Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-30 (of 36 Records) |
Query Trace: Keane M[original query] |
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Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 Salmonella Typhi genomes
Carey ME , Dyson ZA , Ingle DJ , Amir A , Aworh MK , Chattaway MA , Chew KL , Crump JA , Feasey NA , Howden BP , Keddy KH , Maes M , Parry CM , Van Puyvelde S , Webb HE , Afolayan AO , Alexander AP , Anandan S , Andrews JR , Ashton PM , Basnyat B , Bavdekar A , Bogoch II , Clemens JD , da Silva KE , De A , de Ligt J , Diaz Guevara PL , Dolecek C , Dutta S , Ehlers MM , Francois Watkins L , Garrett DO , Godbole G , Gordon MA , Greenhill AR , Griffin C , Gupta M , Hendriksen RS , Heyderman RS , Hooda Y , Hormazabal JC , Ikhimiukor OO , Iqbal J , Jacob JJ , Jenkins C , Jinka DR , John J , Kang G , Kanteh A , Kapil A , Karkey A , Kariuki S , Kingsley RA , Koshy RM , Lauer AC , Levine MM , Lingegowda RK , Luby SP , Mackenzie GA , Mashe T , Msefula C , Mutreja A , Nagaraj G , Nagaraj S , Nair S , Naseri TK , Nimarota-Brown S , Njamkepo E , Okeke IN , Perumal SPB , Pollard AJ , Pragasam AK , Qadri F , Qamar FN , Rahman SIA , Rambocus SD , Rasko DA , Ray P , Robins-Browne R , Rongsen-Chandola T , Rutanga JP , Saha SK , Saha S , Saigal K , Sajib MSI , Seidman JC , Shakya J , Shamanna V , Shastri J , Shrestha R , Sia S , Sikorski MJ , Singh A , Smith AM , Tagg KA , Tamrakar D , Tanmoy AM , Thomas M , Thomas MS , Thomsen R , Thomson NR , Tupua S , Vaidya K , Valcanis M , Veeraraghavan B , Weill FX , Wright J , Dougan G , Argimón S , Keane JA , Aanensen DM , Baker S , Holt KE . Elife 2023 12 BACKGROUND: The Global Typhoid Genomics Consortium was established to bring together the typhoid research community to aggregate and analyse Salmonella enterica serovar Typhi (Typhi) genomic data to inform public health action. This analysis, which marks 22 years since the publication of the first Typhi genome, represents the largest Typhi genome sequence collection to date (n=13,000). METHODS: This is a meta-analysis of global genotype and antimicrobial resistance (AMR) determinants extracted from previously sequenced genome data and analysed using consistent methods implemented in open analysis platforms GenoTyphi and Pathogenwatch. RESULTS: Compared with previous global snapshots, the data highlight that genotype 4.3.1 (H58) has not spread beyond Asia and Eastern/Southern Africa; in other regions, distinct genotypes dominate and have independently evolved AMR. Data gaps remain in many parts of the world, and we show the potential of travel-associated sequences to provide informal 'sentinel' surveillance for such locations. The data indicate that ciprofloxacin non-susceptibility (>1 resistance determinant) is widespread across geographies and genotypes, with high-level ciprofloxacin resistance (≥3 determinants) reaching 20% prevalence in South Asia. Extensively drug-resistant (XDR) typhoid has become dominant in Pakistan (70% in 2020) but has not yet become established elsewhere. Ceftriaxone resistance has emerged in eight non-XDR genotypes, including a ciprofloxacin-resistant lineage (4.3.1.2.1) in India. Azithromycin resistance mutations were detected at low prevalence in South Asia, including in two common ciprofloxacin-resistant genotypes. CONCLUSIONS: The consortium's aim is to encourage continued data sharing and collaboration to monitor the emergence and global spread of AMR Typhi, and to inform decision-making around the introduction of typhoid conjugate vaccines (TCVs) and other prevention and control strategies. FUNDING: No specific funding was awarded for this meta-analysis. Coordinators were supported by fellowships from the European Union (ZAD received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 845681), the Wellcome Trust (SB, Wellcome Trust Senior Fellowship), and the National Health and Medical Research Council (DJI is supported by an NHMRC Investigator Grant [GNT1195210]). | Salmonella Typhi (Typhi) is a type of bacteria that causes typhoid fever. More than 110,000 people die from this disease each year, predominantly in areas of sub-Saharan Africa and South Asia with limited access to safe water and sanitation. Clinicians use antibiotics to treat typhoid fever, but scientists worry that the spread of antimicrobial-resistant Typhi could render the drugs ineffective, leading to increased typhoid fever mortality. The World Health Organization has prequalified two vaccines that are highly effective in preventing typhoid fever and may also help limit the emergence and spread of resistant Typhi. In low resource settings, public health officials must make difficult trade-off decisions about which new vaccines to introduce into already crowded immunization schedules. Understanding the local burden of antimicrobial-resistant Typhi and how it is spreading could help inform their actions. The Global Typhoid Genomics Consortium analyzed 13,000 Typhi genomes from 110 countries to provide a global overview of genetic diversity and antimicrobial-resistant patterns. The analysis showed great genetic diversity of the different strains between countries and regions. For example, the H58 Typhi variant, which is often drug-resistant, has spread rapidly through Asia and Eastern and Southern Africa, but is less common in other regions. However, distinct strains of other drug-resistant Typhi have emerged in other parts of the world. Resistance to the antibiotic ciprofloxacin was widespread and accounted for over 85% of cases in South Africa. Around 70% of Typhi from Pakistan were extensively drug-resistant in 2020, but these hard-to-treat variants have not yet become established elsewhere. Variants that are resistant to both ciprofloxacin and ceftriaxone have been identified, and azithromycin resistance has also appeared in several different variants across South Asia. The Consortium’s analyses provide valuable insights into the global distribution and transmission patterns of drug-resistant Typhi. Limited genetic data were available fromseveral regions, but data from travel-associated cases helped fill some regional gaps. These findings may help serve as a starting point for collective sharing and analyses of genetic data to inform local public health action. Funders need to provide ongoing supportto help fill global surveillance data gaps. | eng |
Factors That Affect Opioid Quality Improvement Initiatives in Primary Care: Insights from Ten Health Systems
Childs E , Tano CA , Mikosz CA , Parchman ML , Hersey CL , Keane N , Shoemaker-Hunt SJ , Losby JL . Jt Comm J Qual Patient Saf 2023 49 (1) 26-33 OBJECTIVE: To improve patient safety and pain management, the Centers for Disease Control and Prevention (CDC) released the Guideline for Prescribing Opioids for Chronic Pain (CDC Guideline). Recognizing that issuing a guideline alone is insufficient for transforming practice, CDC supported an Opioid Quality Improvement (QI) Collaborative, consisting of 10 health care systems that represented more than 120 practices across the United States. The research team identified factors related to implementation success using domains described by the integrated Promoting Action on Research Implementation in Health Services (iPARIHS) implementation science framework. METHODS: Data from interviews, notes from check-in calls, and documents provided by systems were used. The researchers collected data throughout the project through interviews, meeting notes, and documents. RESULTS: The iPARIHS framework was used to identify factors that affected implementation related to the context, innovation (implementing recommendations from the CDC Guideline), recipient (clinicians), and facilitation (QI team). Contextual characteristics were at the clinic, health system, and broader external context, including staffing and leadership support, previous QI experience, and state laws. Characteristics of the innovation were its adaptability and challenges operationalizing the measures. Recipient characteristics included belief in the importance of the innovation but challenges engaging in the initiative. Finally, facilitation characteristics driving differential outcomes included staffing and available time of the QI team, the ability to make changes, and experience with QI. CONCLUSION: As health care systems continue to implement the CDC Guideline, these insights can advance successful implementation efforts by describing common implementation challenges and identifying strategies to prepare for and overcome them. |
Japanese quail (Coturnix japonica) as a novel model to study the relationship between the avian microbiome and microbial endocrinology-based host-microbe interactions
Lyte JM , Keane J , Eckenberger J , Anthony N , Shrestha S , Marasini D , Daniels KM , Caputi V , Donoghue AM , Lyte M . Microbiome 2021 9 (1) 38 BACKGROUND: Microbial endocrinology, which is the study of neuroendocrine-based interkingdom signaling, provides a causal mechanistic framework for understanding the bi-directional crosstalk between the host and microbiome, especially as regards the effect of stress on health and disease. The importance of the cecal microbiome in avian health is well-recognized, yet little is understood regarding the mechanisms underpinning the avian host-microbiome relationship. Neuroendocrine plasticity of avian tissues that are focal points of host-microbiome interaction, such as the gut and lung, has likewise received limited attention. Avian in vivo models that enable the study of the neuroendocrine dynamic between host and microbiome are needed. As such, we utilized Japanese quail (Coturnix japonica) that diverge in corticosterone response to stress to examine the relationship between stress-related neurochemical concentrations at sites of host-microbe interaction, such as the gut, and the cecal microbiome. RESULTS: Our results demonstrate that birds which contrast in corticosterone response to stress show profound separation in cecal microbial community structure as well as exhibit differences in tissue neurochemical concentrations and structural morphologies of the gut. Changes in neurochemicals known to be affected by the microbiome were also identified in tissues outside of the gut, suggesting a potential relationship in birds between the cecal microbiome and overall avian physiology. CONCLUSIONS: The present study provides the first evidence that the structure of the avian cecal microbial community is shaped by selection pressure on the bird for neuroendocrine response to stress. Identification of unique region-dependent neurochemical changes in the intestinal tract following stress highlights environmental stressors as potential drivers of microbial endocrinology-based mechanisms of avian host-microbiome dialogue. Together, these results demonstrate that tissue neurochemical concentrations in the avian gut may be related to the cecal microbiome and reveal the Japanese quail as a novel avian model in which to further examine the mechanisms underpinning these relationships. Video abstract. |
Developing clinical quality improvement measures aligned with the CDC Guideline for Prescribing Opioids for Chronic Pain: An important strategy to support safer prescribing in primary care
Shoemaker-Hunt S , Sargent WJr , Swan H , Mikosz C , Cobb K , McDonald D , Keane N , von Korff M , Parchman M , Losby J . Am J Med Qual 2020 36 (2) 125-128 In 2018, opioids were involved in 46 802 overdose deaths.1 To help address the opioid overdose epidemic, the Centers for Disease Control and Prevention (CDC) released its Guideline for Prescribing Opioids for Chronic Pain (CDC Prescribing Guideline) in March 2016. To support providers in implementing the guideline, a set of 16 quality improvement (QI) measures were developed that align with the CDC Prescribing Guideline. The goal of these QI measures is to provide health care systems with the means to track their progress in implementing recommended practices to improve care over time. As the QI adage states, “You cannot improve what you cannot measure.” |
Mapping and analysis of US state and urban local sodium reduction laws
Sloan AA , Keane T , Pettie JR , Bhuiya AR , Taylor LN , Bates M , Bernard S , Akinleye F , Gilchrist S . J Public Health Manag Pract 2020 26 Suppl 2 S62-s70 CONTEXT: Excessive sodium consumption contributes to high blood pressure, which is a risk factor for cardiovascular disease. OBJECTIVES: To (1) identify state and urban local laws addressing adult or general population sodium consumption in foods and beverages and (2) align findings to a previously published evidence classification review, the Centers for Disease Control and Prevention Sodium Quality and Impact of Component (QuIC) evidence assessment. DESIGN: Systematic collection of sodium reduction laws from all 50 states, the 20 most populous counties in the United States, and the 20 most populous cities in the United States, including Washington, District of Columbia, effective on January 1, 2019. Relevant laws were assigned to 1 or more of 6 interventions: (1) provision of sodium information in restaurants or at point of purchase; (2) consumer incentives to purchase lower sodium foods; and provision of lower sodium offerings in (3) workplaces, (4) vending machines, (5) institutional meal services, and (6) grocery, corner, and convenience stores. The researchers used Westlaw, local policy databases or city Web sites, and general nutrition policy databases to identify relevant laws. RESULTS: Thirty-nine sodium reduction laws and 10 state laws preempting localities from enacting sodium reduction laws were identified. Sodium reduction laws were more common in local jurisdictions and in the Western United States. Sodium reduction laws addressing meal services (n = 17), workplaces (n = 12), labeling (n = 13), and vending machines (n = 11) were more common, while those addressing grocery stores (n = 2) or consumer incentives (n = 6) were less common. Laws with high QuIC evidence classifications were generally more common than laws with low QuIC evidence classifications. CONCLUSIONS: The distribution of sodium laws in the US differed by region, QuIC classification, and jurisdiction type, indicating influence from public health and nonpublic health factors. Ongoing research is warranted to determine how the strength of public health evidence evolves over time and how those changes correlate with uptake of sodium reduction law. |
Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells
Siegrist KJ , Reynolds SH , Porter DW , Mercer RR , Bauer AK , Lowry D , Cena L , Stueckle TA , Kashon ML , Wiley J , Salisbury JL , Mastovich J , Bunker K , Sparrow M , Lupoi JS , Stefaniak AB , Keane MJ , Tsuruoka S , Terrones M , McCawley M , Sargent LM . Part Fibre Toxicol 2019 16 (1) 36 BACKGROUND: The unique physicochemical properties of multi-walled carbon nanotubes (MWCNT) have led to many industrial applications. Due to their low density and small size, MWCNT are easily aerosolized in the workplace making respiratory exposures likely in workers. The International Agency for Research on Cancer designated the pristine Mitsui-7 MWCNT (MWCNT-7) as a Group 2B carcinogen, but there was insufficient data to classify all other MWCNT. Previously, MWCNT exposed to high temperature (MWCNT-HT) or synthesized with nitrogen (MWCNT-ND) have been found to elicit attenuated toxicity; however, their genotoxic and carcinogenic potential are not known. Our aim was to measure the genotoxicity of MWCNT-7 compared to these two physicochemically-altered MWCNTs in human lung epithelial cells (BEAS-2B & SAEC). RESULTS: Dose-dependent partitioning of individual nanotubes in the cell nuclei was observed for each MWCNT material and was greatest for MWCNT-7. Exposure to each MWCNT led to significantly increased mitotic aberrations with multi- and monopolar spindle morphologies and fragmented centrosomes. Quantitative analysis of the spindle pole demonstrated significantly increased centrosome fragmentation from 0.024-2.4 mug/mL of each MWCNT. Significant aneuploidy was measured in a dose-response from each MWCNT-7, HT, and ND; the highest dose of 24 mug/mL produced 67, 61, and 55%, respectively. Chromosome analysis demonstrated significantly increased centromere fragmentation and translocations from each MWCNT at each dose. Following 24 h of exposure to MWCNT-7, ND and/or HT in BEAS-2B a significant arrest in the G1/S phase in the cell cycle occurred, whereas the MWCNT-ND also induced a G2 arrest. Primary SAEC exposed for 24 h to each MWCNT elicited a significantly greater arrest in the G1 and G2 phases. However, SAEC arrested in the G1/S phase after 72 h of exposure. Lastly, a significant increase in clonal growth was observed one month after exposure to 0.024 mug/mL MWCNT-HT & ND. CONCLUSIONS: Although MWCNT-HT & ND cause a lower incidence of genotoxicity, all three MWCNTs cause the same type of mitotic and chromosomal disruptions. Chromosomal fragmentation and translocations have not been observed with other nanomaterials. Because in vitro genotoxicity is correlated with in vivo genotoxic response, these studies in primary human lung cells may predict the genotoxic potency in exposed human populations. |
Pulmonary toxicity and lung tumorigenic potential of surrogate metal oxides in gas metal arc welding-stainless steel fume: Iron as a primary mediator versus chromium and nickel
Falcone LM , Erdely A , Salmen R , Keane M , Battelli L , Kodali V , Bowers L , Stefaniak AB , Kashon ML , Antonini JM , Zeidler-Erdely PC . PLoS One 2018 13 (12) e0209413 In 2017, the International Agency for Research on Cancer classified welding fumes as "carcinogenic to humans" (Group 1). Both mild steel (MS) welding, where fumes lack carcinogenic chromium and nickel, and stainless steel (SS) increase lung cancer risk in welders; therefore, further research to better understand the toxicity of the individual metals is needed. The objectives were to (1) compare the pulmonary toxicity of chromium (as Cr(III) oxide [Cr2O3] and Cr (VI) calcium chromate [CaCrO4]), nickel [II] oxide (NiO), iron [III] oxide (Fe2O3), and gas metal arc welding-SS (GMAW-SS) fume; and (2) determine if these metal oxides can promote lung tumors. Lung tumor susceptible A/J mice (male, 4-5 weeks old) were exposed by oropharyngeal aspiration to vehicle, GMAW-SS fume (1.7 mg), or a low or high dose of surrogate metal oxides based on the respective weight percent of each metal in the fume: Cr2O3 + CaCrO4 (366 + 5 mug and 731 + 11 mug), NiO (141 and 281 mug), or Fe2O3 (1 and 2 mg). Bronchoalveolar lavage, histopathology, and lung/liver qPCR were done at 1, 7, 28, and 84 days post-aspiration. In a two-stage lung carcinogenesis model, mice were initiated with 3-methylcholanthrene (10 mug/g; intraperitoneal; 1x) or corn oil then exposed to metal oxides or vehicle (1 x/week for 5 weeks) by oropharyngeal aspiration. Lung tumors were counted at 30 weeks post-initiation. Results indicate the inflammatory potential of the metal oxides was Fe2O3 > Cr2O3 + CaCrO4 > NiO. Overall, the pneumotoxic effects were negligible for NiO, acute but not persistent for Cr2O3 + CaCrO4, and persistent for the Fe2O3 exposures. Fe2O3, but not Cr2O3 + CaCrO4 or NiO significantly promoted lung tumors. These results provide experimental evidence that Fe2O3 is an important mediator of welding fume toxicity and support epidemiological findings and the IARC classification. |
The phylogeography and incidence of multi-drug resistant typhoid fever in sub-Saharan Africa.
Park SE , Pham DT , Boinett C , Wong VK , Pak GD , Panzner U , Espinoza LMC , von Kalckreuth V , Im J , Schutt-Gerowitt H , Crump JA , Breiman RF , Adu-Sarkodie Y , Owusu-Dabo E , Rakotozandrindrainy R , Soura AB , Aseffa A , Gasmelseed N , Keddy KH , May J , Sow AG , Aaby P , Biggs HM , Hertz JT , Montgomery JM , Cosmas L , Fields B , Sarpong N , Razafindrabe TJL , Raminosoa TM , Kabore LP , Sampo E , Teferi M , Yeshitela B , El Tayeb MA , Sooka A , Meyer CG , Krumkamp R , Dekker DM , Jaeger A , Poppert S , Tall A , Niang A , Bjerregaard-Andersen M , Valborg Løfberg S , Seo HJ , Jeon HJ , Deerin JF , Park J , Konings F , Ali M , Clemens JD , Hughes P , Sendagala JN , Vudriko T , Downing R , Ikumapayi UN , Mackenzie GA , Obaro S , Argimon S , Aanensen DM , Page A , Keane JA , Duchene S , Dyson Z , Holt KE , Dougan G , Marks F , Baker S . Nat Commun 2018 9 (1) 5094 There is paucity of data regarding the geographical distribution, incidence, and phylogenetics of multi-drug resistant (MDR) Salmonella Typhi in sub-Saharan Africa. Here we present a phylogenetic reconstruction of whole genome sequenced 249 contemporaneous S. Typhi isolated between 2008-2015 in 11 sub-Saharan African countries, in context of the 2,057 global S. Typhi genomic framework. Despite the broad genetic diversity, the majority of organisms (225/249; 90%) belong to only three genotypes, 4.3.1 (H58) (99/249; 40%), 3.1.1 (97/249; 39%), and 2.3.2 (29/249; 12%). Genotypes 4.3.1 and 3.1.1 are confined within East and West Africa, respectively. MDR phenotype is found in over 50% of organisms restricted within these dominant genotypes. High incidences of MDR S. Typhi are calculated in locations with a high burden of typhoid, specifically in children aged <15 years. Antimicrobial stewardship, MDR surveillance, and the introduction of typhoid conjugate vaccines will be critical for the control of MDR typhoid in Africa. |
Comparison of classical multi-locus sequence typing software for next-generation sequencing data
Page AJ , Alikhan NF , Carleton HA , Seemann T , Keane JA , Katz LS . Microb Genom 2017 3 (8) e000124 Multi-locus sequence typing (MLST) is a widely used method for categorizing bacteria. Increasingly, MLST is being performed using next-generation sequencing (NGS) data by reference laboratories and for clinical diagnostics. Many software applications have been developed to calculate sequence types from NGS data; however, there has been no comprehensive review to date on these methods. We have compared eight of these applications against real and simulated data, and present results on: (1) the accuracy of each method against traditional typing methods, (2) the performance on real outbreak datasets, (3) the impact of contamination and varying depth of coverage, and (4) the computational resource requirements. |
Evaluation of postural sway and impact forces during ingress and egress of scissor lifts at elevations
Pan CS , Chiou SS , Kau T , Wimer BM , Ning X , Keane P . Appl Ergon 2017 65 152-162 Workers are at risk when entering (ingress) or exiting (egress) elevated scissor lifts. In this study, we recorded ground impact forces and postural sway from 22 construction workers while they performed ingress and egress between a scissor lift and an adjacent work surface with varying conditions: lift opening designs, horizontal and vertical gaps, and sloped work surfaces. We observed higher peak ground shear forces when using a bar-and-chain opening, with larger horizontal gap, with the lift surface more than 0.2 m below the work surface, and presence of a sloped (26) work surface. Similar trends were observed for postural sway, except that the influence of vertical distance was not significant. To reduce slip/trip/fall risk and postural sway of workers while ingress or egress of an elevated scissor lift, we suggest scissor lifts be equipped with a gate-type opening instead of a bar-and-chain design. We also suggest the lift surface be placed no more than 0.2 m lower than the work surface and the horizontal gap between lift and work surfaces be as small as possible. Selecting a non-sloped surface to ingress or egress a scissor lift is also preferred to reduce risk. |
Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of tuberculosis in adults and children
Lewinsohn DM , Leonard MK , LoBue PA , Cohn DL , Daley CL , Desmond E , Keane J , Lewinsohn DA , Loeffler AM , Mazurek GH , O'Brien RJ , Pai M , Richeldi L , Salfinger M , Shinnick TM , Sterling TR , Warshauer DM , Woods GL . Clin Infect Dis 2017 64 (2) 111-115 BACKGROUND: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain. METHODS: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence. The evidence was then used as the basis for recommendations about the diagnosis of tuberculosis disease and LTBI in adults and children. The recommendations were formulated, written, and graded using the Grading, Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Twenty-three evidence-based recommendations about diagnostic testing for latent tuberculosis infection, pulmonary tuberculosis, and extrapulmonary tuberculosis are provided. Six of the recommendations are strong, whereas the remaining 17 are conditional. CONCLUSIONS: These guidelines are not intended to impose a standard of care. They provide the basis for rational decisions in the diagnosis of tuberculosis in the context of the existing evidence. No guidelines can take into account all of the often compelling unique individual clinical circumstances. |
Evolution of welding-fume aerosols with time and distance from the source: a study was conducted on the spatiotemporal variability in welding-fume concentrations for the characterization of first- and second-hand exposure to welding fumes
Cena LG , Chen BT , Keane MJ . Weld J 2016 95 280s-285s Gas metal arc welding fumes were generated from mild-steel plates and measured near the arc (30 cm), representing first-hand exposure of the welder, and farther away from the source (200 cm), representing second-hand exposure of adjacent workers. Measurements were taken during 1-min welding runs and at subsequent 5-min intervals after the welding process was stopped. Number size distributions were measured in real time. Particle mass distributions were measured using a micro-orifice uniform deposition impactor, and total mass concentrations were measured with polytetrafluorothylene filters. Membrane filters were used for collecting morphology samples for electron microscopy. Average mass concentrations measured near the arc were 45 mg/m3 and 9 mg/m3 at the farther distance. The discrepancy in concentrations at the two distances was attributed to the presence of spatter particles, which were observed only in the morphology samples near the source. As fumes aged over time, mass concentrations at the farther distance decreased by 31% (6.2 mg/m3) after 5 min and an additional 13% (5.4 mg/m3) after 10 min. Particle number and mass distributions during active welding were similar at both distances, indicating similar exposure patterns for welders and adjacent workers. Exceptions were recorded for particles smaller than 50 nm and larger than 3 mum, where concentrations were higher near the arc, indicating higher exposures of welders. These results were confirmed by microscopy analysis. As residence time increased, number concentrations decreased dramatically. In terms of particle number concentrations, second-hand exposures to welding fumes during active welding may be as high as first-hand exposures. |
Effects of nickel-oxide nanoparticle pre-exposure dispersion status on bioactivity in the mouse lung
Sager T , Wolfarth M , Keane M , Porter D , Castranova V , Holian A . Nanotoxicology 2016 10 (2) 151-61 Nanotechnology is emerging as one of the world's most promising new technologies. From a toxicology perspective, nanoparticles possess two features that promote their bioactivity. The first involves physical-chemical characteristics of the nanoparticle, which include the surface area of the nanoparticle. The second feature is the ability of the nanoparticle to traverse cell membranes. These two important nanoparticle characteristics are greatly influenced by placing nanoparticles in liquid medium prior to animal exposure. Nanoparticles tend to agglomerate and clump in suspension, making it difficult to reproducibly deliver them for in vivo or in vitro experiments, possibly affecting experimental variability. Thus, we hypothesize that nanoparticle dispersion status will correlate with the in vivo bioactivity/toxicity of the particle. To test our hypothesis, nano-sized nickel oxide was suspended in four different dispersion media (phosphate-buffered saline (PBS), dispersion medium (DM), a combination of dipalmitoyl-phosphatidyl choline (DPPC) and albumin in concentrations that mimic diluted alveolar lining fluid), Survanta(R), or pluronic (Pluronic F-68). Well-dispersed and poorly dispersed suspensions were generated in each media by varying sonication time on ice utilizing a Branson Sonifer 450 (25W continuous output, 20 min or 5 min, respectively). Mice (male, C57BL/6J, 7-weeks-old) were given 0-80 microg/mouse of nano-sized nickel oxide in the different states of dispersion via pharyngeal aspiration. At 1 and 7 d post-exposure, mice underwent whole lung lavage to assess pulmonary inflammation and injury as a function of dispersion status, dose and time. The results show that pre-exposure dispersion status correlates with pulmonary inflammation and injury. These results indicate that a greater degree of pre-exposure dispersion increases pulmonary inflammation and cytotoxicity, as well as decreases in the integrity of the blood-gas barrier in the lung. |
Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray
Chen BT , Schwegler-Berry D , Cumpston A , Cumpston J , Friend S , Stone S , Keane M . J Occup Environ Hyg 2016 13 (7) 0 Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test aerosols might cause artifacts by counting "phantom particles." Overall, the information obtained from this study will help understand the limitations of the SMPS in measuring nanoparticles so that one can adequately interpret the results for risk assessments and exposure prevention in an occupational or ambient environment. |
Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace
Keane M , Siert A , Stone S , Chen BT . J Occup Environ Hyg 2015 13 (1) 0 Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr6+). Elemental manganese, nickel, chromium, iron emissions per unit length of weld and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered and analyzed by inductively-coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr6+. GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a (1/4) in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr6+ ranged from 50 to 7800 mug/min, and Cr6+ generation rates per g electrode ranged from 1 to 270mug/g. Elemental Cr generation rates spanned 13 to 330mug/g. Manganese emission rates ranged from 50 to 300mug/g. Nickel emission rates ranged from 4 to140 mug/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as 5 times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this study can substantially reduce fume, Cr6+, manganese and costs relative to SMAW, the most commonly used welding process, and several have exceptional capabilities for reducing emissions. |
Manganese speciation of laboratory-generated welding fumes
Andrews RN , Keane M , Hanley KW , Feng HA , Ashley K . Anal Methods 2015 7 6403-6410 The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a welding system was operated in short circuit gas metal arc welding (GMAW) mode using both stainless steel (SS) and mild carbon steel (MCS) and also with flux cored arc welding (FCAW) and shielded metal arc welding (SMAW) using MCS. Generated WF samples were collected onto polycarbonate filters before homogenization, weighing and storage in scintillation vials. The extraction procedure consisted of four sequential steps to measure various Mn fractions based upon selective solubility: (1) soluble Mn dissolved in 0.01 M ammonium acetate; (2) Mn(0,ii) dissolved in 25% (v/v) acetic acid; (3) Mn(iii,iv) dissolved in 0.5% (w/v) hydroxylamine hydrochloride in 25% (v/v) acetic acid; and (4) insoluble Mn extracted with concentrated hydrochloric and nitric acids. After sample treatment, the four fractions were analyzed for Mn by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). WF from GMAW and FCAW showed similar distributions of Mn species, with the largest concentrations of Mn detected in the Mn(0,ii) and insoluble Mn fractions. On the other hand, the majority of the Mn content of SMAW fume was detected as Mn(iii,iv). Although the concentration of Mn measured from summation of the four sequential steps was statistically significantly different from that measured from the hot block dissolution method for total Mn, the difference is small enough to be of no practical importance for industrial hygiene air samples, and either method may be used for Mn measurement. The sequential extraction method provides valuable information about the oxidation state of Mn in samples and allows for comparison to results from previous work and from total Mn dissolution methods. |
A field study on the respiratory deposition of the nano-sized fraction of mild and stainless steel welding fume metals
Cena LG , Chisholm WP , Keane MJ , Chen BT . J Occup Environ Hyg 2015 12 (10) 0 A field study was conducted to estimate the amount of Cr, Mn and Ni deposited in the respiratory system of 44 welders in two facilities. Each worker wore a nanoparticle respiratory deposition (NRD) sampler during gas metal arc welding (GMAW) of mild and stainless steel and flux-cored arc welding (FCAW) of mild steel. Several welders also wore side-by-side NRD samplers and closed- face filter cassettes for total particulate samples. The NRD sampler estimates the aerosol's nano-fraction deposited in the respiratory system. Mn concentrations for both welding processes ranged 2.8-199 mug/m3; Ni concentrations ranged 10 -51 mug/m3; Cr concentrations ranged 40-105 mug/m3. Cr(VI) concentrations ranged between 0.5-1.3 mug/m3. For the FCAW process the largest concentrations were reported for welders working in pairs. As a consequence this often resulted in workers being exposed to their own welding fumes and to those generated from the welding partner. Overall no correlation was found between air velocity and exposure (R2=0.002). The estimated percentage of the nano-fraction of Mn deposited in a mild-steel-welder's respiratory system ranged between 10 and 56%. For stainless steel welding, the NRD samplers collected 59% of the total Mn, 90% of the total Cr and 64% of the total Ni. These results indicate that most of the Cr and more than half of the Ni and Mn in the fumes were in the fraction smaller than 300 nm. |
Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events.
Wong VK , Baker S , Pickard DJ , Parkhill J , Page AJ , Feasey NA , Kingsley RA , Thomson NR , Keane JA , Weill FX , Edwards DJ , Hawkey J , Harris SR , Mather AE , Cain AK , Hadfield J , Hart PJ , Thieu NT , Klemm EJ , Glinos DA , Breiman RF , Watson CH , Kariuki S , Gordon MA , Heyderman RS , Okoro C , Jacobs J , Lunguya O , Edmunds WJ , Msefula C , Chabalgoity JA , Kama M , Jenkins K , Dutta S , Marks F , Campos J , Thompson C , Obaro S , MacLennan CA , Dolecek C , Keddy KH , Smith AM , Parry CM , Karkey A , Mulholland EK , Campbell JI , Dongol S , Basnyat B , Dufour M , Bandaranayake D , Naseri TT , Singh SP , Hatta M , Newton P , Onsare RS , Isaia L , Dance D , Davong V , Thwaites G , Wijedoru L , Crump JA , De Pinna E , Nair S , Nilles EJ , Thanh DP , Turner P , Soeng S , Valcanis M , Powling J , Dimovski K , Hogg G , Farrar J , Holt KE , Dougan G . Nat Genet 2015 47 (6) 632-9 The emergence of multidrug-resistant (MDR) typhoid is a major global health threat affecting many countries where the disease is endemic. Here whole-genome sequence analysis of 1,832 Salmonella enterica serovar Typhi (S. Typhi) identifies a single dominant MDR lineage, H58, that has emerged and spread throughout Asia and Africa over the last 30 years. Our analysis identifies numerous transmissions of H58, including multiple transfers from Asia to Africa and an ongoing, unrecognized MDR epidemic within Africa itself. Notably, our analysis indicates that H58 lineages are displacing antibiotic-sensitive isolates, transforming the global population structure of this pathogen. H58 isolates can harbor a complex MDR element residing either on transmissible IncHI1 plasmids or within multiple chromosomal integration sites. We also identify new mutations that define the H58 lineage. This phylogeographical analysis provides a framework to facilitate global management of MDR typhoid and is applicable to similar MDR lineages emerging in other bacterial species. |
An evaluation of welding processes to reduce hexavalent chromium exposures and reduce costs by using better welding techniques
Keane MJ . Environ Health Insights 2014 8 47-50 A group of stainless steel arc welding processes was compared for emission rates of fume and hexavalent chromium, and costs per meter length of weld. The objective was to identify those with minimal emissions and also compare relative labor and consumables costs. The selection included flux-cored arc welding (FCAW), shielded-metal arc welding (SMAW), and multiple gas metal arc welding (GMAW) processes. Using a conical chamber, fumes were collected, and fume generation rates and hexavalent chromium (Cr(6+)) were measured. GMAW processes used were short-circuit (SC) and pulsed-spray modes. Flux-cored welding used gas shielding. Costs were estimated per meter of a 6.3-mm thick horizontal butt weld. Emission rates of Cr(6+) were lowest for GMAW processes and highest for SMAW; several GMAW processes had less than 2% of the SMAW generation rate. Labor and consumable costs for the processes studied were again highest for SMAW, with those of several GMAW types about half that cost. The results show that use of any of the GMAW processes (and flux-cored welding) could substantially reduce fume and Cr(6+) emissions, and greatly reduce costs relative to SMAW. |
Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes
Sriram K , Lin GX , Jefferson AM , Stone S , Afshari A , Keane MJ , McKinney W , Jackson M , Chen BT , Schwegler-Berry D , Cumpston A , Cumpston JL , Roberts JR , Frazer DG , Antonini JM . Toxicology 2014 328 168-78 Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson's disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40mg/m3; 3h/dayx5 d/weekx2 weeks) to fumes generated by gas-metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25V; RVSS) or high voltage (30V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. |
Size distribution and estimated respiratory deposition of total chromium, hexavalent chromium, manganese, and nickel in gas metal arc welding fume aerosols
Cena LG , Chisholm WP , Keane MJ , Cumpston A , Chen BT . Aerosol Sci Technol 2014 48 (12) 1254-1263 A laboratory study was conducted to determine the mass of total Cr, Cr(VI), Mn, and Ni in 15 size fractions for mild and stainless steel gas-metal arc welding (GMAW) fumes. Samples were collected using a nano multi orifice uniform deposition impactor (MOUDI) with polyvinyl chloride filters on each stage. The filters were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography. Limits of detection (LODs) and quantitation (LOQs) were experimentally calculated and percent recoveries were measured from spiked metals in solution and dry, certified welding-fume reference material. The fraction of Cr(VI) in total Cr was estimated by calculating the ratio of Cr(VI) to total Cr mass for each particle size range. Expected, regional deposition of each metal was estimated according to respiratory-deposition models. The weight percent (standard deviation) of Mn in mild steel fumes was 9.2% (6.8%). For stainless steel fumes, the weight percentages were 8.4% (5.4%) for total Cr, 12.2% (6.5%) for Mn, 2.1% (1.5%) for Ni and 0.5% (0.4%) for Cr(VI). All metals presented a fraction between 0.04 and 0.6 ?m. Total Cr and Ni presented an additional fraction <0.03 ?m. On average 6% of the Cr was found in the Cr(VI) valence state. There was no statistical difference between the smallest and largest mean Cr(VI) to total Cr mass ratio (p-value = 0.19), hence our analysis does not show that particle size affects the contribution of Cr(VI) to total Cr. The predicted total respiratory deposition for the metal particles was ?25%. The sites of principal deposition were the head airways (7?10%) and the alveolar region (11?14%). Estimated Cr(VI) deposition was highest in the alveolar region (14%). |
Evaluation of the pulmonary toxicity of a fume generated from a nickel-, copper-based electrode to be used as a substitute in stainless steel welding
Antonini JM , Badding MA , Meighan TG , Keane M , Leonard SS , Roberts JR . Environ Health Insights 2014 8 11-20 Epidemiology has indicated a possible increase in lung cancer among stainless steel welders. Chromium (Cr) is a primary component of stainless steel welding fume. There is an initiative to develop alternative welding consumables [nickel (Ni)- and copper (Cu)-based alloys] that do not contain Cr. No study has been performed to evaluate the toxicity of fumes generated from Ni- and Cu-based consumables. Dose–response and time-course effects on lung toxicity of a Ni- and Cu-based welding fume (Ni–Cu WF) were examined using an in vivo and in vitro bioassay, and compared with two other well-characterized welding fumes. Even though only trace amounts of Cr were present, a persistent increase in lung injury and inflammation was observed for the Ni–Cu WF compared to the other fumes. The difference in response appears to be due to a direct cytotoxic effect by the Ni–Cu WF sample on lung macrophages as opposed to an elevated production of reactive oxygen species (ROS). |
A novel method for assessing respiratory deposition of welding fume nanoparticles
Cena LG , Keane MJ , Chisholm WP , Stone S , Harper M , Chen BT . J Occup Environ Hyg 2014 11 (12) 771-80 Welders are exposed to high concentrations of nanoparticles. Compared to larger particles, nanoparticles have been associated with more toxic effects at the cellular level, including the generation of more reactive oxygen species activity. Current methods for welding-fume aerosol exposures do not differentiate between the nano-fraction and the larger particles. The objectives of this work are to establish a method to estimate the respiratory deposition of the nano-fraction of selected metals in welding fumes and test this method in a laboratory setting. Manganese (Mn), Nickel (Ni), Chromium (Cr) and hexavalent chromium (Cr(VI)) are commonly found in welding fume aerosols and have been linked with severe adverse health outcomes. Inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC) were evaluated as methods for analyzing the content of Mn, Ni, Cr and Cr(VI) nanoparticles in welding fumes collected with nanoparticle respiratory deposition (NRD) samplers. NRD samplers collect nanoparticles at deposition efficiencies that closely resemble physiological deposition in the respiratory tract. The limits of detection (LODs) and quantitation (LOQs) for ICP-MS and IC were determined analytically. Mild and stainless steel welding fumes generated with a robotic welder were collected with NRD samplers inside a chamber. LODs (LOQs) for Mn, Ni, Cr, and Cr(VI) were 1.3 mug (4.43 mug); 0.4 mug (1.14 mug), 1.1 mug (3.33 mug), and 0.4 mug (1.42 mug), respectively. Recovery of spiked samples and certified welding fume reference material was greater than 95%. When testing the method, the average percentage of total mass concentrations collected by the NRD samplers was approximately 30% for Mn, approximately 50% for Cr and approximately 60% for Ni, indicating that a large fraction of the metals may lay in the nanoparticle fraction. This knowledge is critical to the development of toxicological studies aimed at finding links between exposure to welding fume nanoparticles and adverse health effects. Future work will involve the validation of the method in workplace settings. |
Genotoxicity of multi-walled carbon nanotubes at occupationally relevant doses
Siegrist KJ , Reynolds SH , Kashon ML , Lowry DT , Dong C , Hubbs AF , Young SH , Salisbury JL , Porter DW , Benkovic SA , McCawley M , Keane MJ , Mastovich JT , Bunker KL , Cena LG , Sparrow MC , Sturgeon JL , Dinu CZ , Sargent LM . Part Fibre Toxicol 2014 11 6 Carbon nanotubes are commercially-important products of nanotechnology; however, their low density and small size makes carbon nanotube respiratory exposures likely during their production or processing. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to single-walled carbon nanotubes (SWCNT). In this study, we examined whether multi-walled carbon nanotubes (MWCNT) cause mitotic spindle damage in cultured cells at doses equivalent to 34 years of exposure at the NIOSH Recommended Exposure Limit (REL). MWCNT induced a dose responsive increase in disrupted centrosomes, abnormal mitotic spindles and aneuploid chromosome number 24 hours after exposure to 0.024, 0.24, 2.4 and 24 mug/cm(2) MWCNT. Monopolar mitotic spindles comprised 95% of disrupted mitoses. Three-dimensional reconstructions of 0.1 mum optical sections showed carbon nanotubes integrated with microtubules, DNA and within the centrosome structure. Cell cycle analysis demonstrated a greater number of cells in S-phase and fewer cells in the G2 phase in MWCNT-treated compared to diluent control, indicating a G1/S block in the cell cycle. The monopolar phenotype of the disrupted mitotic spindles and the G1/S block in the cell cycle is in sharp contrast to the multi-polar spindle and G2 block in the cell cycle previously observed following exposure to SWCNT. One month following exposure to MWCNT there was a dramatic increase in both size and number of colonies compared to diluent control cultures, indicating a potential to pass the genetic damage to daughter cells. Our results demonstrate significant disruption of the mitotic spindle by MWCNT at occupationally relevant exposure levels. |
Profiling mild steel welding processes to reduce fume emissions and costs in the workplace
Keane MJ , Siert A , Chen BT , Stone SG . Ann Occup Hyg 2014 58 (4) 403-12 To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer, Regulated Metal Deposition, and Cold Metal Transfer (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13mg fume g-1 electrode) and lowest for GMAW processes such as pulsed spray (~1.5mg g-1) and CMT (~1mg g-1). Manganese emission rates per gram of electrode consumed ranged from 0.45mg g-1 (SMAW) to 0.08mg g-1 (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004mg g-1 (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49mg g-1 (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides information to aid in those choices. Suggestions for overcoming barriers to utilizing new and less hazardous welding processes are also discussed. |
Impact of prostate cancer on sexual relationships: a longitudinal perspective on intimate partners' experiences
Ramsey SD , Zeliadt SB , Blough DK , Moinpour CM , Hall IJ , Smith JL , Ekwueme DU , Fedorenko CR , Fairweather ME , Koepl LM , Thompson IM , Keane TE , Penson DF . J Sex Med 2013 10 (12) 3135-43 INTRODUCTION: In this prospective study of localized prostate cancer patients and their partners, we analyzed how partner issues evolve over time, focusing on satisfaction with care, influence of cancer treatment, and its impact on relationship with patient, cancer worry, and personal activities. AIMS: Our study aims were twofold: (i) to determine whether the impact of treatment on patients and partners moderate over time and (ii) if receiving surgery (i.e., radical prostatectomy) influences partner issues more than other treatments. METHODS: Patients newly diagnosed with localized prostate cancer and their female partners were recruited from three states to complete surveys by mail at three time points over 12 months. MAIN OUTCOME MEASURES: The four primary outcomes assessed in the partner analysis included satisfaction with treatment, cancer worry, and the influence of cancer and its treatment on their relationship (both general relationship and sexual relationship). RESULTS: This analysis included 88 patient-partner pairs. At 6 months, partners reported that cancer had a negative impact on their sexual relationship (39%-somewhat negative and 12%-very negative). At 12 months, this proportion increased substantially (42%-somewhat negative and 29%-very negative). Partners were significantly more likely to report that their sexual relationship was worse when the patient reported having surgery (P = 0.0045, odds ratio = 9.8025, 95% confidence interval 2.076-46.296). A minority of partners reported significant negative impacts in other areas involving their personal activities (16% at 6 months and 25% at 12 months) or work life (6% at 6 months, which increased to 12% at 12 months). CONCLUSION: From partners' perspectives, prostate cancer therapy has negative impact on sexual relationships and appears to worsen over time. |
Lung tumor promotion by chromium-containing welding particulate matter in a mouse model
Zeidler-Erdely PC , Meighan TG , Erdely A , Battelli LA , Kashon ML , Keane M , Antonini JM . Part Fibre Toxicol 2013 10 (1) 45 BACKGROUND: Epidemiology suggests that occupational exposure to welding particulate matter (PM) may increase lung cancer risk. However, animal studies are lacking to conclusively link welding with an increased risk. PM derived from stainless steel (SS) welding contains carcinogenic metals such as hexavalent chromium and nickel. We hypothesized that welding PM may act as a tumor promoter and increase lung tumor multiplicity in vivo. Therefore, the capacity of chromium-containing gas metal arc (GMA)-SS welding PM to promote lung tumors was evaluated using a two-stage (initiation-promotion) model in lung tumor susceptible A/J mice. METHODS: Male mice (n = 28-30/group) were treated either with the initiator 3-methylcholanthrene (MCA;10 microg/g; IP) or vehicle (corn oil) followed by 5 weekly pharyngeal aspirations of GMA-SS (340 or 680 microg/exposure) or PBS. Lung tumors were enumerated at 30 weeks post-initiation. RESULTS: MCA initiation followed by GMA-SS welding PM exposure promoted tumor multiplicity in both the low (12.1 = 1.5 tumors/mouse) and high (14.0 +/- 1.8 tumors/mouse) exposure groups significantly above MCA/sham (4.77 +/- 0.7 tumors/mouse; p = 0.0001). Multiplicity was also highly significant (p < 0.004) across all individual lung regions of GMA-SS-exposed mice. No exposure effects were found in the corn oil groups at 30 weeks. Histopathology confirmed the gross findings and revealed increased inflammation and a greater number of malignant lesions in the MCA/welding PM-exposed groups. CONCLUSIONS: GMA-SS welding PM acts as a lung tumor promoter in vivo. Thus, this study provides animal evidence to support the epidemiological data that show welders have an increased lung cancer risk. |
Burden among partner caregivers of patients diagnosed with localized prostate cancer within 1 year after diagnosis: an economic perspective
Li C , Zeliadt SB , Hall IJ , Smith JL , Ekwueme DU , Moinpour CM , Penson DF , Thompson IM , Keane TE , Ramsey SD . Support Care Cancer 2013 21 (12) 3461-9 PURPOSE: Informal care plays an important role in the overall care for people with cancer. This study estimates lost productivity and informal caregiving and associated costs among partner caregivers of localized prostate cancer patients within 1 year after diagnosis. METHODS: We applied data from the Family and Cancer Therapy Selection study, a three-wave self-administered survey among patients diagnosed with localized prostate cancer and their partner caregivers in multiple clinics in the USA. Time spent was measured by the sum of working hours lost, informal caregiving hours performed, and hours spent on household chores. The national median income for women 55 years or older was used to calculate costs associated with the time spent using the opportunity cost method. Descriptive and bivariate analyses were conducted. RESULTS: The average working hours decreased from 14.0 h/week (SD = 17.6) to 10.9 h/week (SD = 15.9), without a significant change in responsibility/intensity at work. The mean annual time spent on informal caregiving and household chores was 65.9 h/year (SD = 172.4) and 76.2 h/year (SD = 193.3), respectively. The mean annual economic burden among partner caregivers was US$6,063 (range US$571-US$47,105) in 2009 dollars accounted for by a mean of 276.2 h (range 26-2,146) in the study sample. The time spent on informal caregiving and household chores varied by patient and caregiver characteristics. CONCLUSIONS: Pilot estimates on non-medical economic burden among partner caregivers (spouses) during the initial phase of the treatment provide important information for comprehensive estimation of disease burden and can be used in cost-effectiveness analyses of prostate cancer interventions. |
Selecting processes to minimize hexavalent chromium from stainless steel welding
Keane M , Siert A , Stone S , Chen B , Slaven J , Cumpston A , Antonini J . Weld J 2012 91 (9) 241S-246S Eight welding processes/shielding gas combinations were assessed for generation of hexavalent chromium (Cr6+) in stainless steel welding fumes. The processes examined were gas metal arc welding (GMAW) (axial spray, short circuit, and pulsed spray modes), flux cored arc welding (FCAW), and shielded metal arc welding (SMAW). The Cr6+ fractions were measured in the fumes; fume generation rates, Cr6+ generation nates, and Cr6+ generation rates per unit mass of welding wire were determined. A limited controlled comparison study was done in a welding shop including SMAW, FCAW, and three GMAW methods. The processes studied were compared for costs, including relative labor costs. Results indicate the Cr6+ in the fume varied widely, from a low of 2800 to a high of 34,000 ppm. Generation rates of Cr6+ ranged from 69 to 7800 mcg/min, and Cr6+ generation rates per unit of wire ranged from 1 to 270 mcg/g. The results of field study were similar to the findings in the laboratory. The Cr6+ (ppm) in the fume did not necessarily correlate with the Cr6+ generation rate. Physical properties were similar for the processes, with mass median aerodynamic diameters ranging from 250 to 336 nm, while the FCAW and SMAW fumes were larger (360 and 670 nm, respectively). CONCLUSION: The pulsed axial spray method was the best choice of the processes studied based on minimal fume generation, minimal Cr6+ generation, and cost per weld. This method is usable in any position, has a high metal deposition rate, and is relatively simple to learn and use. |
Action Learning: a new method to increase tractor rollover protective structure (ROPS) adoption
Biddle EA , Keane PR . J Agromedicine 2012 17 (4) 398-409 Action Learning is a problem-solving process that is used in various industries to address difficult problems. This project applied Action Learning to a leading problem in agricultural safety. Tractor overturns are the leading cause of fatal injury to farmworkers. This cause of injury is preventable using rollover protective structures (ROPS), protective equipment that functions as a roll bar structure to protect the operator in the event of an overturn. For agricultural tractors manufactured after 1976 and employee operated, Occupational Safety and Health Administration (OSHA) regulation requires employers to equip them with ROPS and seat belts. By the mid-1980s, US tractor manufacturers began adding ROPS on all farm tractors over 20 horsepower sold in the United States (http://www.nasdonline.org/document/113/d001656/rollover-protection-for-farm-tract or-operators.html). However, many older tractors remain in use without ROPS, putting tractor operators at continued risk for traumatic injury and fatality. For many older tractor models ROPS are available for retrofit, but for a variety of reasons, tractor owners have not chosen to retrofit those ROPS. The National Institute for Occupational Safety and Health (NIOSH) attempted various means to ameliorate this occupational safety risk, including the manufacture of a low-cost ROPS for self-assembly. Other approaches address barriers to adoption. An Action Learning approach to increasing adoption of ROPS was followed in Virginia and New York, with mixed results. Virginia took action to increase the manufacturing and adoption of ROPS, but New York saw problems that would be insurmountable. Increased focus on team composition might be needed to establish effective Action Learning teams to address this problem. |
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