Filterable PM2.5 concentrations and their chemical characterizations were analyzed for 67 boilers and 25 indirect furnaces located in the Metropolitan Area of Costa Rica from February 2014 to November 2015. The PM2.5 samples were characterized by their composition, focusing on trace elements, inorganic ions and organic and elemental carbon. The results of PM2.5 concentrations ranged from 72 to 735 mgm-3, with the highest concentrations found for sources using biomass fuel, particularly Type B boilers, and the lowest values for diesel boilers. Further speciation of fine particulate matter (PM) showed significant levels of vanadium and nickel for boilers that use heavy fuel oil (bunker); 4886 and 1942 μgm-3, respectively. Copper and manganese were the most relevant metals for biomass burning sources, due to plant absorption from the soil. As for ion concentration, sulfate presented the highest concentrations for biomass boilers and furnaces, whereas chloride only presented the highest concentrations for furnaces. To complete the balance, organic and elemental carbon (OC and EC) analyses were made, in which biomass burning sources presented values five times higher than oil fuels. A Spearman's correlation analysis was made for the data set, revealing significant relationships between heavy metals, sulfate, and fine PM with respect to heavy fuel oil. For the biomass sources, the correlations pointed to K, Na, Mn and, in some cases, oxygen. | Se analizaron las concentraciones filtrables de PM2.5 y sus caracterizaciones químicas para 67 calderas y 25 hornos indirectos ubicados en el Área Metropolitana de Costa Rica desde febrero de 2014 hasta noviembre de 2015. Las muestras de PM2.5 se caracterizaron por su composición, centrándose en oligoelementos, iones inorgánicos y carbono orgánico y elemental. Los resultados de las concentraciones de PM2.5 variaron de 72 a 735 mgm-3, con las concentraciones más altas encontradas para fuentes que utilizan combustible de biomasa, particularmente calderas Tipo B, y el valores más bajos para calderas diesel. Una mayor especiación de partículas finas (PM) mostró una significativa niveles de vanadio y níquel para calderas que utilizan fuel oil pesado (bunker); 4886 y 1942 mgm-3, respectivamente. El cobre y el manganeso fueron los metales más relevantes para las fuentes de combustión de biomasa, debido a Absorción de plantas del suelo. En cuanto a la concentración de iones, el sulfato presentó las mayores concentraciones para calderas y hornos de biomasa, mientras que el cloruro solo presentó las concentraciones más altas para los hornos. Para completar el balance, se realizaron análisis de carbono orgánico y elemental (OC y EC), en los cuales las fuentes de combustión de biomasa presentaron valores cinco veces superiores a los combustibles derivados del petróleo. La correlación de Spearman. Se realizó un análisis para el conjunto de datos, revelando relaciones significativas entre metales pesados, sulfato y PM fino con respecto al fuelóleo pesado. Para las fuentes de biomasa, las correlaciones apuntaron a K, Na, Mn y, en algunos casos, oxígeno. | As concentrações filtráveis ​​de PM2,5 e suas caracterizações químicas foram analisadas para 67 caldeiras e 25 fornos indiretos localizados na Região Metropolitana da Costa Rica de fevereiro de 2014 a novembro de 2015. As amostras de PM2,5 foram caracterizadas por sua composição, com foco em oligoelementos, íons inorgânicos e carbono orgânico e elementar. Os resultados para as concentrações de PM2,5 variaram de 72 a 735 mgm-3, com as concentrações mais altas encontradas para fontes que usam combustível de biomassa, particularmente caldeiras Tipo B, e os valores mais baixos para caldeiras a diesel. A maior especiação de partículas finas (PM) mostrou níveis significativos de vanádio e níquel para caldeiras que usam óleo combustível pesado (bunker); 4886 e 1942 mgm-3, respectivamente. O cobre e o manganês foram os metais mais relevantes para as fontes de combustão da biomassa, devido à absorção das plantas do solo. Em relação à concentração de íons, o sulfato apresentou as maiores concentrações para caldeiras e fornos a biomassa, enquanto o cloreto apresentou as maiores concentrações apenas para os fornos. Para completar o balanço, foram realizadas análises de carbono orgânico e elementar (OC e EC), nas quais as fontes de combustão de biomassa apresentaram valores cinco vezes maiores que os combustíveis derivados do petróleo. A correlação de Spearman. Uma análise foi realizada para o conjunto de dados, revelando relações significativas entre metais pesados, sulfato e MP fino em relação ao óleo combustível pesado. Para fontes de biomassa, as correlações apontaram para K, Na, Mn e, em alguns casos, oxigênio. | Universidad Nacional, Costa Rica | Universidad Autónoma Metropolitana, México | Escuela de Ciencias Ambientales

Polycyclic aromatic hydrocarbons (PAHs) concentrations in PM10 and PM2.5 particles were measured at 14 monitoring sites (12 for PM10 and 2 for PM2.5), located in the Metropolitan Area of Costa Rica, from January to November 2013. High-volume air samplers with pretreated quartz filters were used to collect the particles. The analytical determination was carried out using high-performance liquid chromatography (HPLC). The most abundant PAHs were benzo[a]anthracene, indeno(1,2,3-cd)pyrene, dibenz[a,h]anthracene and acenaphthylene. Ratios obtained by correlating the concentration of some PAHs, both PM10 and PM2.5, suggest that gasoline and diesel vehicles are the main sources in the area being studied. This is consistent with the results obtained when applying the positive matrix factorization (PMF) analysis, since vehicles accounted for 62–74% of total emissions in the area; burning wood fuel was the second source of emissions, contributing between 7 and 15%; and road dust was third, with almost 8%. | Se midieron las concentraciones de hidrocarburos aromáticos policíclicos (HAP) en partículas PM10 y PM2.5 en 14 sitios de monitoreo (12 para PM10 y 2 para PM2.5), ubicados en el Área Metropolitana de Costa Rica, de enero a noviembre de 2013. Alto volumen Se utilizaron muestreadores de aire con filtros de cuarzo pretratados para recoger las partículas. La determinación analítica se realizó mediante cromatografía líquida de alta resolución (HPLC). Los HAP más abundantes fueron benzo [a] antraceno, indeno (1,2,3-cd) pireno, dibenz [a, h] antraceno y acenaftileno. Los ratios obtenidos al correlacionar la concentración de algunos HAP, tanto de PM10 como de PM2,5, sugieren que los vehículos de gasolina y diésel son las principales fuentes en el área de estudio. Esto es consistente con los resultados obtenidos al aplicar el análisis de factorización matricial positiva (PMF), ya que los vehículos representaron 62-74% de las emisiones totales en el área; la quema de leña fue la segunda fuente de emisiones, contribuyendo entre el 7 y el 15%; y el polvo de la carretera ocupó el tercer lugar, con casi el 8%. | Universidad Nacional, Costa Rica | Laboratorio de Análisis Ambiental. Facultad de Ciencias Ambientales. Universidad Nacional, Costa Rica

This study analyzed the profiles of polycyclic aromatic hydrocarbons (PAHs) in filterable PM2.5 particles collected from a total of 71 boilers and 22 indirect type furnaces that burn liquid and biomass fuels in the Metropolitan Area of Costa Rica, from February 2014 to November 2015. Modified method NIOSH 5506 was used to analyze PAHs content present in the filter samples. The average concentration of PM2.5 showed values between 18 and 735 mg m−3, based on the source and fuel type used, while the total PAHs in the PM2.5 fraction ranged 1.02–592 μgm−3. For biomass boilers, the most abundant species were Benzo[g,h,i]perylene (BghiP) (35.7–46.5%), Indeno[1,2,3-cd]pyrene (IND) (20.6–27.1%), Benzo[a]pyrene (BaP) (5.2–14.7%) and Dibenzo[a,h]anthracene (DBA) (3.2–13.9%), while for liquid fuels IND (12.8–20.5%), BghiP (7.9–21.2%), Fluoranthene (Flu) (14.5–21.3%) and Pyrene (Pyr) (9.8–14.5%) prevailed. The particles from biomass furnace emissions present higher concentrations of PAHs classified by the U.S. EPA as probable human carcinogens causing a greater health risk than other fuels. Among the diagnostic concentration ratios examined, only BaP/(BaP+Chr), BaA/Chr, BaA/BaP and Pyr/BaP coefficients demonstrated codependency on the type of fuel used. | Este estudio analizó los perfiles de hidrocarburos aromáticos policíclicos (HAP) en partículas filtrables PM2.5 recolectadas de un total de 71 calderas y 22 hornos de tipo indirecto que queman combustibles líquidos y de biomasa en el Área Metropolitana de Costa Rica, de febrero de 2014 a noviembre de 2015 Se utilizó el método modificado NIOSH 5506 para analizar el contenido de PAH presentes en las muestras de filtro. La concentración promedio de PM2.5 mostró valores entre 18 y 735 mg m − 3, según la fuente y el tipo de combustible utilizado, mientras que los PAH totales en la fracción de PM2.5 variaron entre 1.02 y 592 μgm − 3. Para las calderas de biomasa, las especies más abundantes fueron Benzo [g, h, i] perileno (BghiP) (35,7–46,5%), Indeno [1,2,3-cd] pireno (IND) (20,6–27,1%), Benzo [a] pireno (BaP) (5,2–14,7%) y Dibenzo [a, h] antraceno (DBA) (3,2–13,9%), mientras que para los combustibles líquidos IND (12,8–20,5%), BghiP (7,9–21,2%) , Predominaron el fluoranteno (gripe) (14,5–21,3%) y el pireno (Pyr) (9,8–14,5%). Las partículas de las emisiones de los hornos de biomasa presentan concentraciones más altas de HAP clasificados por la EPA de los EE. UU. Como probables carcinógenos humanos y causan un mayor riesgo para la salud que otros combustibles. Entre las relaciones de concentración de diagnóstico examinadas, solo los coeficientes BaP / (BaP + Chr), BaA / Chr, BaA / BaP y Pyr / BaP demostraron codependencia en el tipo de combustible utilizado. | Este estudo analisou os perfis de hidrocarbonetos policíclicos aromáticos (PAHs) em partículas filtráveis ​​de PM2,5 coletadas de um total de 71 caldeiras e 22 fornos do tipo indireto que queimam combustíveis líquidos e de biomassa na Área Metropolitana da Costa Rica, de fevereiro de 2014 a novembro de 2015 O método modificado NIOSH 5506 foi usado para analisar o conteúdo de PAHs presentes nas amostras de filtro. A concentração média de PM2,5 apresentou valores entre 18 e 735 mg m − 3, com base na fonte e no tipo de combustível usado, enquanto o total de PAHs na fração PM2,5 variou de 1,02–592 μgm − 3. Para caldeiras de biomassa, as espécies mais abundantes foram Benzo [g, h, i] perileno (BghiP) (35,7-46,5%), Indeno [1,2,3-cd] pireno (IND) (20,6-27,1%), Benzo [a] pireno (BaP) (5,2–14,7%) e Dibenzo [a, h] antraceno (DBA) (3,2–13,9%), enquanto que para combustíveis líquidos IND (12,8–20,5%), BghiP (7,9–21,2%) , Fluoranteno (Flu) (14,5–21,3%) e Pireno (Pyr) (9,8–14,5%) prevaleceram. As partículas das emissões do forno de biomassa apresentam maiores concentrações de PAHs classificados pela U.S. EPA como prováveis ​​carcinógenos humanos, causando um maior risco à saúde do que outros combustíveis. Dentre as razões de concentração diagnósticas examinadas, apenas os coeficientes BaP / (BaP + Chr), BaA / Chr, BaA / BaP e Pyr / BaP demonstraram co-dependência do tipo de combustível utilizado. | Universidad Nacional, Costa Rica | Universidad Autónoma Metropolitana, México | Escuela de Ciencias Ambientales

A number of methods have been reported for determining hydrophobic organic compound adsorption to dispersed carbon nanotubes (CNTs), but their accuracy and reliability remain uncertain. We have evaluated three methods to investigate the adsorption of phenanthrene (a model polycyclic aromatic hydrocarbon; PAH) to CNTs with different physicochemical properties; dialysis tube (DT) protected negligible depletion solid phase microextraction (DT-nd-SPME), ultracentrifugation and filtration using various types of filters. Dispersed CNTs adhered to the unprotected PDMS-coated fibers used in nd-SPME. Protection of the fibers from CNT adherence was investigated with hydrophilic DT, but high PAH sorption to the DT was observed. The efficiency of ultracentrifugation and filtration to separate CNTs from the water phase depended on CNT physicochemical properties. While non-functionalized CNTs were efficiently separated from the water phase using ultracentrifugation, incomplete separation of carboxyl functionalized CNTs was observed. Filtration efficiency varied with different filter types (composition and pore size), and non-functionalized CNTs were more easily separated from the water phase than functionalized CNTs. Sorption of phenanthrene was high (<70%) for three of the filters tested, making them unsuitable for the assessment of phenanthrene adsorption to CNTs. Filtration using a hydrophilic polytetrafluoroethylene (PTFE) filter membrane (0.1 µm) was found to be a simple and precise technique for the determination of phenanthrene adsorption to a range of CNTs, efficiently separating all types of CNTs and exhibiting a good and highly reproducible recovery of phenanthrene (82%) over the concentration range tested (70-735 µg/L). | acceptedVersion

International audience

Contamination of aquatic ecosystems is considered as one of the main threats to global freshwater biodiversity. Within the European Water Framework Directive (EU-WFD) a particular attention is dedicated to assess ecological risks of surface water contamination and mitigation of chemical pressures on aquatic ecosystems. In this work, we evaluated ecological risks of surface water contamination for fish populations in four EU-WFD rivers through an integrative approach investigating three Lines of Evidence (chemical contamination, biomarker responses as early warning signals of contamination impacting individuals and ecological analyses as an indicator of fish community disturbances). This work illustrates through 4 case studies the complementary role of biomarkers, chemical and ecological analyses which, used in combination, provide fundamental information to understand impacts of chemical pressures that can affect fish population dynamics. We discuss the limitations of this approach and future improvements needed within the EU-WFD to assess ecological risk of river contamination for fish populations.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE | International audience | In typical life cycle impact assessment (LCIA) studies of urban wastewater systems (UWS), average conditions are modelled but there are many annual flooding events with releases of raw sewage. Such peak conditions are not considered and present a high temporal variability which is not currently accounted for. In addition, the aggregation of the loads from several storm events could bring an issue for the impact assessment on the aquatic categories of eutrophication and ecotoxicity. Hence we are investigating the contributions of these wet weather-induced discharges along with the inclusion of temporal variability in the life cycle inventory (LCI) for UWS.