Measurements of volatile organic compounds using proton transfer reaction ? mass spectrometry during the MILAGRO 2006 Campaign

International audienceVolatile organic compounds (VOCs) were measured by proton transfer reaction ? mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative ? Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in this region of the MCMA, their diurnal patterns and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations show the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including of elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the probability of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA

Examining Interdisciplinary Research Collaborations to Inform Agricultural and Environmental Science Communication: A Meta-synthesis Approach

Agriculturalists and environmentalists must navigate complex challenges as the global population continues to increase and environmental resources are depleted. Colleges of agricultural and environmental sciences are tasked with addressing the nexus between environmental and agricultural challenges through research, education, and communication. However, the amount of research being conducted with both agriculture and the environment considered is largely unknown and, as a result, their corresponding communication messages may not provide coherent messages from the college. Therefore, the purpose of this study was to identify if research within a college of agricultural and environmental sciences takes a holistic approach so that communication efforts coming from the college can encompass both perspectives. The data were collected from a web-based system containing university research publications and analyzed using a thematic analysis and meta-synthesis. The meta-synthesis revealed 212 codes overlapping agricultural and environmental themes compared to the total 4,325 codes found across all publications. The findings indicated there was a limited amount of collaboration occurring between environmental and agricultural researchers within the college. Without collaborative research, agricultural communicators cannot develop science communication efforts that holistically integrate evidence-based science. As new challenges emerge at the nexus of agriculture and the environment, researchers must shift toward a collaborative and interdisciplinary approach to ensure the science communication efforts sharing their findings are inclusive

Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign

Volatile organic compounds (VOCs) were measured by proton transfer reaction – mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative – Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA. Atmos. Chem. Phys., 9, 467–481, 2009.Robert A. Welch Foundation (Grant A-1417)Texas A & M University. Center for Atmospheric Chemistry and EnvironmentNational Science Foundation (U.S.) (ATM-0528227

Teenage acne and cancer risk in U.S. women: A prospective cohort study

BACKGROUND: Acne reflects hormone imbalance and is a key component of several systemic diseases. We hypothesized that diagnosis of acne as a teenager might predict subsequent risk of hormone-related cancers. METHODS: We followed 99,128 female nurses in the Nurses' Health Study II cohort for 20 years (1989-2009) and used Cox proportional hazards models to estimate the hazard ratios (HRs) of 8 specific cancers (breast, thyroid, colorectal, ovarian, cervical, and endometrial cancers, melanoma, and non-Hodgkin lymphoma) for women with a history of severe teenage acne. RESULTS: After thoroughly adjusting for the previously known risk factors for each cancer, we found that among women with a history of severe teenage acne, the relative risk increased, with a multivariable-adjusted HR of 1.44 (95% confidence interval [CI], 1.03-2.01) for melanoma. We replicated this association in an independent melanoma case-control study of 930 cases and 1026 controls (multivariable-adjusted odds ratio, 1.27; 95% CI, 1.03-1.56). We also found that in both studies the individuals with teenage acne were more likely to have moles (52.7% vs 50.1%, P < .001 in the cohort study; and 55.2% vs 45.1%, P = .004 in the case-control study). CONCLUSIONS: Our findings suggest that a history of teenage acne might be a novel risk factor for melanoma independent from the known factors, which supports a need for continued investigation of these relationships

Characterization of uranium- and plutonium-contaminated soils by electron microscopy

Electron beam techniques have been used to characterize uranium-contaminated soils from the Fernald Site in Ohio, and also plutonium-bearing `hot particles, from Johnston Island in the Pacific Ocean. By examining Fernald samples that had undergone chemical leaching it was possible to observe the effect the treatment had on specific uranium-bearing phases. The technique of Heap leaching, using carbonate solution, was found to be the most successful in removing uranium from Fernald soils, the Heap process allows aeration, which facilitates the oxidation of uraninite. However, another refractory uranium(IV) phase, uranium metaphosphate, was not removed or affected by any soil-washing process. Examination of ``hot particles`` from Johnston Island revealed that plutonium and uranium were present in 50--200 nm particles, both amorphous and crystalline, within a partially amorphous aluminum oxide matrix. The aluminum oxide is believed to have undergone a crystalline-to-amorphous transition caused by alpha-particle bombardment during the decay of the plutonium

Real-Time Measurements of Engine-Out Trace Elements: Application of a Novel Soot Particle Aerosol Mass Spectrometer for Emissions Characterization

Lubricant-derived trace element emissions are the largest contributors to the accumulation of incombustible ash in diesel particulate filters (DPF), eventually leading to filter plugging and an increase in engine fuel consumption. Particulate trace element emissions also pose adverse health effects and are the focus of increasingly stringent air quality regulations. To date, the rates and physical and chemical properties of lubricant-derived additive emissions are not well characterized, largely due to the difficulties associated with conducting the measurements. This work investigated the potential for conducting real-time measurements of lubricant-derived particle emissions. The experiment used the Soot Particle Aerosol Mass Spectrometer (SP-AMS) developed by Aerodyne Research to measure the size, mass and composition of submicron particles in the exhaust. Results confirm the ability of the SP-AMS to measure engine-out emissions of calcium, zinc, magnesium, phosphorous, and sulfur. Further, emissions of previously difficult to detect elements, such as boron, and low-level engine wear metals, such as lead, were also measured. This paper provides an overview of the results obtained with the SP-AMS, and demonstrates the utility of applying real-time techniques to engine-out and tailpipe-out trace element emissions. Application of the SP-AMS for engine exhaust characterization followed a two-part approach: (1) measurement validation, and (2) measurement of engine-out exhaust. Measurement validation utilized a diesel burner with precise control of lubricant consumption. Results showed a good correlation between CJ-4 oil consumption and measured levels of lubricant-derived trace elements in the particle phase. Following measurement validation, the SP-AMS measured engine-out emissions from a medium-duty diesel engine, operated over a standard speed/load matrix. This work demonstrates the utility of state-of-the-art online techniques (such as the SP-AMS) to measure engine-out emissions, including trace species derived from lubricant additives. Results help optimize the combined engine-lubricant-aftertreatment system and provide a real-time characterization of emissions. As regulations become more stringent and emission controls more complex, advanced measurement techniques with high sensitivity and fast time response will become an increasingly important part of engine characterization studies.United States. Environmental Protection Agency (Grant RD834560

Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors

In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons