1,721,011 research outputs found
Fluoride and manganese
No full textChildren can be exposed to many hazardous metals in the environment, including fluoride and manganese. Sources of exposure may include drinking water, foods and dietary supplements, and metal-containing particles released into the air from industrial and vehicular sources. Exposures may be especially intense near active and abandoned industrial "hotspots." Children's routes of absorption include ingestion and inhalation. Adherence of metal-contaminated particles to the skin of small children contributes to the inadvertent ingestion of contaminated dust and soil. The effects of metals on children's health include toxicity to the nervous system, lungs, kidneys, liver, and, in the case of excessive fluorides, the teeth and bones. Prevention of children's exposure to metals is multifaceted. Primary prevention that reduces unnecessary uses of metals and prevents environmental contamination at its source is the most effective strategy. Children should not be allowed to come into contact with metallic particles transported home on working parents' contaminated shoes and work clothing. Well water, especially from unregulated private wells, needs to be tested for metal content
Evidence From Epidemiology and Health Surveillance
No full textAsbestos exposure is still relevant across the world and increases the risk of malignant mesothelioma through known and less known occupational exposure, as well as nonoccupational exposure. Cumulative exposure increases the risk of mesothelioma even at low doses of less than 0.1 (fiber/mL) years. Therefore, current legal standards are not protective for prolonged exposure and incremental exposure at any concentration can increase the risk of the disease. Individuals with previous exposure should not be further exposed even at “low” levels to avoid increased risk. Even after 40–50 years after the exposure, the risk of mesothelioma increases and it is not clear whether it may reduce afterwards
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Traces of heavy metals in children toenails as a bio-indicator of environmental exposure in Forlì (Northern Italy): an observational study
No full textOBJECTIVES: to assess the concentration of heavy metals in the nails of children aged 6-9 years residing in Forlì (Emilia-Romagna Region, Northern Italy). DESIGN: biomonitoring survey. SETTING AND PARTICIPANTS: in March 2017, a total of 236 toenail samples were collected, 221 of them were eligible; the concentration of 23 metals were measured in these eligible samples. MAIN OUTCOME MEASURES: a spatial analysis was conducted, considering home addresses as grouped in the four macroareas in which the local territory is administratively divided. RESULTS: In the two North-Center and East areas - which include various industrial operations, two waste incinerators and a motorway - the total concentration of all metals resulted 60% higher than in the West and South areas. Given the lack of Italian reference values, comparison tests between areas were performed for aluminum (Al), cadmium (Cd), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn), which concentrations were detectable in over 50% of the subjects. Higher concentrations were observed in the East area compared with the other areas, with statistical significance for Al (vs North-Center), Cu and Zn (vs West), and Al and Mn (vs South). Further comparisons showed significantly higher concentration of Cu in Nord-Center vs West, which in turn had higher concentrations of Zn compared to the Southern area. By applying a Tobit regression to evaluate possible confounding factors, a marginally significant correlation resulted for the nail concentration of Mn among children practicing outdoor sports and eating locally grown vegetables. The consumption of local vegetables was at the limits of significance also for Cd. CONCLUSIONS: the data obtained came from a voluntary and crowdfunded study and suggest a possible relationship between the exposure to air pollutants and subsequent accumulation of metals in the nails. Further and more detailed epidemiological studies are warranted to identify the exposure sources and to yield preventive intervention
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Hair as a biomarker of environmental manganese exposure
No full textThe absence of well-validated biomarkers of manganese (Mn) exposure in children remains a major obstacle for studies of Mn toxicity. We developed a hair cleaning methodology to establish the utility of hair as an exposure biomarker for Mn and other metals (Pb, Cr, Cu), using ICPMS, scanning electron microscopy, and laser ablation ICPMS to evaluate cleaning efficacy. Exogenous metal contamination on hair that was untreated or intentionally contaminated with dust or Mn-contaminated water was effectively removed using a cleaning method of 0.5%Triton X-100 sonication plus 1 N nitric acid sonication. This cleaning method was then used on hair samples from children (n = 121) in an ongoing study of environmental Mn exposure and related health effects. Mean hair Mn levels were 0.121 μg/g (median = 0.073 μg/g, range = 0.011-0.736 μg/g), which are ∼4 to 70-fold lower than levels reported in other pediatric Mn studies. Hair Mn levels were also significantly higher in children living in the vicinity of active, but not historic, ferroalloy plant emissions compared to controls (P < 0.001). These data show that hair can be effectively cleaned of exogenous metal contamination, and they substantiate the use of hair Mn levels as a biomarker of environmental Mn exposure in children. © 2012 American Chemical Society
Polychlorinated Biphenyls and Pulmonary Hypertension
Full text linkPolychlorinated biphenyls (PCBs) are persistent environmental pollutants that were banned because of their potential carcinogenicity. Population studies have shown that PCBs are associated with lung toxicity and hypertension. The objective of this study was to evaluate whether higher exposure to PCB congeners is associated with the risk of pulmonary hypertension. Serum levels of PCBs in 284 subjects with combined risk factors for pulmonary arterial hypertension (PAH) were compared to 4210 subjects with no risk for PAH using the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. The major findings from this study include significantly higher PCB levels in PAH subjects compared to non-PAH subjects; for example, the geometric mean (GM) of PCB74 was 15.91 (ng/g) (14.45–17.53) vs. 11.48 (ng/g) (10.84–12.16), respectively. Serum levels of PCB congeners showed an increasing trend in the age group 20–59 years as PCB180 GM was 19.45 (ng/g) in PAH vs. 12.75 (ng/g) in the control. A higher body burden of PCB153 followed by PCB138, PCB180, and PCB118 was observed. Estimated age, race, BMI, and gender-adjusted ORs for PCB congener levels in subjects with the combined risk factors for PAH compared to controls was significant; for example, PCB99 (OR: 1.5 (CI: 1.49–1.50). In summary, these findings indicate that exposure, as well as body burden estimated based on lipid adjustment of PCBs, were higher in people with risk factors for PAH, and PCB congeners accumulated with age. These findings should be interpreted with caution because of the use of cross-sectional self-reported data and a small sample size of subjects with combined risk factors for pulmonary arterial hypertension. Nonetheless, our finding emphasizes a need for a comprehensive environmental molecular epidemiologic study to determine the potential role of environmental exposures to PCBs in the development of pulmonary arterial hypertension
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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