Although many studies on the fishery biology of jumbo flying squid, Dosidicus gigas, have been conducted in the coastal areas within Exclusive Economic Zones （EEZs） of various countries due to its commercial and eco...Although many studies on the fishery biology of jumbo flying squid, Dosidicus gigas, have been conducted in the coastal areas within Exclusive Economic Zones （EEZs） of various countries due to its commercial and ecological importance, limited biological information is available from waters outside these EEZs. In this paper, we examined D. gigas fishery biology from waters outside Chilean, Peruvian and Costa Rican EEZs, based on the fishery data collected by Chinese jigging vessels during 2006 to 2010. The dominant mantle lengths olD. gigas were 350-450 mm, 250-400 mm and 250-350 mm outside Chilean, Peruvian and Costa Rican EEZs, respectively. Size structure analysis show that a medium-sized group existed mostly in the waters outside the Chilean and Peruvian EEZs, whereas a small-sized group occurred mainly in the waters outside the Costa Rican EEZ. The longevity of the squid outside the Costa Rican EEZ was less than 10 months, while most of those outside Chilean and Peruvian EEZs were about 1-1.5 years and very few large individuals were 1.5-2 years old. A higher percentage of mature individuals existed outside Costa Rican EEZ implying the region as a potential spawning ground, while lower proportions of mature squid outside the Peruvian and Chilean EEZs indicated that spawning may be occurring outside our study area. Spatial differences in sizes at maturity of the squid are thought to be result from different environmental factors especially different temperature and nutrition among the three areas. Stomach-content analysis showed that cannibalism was important in the diet of D. gigas. Stress generated by jigging may increase the incidence of cannibalism.展开更多
AIM： To evaluate several risk factors for gastric cancer （GC） in Costa Rican regions with contrasting GC incidence rate （GCIR）. METHODS： According to GCIR, 191 Helicobacter pylori （H pylori）-positive patients ...AIM： To evaluate several risk factors for gastric cancer （GC） in Costa Rican regions with contrasting GC incidence rate （GCIR）. METHODS： According to GCIR, 191 Helicobacter pylori （H pylori）-positive patients were classified into groups A （high GCIR, n = 101） and B （low GCIR, n = 90）. Human DNA obtained from biopsy specimens was used in the determination of polymorphisms of the genes coding for interleukin （IL）-1β and IL-10 by PCRRFLP, and IL-1RN by PCR. H pylori DNA extractions obtained from clinical isolates of 83 patients were used for PCR-based genotyping of H pylori cagA, vacA and babA2. Human DNA from gastric biopsies of 52 GC patients was utilized for comparative purposes. RESULTS： Cytokine polymorphisms showed no association with GCIR variability. However, gastric atrophy, intestinal metaplasia and strains with different vacA genotypes in the same stomach （mixed strain infection） were more frequently found in group A than in group B, and cagA and vacA s1b were significantly associated with high GCIR （P = 0.026 and 0.041, respectively）. IL- 1β＋3954_T/C （OR 2.1, 1.0-4.3）, IL-1RN^＊2/L （OR 3.5, 1.7-7.3） and IL-10-592_C/A （OR 3.2, 1.5-6.8） were individually associated with GC, and a combination of these cytokine polymorphisms with Hpylori vacA slb and ml further increased the risk （OR 7.2, 1.4-36.4）. CONCLUSION： Although a proinflammatory cytokine genetic profile showed an increased risk for developing GC, the characteristics of Hpylori infection, in particular the status of cagA and vacA genotype distribution seemed to play a major role in GCIR variability in Costa Rica.展开更多
This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer inciden...This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.展开更多
During the review and identification of specimens of the genus Damasippus Stål, 1875 deposited in the National Museum of Costa Rica, some specimens were found that corresponded to four non-described species: D. s...During the review and identification of specimens of the genus Damasippus Stål, 1875 deposited in the National Museum of Costa Rica, some specimens were found that corresponded to four non-described species: D. sepia n.sp., D. viridicorpus n.sp, D. duoviridis n.sp and D. viridilabrum n. sp. Due to the above, a review of the literature describing the species of this group was carried out, with which an illustrated dichotomous key was developed to identify the 16 species, in addition to a partial phylogenetic analysis to corroborate that they do not correspond to the species D. fuscipes, due to its morphological similarity.展开更多
AIM:To evaluate the prevalence of Helicobacter pylori(H.pylori ) babA2 ,babB and a recombinant gene between babA2 and babB(babA2/B ),and their role in the development of atrophic gastritis in Costa Rican and Japanese ...AIM:To evaluate the prevalence of Helicobacter pylori(H.pylori ) babA2 ,babB and a recombinant gene between babA2 and babB(babA2/B ),and their role in the development of atrophic gastritis in Costa Rican and Japanese clinical isolates.METHODS:A total of 95 continuous H.pylori-positive Costa Rican(41 males and 54 females;mean age,50.65 years;SD,± 13.04 years) and 95 continuous H.pylori-positive Japanese(50 males and 45 females;mean age,63.43;SD,± 13.21 years) patients underwent upper endoscopy from October 2005 to July 2006.They were enrolled for the polymerase chain reaction(PCR)-based genotyping of the H.pylori babA2 ,babB and babA2/B genes.Statistical analysis was performed using the χ2 test and the Fisher's exact probability test and multivariate analysis was performed by logistic regression adjusting for gender and age.P < 0.05 was regarded as statistically significant.RESULTS:The PCR-based genotyping of 95 Costa Rican and 95 Japanese isolates showed a higher prevalence of babA2 in Japan(96.8%) than in Costa Rica(73.7%),while that of babA2/B was higher in Costa Rica(11.6%) than in Japan(1.1%).In Costa Rican isolates only,babA2 was significantly associated with atrophic gastritis(P = 0.01).CONCLUSION:These results suggest that the status of babA2 and babA2/B shows geographic differences,and that babA2 has clinical relevance in Costa Rica.展开更多
This study estimates job creation from Costa Rica's transition to net-zero emissions by 2050,contrasting it with a business-as-usual scenario(BAU)using employment multipliers from Costa Rica's input-output mat...This study estimates job creation from Costa Rica's transition to net-zero emissions by 2050,contrasting it with a business-as-usual scenario(BAU)using employment multipliers from Costa Rica's input-output matrix.The model is soft-linked with a bottom-up technology-rich regional model of the CLEW sectors in Costa Rica.A robust decision-making-inspired approach is taken to assess the effects of uncertainty on the estimations.The study addresses a literature gap in modeling subnational employment while accounting for long-term uncertainty and allows to identify economic activities affected by the transformation,so that policies regarding a just transition can be properly developed and stakeholders incentivized to take active participation in the process.Under baseline assumptions,a net-zero economy would have 135 thousand more jobs by 2050 than the BAU,equivalent to 7%of the employed population in 2017.Energy-related jobs would triple by mid-21st century,and regions capitalizing on renewables would perceive the highest gain.When considering uncertainty,the net jobs range between 35-750 thousand.Since net positive outcomes in terms of jobs are feasible,global governance should focus efforts on policies that enhance these.展开更多
Tumor-specific antigens or neoantigens are peptides that are expressed only in cancer cells and not in healthy cells.Some of these molecules can induce an immune response,and therefore,their use in immunotherapeutic s...Tumor-specific antigens or neoantigens are peptides that are expressed only in cancer cells and not in healthy cells.Some of these molecules can induce an immune response,and therefore,their use in immunotherapeutic strategies based on cancer vaccines has been extensively explored.Studies based on these approaches have been triggered by the current high-throughput DNA sequencing technologies.However,there is no universal nor straightforward bioinformatic protocol to discover neoan-tigens using DNA sequencing data.Thus,we propose a bioinformatic protocol to detect tumor-specific antigens associated with single nucleotide variants(SNVs)or“mutations”in tumoral tissues.For this purpose,we used publicly available data to build our model,including exome sequencing data from colorectal cancer and healthy cells obtained from a single case,as well as frequent human leukocyte antigen(HLA)class I alleles in a specific population.HLA data from Costa Rican Central Valley population was selected as an example.The strategy included three main steps:(1)pre-processing of sequencing data;(2)variant calling analysis to detect tumor-specific SNVs in comparison with healthy tissue;and(3)prediction and characterization of peptides(protein fragments,the tumor-specific antigens)derived from the variants,in the context of their affinity with frequent alleles of the selected population.In our model data,we found 28 non-silent SNVs,present in 17 genes in chromosome one.The protocol yielded 23 strong binders peptides derived from the SNVs for frequent HLA class I alleles for the Costa Rican population.Although the analyses were performed as an example to implement the pipeline,to our knowledge,this is the first study of an in silico cancer vaccine using DNA sequencing data in the context of the HLA alleles.It is concluded that the standardized protocol was not only able to identify neoantigens in a specific but also provides a complete pipeline for the eventual design of cancer vaccines using the best bioinformatic practices.展开更多
The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. ...The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°–9°N and 91°–94°W and by 6°30′–7°30′N and 96°–97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29℃. The sex ratio of the total catch was 3.75:1(female: male). The mantle length of the squid ranged from 211 to 355 mm(male) and from 204 to 429 mm(female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length(mm) and body weight(g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size(mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs(70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.展开更多
With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to cha...With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to characterize changes in temperature at different heights in the sub-canopy of both secondary forest and 15-year-old agroforestry plots. Results show that while agroforestry plots had different temperature profiles from the secondary forest, the monoculture plot (consisting of Pentaclethra macroloba) had temperatures similar to the profile found in the secondary forest. This suggests that the replication of temperature profiles in a secondary forest may be independent of the number of tree species in a plot (e.g. polyculture), but may instead depend on the density of a given trees species. These findings further suggest that characterizing temperature microclimates in secondary forests can serve to improve the ecological sustainability of agro-forestry systems.展开更多
Little information is available for Central America regarding methane and carbon dioxide mixing ratios in urban areas. This work reports a representative spatial and seasonal study of near surface carbon dioxide and m...Little information is available for Central America regarding methane and carbon dioxide mixing ratios in urban areas. This work reports a representative spatial and seasonal study of near surface carbon dioxide and methane, carried out between July 2014 and January 2015 (27 weeks) in the Central Valley of Costa Rica, and other urban and rural sites across the country and covering three distinct seasons: Mid-summer drought (July-August), wet season (September-November) and transition period (December-January). The mixing ratios of both gases are clearly influenced by the metropolitan area, and by the prevailing atmospheric conditions during the wet season months. Average carbon dioxide concentration (629 ± 80 ppm) and average methane concentration (2192 ± 110 ppb) were up to 8% and up to 10%, respectively, higher during the wet season than the values recorded outside this period. HYSPLIT back air mass trajectories analysis, and weather data available for the Central Valley, suggest that these differences arise as result of a reduction in the mixing layer of depth (~425 m) and the wind speed (~1.5 m/s) across the valley, favoring the accumulation of polluted air masses in the metropolitan area. Other natural and anthropogenic sources, like the volcanic emissions of the Turrialba Volcano and the livestock activities at rural sites, apparently influence the mixing ratios of both gases across Costa Rica. Although the scope of this study is limited to representative seasonal conditions of the Central Valley in 2014 and 2015, it is possible considering the information presented in this work that the “dome” phenomenon can be assumed to exist.展开更多
<b><span style="font-family:Verdana;">Introduction:</span></b><b><span style="font-family:;" "=""> </span></b><span style="fon...<b><span style="font-family:Verdana;">Introduction:</span></b><b><span style="font-family:;" "=""> </span></b><span style="font-family:;" "=""><span style="font-family:Verdana;">The consumption of energy drinks and its mix with alcohol has been associated with negative and violent behaviors in youngsters. </span><b><span style="font-family:Verdana;">Objective:</span></b> </span><span style="font-family:Verdana;">To </span><span style="font-family:Verdana;">determine the risk-taking behaviors associated with the consumption of energy drinks mixed with alcohol</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">in Costa Rican adolescents. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> A mixed cross-sectional study was performed with a population of 2667 students of 64 educative centers in 2016. Descriptive statistics were performed with the program SPSS 20.0 and a value of p <</span></span><span> </span><span style="font-family:Verdana;">0.05 was considered significant. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The third part of the study population is usually a consumer of energy drinks (30%) and 3% make use of drinks mixed with alcohol.</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">The children and adolescents, who consume energy-alcohol mixed drinks, are more likely to present risk-taking behaviors than those who do not consume these mixed beverages: combined use of medicines to get high;cocaine consumption, consumption of cement/glue, consumption of marijuana, physical violence (fighting), use of weapons, suicidal ideation, deliberate self-harm, low educational expectation, sexual intercourses, cyberbullying and school apathy. The students perceived the intake of energy beverages as of low risk for their health. They also agree that frequent consumption is because drinks 展开更多
Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to d...Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to develop its cultivation following a pilot-commercial approach. Twelve years after his introduction to Panama, the species was found to the south Caribbean coast. In the present study, we report the first record of K. alvarezii collected in Costa Rican waters. Genetic identification of the sample was performed with the mitochondrial marker cox2-cox3 intergenic spacer, and phylogenetic analyses showed that the sample collected grouped into a monophyletic clade with GenBank sequences from Vietnam, Indonesia, the Philippines, Brazil and Venezuela. Here we provide further description of its position with respect to other strains of K. alvarezii collected globally. Its possible route of entry to the Caribbean coast of Costa Rica is discussed. To date, it is possible to locate K. alvarezii in different areas away from the production fields which show its dispersion, and that the species is expanding;but more studies are needed to know the phase of colonization in which it is located because it is a combination of natural factors and human exploitation that determines the invasive potential of the species.展开更多
Restoration treatments can impact the growth and development of tree seedlings;however, it is often difficult to discern whether responses are driven by changes in microclimate, biotic interactions, or soil properties...Restoration treatments can impact the growth and development of tree seedlings;however, it is often difficult to discern whether responses are driven by changes in microclimate, biotic interactions, or soil properties. To isolate for the latter, we quantified the growth response of four species [Ocotea puberula (Lauraceae);Otoba novogranatensis (Myristicaceae);Pseudolmedia mollis (Moraceae);Senna papillosa (Fabaceae)] grown under similar shade-house conditions in soils collected from 6 - 7 year old active (four species plantation) and passive restoration plots (natural recovery), and nearby reference forest sites in Costa Rica. We also evaluated the role of parent tree by collecting individuals from five mother trees. We measured height, above- and below-ground biomass, and determined root: shoot ratios (RSR). Species differed markedly in their responses. Ocotea, and to a lesser extent Pseudolmedia, were largely driven by parent tree. In contrast, Senna showed a strong soil response for all variables with more growth in active than passive restoration soils;reference forest seedlings were typically intermediate. An interaction suggested that some genotypes are more responsive to different soil properties than others. Otoba had higher soil-driven RSR in both restoration treatments. Surprisingly most soil nutrients, including %N, were similar or significantly lower in active restoration soils, suggesting that seedlings are responding to differences in soil microbial communities or more labile nutrients (e.g., NH4+ and NO3-). Active restoration appears to facilitate the growth of other species by improving certain soil properties. Additionally, genotypes are an important driver of seedling vigor and some species may be more responsive to subtle differences in soil properties than others.展开更多
The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from the Caribbean Sea and the Pacific Ocean. In Costa Rica, stable isotope monitori...The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from the Caribbean Sea and the Pacific Ocean. In Costa Rica, stable isotope monitoring was conducted by the International Atomic Energy Agency and the World Meteorological Association as part of the worldwide effort entitled Global Network of Isotopes in Precipitation. Sampling campaigns were mainly comprised of monthly-integrated samples during intermittent years from 1990 to 2005. The main goal of this study was to determine spatial and temporal isotopic variations of meteoric waters in Costa Rica using historic records. Samples were grouped in four main regions: Nicoya Peninsula (d2H = 6.65d18O -0.13;r2 = 0.86);Pacific Coast (d2H = 7.60d18O + 7.95;r2 = 0.99);Caribbean Slope (d2H = 6.97d18O + 4.97;r2 = 0.97);and Central Valley (d2H = 7.94d18O + 10.38;r2 = 0.98). The water meteoric line for Costa Rica can be defined as d2H = 7.61d18O + 7.40 (r2 = 0.98). The regression of precipitation amount and annual arithmetic means yields a slope of ﹣1.6‰ d18O per 100 mm of rain (r2 = 0.57) which corresponds with a temperature effect of ﹣0.37‰ d18O/°C. A strong correlation (r2 = 0.77) of ﹣2.0‰ d18O per km of elevation was found. Samples within the Nicoya Peninsula and Caribbean lowlands appear to be dominated by evaporation enrichment as shown in d-excess interpolation, especially during the dry months, likely resulting from small precipitation amounts. In the inter-mountainous region of the Central Valley and Pacific slope, complex moisture recycling processes may dominate isotopic variations. Generally, isotopic values tend to be more depleted as the rainy season progresses over the year. Air parcel back trajectories indicate that enriched isotopic compositions both in Turrialba and Monteverde are related to central Caribbean parental moisture and low rainfall intensities. Depleted events appear to be related to high rainfall amounts despite the parental origin of the moisture.展开更多
In this work, receptor models were used to identify the PM2.5 sources and its contribution to the air quality in residential, comercial and industrial sampling sites in the Metropolitan Area of Costa Rica. Principal c...In this work, receptor models were used to identify the PM2.5 sources and its contribution to the air quality in residential, comercial and industrial sampling sites in the Metropolitan Area of Costa Rica. Principal component analysis with absolute principal component scores (PCA-APCS), UNIMX and positive matrix factorization (PMF) was applied to analyze the data collected during 1 year of sampling campaign (2010-2011). The PM2.5 samples were characterized through its composition looking for trace elements, inorganic ions and organic and elemental carbon. These three models identified some common sources of PM2.5: marine aerosol, crustal material, traffic, secondary aerosols (secondary sulfate and secondary nitrate resolved by PMF), a mixed source of heavy fuels combustion and biomass burning, and industrial emissions. The three models predicted that the major sources of PM2.5 in the Metropolitan Area of Costa Rica were related to anthropogenic sources (73%, 65% and 69%, respectively, for PCA-APCS, Unmix and PMF) although natural sources also contributed to PM2.5 (21%, 24% and 26%). On average, PCA and PMF methods resolved 94% and 95% of the PM2.5 mass concentrations, respectively. The results were comparable to the estimate using UNMIX.展开更多
The results obtained in this study highlight that further the macroalgae diversity in this region is even higher than what is reported to date. Here we present eight new records of marine macroalgae collected from the...The results obtained in this study highlight that further the macroalgae diversity in this region is even higher than what is reported to date. Here we present eight new records of marine macroalgae collected from the Caribbean coast of Costa Rica between March 2011 and May 2019. The morphological characteristics of Bryocladia cuspidata, Ceratodictyon variabile, Gracilaria hayi, Padina boergesenii, Zonaria tournefortii, Sargassum furcatum, Chaetomorpha aerea, and Bryopsis pennata var. secunda are described. The genera Bryocladia and Zonaria are reported for the first time for this region.展开更多
This paper summarizes the national inventory of mercury released into all environmental sectors (air, water, land, impurity in products, general wastes and sector specific treatment/disposal) for the year 2008 in the ...This paper summarizes the national inventory of mercury released into all environmental sectors (air, water, land, impurity in products, general wastes and sector specific treatment/disposal) for the year 2008 in the country of Costa Rica, using the United Nations Environment Programme (UNEP) mercury toolkit. The data collection about the input and output of mercury for the year 2008, was carried out during the years 2014 and 2015. The data used for estimation are mainly obtained from the Costa Rican Government’s official publications. The research was developed in order to create a national inventory of mercury releases into all environmental sectors in order to aid mercury management in Costa Rica. Total input and output of mercury, distribution into different environmental sectors, major contributions by mercury sources (“steps” “categories” and “subcategories”) are discussed. The standard estimation of total mercury input is 7174.00 kg/year. The biggest mercury input are “waste treatment and recycling” (3086.00 kg Hg, 43.17%) and “general consumption of mercury in products, as metal mercury and as mercury containing substances” (3189.00 kg Hg, 44.62%). The total mercury released is 31,689.29 kg/year. The biggest emission of mercury corresponds to the source “waste treatment and recycling” (28,359.29 kg/year, 89.49%). The “air” is the main impacted environmental sector due the different mercury inputs. A total of 28,155.60 kg/year (88.55%) is released in this media. Only 1635.10 kg/year (5.16%) of the total mercury emissions is deposited in the environmental sector named “general waste”. The rest of the environmental sectors evaluated are impacted with less of 3.00% of the total mercury released.展开更多
This study reports the benzene exposure levels of commuters traveling within the metropolitan area of Costa Rica using personal cars, buses, and urban trains. 47 in-vehicle samples were collected in the 2014 wet seaso...This study reports the benzene exposure levels of commuters traveling within the metropolitan area of Costa Rica using personal cars, buses, and urban trains. 47 in-vehicle samples were collected in the 2014 wet season under three different driving conditions: rush hour traffic, normal traffic and weekends. Samples were collected in Tedlar bags and analyzed using 75 μm carboxenpolydimethylsiloxane (CAR/PDMS) and gas chromatography with flame ionization detection (GC-FID). Additionally, duplicate samples were collected on adsorption tubes filled with Tenax TA and analyzed by thermal desorption (TD) and GC-FID. Results indicate that travelling in cars and buses under rush hour conditions exposes commuters to statistically equal average benzene concentration of 48.7 and 51.6 μg/m3, respectively. Average benzene levels in urban trains (33.0 μg/m3) were measured only during morning rush hours. Greater benzene levels in buses than personal cars concentrations may be attributable to the immersion of traffic-related emission within the bus cabins. Factors, such as the driving pattern, the number of vehicles on the route, the road infrastructure, and the prevalence of gasoline-fueled vehicles in Costa Rica, may increase ambient benzene concentrations. Benzene levels inside car cabins reported in this study are in the range of those reported in other urban areas;however, the corresponding concentrations inside buses and urban trains (rush hour only) are higher than previously published exposure levels.展开更多
The surface flux emissions for volatile organic compounds (VOC’s) (alcohols and aromatic species), priority carbonyls and greenhouse gases, were measured in three different final disposal sites for urban solid waste ...The surface flux emissions for volatile organic compounds (VOC’s) (alcohols and aromatic species), priority carbonyls and greenhouse gases, were measured in three different final disposal sites for urban solid waste located in the metropolitan area of Costa Rica, between July and October 2014. The emissions fluxes were determined using the static sampling chamber technique coupled to two different adsorption tubes: active charcoal (Supelco, ORBO 32) to capture BTEX and alcohols;and 2,4-DNPH coated silica gel (SKC, 226-119) for carbonyls. As for the VOCs, the BTEX, Alcohols, and Carbonyls total fluxes were in the range of 3 to 258, 1 to 318 and 0.4 to 8.5 mg/(m2día), respectively. The magnitudes per site were in the following order La Carpio > El Huaso > Rio Azul. Ethanol and BTEX presented a high correlation in all the cases because possibly they are sharing the same sources or formation mechanisms. The emission fluxes spatial distributions among the sites were very variable and dependent on the location of the active cells and their age. Only La Carpio showed a more homogeneous distribution due to its middle age.展开更多
基金Supported by the National Natural Science Foundation of China(No.NSFC41276156)Innovation Program of Shanghai Municipal Education Commission(No.13YE091)+5 种基金Industrialization Project of National Development and Reform Commission(No.2159999)Project of Shanghai Science and Technology Commission(No.12231203900)National High Technology Research and Development Program of China(863 Program)(No.2012AA092303)Shanghai Leading Academic Discipline Project(Fisheries Discipline)National Distant-Water Fisheries Engineering Research Centerthe Scientific Observing and Experimental Station of Oceanic Fishery Resources,Ministry of Agriculture
文摘Although many studies on the fishery biology of jumbo flying squid, Dosidicus gigas, have been conducted in the coastal areas within Exclusive Economic Zones （EEZs） of various countries due to its commercial and ecological importance, limited biological information is available from waters outside these EEZs. In this paper, we examined D. gigas fishery biology from waters outside Chilean, Peruvian and Costa Rican EEZs, based on the fishery data collected by Chinese jigging vessels during 2006 to 2010. The dominant mantle lengths olD. gigas were 350-450 mm, 250-400 mm and 250-350 mm outside Chilean, Peruvian and Costa Rican EEZs, respectively. Size structure analysis show that a medium-sized group existed mostly in the waters outside the Chilean and Peruvian EEZs, whereas a small-sized group occurred mainly in the waters outside the Costa Rican EEZ. The longevity of the squid outside the Costa Rican EEZ was less than 10 months, while most of those outside Chilean and Peruvian EEZs were about 1-1.5 years and very few large individuals were 1.5-2 years old. A higher percentage of mature individuals existed outside Costa Rican EEZ implying the region as a potential spawning ground, while lower proportions of mature squid outside the Peruvian and Chilean EEZs indicated that spawning may be occurring outside our study area. Spatial differences in sizes at maturity of the squid are thought to be result from different environmental factors especially different temperature and nutrition among the three areas. Stomach-content analysis showed that cannibalism was important in the diet of D. gigas. Stress generated by jigging may increase the incidence of cannibalism.
文摘AIM： To evaluate several risk factors for gastric cancer （GC） in Costa Rican regions with contrasting GC incidence rate （GCIR）. METHODS： According to GCIR, 191 Helicobacter pylori （H pylori）-positive patients were classified into groups A （high GCIR, n = 101） and B （low GCIR, n = 90）. Human DNA obtained from biopsy specimens was used in the determination of polymorphisms of the genes coding for interleukin （IL）-1β and IL-10 by PCRRFLP, and IL-1RN by PCR. H pylori DNA extractions obtained from clinical isolates of 83 patients were used for PCR-based genotyping of H pylori cagA, vacA and babA2. Human DNA from gastric biopsies of 52 GC patients was utilized for comparative purposes. RESULTS： Cytokine polymorphisms showed no association with GCIR variability. However, gastric atrophy, intestinal metaplasia and strains with different vacA genotypes in the same stomach （mixed strain infection） were more frequently found in group A than in group B, and cagA and vacA s1b were significantly associated with high GCIR （P = 0.026 and 0.041, respectively）. IL- 1β＋3954_T/C （OR 2.1, 1.0-4.3）, IL-1RN^＊2/L （OR 3.5, 1.7-7.3） and IL-10-592_C/A （OR 3.2, 1.5-6.8） were individually associated with GC, and a combination of these cytokine polymorphisms with Hpylori vacA slb and ml further increased the risk （OR 7.2, 1.4-36.4）. CONCLUSION： Although a proinflammatory cytokine genetic profile showed an increased risk for developing GC, the characteristics of Hpylori infection, in particular the status of cagA and vacA genotype distribution seemed to play a major role in GCIR variability in Costa Rica.
文摘This commentary delves into the evolving landscape of cancer incidence and mortality in Costa Rica, presenting a comprehensive analysis of the data. Key findings reveal a concerning upward trajectory in cancer incidence rates, placing Costa Rica at the forefront within Central America. While prostate cancer and breast cancer dominate, disparities emerge when scrutinizing gender-specific trends. Notably, stomach and cervical cancers show declines, potentially attributed to targeted interventions. However, colorectal and liver cancers witness mortality increases, necessitating strategic responses. Geographical disparities persist across provinces, highlighting the need for equitable healthcare access. In conclusion, this commentary underscores the urgency of addressing the burgeoning cancer burden in Costa Rica, calling for evidence-based interventions and collaborative efforts on a global scale.
文摘During the review and identification of specimens of the genus Damasippus Stål, 1875 deposited in the National Museum of Costa Rica, some specimens were found that corresponded to four non-described species: D. sepia n.sp., D. viridicorpus n.sp, D. duoviridis n.sp and D. viridilabrum n. sp. Due to the above, a review of the literature describing the species of this group was carried out, with which an illustrated dichotomous key was developed to identify the 16 species, in addition to a partial phylogenetic analysis to corroborate that they do not correspond to the species D. fuscipes, due to its morphological similarity.
基金Supported by (in part) A Grant-in-Aid for Scientific Research from the Ministry of Education,Science and Culture of Japan(21590631)the Project Research Fund from the Kochi University
文摘AIM:To evaluate the prevalence of Helicobacter pylori(H.pylori ) babA2 ,babB and a recombinant gene between babA2 and babB(babA2/B ),and their role in the development of atrophic gastritis in Costa Rican and Japanese clinical isolates.METHODS:A total of 95 continuous H.pylori-positive Costa Rican(41 males and 54 females;mean age,50.65 years;SD,± 13.04 years) and 95 continuous H.pylori-positive Japanese(50 males and 45 females;mean age,63.43;SD,± 13.21 years) patients underwent upper endoscopy from October 2005 to July 2006.They were enrolled for the polymerase chain reaction(PCR)-based genotyping of the H.pylori babA2 ,babB and babA2/B genes.Statistical analysis was performed using the χ2 test and the Fisher's exact probability test and multivariate analysis was performed by logistic regression adjusting for gender and age.P < 0.05 was regarded as statistically significant.RESULTS:The PCR-based genotyping of 95 Costa Rican and 95 Japanese isolates showed a higher prevalence of babA2 in Japan(96.8%) than in Costa Rica(73.7%),while that of babA2/B was higher in Costa Rica(11.6%) than in Japan(1.1%).In Costa Rican isolates only,babA2 was significantly associated with atrophic gastritis(P = 0.01).CONCLUSION:These results suggest that the status of babA2 and babA2/B shows geographic differences,and that babA2 has clinical relevance in Costa Rica.
基金supported by the French Development Agency (AML-2021-0290)。
文摘This study estimates job creation from Costa Rica's transition to net-zero emissions by 2050,contrasting it with a business-as-usual scenario(BAU)using employment multipliers from Costa Rica's input-output matrix.The model is soft-linked with a bottom-up technology-rich regional model of the CLEW sectors in Costa Rica.A robust decision-making-inspired approach is taken to assess the effects of uncertainty on the estimations.The study addresses a literature gap in modeling subnational employment while accounting for long-term uncertainty and allows to identify economic activities affected by the transformation,so that policies regarding a just transition can be properly developed and stakeholders incentivized to take active participation in the process.Under baseline assumptions,a net-zero economy would have 135 thousand more jobs by 2050 than the BAU,equivalent to 7%of the employed population in 2017.Energy-related jobs would triple by mid-21st century,and regions capitalizing on renewables would perceive the highest gain.When considering uncertainty,the net jobs range between 35-750 thousand.Since net positive outcomes in terms of jobs are feasible,global governance should focus efforts on policies that enhance these.
基金funded by Vicerrectoría de Investigación—Universidad de Costa Rica,with the Project“C1163 proNGS 2.0:Protocolos operativos estandarizados de análisis de datos moleculares obtenidos por NGS o afines y de algoritmos de inteligencia artificial en modelos biológicos(2021–2023)”.
文摘Tumor-specific antigens or neoantigens are peptides that are expressed only in cancer cells and not in healthy cells.Some of these molecules can induce an immune response,and therefore,their use in immunotherapeutic strategies based on cancer vaccines has been extensively explored.Studies based on these approaches have been triggered by the current high-throughput DNA sequencing technologies.However,there is no universal nor straightforward bioinformatic protocol to discover neoan-tigens using DNA sequencing data.Thus,we propose a bioinformatic protocol to detect tumor-specific antigens associated with single nucleotide variants(SNVs)or“mutations”in tumoral tissues.For this purpose,we used publicly available data to build our model,including exome sequencing data from colorectal cancer and healthy cells obtained from a single case,as well as frequent human leukocyte antigen(HLA)class I alleles in a specific population.HLA data from Costa Rican Central Valley population was selected as an example.The strategy included three main steps:(1)pre-processing of sequencing data;(2)variant calling analysis to detect tumor-specific SNVs in comparison with healthy tissue;and(3)prediction and characterization of peptides(protein fragments,the tumor-specific antigens)derived from the variants,in the context of their affinity with frequent alleles of the selected population.In our model data,we found 28 non-silent SNVs,present in 17 genes in chromosome one.The protocol yielded 23 strong binders peptides derived from the SNVs for frequent HLA class I alleles for the Costa Rican population.Although the analyses were performed as an example to implement the pipeline,to our knowledge,this is the first study of an in silico cancer vaccine using DNA sequencing data in the context of the HLA alleles.It is concluded that the standardized protocol was not only able to identify neoantigens in a specific but also provides a complete pipeline for the eventual design of cancer vaccines using the best bioinformatic practices.
基金the supports of the two scientific surveys made by Fenghui No 16 and Zhe Yunyu No 807funded by National Nature Science Foundation of China (NSFC 41276156)+5 种基金National High-tech R&D Program of China (863 Program 2012AA092303)Project of Shanghai science and technology innovation (12231203900)Industrialization program of National Development and Reform Commission (2159999)Shanghai Leading Academic Discipline Projectsupported by National Distant-water Fisheries Engineering Research Center
文摘The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°–9°N and 91°–94°W and by 6°30′–7°30′N and 96°–97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29℃. The sex ratio of the total catch was 3.75:1(female: male). The mantle length of the squid ranged from 211 to 355 mm(male) and from 204 to 429 mm(female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length(mm) and body weight(g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size(mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs(70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.
文摘With urbanization encroaching upon forestlands, characterizing microclimates in secondary forests will be important for the sustainable management of microclimates in agroforestry systems. We used micro-sensors to characterize changes in temperature at different heights in the sub-canopy of both secondary forest and 15-year-old agroforestry plots. Results show that while agroforestry plots had different temperature profiles from the secondary forest, the monoculture plot (consisting of Pentaclethra macroloba) had temperatures similar to the profile found in the secondary forest. This suggests that the replication of temperature profiles in a secondary forest may be independent of the number of tree species in a plot (e.g. polyculture), but may instead depend on the density of a given trees species. These findings further suggest that characterizing temperature microclimates in secondary forests can serve to improve the ecological sustainability of agro-forestry systems.
文摘Little information is available for Central America regarding methane and carbon dioxide mixing ratios in urban areas. This work reports a representative spatial and seasonal study of near surface carbon dioxide and methane, carried out between July 2014 and January 2015 (27 weeks) in the Central Valley of Costa Rica, and other urban and rural sites across the country and covering three distinct seasons: Mid-summer drought (July-August), wet season (September-November) and transition period (December-January). The mixing ratios of both gases are clearly influenced by the metropolitan area, and by the prevailing atmospheric conditions during the wet season months. Average carbon dioxide concentration (629 ± 80 ppm) and average methane concentration (2192 ± 110 ppb) were up to 8% and up to 10%, respectively, higher during the wet season than the values recorded outside this period. HYSPLIT back air mass trajectories analysis, and weather data available for the Central Valley, suggest that these differences arise as result of a reduction in the mixing layer of depth (~425 m) and the wind speed (~1.5 m/s) across the valley, favoring the accumulation of polluted air masses in the metropolitan area. Other natural and anthropogenic sources, like the volcanic emissions of the Turrialba Volcano and the livestock activities at rural sites, apparently influence the mixing ratios of both gases across Costa Rica. Although the scope of this study is limited to representative seasonal conditions of the Central Valley in 2014 and 2015, it is possible considering the information presented in this work that the “dome” phenomenon can be assumed to exist.
文摘<b><span style="font-family:Verdana;">Introduction:</span></b><b><span style="font-family:;" "=""> </span></b><span style="font-family:;" "=""><span style="font-family:Verdana;">The consumption of energy drinks and its mix with alcohol has been associated with negative and violent behaviors in youngsters. </span><b><span style="font-family:Verdana;">Objective:</span></b> </span><span style="font-family:Verdana;">To </span><span style="font-family:Verdana;">determine the risk-taking behaviors associated with the consumption of energy drinks mixed with alcohol</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">in Costa Rican adolescents. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> A mixed cross-sectional study was performed with a population of 2667 students of 64 educative centers in 2016. Descriptive statistics were performed with the program SPSS 20.0 and a value of p <</span></span><span> </span><span style="font-family:Verdana;">0.05 was considered significant. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The third part of the study population is usually a consumer of energy drinks (30%) and 3% make use of drinks mixed with alcohol.</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">The children and adolescents, who consume energy-alcohol mixed drinks, are more likely to present risk-taking behaviors than those who do not consume these mixed beverages: combined use of medicines to get high;cocaine consumption, consumption of cement/glue, consumption of marijuana, physical violence (fighting), use of weapons, suicidal ideation, deliberate self-harm, low educational expectation, sexual intercourses, cyberbullying and school apathy. The students perceived the intake of energy beverages as of low risk for their health. They also agree that frequent consumption is because drinks
文摘Kappaphycus alvarezii, a red macroalgal species native to South-East Asia, has been introduced for commercial purposes to more than 20 tropical countries. In 2000, Panama became the first Central American country to develop its cultivation following a pilot-commercial approach. Twelve years after his introduction to Panama, the species was found to the south Caribbean coast. In the present study, we report the first record of K. alvarezii collected in Costa Rican waters. Genetic identification of the sample was performed with the mitochondrial marker cox2-cox3 intergenic spacer, and phylogenetic analyses showed that the sample collected grouped into a monophyletic clade with GenBank sequences from Vietnam, Indonesia, the Philippines, Brazil and Venezuela. Here we provide further description of its position with respect to other strains of K. alvarezii collected globally. Its possible route of entry to the Caribbean coast of Costa Rica is discussed. To date, it is possible to locate K. alvarezii in different areas away from the production fields which show its dispersion, and that the species is expanding;but more studies are needed to know the phase of colonization in which it is located because it is a combination of natural factors and human exploitation that determines the invasive potential of the species.
文摘Restoration treatments can impact the growth and development of tree seedlings;however, it is often difficult to discern whether responses are driven by changes in microclimate, biotic interactions, or soil properties. To isolate for the latter, we quantified the growth response of four species [Ocotea puberula (Lauraceae);Otoba novogranatensis (Myristicaceae);Pseudolmedia mollis (Moraceae);Senna papillosa (Fabaceae)] grown under similar shade-house conditions in soils collected from 6 - 7 year old active (four species plantation) and passive restoration plots (natural recovery), and nearby reference forest sites in Costa Rica. We also evaluated the role of parent tree by collecting individuals from five mother trees. We measured height, above- and below-ground biomass, and determined root: shoot ratios (RSR). Species differed markedly in their responses. Ocotea, and to a lesser extent Pseudolmedia, were largely driven by parent tree. In contrast, Senna showed a strong soil response for all variables with more growth in active than passive restoration soils;reference forest seedlings were typically intermediate. An interaction suggested that some genotypes are more responsive to different soil properties than others. Otoba had higher soil-driven RSR in both restoration treatments. Surprisingly most soil nutrients, including %N, were similar or significantly lower in active restoration soils, suggesting that seedlings are responding to differences in soil microbial communities or more labile nutrients (e.g., NH4+ and NO3-). Active restoration appears to facilitate the growth of other species by improving certain soil properties. Additionally, genotypes are an important driver of seedling vigor and some species may be more responsive to subtle differences in soil properties than others.
文摘The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from the Caribbean Sea and the Pacific Ocean. In Costa Rica, stable isotope monitoring was conducted by the International Atomic Energy Agency and the World Meteorological Association as part of the worldwide effort entitled Global Network of Isotopes in Precipitation. Sampling campaigns were mainly comprised of monthly-integrated samples during intermittent years from 1990 to 2005. The main goal of this study was to determine spatial and temporal isotopic variations of meteoric waters in Costa Rica using historic records. Samples were grouped in four main regions: Nicoya Peninsula (d2H = 6.65d18O -0.13;r2 = 0.86);Pacific Coast (d2H = 7.60d18O + 7.95;r2 = 0.99);Caribbean Slope (d2H = 6.97d18O + 4.97;r2 = 0.97);and Central Valley (d2H = 7.94d18O + 10.38;r2 = 0.98). The water meteoric line for Costa Rica can be defined as d2H = 7.61d18O + 7.40 (r2 = 0.98). The regression of precipitation amount and annual arithmetic means yields a slope of ﹣1.6‰ d18O per 100 mm of rain (r2 = 0.57) which corresponds with a temperature effect of ﹣0.37‰ d18O/°C. A strong correlation (r2 = 0.77) of ﹣2.0‰ d18O per km of elevation was found. Samples within the Nicoya Peninsula and Caribbean lowlands appear to be dominated by evaporation enrichment as shown in d-excess interpolation, especially during the dry months, likely resulting from small precipitation amounts. In the inter-mountainous region of the Central Valley and Pacific slope, complex moisture recycling processes may dominate isotopic variations. Generally, isotopic values tend to be more depleted as the rainy season progresses over the year. Air parcel back trajectories indicate that enriched isotopic compositions both in Turrialba and Monteverde are related to central Caribbean parental moisture and low rainfall intensities. Depleted events appear to be related to high rainfall amounts despite the parental origin of the moisture.
文摘In this work, receptor models were used to identify the PM2.5 sources and its contribution to the air quality in residential, comercial and industrial sampling sites in the Metropolitan Area of Costa Rica. Principal component analysis with absolute principal component scores (PCA-APCS), UNIMX and positive matrix factorization (PMF) was applied to analyze the data collected during 1 year of sampling campaign (2010-2011). The PM2.5 samples were characterized through its composition looking for trace elements, inorganic ions and organic and elemental carbon. These three models identified some common sources of PM2.5: marine aerosol, crustal material, traffic, secondary aerosols (secondary sulfate and secondary nitrate resolved by PMF), a mixed source of heavy fuels combustion and biomass burning, and industrial emissions. The three models predicted that the major sources of PM2.5 in the Metropolitan Area of Costa Rica were related to anthropogenic sources (73%, 65% and 69%, respectively, for PCA-APCS, Unmix and PMF) although natural sources also contributed to PM2.5 (21%, 24% and 26%). On average, PCA and PMF methods resolved 94% and 95% of the PM2.5 mass concentrations, respectively. The results were comparable to the estimate using UNMIX.
文摘The results obtained in this study highlight that further the macroalgae diversity in this region is even higher than what is reported to date. Here we present eight new records of marine macroalgae collected from the Caribbean coast of Costa Rica between March 2011 and May 2019. The morphological characteristics of Bryocladia cuspidata, Ceratodictyon variabile, Gracilaria hayi, Padina boergesenii, Zonaria tournefortii, Sargassum furcatum, Chaetomorpha aerea, and Bryopsis pennata var. secunda are described. The genera Bryocladia and Zonaria are reported for the first time for this region.
文摘This paper summarizes the national inventory of mercury released into all environmental sectors (air, water, land, impurity in products, general wastes and sector specific treatment/disposal) for the year 2008 in the country of Costa Rica, using the United Nations Environment Programme (UNEP) mercury toolkit. The data collection about the input and output of mercury for the year 2008, was carried out during the years 2014 and 2015. The data used for estimation are mainly obtained from the Costa Rican Government’s official publications. The research was developed in order to create a national inventory of mercury releases into all environmental sectors in order to aid mercury management in Costa Rica. Total input and output of mercury, distribution into different environmental sectors, major contributions by mercury sources (“steps” “categories” and “subcategories”) are discussed. The standard estimation of total mercury input is 7174.00 kg/year. The biggest mercury input are “waste treatment and recycling” (3086.00 kg Hg, 43.17%) and “general consumption of mercury in products, as metal mercury and as mercury containing substances” (3189.00 kg Hg, 44.62%). The total mercury released is 31,689.29 kg/year. The biggest emission of mercury corresponds to the source “waste treatment and recycling” (28,359.29 kg/year, 89.49%). The “air” is the main impacted environmental sector due the different mercury inputs. A total of 28,155.60 kg/year (88.55%) is released in this media. Only 1635.10 kg/year (5.16%) of the total mercury emissions is deposited in the environmental sector named “general waste”. The rest of the environmental sectors evaluated are impacted with less of 3.00% of the total mercury released.
文摘This study reports the benzene exposure levels of commuters traveling within the metropolitan area of Costa Rica using personal cars, buses, and urban trains. 47 in-vehicle samples were collected in the 2014 wet season under three different driving conditions: rush hour traffic, normal traffic and weekends. Samples were collected in Tedlar bags and analyzed using 75 μm carboxenpolydimethylsiloxane (CAR/PDMS) and gas chromatography with flame ionization detection (GC-FID). Additionally, duplicate samples were collected on adsorption tubes filled with Tenax TA and analyzed by thermal desorption (TD) and GC-FID. Results indicate that travelling in cars and buses under rush hour conditions exposes commuters to statistically equal average benzene concentration of 48.7 and 51.6 μg/m3, respectively. Average benzene levels in urban trains (33.0 μg/m3) were measured only during morning rush hours. Greater benzene levels in buses than personal cars concentrations may be attributable to the immersion of traffic-related emission within the bus cabins. Factors, such as the driving pattern, the number of vehicles on the route, the road infrastructure, and the prevalence of gasoline-fueled vehicles in Costa Rica, may increase ambient benzene concentrations. Benzene levels inside car cabins reported in this study are in the range of those reported in other urban areas;however, the corresponding concentrations inside buses and urban trains (rush hour only) are higher than previously published exposure levels.
文摘The surface flux emissions for volatile organic compounds (VOC’s) (alcohols and aromatic species), priority carbonyls and greenhouse gases, were measured in three different final disposal sites for urban solid waste located in the metropolitan area of Costa Rica, between July and October 2014. The emissions fluxes were determined using the static sampling chamber technique coupled to two different adsorption tubes: active charcoal (Supelco, ORBO 32) to capture BTEX and alcohols;and 2,4-DNPH coated silica gel (SKC, 226-119) for carbonyls. As for the VOCs, the BTEX, Alcohols, and Carbonyls total fluxes were in the range of 3 to 258, 1 to 318 and 0.4 to 8.5 mg/(m2día), respectively. The magnitudes per site were in the following order La Carpio > El Huaso > Rio Azul. Ethanol and BTEX presented a high correlation in all the cases because possibly they are sharing the same sources or formation mechanisms. The emission fluxes spatial distributions among the sites were very variable and dependent on the location of the active cells and their age. Only La Carpio showed a more homogeneous distribution due to its middle age.
