Occupational exposure to air pollutants: particulate matter and respiratory symptoms affecting traffic-police in bogotá

Objectives Quantifying personal exposure to particles less than 10 micrometres in diameter (PM10) and determining the prevalence of respiratory symptoms in trafficpolice officers working in Bogotá’s metropolitan area.Methods This was a cross-sectional study of 574 traffic-police officers divided into two groups (477 traffic-police and 97 police working in an office). They were given a questionnaire inquiring about respiratory symptoms, toxicological medical evaluation, lung unction tests and personal PM10 monitoring. The differences between groups were found using stratified analysis (i.e. comparing odds ratios). Multivariate analysis of factors related to symptoms and diagnosis of respiratory alteration was also performed.Results Respiratory symptoms concerned a higher prevalence of cough, expectoration and rhinosinusitis in the traffic-police group. Medical examination revealed that the traffic-police group had higher nasal irritation prevalence; lung function tests showed no difference. Mean PM10 levels were higher for the trafficpolice group (139.4 μg/m3), compared to the office work group (86.03 μg/m3).Discussion PM10 values in both groups did not exceed allowable limits for respirable particles in the workplace according to ACGIH standards. Traffic-police exposed to air pollution had an increased risk of developing respiratory symptoms and signs, thereby agreeing with the results of this and other studies. Personal monitoring is a valuable tool when quantifying the concentration of PM10 to whichan individual has been exposed during a normal workday. This study contributes towards further research in to the effects of PM10 in populations at risk

Evaluacion del sistema de información del desempeño en el Hospital Regional de Talca

127 p.La presente investigación tiene por objeto realizar un análisis del sistema de evaluación del desempeño utilizado actualmente por el Hospital Regional de Talca, en cuanto a los resultados que arroja y la forma en que se realiza. Para ello se procedió a tomar datos históricos desde el inicio del proceso califica torio en 1991, que según el diagnostico realizado, demostraron estar altamente sesgados, con mas de un 90% de los funcionarios calificados con notas 6 y 7. Esto llevo a indagar en los problemas de implementación del sistema, que permitieran establecer relaciones de causa efecto para explicar el por que de las notas tan elevadas, encontrándose que existen falencias en la capacitaci6n de los evaluadores, definiciones vagas de los subfactores del desempeño, y la presencia de los cinco errores que puede cometer un evaluador en su juicio contra un evaluado, de los cuales el mas importante es el efecto de razones subconscientes. Junto con lo anterior, se procedió a objetivizar la- herramienta de calificación, definiendo mas específicamente los subfactores sujetos a evaluación, mediante tres métodos de evaluación. Sin embargo, debido a las características de los puestos de trabajo de la institución hospitalaria, no es posible llegar a una objetivizacion total de las variables o conceptos que determinan el desempeño, pero sin duda se logro un claro avance en la especificación y comprensión de dichos subfactores

GAPS-megacities: A new global platform for investigating persistent organic pollutants and chemicals of emerging concern in urban air

A pilot study was initiated in 2018 under the Global Atmospheric Passive Sampling (GAPS) Network named GAPS-Megacities. This study included 20 megacities/major cities across the globe with the goal of better understanding and comparing ambient air levels of persistent organic pollutants and other chemicals of emerging concern, to which humans residing in large cities are exposed. The first results from the initial period of sampling are reported for 19 cities for several classes of flame retardants (FRs) including organophosphate esters (OPEs), polybrominated diphenyl ethers (PBDEs), and halogenated flame retardants (HFRs) including new flame retardants (NFRs), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDD). The two cities, New York (USA) and London (UK) stood out with ∼3.5 to 30 times higher total FR concentrations as compared to other major cities, with total concentrations of OPEs of 15,100 and 14,100 pg/m3, respectively. Atmospheric concentrations of OPEs significantly dominated the FR profile at all sites, with total concentrations in air that were 2-5 orders of magnitude higher compared to other targeted chemical classes. A moderately strong and significant correlation (r = 0.625, p < 0.001) was observed for Gross Domestic Product index of the cities with total OPEs levels. Although large differences in FR levels were observed between some cities, when averaged across the five United Nations regions, the FR classes were more evenly distributed and varied by less than a factor of five. Results for Toronto, which is a "reference city" for this study, agreed well with a more in-depth investigation of the level of FRs over different seasons and across eight sites representing different urban source sectors (e.g. traffic, industrial, residential and background). Future sampling periods under this project will investigate trace metals and other contaminant classes, linkages to toxicology, non-targeted analysis, and eventually temporal trends. The study provides a unique urban platform for evaluating global exposome.Fil: Saini, Amandeep. Environment and Climate Change; CanadáFil: Harner, Tom. Environment and Climate Change; CanadáFil: Chinnadhurai, Sita. Environment and Climate Change; CanadáFil: Schuster, Jasmin K.. Environment and Climate Change; CanadáFil: Yates, Alan. Environment and Climate Change; CanadáFil: Sweetman, Andrew. Lancaster Environment Centre; Reino UnidoFil: Aristizabal Zuluaga, Beatriz H.. Universidad Nacional de Colombia; ColombiaFil: Jiménez, Begoña. Consejo Superior de Investigaciones Científicas; EspañaFil: Manzano, Carlos A.. Universidad de Chile; ChileFil: Gaga, Eftade O.. Eskisehir Technical University; TurquíaFil: Stevenson, Gavin. National Measurement Institute; AustraliaFil: Falandysz, Jerzy. Uniwersytet Gdanski; PoloniaFil: Ma, Jianmin. Peking University; ChinaFil: Miglioranza, Karina Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Kannan, Kurunthachalam. Nyu Grossman School Of Medicine; Estados UnidosFil: Tominaga, Maria. Sao Paulo State Environmental Company; BrasilFil: Jariyasopit, Narumol. No especifíca;Fil: Rojas, Nestor Y.. Universidad Nacional de Colombia; ColombiaFil: Amador-Muñoz, Omar. Universidad Nacional Autónoma de México; MéxicoFil: Sinha, Ravindra. Patna University; IndiaFil: Alani, Rose. University of Lagos; NigeriaFil: Suresh, R.. No especifíca;Fil: Nishino, Takahiro. Tokyo Metropolitan Research Institute for Environmental Protection; JapónFil: Shoeib, Tamer. American University In Cairo; Egipt

Native diversity buffers against severity of non-native tree invasions

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species$^{1,2}$. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies$^{3,4}$. Here, leveraging global tree databases$^{5,6,7}$, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions

The global biogeography of tree leaf form and habit.

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling

Native diversity buffers against severity of non-native tree invasions.

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5-7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions

Evenness mediates the global relationship between forest productivity and richness

1. Biodiversity is an important component of natural ecosystems, with higher species richness often correlating with an increase in ecosystem productivity. Yet, this relationship varies substantially across environments, typically becoming less pronounced at high levels of species richness. However, species richness alone cannot reflect all important properties of a community, including community evenness, which may mediate the relationship between biodiversity and productivity. If the evenness of a community correlates negatively with richness across forests globally, then a greater number of species may not always increase overall diversity and productivity of the system. Theoretical work and local empirical studies have shown that the effect of evenness on ecosystem functioning may be especially strong at high richness levels, yet the consistency of this remains untested at a global scale. 2. Here, we used a dataset of forests from across the globe, which includes composition, biomass accumulation and net primary productivity, to explore whether productivity correlates with community evenness and richness in a way that evenness appears to buffer the effect of richness. Specifically, we evaluated whether low levels of evenness in speciose communities correlate with the attenuation of the richness–productivity relationship. 3. We found that tree species richness and evenness are negatively correlated across forests globally, with highly speciose forests typically comprising a few dominant and many rare species. Furthermore, we found that the correlation between diversity and productivity changes with evenness: at low richness, uneven communities are more productive, while at high richness, even communities are more productive. 4. Synthesis. Collectively, these results demonstrate that evenness is an integral component of the relationship between biodiversity and productivity, and that the attenuating effect of richness on forest productivity might be partly explained by low evenness in speciose communities. Productivity generally increases with species richness, until reduced evenness limits the overall increases in community diversity. Our research suggests that evenness is a fundamental component of biodiversity–ecosystem function relationships, and is of critical importance for guiding conservation and sustainable ecosystem management decisions

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cyclin