193 research outputs found

    Near-highway pollutants in motor vehicle exhaust: A review of epidemiologic evidence of cardiac and pulmonary health risks

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    There is growing evidence of a distinct set of freshly-emitted air pollutants downwind from major highways, motorways, and freeways that include elevated levels of ultrafine particulates (UFP), black carbon (BC), oxides of nitrogen (NOx), and carbon monoxide (CO). People living or otherwise spending substantial time within about 200 m of highways are exposed to these pollutants more so than persons living at a greater distance, even compared to living on busy urban streets. Evidence of the health hazards of these pollutants arises from studies that assess proximity to highways, actual exposure to the pollutants, or both. Taken as a whole, the health studies show elevated risk for development of asthma and reduced lung function in children who live near major highways. Studies of particulate matter (PM) that show associations with cardiac and pulmonary mortality also appear to indicate increasing risk as smaller geographic areas are studied, suggesting localized sources that likely include major highways. Although less work has tested the association between lung cancer and highways, the existing studies suggest an association as well. While the evidence is substantial for a link between near-highway exposures and adverse health outcomes, considerable work remains to understand the exact nature and magnitude of the risks

    Changes in Traffic Patterns and Air Quality Along Mystic Avenue in Medford and Somerville, Massachusetts, After Installation of an Intermittent Bus Lane

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    The City of Medford, MA, (pop. 60,000) and the City of Somerville (pop. 76,000) immediately to the south are home to several major roadways including Interstate 93 and Massachusetts State Highways 28 and 38. These are among the busiest roadways in the Boston metropolitan area, together carrying over 240,000 vehicles per day through the two cities (Boston MPO, 2022). In an effort to increase bus efficiency, reduce traffic burden, and improve air quality in their communities, Medford and Somerville tested a bus lane with intermittent prioritization on Massachusetts Bay Transportation Authority (MBTA) bus route #95, which runs along Route 38 (Mystic Avenue) within the two cities.The goal of this study was to determine whether the bus lane on Mystic Avenue caused short term (months) changes in traffic patterns and improved air quality along the length of the bus lane

    Effects of Eutrophication and Runoff on Arsenic Cycling in an Urban Lake

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    Urban lakes are important recreational and natural resources that add to the quality of life for city residents. Unfortunately, urban watersheds often contribute contaminants to these lakes, including organic chemicals, metals, nutrients, and pathogens. Nitrogen and phosphorus are very high in urban and suburban runoff, mostly as a result of animal waste and fertilizers, although leaky sewage systems may also contribute. These nutrients promote plant and algal growth in urban lakes, ultimately resulting in hyper-eutrophic conditions. Eutrophication, in turn, may affect the cycling and mobility of contaminants, such as arsenic and other toxic metals. Spy Pond, located in Arlington, Massachusetts, was recently discovered to be heavily contaminated with arsenic of unknown origin. Surface sediment concentrations above 2,500 ppm have been measured. Subsequent investigations have also revealed that total arsenic levels in the overlying hypolimnetic waters reach over 150 ppb. However, the two interconnected basins that constitute Spy Pond have been found to differ by an order of magnitude in the concentrations of arsenic found in hypolimnetic waters. The goal of this study is to determine the mechanisms responsible for the differences in arsenic mobility in the two basins of Spy Pond, and how this may impact the potential for minimizing human and ecological arsenic exposure. Based on differences in the concentrations of chemical constituents (e.g. iron, sulfur, conductivity, etc.) measured in each basin, we hypothesize that the greater arsenic concentrations found in the bottom waters of the South Basin of Spy Pond are caused by the combined effects of eutrophication, differences in the Fe/S ratio of the two basins, and the physical and chemical impacts of salts in highway runoff

    Measurement of C_(24)H_(14) Polycyclic Aromatic Hydrocarbons Associated with a Size-Segregated Urban Aerosol

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    Six-ring C_(24)H_(14) (MW 302) polycyclic aromatic hydrocarbons (PAH), some of which are potent mutagens, are present in urban aerosols. Size-segregated atmospheric aerosol samples from Boston, MA, were analyzed for C_(24)H_(14) PAH by gas chromatography/mass spectrometry. Eleven peaks were found with mass to charge ratios of 302; of these, eight were identified using authentic standards. Five of the peaks were quantified. For each of these five, the distributions with respect to particle size were bimodal with the majority of the mass associated with accumulation mode particles (0.3−1.0 μm) and a smaller fraction of the mass associated with ultrafine mode particles (0.09−0.14 μm). These distribu tions are similar to those observed for PAH of molecular weight 252−278 in the same sample but different from those of benzo[ghi]perylene (MW 276) and coronene (MW 300), which were associated to a greater degree with ultrafine particles. The data suggest that C_(24)H_(14) PAH repartition to larger particles by vaporization and sorption more rapidly than do benzo[ghi]perylene and coronene. The total concentration of C_(24)H_(14) PAH (1.5 ng/m^3) was comparable to that of benzo[a]pyrene in the same sample. Because of their mutagenicities, C_(24)H_(14) PAH may make a contribution to the genotoxicity of urban aerosols comparable to that of benzo[a]pyrene

    Measurement of C_(24)H_(14) Polycyclic Aromatic Hydrocarbons Associated with a Size-Segregated Urban Aerosol

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    Six-ring C_(24)H_(14) (MW 302) polycyclic aromatic hydrocarbons (PAH), some of which are potent mutagens, are present in urban aerosols. Size-segregated atmospheric aerosol samples from Boston, MA, were analyzed for C_(24)H_(14) PAH by gas chromatography/mass spectrometry. Eleven peaks were found with mass to charge ratios of 302; of these, eight were identified using authentic standards. Five of the peaks were quantified. For each of these five, the distributions with respect to particle size were bimodal with the majority of the mass associated with accumulation mode particles (0.3−1.0 μm) and a smaller fraction of the mass associated with ultrafine mode particles (0.09−0.14 μm). These distribu tions are similar to those observed for PAH of molecular weight 252−278 in the same sample but different from those of benzo[ghi]perylene (MW 276) and coronene (MW 300), which were associated to a greater degree with ultrafine particles. The data suggest that C_(24)H_(14) PAH repartition to larger particles by vaporization and sorption more rapidly than do benzo[ghi]perylene and coronene. The total concentration of C_(24)H_(14) PAH (1.5 ng/m^3) was comparable to that of benzo[a]pyrene in the same sample. Because of their mutagenicities, C_(24)H_(14) PAH may make a contribution to the genotoxicity of urban aerosols comparable to that of benzo[a]pyrene

    Tpl2 kinase regulates T cell interferon-γ production and host resistance to Toxoplasma gondii

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    Tpl2 (Tumor progression locus 2), also known as Cot/MAP3K8, is a hematopoietically expressed serine-threonine kinase. Tpl2 is known to have critical functions in innate immunity in regulating tumor necrosis factor–α, Toll-like receptor, and G protein–coupled receptor signaling; however, our understanding of its physiological role in T cells is limited. We investigated the potential roles of Tpl2 in T cells and found that it was induced by interleukin-12 in human and mouse T cells in a Stat4-dependent manner. Deficiency of Tpl2 was associated with impaired interferon (IFN)-γ production. Accordingly, Tpl2−/− mice had impaired host defense against Toxoplasma gondii with reduced parasite clearance and decreased IFN-γ production. Furthermore, reconstitution of Rag2−/− mice with Tpl2-deficient T cells followed by T. gondii infection recapitulated the IFN-γ defect seen in the Tpl2-deficient mice, confirming a T cell–intrinsic defect. CD4+ T cells isolated from Tpl2−/− mice showed poor induction of T-bet and failure to up-regulate Stat4 protein, which is associated with impaired TCR-dependent extracellular signal-regulated kinase activation. These data underscore the role of Tpl2 as a regulator of T helper cell lineage decisions and demonstrate that Tpl2 has an important functional role in the regulation of Th1 responses

    Effective Control of Schistosoma haematobium Infection in a Ghanaian Community following Installation of a Water Recreation Area

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    BackgroundUrogenital schistosomiasis caused by Schistosoma haematobium was endemic in Adasawase, Ghana in 2007. Transmission was reported to be primarily through recreational water contact.MethodsWe designed a water recreation area (WRA) to prevent transmission to school-aged children. The WRA features a concrete pool supplied by a borehole well and a gravity-driven rainwater collection system; it is 30 m2 and is split into shallow and deep sections to accommodate a variety of age groups. The WRA opened in 2009 and children were encouraged to use it for recreation as opposed to the local river. We screened children annually for S. haematobium eggs in their urine in 2008, 2009, and 2010 and established differences in infection rates before (2008–09) and after (2009–10) installation of the WRA. After each annual screening, children were treated with praziquantel and rescreened to confirm parasite clearance.Principal FindingsInitial baseline testing in 2008 established that 105 of 247 (42.5%) children were egg-positive. In 2009, with drug treatment alone, the pre-WRA annual cumulative incidence of infection was 29 of 216 (13.4%). In 2010, this incidence rate fell significantly (p<0.001, chi-squared) to 9 of 245 (3.7%) children after installation of the WRA. Logistic regression analysis was used to determine correlates of infection among the variables age, sex, distance between home and river, minutes observed at the river, low height-for-age, low weight-for-age, low Body Mass Index (BMI)-for-age, and previous infection status.Conclusion/SignificanceThe installation and use of a WRA is a feasible and highly effective means to reduce the incidence of schistosomiasis in school-aged children in a rural Ghanaian community. In conjunction with drug treatment and education, such an intervention can represent a significant step towards the control of schistosomiasis. The WRA should be tested in other water-rich endemic areas to determine whether infection prevalence can be substantially reduced.Author SummaryUrogenital schistosomiasis is a disease caused by the parasite Schistosoma haematobium; it is often characterized by bloody urine and tends to disproportionately affect school-aged children in rural tropical regions. The parasite is transmitted via skin contact with surface water that is contaminated by human waste. The disease was endemic in Adasawase, a rural Ghanaian community, in 2007. Transmission occurred mainly through recreational water contact. We collaborated with community members to design a water recreation area (WRA) featuring a concrete pool supplied by a borehole well and a rainwater collection system. We opened the pool in 2009 and local officials encouraged children to use the WRA for recreation. We screened local children annually (2008, 2009, 2010) for S. haematobium infection. After each screening, children were treated with praziquantel and rescreened. Baseline testing in 2008 established that at least 105 of 247 (42.5%) children were infected. In 2009, 29 of 216 (13.4%) children were infected, reflecting annual cumulative incidence. In 2010, a significantly smaller percentage of children (9 of 245, 3.7%) were infected. We conclude that the WRA effectively reduced infection in Adasawase, and that it should be tested in other water-rich endemic areas

    “F*ck it! Let’s get to drinking – poison our livers!”: a thematic analysis of alcohol content in contemporary YouTube music videos

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    Purpose: To describe the portrayal of alcohol content in popular YouTube music videos. Methods: We used inductive thematic analysis to explore the lyrics and visual imagery in 49 UK Top 40 songs and music videos previously found to contain alcohol content, and watched by many British adolescents aged between 11-18 years, and to examine if branded content contravened alcohol industry advertising codes of practice. Results: The analysis generated three themes. First, alcohol content was associated with sexualised imagery or lyrics and the objectification of women. Second, alcohol was associated with image, lifestyle and sociability. Finally, some videos showed alcohol overtly encouraging excessive drinking and drunkenness, including those containing branding, with no negative consequences to the drinker. Conclusion: Our results suggest that YouTube music videos promote positive associations with alcohol use. Further, several alcohol companies adopt marketing strategies in the video medium that are entirely inconsistent with their own or others agreed advertising codes of practice. We conclude that, as a harm reduction measure, policies should change to prevent adolescent exposure to the positive promotion of alcohol and alcohol branding in music videos

    Saving the world’s terrestrial megafauna

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    From the late Pleistocene to the Holocene, and now the so called Anthropocene, humans have been driving an ongoing series of species declines and extinctions (Dirzo et al. 2014). Large-bodied mammals are typically at a higher risk of extinction than smaller ones (Cardillo et al. 2005). However, in some circumstances terrestrial megafauna populations have been able to recover some of their lost numbers due to strong conservation and political commitment, and human cultural changes (Chapron et al. 2014). Indeed many would be in considerably worse predicaments in the absence of conservation action (Hoffmann et al. 2015). Nevertheless, most mammalian megafauna face dramatic range contractions and population declines. In fact, 59% of the world’s largest carnivores (≥ 15 kg, n = 27) and 60% of the world’s largest herbivores (≥ 100 kg, n = 74) are classified as threatened with extinction on the International Union for the Conservation of Nature (IUCN) Red List (supplemental table S1 and S2). This situation is particularly dire in sub-Saharan Africa and Southeast Asia, home to the greatest diversity of extant megafauna (figure 1). Species at risk of extinction include some of the world’s most iconic animals—such as gorillas, rhinos, and big cats (figure 2 top row)—and, unfortunately, they are vanishing just as science is discovering their essential ecological roles (Estes et al. 2011). Here, our objectives are to raise awareness of how these megafauna are imperiled (species in supplemental table S1 and S2) and to stimulate broad interest in developing specific recommendations and concerted action to conserve them
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