the potential health risks from ionizing radiation have peaked recently (Coakley et al., 2011) following widespread press and media coverage of the projected cancer risks from the increasing use of computed tomography (CT) (Berrington et al., 2007). The typical young and educated patient with inflammatory bowel disease (IBD) may in particular be conscious of his/her exposure to ionising radiation as a result of diagnostic imaging. Cumulative effective doses (CEDs) in patients with IBD have been reported as being high and are rising, primarily due to the more widespread and repeated use of CT (Desmond et al., 2008). Radiologists, technologists, and referring physicians have a responsibility to firstly counsel their patients accurately regarding the actual risks of ionizing radiation exposure; secondly to limit the use of those imaging modalities which involve ionising radiation to clinical situations where they are likely to change management; thirdly to ensure that a diagnostic quality imaging examination is acquired with lowest possible radiation exposure. In this paper, we synopsize available evidence related to radiation exposure and risk and we report advances in low-dose CT technology and examine the role for alternative imaging modalities such as ultrasonography or magnetic resonance imaging which avoid radiation exposure.
Resumo:
The overall objective of the research presented in this dissertation was to assess exposure to endocrine disrupting chemicals (EDCs), polychlorinated biphenyls (PCBs), phthalates, and bisphenol A (BPA) in the general population and evaluate their associations with adverse reproductive health effects, including cancers, in women. Given the proven contribution of unopposed estrogens to the risk for endometrial neoplasia or breast cancer, renewed health concerns have aroused about estrogen mimicking EDCs found in food, personal care products or as environmental contaminants. Our meta-analysis showed that exposure to estrogen mimicking PCBs increased summary risk of breast cancer and endometriosis. We further evaluated the relationship between endometriosis and breast cancer, and EDCs using a bioinformatics method. Our bioinformatics approach was able to identify genes with the potential to be involved in interaction with PCB, phthalates and BPA that may be important to the development of breast cancer and endometriosis. Therefore, we hypothesized that exposure to EDCs such as PCBs, phthalates, and BPA, results in adverse reproductive health effects in women. Using subject data and biomarkers available from the Center for Disease Controls National Health and Nutrition Examination Survey database we conducted a cross-sectional study of EDCs in relation to self-reported history of endometriosis, uterine leiomyomas, breast cancer, cervical cancer, ovarian cancer, and uterine cancer. Significantly higher body burdens of PCBs were found in women diagnosed with breast cancer, ovarian cancer, and uterine cancer compared to women without cancer. PCB 138 was significantly associated with breast cancer, cervical cancer, and uterine cancer, while PCBs 74 and 118 were significantly associated with ovarian cancer. The sum of dioxin-like PCBs were significantly associated with ovarian cancer (OR of 2.02, 95% CI: 1.06-3.85) and the sum of non-dioxin-like PCBs were significantly associated with uterine cancer (OR of 1.12, 95%CI: 1.03-1.23). Significantly higher body burdens of PCBs were also found in women diagnosed with endometriosis and uterine leiomyomas. Documenting the exposure to EDCs among the general U.S. population, and identifying agents associated with reproductive toxicity have the potential to fill research gaps and facilitate our understanding of the complex role environmental chemicals play in producing toxicity in reproductive organs.
Resumo:
Flame retardants (FRs) are added to materials to enhance the fire safety level of readily combustible polymers. Although they have been purported to aid in preventing fires in some cases, they have also become a significant cause for concern given the vast data on environmental persistence and human and animal adverse health effects. Evidence since the 1980s has shown that Canadian, American and Europeans have detectable levels of FRs in their bodies. North Americans in particular have high levels of these chemicals due to stringent flammability standards and the higher use of polybrominated diphenyl ethers (PBDEs) in North America as opposed to Europe. FRs have been detected in household dust and some evidence suggests that TVs could be a significant source of exposure to FRs. It is imperative to re-visit the flammability standard (UL94V) that allows for FR use in TVs plastic materials by providing a risk versus benefit analysis to determine if this standard provides a fire safety benefit and if it plays a major role in FR exposure. This report first examined the history of televisions and the progression to the UL94V flammability test standard to understand why FRs were first added to polymers used in the manufacturing of TVs. It has been demonstrated to be due to fire hazards resulting from the use of plastic materials in cathode-ray tube (CRT) TVs that had an “instant-on” feature and high voltage and operating temperatures. In providing a risk versus benefit analysis, this paper presents the argument that 1) by providing a market survey the current flammability test standard (UL94V) is outdated and lacks relevance to current technology as flat, thin, energy efficient Liquid Crystal Displays (LCDs) dominate over traditionally used heavy, bulky and energy-intensive CRTs; 2) FRs do not impart fire safety benefits considering that there is a lack of valid fire safety concern, such as reduced internal and external ignition and fire hazard, and a lack of valid fire data and hazard for television fires in general and finally; 3) the standard is overly stringent as it does not consider the risk due to exposure to FRs in household dust due to the proliferation and greater use of televisions in households. Therefore, this report argues that the UL94V standard has become trapped in history and needs to be updated as it may play a major role in FR exposure.
Resumo:
Drawing upon critical, communications, and educational theories, this thesis develops a novel framing of the problem of social risk in the extractive sector, as it relates to the building of respectful relationships with indigenous peoples. Building upon Bakhtin’s dialogism, the thesis demonstrates the linkage of this aspect of social risk to professional education, and specifically, to the undergraduate mining engineering curriculum, and develops a framework for the development of skills related to intercultural competence in the education of mining engineers. The knowledge of social risk, as well as the level of intercultural competence, of students in the mining engineering program, is investigated through a mixture of surveys and focus groups – as is the impact of specific learning interventions. One aspect of this investigation is whether development of these attributes alters graduates’ conception of their identity as mining engineers, i.e. the range and scope of responsibilities, and understanding of to whom responsibilities are owed, and their role in building trusting relationships with communities. Survey results demonstrate that student openness to the perspectives of other cultures increases with exposure to the second year curriculum. Students became more knowledgeable about social dimensions of responsible mining, but not about cultural dimensions. Analysis of focus group data shows that students are highly motivated to improve community perspectives and acceptance. It is observed that students want to show respect for diverse peoples and communities where they will work, but they are hampered by their inability to appreciate the viewpoints of people who do not share their values. They embrace benefit sharing and environmental protection as norms, but they mistakenly conclude that opposition to mining is rooted in a lack of education rather than in cultural values. Three, sequential, threshold concepts are identified as impeding development of intercultural competence: Awareness and Acknowledgement of Different Forms of Knowledge; Recognition that Value Systems are a Function of Culture; Respect for varied perceptions of Social Wellbeing and Quality of Life. Future curriculum development in the undergraduate mining engineering program, as well as in other educational programs relevant to the extractive sector, can be effectively targeted by focusing on these threshold concepts.
Resumo:
Valproic acid (VPA), a commonly-used anticonvulsant drug, is associated with increased risk of fetal malformations, including neural tube defects (NTDs). Previous in vivo studies determined that VPA-exposed embryos with a NTD had altered expression of several proteins regulated by p300, a histone acetyltransferase (HAT) protein. p300 is capable of acetylating histones and non-histone proteins through its HAT activity, allowing it to transcriptionally regulate genes as well as modulate the stability and activity of specific proteins. NFκB, Stat3 and Egr1, all of which function as transcription factors, are regulated by p300 through its HAT activity. Together, these proteins all play an important role in maintaining the balance of apoptosis, proliferation and differentiation, the regulation of which is extremely important for proper embryonic development. The studies in this thesis utilized P19 embryonal carcinoma (EC) cells in order to determine the effects of VPA exposure on the expression of p300 and the aforementioned transcription factors, as well as apoptosis and proliferation, in vitro. P19 EC cells were exposed to C646, a selective p300 inhibitor, in order to assess whether the effects observed as a result of VPA exposure were due to p300 protein degradation. It was found that VPA exposure for 24 hours in P19 EC cells in vitro resulted in a significant decrease in p300 protein expression. VPA exposure also significantly decreased NFκB protein expression, while resulting in increased Stat3 protein expression. However, Stat3 acetylation and phosphorylation, which both contribute to Stat3 activation, were significantly decreased as a result of VPA exposure. p300 inhibition resulted in a significant decrease in NFκB, similar to what was observed as a result of VPA exposure, which suggests that VPA-mediated degradation of p300 may play a role in reduced NFκB protein expression following VPA exposure. Conversely, Stat3 protein expression, acetylation and phosphorylation were not significantly changed as a result of p300 inhibition, suggesting that p300 degradation does not play a role in VPA’s effects on Stat3 protein expression and activation. VPA exposure also resulted in a significant increase in apoptosis, while p300 inhibition did not significantly increase apoptosis. These data suggest that p300 degradation plays a role in VPA-mediated teratogenicity, and that VPA may target other cellular mechanisms in order to exert its teratogenic effects.
Resumo:
Currently, there is increasing use of nanomaterials in the food industry thanks to the many advantages offered and make the products that contain them more competitive in the market. Their physicochemical properties often differ from those of bulk materials, which require specialized risk assessment. This should cover the risks to the health of workers and consumers as well as possible environmental risks. The risk assessment methods must go updating due to more widespread use of nanomaterials, especially now that are making their way down to consumer products. Today there is no specific legislation for nanomaterials, but there are several european dispositions and regulations that include them. This review gives an overview of the risk assessment and the existing current legislation regarding the use of nanotechnology in the food industry.
Resumo:
It is apparent that most of the techniques that make use of ionising radiation in human medical practices are now being applied in veterinary medicine. Steps are being taken by the IAEA to provide guidance for humans involved in such practices, but there appears to be no international initiative that considers the protection or welfare of the animal as a patient. There is therefore a risk that the deliberate exposure of an animal, particularly in the therapeutic application of radiation, could do more harm than good. In the light of recent developments in dosimetric modelling and the application of known effects of radiation on different types of animals, for the purposes of the protection of biota in an environmental context, it is argued that it would be sensible now to start a serious consideration of this issue. Some suggestions are made with regard to a number of areas that could be considered further, both specifically and with regard to the field of radiological protection as a whole.
Resumo:
It is apparent that most of the techniques that make use of ionising radiation in human medical practices are now being applied in veterinary medicine. Steps are being taken by the IAEA to provide guidance for humans involved in such practices, but there appears to be no international initiative that considers the protection or welfare of the animal as a patient. There is therefore a risk that the deliberate exposure of an animal, particularly in the therapeutic application of radiation, could do more harm than good. In the light of recent developments in dosimetric modelling and the application of known effects of radiation on different types of animals, for the purposes of the protection of biota in an environmental context, it is argued that it would be sensible now to start a serious consideration of this issue. Some suggestions are made with regard to a number of areas that could be considered further, both specifically and with regard to the field of radiological protection as a whole.
Resumo:
Background & Aims: Certain subsets of colorectal serrated polyps (SP) have malignant potential. Weperformed a systematic review and meta-analysis to investigate the association between modifiablelifestyle factors and risk for SPs.
Methods: We conducted a systematic search of Medline, Embase, and Web of Science, forobservational or interventional studies that contained the terms risk or risk factor, and serrated orhyperplastic, and polyps or adenomas, and colorectal (or synonymous terms), published by March2016. Titles and abstracts of identified articles were independently reviewed by at least 2 reviewers.Adjusted relative risks (RR) and 95% CIs were combined using random effects meta-analyses toassess the risk of SP, when possible.
Results: We identified 43 studies of SP risk associated with 7 different lifestyle factors: smoking,alcohol, body fatness, diet, physical activity, medication and/or hormone replacement therapy.When we compared the highest and lowest categories of exposure, factors we found to significantlyincrease risk for SP included tobacco smoking (RR, 2.47; 95% CI, 2.12–2.87), alcohol intake (RR, 1.33;95% CI, 1.17–1.52), body mass index (RR, 1.40; 95% CI, 1.22–1.61), and high intake of fat or meat.Direct associations for smoking and alcohol, but not body fat, tended to be stronger for sessileserrated adenomas/polyps than hyperplastic polyps. In contrast, factors we found to significantlydecrease risks for SP included use of non-steroidal anti-inflammatory drugs (RR, 0.77; 95% CI, 0.65–0.92) or aspirin (RR, 0.81; 95% CI, 0.67–0.99), as well as high intake of folate, calcium, or fiber. Nosignificant associations were detected between SP risk and physical activity or hormone replacementtherapy.
Conclusions: Several lifestyle factors, most notably smoking and alcohol, are associated with SP risk.These findings enhance our understanding of mechanisms of SP development and indicate that riskof serrated pathway colorectal neoplasms could be reduced with lifestyle changes.
Resumo:
Evidence of an association between early pregnancy exposure to selective serotonin reuptake inhibitors (SSRI) and congenital heart defects (CHD) has contributed to recommendations to weigh benefits and risks carefully. The objective of this study was to determine the specificity of association between first trimester exposure to SSRIs and specific CHD and other congenital anomalies (CA) associated with SSRI exposure in the literature (signals). A population-based case-malformed control study was conducted in 12 EUROCAT CA registries covering 2.1 million births 1995-2009 including livebirths, fetal deaths from 20 weeks gestation and terminations of pregnancy for fetal anomaly. Babies/fetuses with specific CHD (n = 12,876) and non-CHD signal CA (n = 13,024), were compared with malformed controls whose diagnosed CA have not been associated with SSRI in the literature (n = 17,083). SSRI exposure in first trimester pregnancy was associated with CHD overall (OR adjusted for registry 1.41, 95% CI 1.07-1.86, fluoxetine adjOR 1.43 95% CI 0.85-2.40, paroxetine adjOR 1.53, 95% CI 0.91-2.58) and with severe CHD (adjOR 1.56, 95% CI 1.02-2.39), particularly Tetralogy of Fallot (adjOR 3.16, 95% CI 1.52-6.58) and Ebstein's anomaly (adjOR 8.23, 95% CI 2.92-23.16). Significant associations with SSRI exposure were also found for ano-rectal atresia/stenosis (adjOR 2.46, 95% CI 1.06-5.68), gastroschisis (adjOR 2.42, 95% CI 1.10-5.29), renal dysplasia (adjOR 3.01, 95% CI 1.61-5.61), and clubfoot (adjOR 2.41, 95% CI 1.59-3.65). These data support a teratogenic effect of SSRIs specific to certain anomalies, but cannot exclude confounding by indication or associated factors.
Resumo:
To get a better insight into the radiological features of industrial by-products that can be reused in building materials a review of the reported scientific data can be very useful. The current study is based on the continuously growing database of the By-BM (H2020-MSCA-IF-2015) project (By-products for Building Materials). Currently, the By-BM database contains individual data of about 431 by-products and 1095 building and raw materials. It was found that in case of the building materials the natural radionuclide content varied widely (Ra-226: <DL-27851 Bq/kg; Th-232: <DL-906 Bq/kg, K-40: <DL-17922 Bq/kg), more so than for the by-products (Ra-226: 7-3152 Bq/kg; Th-232: <DL-1350 Bq/kg, K-40: <DL-3001 Bq/kg). The average Ra-226, Th-232 and K-40 contents of the reported by-products were respectively 2.52, 2.35 and 0.39 times higher than the building materials. The gamma exposure of bulk building products was calculated according to IAEA Specific Safety Guide No. SSG-32 and the European Commission Radiation Protection 112 based I-index (EU BSS). It was found that in most cases the I-index without density consideration provides a significant overestimation in excess effective dose.
Resumo:
[EN]All the relevant risk factors contributing to breast cancer etiology are not fully known. Exposure to organochlorine pesticides has been linked to an increased incidence of the disease, although not all data have been consistent. Most published studies evaluated the exposure to organochlorines individually, ignoring the potential effects exerted by the mixtures of chemicals.