[Cases of COVID-19 in relation to environmental parameters in five departments of Catamarca province, Argentina]. / Casos de COVID-19 en relación con parámetros ambientales en cinco departamentos de la provincia de Catamarca, Argentina.

INTRODUCTION: The aim of the study was to investigate the relationship between the number of positive cases of COVID-19 and the environmental parameters of temperature and humidity in five departments of the province of Catamarca, Argentina. METHODS: The departments Capital, Andalgalá, Paclín, Ambato and Tinogasta, Catamarca, Argentina, were studied. Between April 2021 and April 2022 variables analyzed were: number of COVID-19 cases, temperature, and percentage of environmental humidity. The correlation of variables was analyzed by the coefficient of Spearman. RESULTS: The temperature with the numbers of COVID-19 cases show inverse correlation values that ranged between -0.56 and -0.34. The humidity percentages show a slightly positive relationship only for Capital and Andalgalá, with values of 0.34 and 0.40 with the number of cases. CONCLUSION: The results showed a relationship between the number of positive cases of COVID-19 and the environmental parameters of temperature and humidity in five departments in the province of Catamarca.

Introducción: El objetivo del trabajo fue estudiar la relación entre el número de casos positivos de COVID-19 y los parámetros ambientales de temperatura y humedad en cinco departamentos de la provincia de Catamarca. Métodos: Los departamentos estudiados fueron Capital, Andalgalá, Paclín, Ambato y Tinogasta, Catamarca, Argentina. Las variables número de casos COVID-19, temperatura y porcentaje de humedad ambiental fueron obtenidos entre abril de 2021 y abril de 2022. La correlación de variables se analizó mediante el coeficiente de Spearman. Resultados: La temperatura, en relación con los nú- meros de casos por COVID-19 mostró valores de correlación inversa que oscilaron entre -0.56 y -0.34. El porcentaje de humedad, indicó una relación levemente positiva con el número de casos solo para Capital y Andalgalá con valores de 0.34 y 0.40. Conclusión: Los resultados muestran una relación entre el número de casos positivos de COVID-19 y los parámetros ambientales de temperatura y humedad en cinco departamentos de la provincia de Catamarca.

Casos de COVID-19 en relación con parámetros ambientales en cinco departamentos de la provincia de Catamarca, Argentina / Cases of COVID-19 in relation to environmental parameters in five departments of Catamarca province, Argentina

Resumen Introducción : El objetivo del trabajo fue estudiar la relación entre el número de casos positivos de CO VID-19 y los parámetros ambientales de temperatura y humedad en cinco departamentos de la provincia de Catamarca. Métodos : Los departamentos estudiados fueron Ca pital, Andalgalá, Paclín, Ambato y Tinogasta, Catamarca, Argentina. Las variables número de casos COVID-19, temperatura y porcentaje de humedad ambiental fueron obtenidos entre abril de 2021 y abril de 2022. La corre lación de variables se analizó mediante el coeficiente de Spearman. Resultados : La temperatura, en relación con los nú meros de casos por COVID-19 mostró valores de co rrelación inversa que oscilaron entre -0.56 y -0.34. El porcentaje de humedad, indicó una relación levemente positiva con el número de casos solo para Capital y Andalgalá con valores de 0.34 y 0.40. Conclusión : Los resultados muestran una relación entre el número de casos positivos de COVID-19 y los parámetros ambientales de temperatura y hu medad en cinco departamentos de la provincia de Catamarca.

Abstract Introduction : The aim of the study was to investi gate the relationship between the number of positive cases of COVID-19 and the environmental parameters of temperature and humidity in five departments of the province of Catamarca, Argentina. Methods : The departments Capital, Andalgalá, Paclín, Ambato and Tinogasta, Catamarca, Argentina, were stud ied. Between April 2021 and April 2022 variables analyzed were: number of COVID-19 cases, temperature, and per centage of environmental humidity. The correlation of variables was analyzed by the coefficient of Spearman. Results : The temperature with the numbers of CO VID-19 cases show inverse correlation values that ranged between -0.56 and -0.34. The humidity percentages show a slightly positive relationship only for Capital and Andal galá, with values of 0.34 and 0.40 with the number of cases. Conclusion : The results showed a relationship be tween the number of positive cases of COVID-19 and the environmental parameters of temperature and humidity in five departments in the province of Catamarca.

Characterizing Meat- and Milk/Dairy-like Vegetarian Foods and Their Counterparts Based on Nutrient Profiling and Food Labels.

Vegetarian foods are plant-based (PB) foods, often perceived as healthier foods than animal-based (AB) foods. The objective of this study was to analyze the nutritional quality of a set of PB foods (meat, milk and dairy products) marketed in Spain, and to compare their nutrient profiles with respect to some AB counterparts. Nutritional information per 100 g or mL, ingredients, and nutritional declarations, as well as the Nutri-Score, NOVA, and Eco-Score of each food were collected from Open Food Facts. Differences in the nutrient compositions between PB foods and their counterparts, and between the different groups of PB foods, were assessed at a 5% significance level. A total of 544 PB foods and 373 AB foods were identified. Overall, PB foods had a higher median content of fiber and carbohydrates, but a lower amount of proteins (except PB "meat" analogues: 14 g) and saturated fats (except PB "cheese alternatives": 12.5 g), than the AB counterparts (p < 0.05). PB "milk alternatives", particularly oat "milk", showed a higher median content of total carbohydrates (8 g) and sugars (5.5 g) compared to cow milks (4.7 g carbohydrates/sugars, on average; p < 0.001). PB "meat alternatives" also had a significantly higher value of carbohydrates (9 g) than AB meats (2 g, on average; p < 0.001). PB foods were mostly classified as Nutri-Score A and B (86%). However, more than half of them were of NOVA groups 3 and 4. Thus, there is a great diversity of PB meat and milk/dairy product alternatives on the Spanish market. Despite being products of good nutritional quality compared to AB foods, they also carry drawbacks that could have an impact on nutritional health.

Chemical Speciation and Leaching Behavior of Hazardous Trace Elements in Coal Combustion Products from Coal-Fired Power Stations in China.

This paper reports on the chemical speciation and leaching behavior of a selected group of hazardous trace pollutants in lignite and lignite-petcoke blend co-combustion products from three power stations in China. The evaluation of speciation results showed that, during combustion, oxidizable elements, mainly As and Mo, bound to organic matter and sulfides in coals were mostly transferred to easily water-soluble forms or to slightly acidic states in the ashes. This manner was the most readily bioavailable condition for such an environment. The evaluation of the leaching results shows that the use of petroleum coke as co-fuel has an impact on the ash composition and on the leaching behavior of some inorganic trace pollutants such as Mo and V. The leaching results compared to the European waste acceptance criteria for landfills reveal that the Mo and As' leaching yield brand the coal combustion products as materials that necessitate preventative measures to reduce their potential leaching. Future work will be focused on the application of our novel chemical stabilization method to these coal ashes to reduce the mobility of elements such as Mo and As, and other potentially leachable elements, and on the use of the resulting ash with aggregate products as a substitute for concrete production.

Geochemistry and oxidative potential of the respirable fraction of powdered mined Chinese coals.

This study evaluates geochemical and oxidative potential (OP) properties of the respirable (finer than 4 µm) fractions of 22 powdered coal samples from channel profiles (CP4) in Chinese mined coals. The CP4 fractions extracted from milled samples of 22 different coals were mineralogically and geochemically analysed and the relationships with the OP evaluated. The evaluation between CP4/CP demonstrated that CP4 increased concentrations of anatase, Cs, W, Zn and Zr, whereas sulphates, Fe, S, Mo, Mn, Hf and Ge decreased their CP4 concentrations. OP results from ascorbic acid (AA), glutathione (GSH) and dithiothreitol (DTT) tests evidenced a clear link between specific inorganic components of CP4 with OPAA and the organic fraction of OPGSH and OPDTT. Correlation analyses were performed for OP indicators and the geochemical patterns of CP4. These were compared with respirable dust samples from prior studies. They indicate that Fe (r = 0.83), pyrite (r = 0.66) and sulphate minerals (r = 0.42) (tracing acidic species from pyrite oxidation), followed by S (r = 0.50) and ash yield (r = 0.46), and, to a much lesser extent, Ti, anatase, U, Mo, V and Pb, are clearly linked with OPAA. Moreover, OPGSH correlation was identified by organic matter, as moisture (r = 0.73), Na (r = 0.56) and B (r = 0.51), and to a lesser extent by the coarse particle size, Ca and carbonate minerals. In addition, Mg (r = 0.70), B (r = 0.47), Na (r = 0.59), Mn, Ba, quartz, particle size and Sr regulate OPDTT correlations. These became more noticeable when the analysis was done for samples of the same type of coal rank, in this case, bituminous.

Evaluation of chemical stabilisation methods of coal-petcoke fly ash to reduce the mobility of Mo and Ni against environmental concerns.

Reducing the potential leaching of Mo and Ni from the fly ash (FA) of petroleum coke is an increasingly important issue as Asia and Europe's demand is expected to drastically intensify as continuing urbanisation and technological innovation demands ever more electricity. In the present study, we investigated coal combustion products (CCP) from a large coal-fired power station fed with a 56:44 coal/petroleum coke blend. Results revealed that leachable concentrations of Mo and Ni from FA were in the upper non-hazardous limit and in the inert limit, respectively (2003/33/EC). Whilst common prevention measures for Mo and Ni based on the adsorption capacity of boiler slag (BS), a mixture of BS: goethite, and jarosite, were considered insufficient to reduce the potential leaching of Mo into FA leachates, a novel chemical stabilisation method based on an aggregate product of portlandite and FA immobilised both Mo and Ni such that the resulting concentrations were below the limits established in the abovementioned 2003 EC Decision. Precipitation may be responsible for the fixation of Mo and Ni in the FA: portlandite aggregates as Ca(MoO4) and NiMoO4, respectively. The findings of this novel study support the use of this aggregate to reduce FA pollutants, which will be of particular interest to nations that remain largely coal/petroleum coke-dependant.

Mineralogy, geochemistry and toxicity of size-segregated respirable deposited dust in underground coal mines.

We focus on a comparison of the geochemistry and mineralogy patterns found in coal, deposited dust (DD), respirable deposited dust (RDD) and inhalable suspended dust (PM10) from a number of underground mines located in China, with an emphasis on potential occupational health relevance. After obtaining the RDD from DD, a toxicological analysis (oxidative potential, OP) was carried out and compared with their geochemical patterns. The results demonstrate: i) a dependence of RDD/DD on the moisture content for high rank coals that does not exist for low rank coals; ii) RDD enrichment in a number of minerals and/or elements related to the parent coal, the wear on mining machinery, lime gunited walls and acid mine drainage; and iii) the geochemical patterns of RDD obtained from DD can be compared with PM10 with relatively good agreement, demonstrating that the characterization of DD and RDD can be used as a proxy to help evaluate the geochemical patterns of suspended PM10. With regards to the toxicological properties of RDD, the Fe content and other by-products of pyrite oxidation, as well as that of anatase, along with Si, Mn and Ba, and particle size (among others), were highly correlated with Ascorbic Acid and/or Glutathione OP.

The geochemical evolution of brines from phosphogypsum deposits in Huelva (SW Spain) and its environmental implications.

The present study focuses on the geochemistry of large phosphogypsum deposits in Huelva (SW Spain). Phosphogypsum slurry waste from fertiliser production was disposed in large ponds containing aqueous waste (i.e. brines) and exposed to weathering. These evaporation ponds were found to be dynamic environments far from attaining steady state conditions where a number of trace pollutants are subjected to temporal variations in response to changing environmental conditions. Chemical, mineralogical and morphological data were used to improve our understanding on the dynamics of a large number of elements in the phosphogypsum-brine-evaporation deposits system. Weekly sampling of brines over the course of 1 yr indicated a substantial enrichment in potentially harmful elements (e.g. As, Cr, Cu, F, Ni, U, V, Zn) present in time-dependent concentrations. The evaporation deposits formed multi-layered precipitates of chlorides, sulphates, phosphates and fluorides containing a large number of pollutants in readily soluble forms. The precipitation sequence revealed a time-dependent composition reflecting alternating precipitation and re-dissolution processes associated with seasonal changes in the local weather conditions. Concatenation of precipitation/re-dissolution stages was found to progressively enrich the brines in pollutants. These findings were supported by the observations from a tank experiment simulating the phosphogypsum-brine-evaporation deposits system under laboratory conditions. Given the substantially high concentrations of pollutants present in mobile forms in the brine-salt system, actions to abate these compounds should be implemented.

Overcoming Barriers in the Implementation of Programs for Breast and Cervical Cancers in Cali, Colombia: A Pilot Model.

Breast and cervical cancers are leading causes of mortality among women in Latin America. Colombia has universal health care and a government-sponsored 10-year cancer control plan focused on prevention, early detection, and treatment. However, many administrative and social barriers have hindered its success, and a majority of patients are diagnosed at a late stage. Established in 2012, Partners for Cancer Care and Prevention (PFCCAP) works to decrease the burden of these cancers by mitigating the obstacles women face during their cancer diagnosis and treatment. Through community outreach meetings with medical personnel, hospital directors, and government officials, PFCCAP identified major barriers, including lack of trained health care personnel, few centers with adequate screening equipment, and a fragmented health system with significant administrative delays and poor continuity of care. Its solution included monthly teleconferences, biannual on-site training, quality control programs, and improved access to screening equipment. PFCCAP also initiated a patient navigation project. After implementation of the PFCCAP plan of action, from 2012 to 2018, the average time from initial consult to biopsy decreased from 65 to 20 days; from biopsy to diagnosis, 33 to 4 days; and from diagnosis to surgery, 121 to 60 days. To date, more than 1,500 women have benefited from this initiative, which has expanded to other regions. Overall, PFCCAP is creating centers of excellence in strategically located hospitals and promoting the implementation of national guidelines. Although several barriers still exist, PFCCAP is helping to implement an efficient health care model that can be replicated in other underserved populations.

[Distribution of Rotavirus G Genotypes during 10 years in children with acute diarrhea of the city of La Rioja, Argentina. Implications for vaccination] / Genotipos G de rotavirus durante 10 años en niños con diarrea aguda de la ciudad de La Rioja, Argentina. Implicancias en la vacunación.

Vaccination against rotavirus in Argentina is obligatory from January 2015. From 418 stools in children with acute diarrhea were collected from 2000 to 2010 in city of La Rioja, Argentina, Rotavirus was detected. The 90 rotavirus positive stools samples (21.53%) were amplified by RT-PCR and genotyped by PCR-Mix for G1, G2, G3, G4, G9 and G8. The results show that during 2000-2003, the most frequent genotype was G1 and but since 2008, the G2, G3 and G9 genotypes in single and mixed infections were detected. In La Rioja, the vaccines could prevent dehydration in older children the year but children under one year could be vulnerable to the emergence of strains with genic aberrations due to the implementation of vaccination in our region.

La vacunación para rotavirus es obligatoria en Argentina desde enero del 2015. Los genotipos G de rotavirus circulantes previo a la vacunación no fueron estudiados en la Provincia de La Rioja. El objetivo del presente trabajo fue determinar los genotipos G de rotavirus que circulan en La Rioja en niños con diarrea desde 2000 a 2010. Se determinó la presencia de rotavirus del Grupo A por Inmunocromatografía (Biomerieux) en 418 muestras de materias fecales obtenidas en niños con diarrea aguda, hospitalizados y ambulatorios, en ciudad de La Rioja, Argentina. El 40 % de los niños estudiados provenía del interior de la provincia. Las 90 muestras positivas (21,53%) fueron amplificadas por RT-PCR y genotipificadas por Multiplex-PCR para genotipos G1, G2, G3, G4, G9 y G8. Los resultados muestran que el genotipo más frecuente de2000 a2003 fue G1 pero que desde el 2008 se detectaron los genotipos G2, G3 y G9 en infecciones simples y mixtas. Los genotipos G9 y las infecciones mixta, cuádruple y quíntuple, se presentaron en niños menores de un año de vida. Este es el primer reporte de los genotipos G de rotavirus en La Rioja. Los resultados indican que los genotipos G circulantes de rotavirus son compatibles con los que se dispone en la vacuna aunque la presencia de infecciones mixtas y Genotipo G9 en niños menores de un año sugieren una mayor vulnerabilidad de este grupo para la aparición de cepas con derivas génicas durante la implementación de la vacunación en esta Provincia

Tabaquismo, su relación con la salud bucal en adultos jóvenes de La Rioja, Argentina / Smoking, its relationship with oral health in young adults of La Rioja, Argentina

El tabaquismo es una adicción perjudicial para la salud general y bucal; la nicotina del tabaco estimulala producción de dopamina en el cerebro medio favoreciendo la instalación de la adicción. Desconocemos el estado bucal en los adultos jóvenes que fuman en nuestra provincia. Objetivo: estudiar la salud bucal relacionada con el tabaquismo en adultos jóvenes en estado saludable de La Rioja. Materiales y Métodos: desde febrero de 2015 hasta mayo de 2016 se obtuvo una muestra de 268 adultos, se dividió en grupo Problema y Control, n=134 y ambos grupos se subdividieron en 67 hombres y mujeres respectivamente. Se registraron en la historia clínica: edad, sexo, lugar de nacimiento, estudios, actividad laboral, fuma sí/no, cantidad de cigarrillos diarios, gingivitis, dientes con caries y manchados por nicotina. Diseño observacional de casos y controles, se aplicó ANOVA, Chi cuadrado con p≤0,05. Resultados: En los fumadores prevalece la educación primaria p=0,022, el trabajo en relación de dependencia p= 0,021, gingivitisp=0,009, dientes manchados por nicotina p<0,001, los hombres fuman 10,8±9,1 cigarrillos promedio por día y las mujeres 8,1±7,6. La mujer tiene promedio 4,73 caries y 2,36 dientes extraídos y el hombre 3,79 y 1,19 respectivamente. Conclusiones: En el tabaquismo prevalece: educación primaria, trabajo en relación de dependencia, gingivitis y dientes manchados por nicotina. Los hombres fuman más que las mujeres y las mujeres tienen más piezas extraídas que los hombres. Se debe concientizar a la población de las consecuencias del tabaquismo para la salud bucal.

Smoking is a harmful addiction to health. Tobacco nicotine stimulates the production of dopaminein the middle brain favoring the installation of addiction. We do not know the oral condition in youngadults who smoke in our province. Objective: to study oral health related to smoking in healthy youngadults in La Rioja. Materials and Methods: a sample of 268 adults was obtained from February 2015to May 2016, divided into a Problem and Control group, n=134, and both groups were subdividedinto 67 men and women respectively. They were recorded in the medical history: age, sex, place ofbirth, studies, work activity, smoke yes / no, number of cigarettes per day, gingivitis, teeth with cariesand stained by nicotine. Observational design of cases and controls, ANOVA was applied, Chi squarewith p≤0.05. Results: Predominates in smokers primary education p=0.022, dependency work p=0.021,gingivitis p=0.009, nicotine stained teeth p<0.001, men smoke 10, 8± 9, 1 cigarettes per day and women8,1±7,6. Women has an average of 4.73 caries and the man 3,79 with p=0.029. The women has moreextracted teeth 2,36 than man 1,19; p=0,0255. Conclusions: smoking prevalence: primary education, employee, gingivitis, nicotine stained teeth, men smoke more than women, and women have more extracted teeth than men. The application of law number 7.525 in the province should be strengthenedto preserve the oral health of the population. The population should be made aware of the consequences of smoking for oral health.

Comparison of Antigenic Dominants of VP7 in G9 and G1 Rotavirus Strains Circulating in La Rioja, Argentina, with the Vaccine Strains.

A massive vaccination in Argentina was implemented recently. The antigenic dominants of VP7 in G9 and G1 rotavirus strains, circulating in La Rioja, Argentina with strain vaccines were compared. From 2000 to 2010 in several attention centers of La Rioja, at northwestern Argentina, 418 stool samples from children younger than 5 years old were collected. Ninety were positive by immunochromatography and 51 were genotyped by reverse transcriptase-polymerase chain reaction followed by nested-multiplex polymerase chain reaction (PCR) with type-specific primers. Six G9 strains and four G1 strains were sequenced by MACROGEN Korea. The phylogenetic analysis was conducted in MEGA 6.0. The 940 bp were aligned using CLUSTALW and the tree was inferred using the UPGMA method. The antigenic dominants of VP7, 7-1a, 7-1b, and 7-2 were studied using BioEdit, 7.2.5. In the comparison between G9-lineage III d rotavirus (RV) strains circulating in La Rioja with ROTAVAC vaccine strain, three differences were detected corresponding to 100, 211, and 145 positions. In the comparison between G1-Lineage 1 strains and G1 Rotarix and G1 RotaTeq, three differences were observed in 94, 123, and 217 positions. All these positions were important for the escape to neutralization for study with monoclonal antibody. In conclusion, the differences between the G1 strains in La Rioja, Argentina and the G1 components of the RotaTeq and Rotarix vaccine strains are few, but important for the escape immunologic, and need to be monitored for appropriate evaluation of long-term impact of vaccine used in Argentina. Nevertheless, the VP7 antigenic regions of G9 RV strains circulating in La Rioja and ROTAVAC vaccine strains are different to other zones of Argentina and could play an important role in the failure of vaccine response in these regions and Argentina.

Estudio de infestación de caninos con Echinococcus granulosus en la provincia de La Rioja, Argentina / Study of infestatioon of dogs with Echinococcus granulosus in the province of La Rioja, Argentina

Este trabajo fue realizado en la provincia de La Rioja, ubicada en el noroeste argentino. El objetivo fue estimar el porcentaje de heces de caninos con presencia de antígenos de Echinococcus sp. en las distintas regiones de la provincia. Se tomaron un total de 269 muestras de materia fecal seca de caninos, que fueron analizadas por la técnica de copro-ELISA. La zona más afectada fue la zona IV, que contó con un 30,5% de muestras positivas. La zona I, que corresponde al Departamento Capital, tuvo un 12% de positividad. En el resto de las zonas, los porcentajes variaron entre el 11,4 y el 14,8%. Este es el primer estudio en la provincia sobre la existencia de la enfermedad en caninos. La falta de estrategias para el control de la equinococosis ha permitido la dispersión de la enfermedad

This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis

[Study of infestation of dogs with Echinococcus granulosus in the province of La Rioja, Argentina]. / Estudio de infestación de caninos con Echinococcus granulosus en la provincia de La Rioja, Argentina.

This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis.

Speciation, behaviour, and fate of mercury under oxy-fuel combustion conditions.

The work presented here reports the first study in which the speciation, behaviour and fate of mercury (Hg) have been evaluated under oxy-fuel combustion at the largest oxy-Pulverised Coal Combustion (oxy-PCC) demonstration plant to date during routine operating conditions and partial exhaust flue gas re-circulation to the boiler. The effect of the CO2-rich flue gas re-circulation on Hg has also been evaluated. Results reveal that oxy-PCC operational conditions play a significant role on Hg partitioning and fate because of the continuous CO2-rich flue gas re-circulations to the boiler. Mercury escapes from the cyclone in a gaseous form as Hg(2+) (68%) and it is the prevalent form in the CO2-rich exhaust flue gas (99%) with lower proportions of Hg(0) (1.3%). The overall retention rate for gaseous Hg is around 12%; Hg(0) is more prone to be retained (95%) while Hg(2+) shows a negative efficiency capture for the whole installation. The negative Hg(2+) capture efficiencies are due to the continuous CO2-rich exhaust flue gas recirculation to the boiler with enhanced Hg contents. Calculations revealed that 44mg of Hg were re-circulated to the boiler as a result of 2183 re-circulations of CO2-rich flue gas. Especial attention must be paid to the role of the CO2-rich exhaust flue gas re-circulation to the boiler on the Hg enrichment in Fly Ashes (FAs).

The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions.

Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation (FGD)-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the pH and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the pH value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO2SO4, H2Se, and HAsO2 are the aqueous complexes with the highest activities under acidic conditions. The speciation of Zn, Li, and Ni is not affected in spite of pH changes; these elements occur as free cations and associated to SO4(2) in the FGD-gypsum leachates. The mobility of Cu and Mo decreases by decreasing the pH of the FGD-gypsum leachates, which might be associated to the precipitation of CuSe2 and MoSe2, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples.

Effects of road dust suppressants on PM levels in a Mediterranean urban area.

The abatement of road dust emissions is currently a major challenge for sustainable transportation, causing exceedances of limits on particulate matter (PM) and high population exposures to mineral dust and metals. Mitigation measures have been proposed such as improved street cleaning and the use of dust suppressants. This study evaluated, for the first time, the effectiveness of calcium-magnesium acetate (CMA) and MgCl2 in reducing road dust emissions in a Mediterranean city. During a two-month campaign, a typical urban road in the city of Barcelona was sprayed, and changes in PMx levels and components were monitored at four traffic sites and one background monitoring sites. The integrated results indicate no statistically significant effectiveness of dust suppressants on PM10 and PM2.5-10 levels. Episodic reductions of Al, K, Mg, Cr, Li, Cu, and Zn were observed during CMA applications, but they were not systematically statistically significant over different stations and spreading days. MgCl2 days showed lower PM10 mean concentrations, but these reductions were not statistically significant and were not supported by significant drops in mineral and brake-wear metals. Based on our literature review, it can be postulated that the higher the road dust loading, the higher the dust suppressant effectiveness.