New advances in the method validation, extraction methods and measurement uncertainty for the determination of water-soluble hexavalent chromium in hydraulic cement.

The quantification of Cr (VI) in the cement matrix is highly important, given the possibility of suffering illnesses including dermatitis, induced nasal carcinoma, and DNA damage produced by inhalation of and/or direct contact with this substance by construction workers. This study presents an analytical validation of the determination of water-soluble Cr (VI) using Ultraviolet-Visible Spectroscopy (UV-Vis) with 1.5-diphenylcarbazide. To do so, different performance characteristics were determined: working interval, analytical sensitivity, linearity, limits of detection (LOD) and quantification (LOQ), as well as measurement uncertainty, in order to provide better metrological information about the performance of this method. The study also focused on evaluating the impact of use of different types of standard sands (ASTM C-778 and CEN) for preparing mortar cement and extracting water soluble Cr (VI) present in the cement. For this purpose, two cements with different concentrations (2.01 ± 0.21 and 0.75 ± 0.09 mg-kg-1) of Cr (IV) were created to evaluate extraction using three types of treatments: oxidized with potassium peroxidisulfite, non-oxidized, and an alternative method using cement paste. It was observed that mortar cement using ASTM C-778 sand tends to underestimate Cr (IV) content when concentrations are below 0.8 mg kg-1, while at higher concentrations of ~2.0 mg kg-1 it does not generate different results compared to those obtained using mortar cement made with CEN-standard sand. An alternative method called "paste extraction" also showed statistically comparable results with respect to standard mortar for both concentration levels evaluated. Finally, samples of cement marketed in Costa Rica were analyzed using different types of water soluble Cr (IV) extraction methods. The results show concentrations between 0.70 ± 0.13 mg kg-1 and 1.30 ± 0.13 mg kg-1, demonstrating that they comply with the limits established by international standards and national regulations in Costa Rica.

Development and modelling of realistic retrofitted Nature-based Solution scenarios to reduce flood occurrence at the catchment scale.

Decentralized Nature-based Solutions such as Urban Green Infrastructures (UGI) are increasingly promoted to reduce flooding in urban areas. Many studies have shown the effectiveness of flood control of UGI at a plot or neighbourhood level. Modelling approaches that extrapolate their flood reducing impact to larger catchment scales are often based on a simplistic assumption of different percentages of UGI implementation. Additionally, such approaches typically do not consider the suitable space for UGI and potential implementation constraints. This study proposes a scenario development and modelling approach for a more realistic upscaling of UGI based on empirical insights from a representative neighbourhood. The results from this study, conducted in the metropolitan area of Costa Rica, show that upscaling the full potential for UGI could significantly reduce surface runoff, peak flows, and flood volumes. In particular, the permeable pavement has the highest potential for flood reducing in public space while cisterns perform best at the property level. These results can guide the formation of policies that promote UGI.

Smart Device-Based Notifications to Promote Healthy Behavior Related to Childhood Obesity and Overweight.

Obesity is one of the most serious public health challenges of the 21st century and it is a threat to the life of people according to World Health Organization. In this scenario, family environment is important to establish healthy habits which help to reduce levels of obesity and control overweight in children. However, little efforts have been focused on helping parents to promote and have healthy lifestyles. In this paper, we present two smart device-based notification prototypes to promote healthy behavior with the aim of avoiding childhood overweight and obesity. The first prototype helps parents to follow a healthy snack routine, based on a nutritionist suggestion. Using a fridge magnet, parents receive graphical reminders of which snacks they and their children should consume. The second prototype provides a graphical reminder that prevents parents from forgetting the required equipment to practice sports. Prototypes were evaluated by nine nutritionists from three countries (Costa Rica, Mexico and Spain). Evaluations were based on anticipation of use and the ergonomics of human-system interaction according to the ISO 9241-210. Results show that the system is considered useful. Even though they might not be willing to use the system, they would recommend it to their patients. Based on the ISO 9241-210 the best ranked features were the system's comprehensibility, the perceived effectiveness and clarity. The worst ranked features were the system's suitability for learning and its discriminability.

Assessment of Environmental Quality, Degree of Optimism, and the Assignment of Responsibility Regarding the State of the Environment in Latin America / Evaluación de la Calidad Ambiental, Grado de Optimismo y Asignación de Responsabilidad con Respecto al Estado del Ambiente en Latinoamérica

This study explores the assessments made by the inhabitants of eight Latin American countries regarding the current state of the environment, at a local, national and global scale, and how it is perceived looking ahead to the future. It also examines the assignment of responsibility in the future management of the environment. A total of 944 people took part in the study from the eight participating countries, men and women over the age of 18 with different levels of education. The study uses the Environmental Futures Scale to which two relevant items have been added to assess the environment in the region, as well as the Assignment of Environmental Responsibility Scale. The results show differences between the countries, although in general they are pessimistic regarding the current and future state of the environment at the local, national and global level, with the exception of Brazil. In general, and with the exception of Brazil, in the countries surveyed, people assign a high level of responsibility to external social agents at the different levels, increasing their judgement of external responsibility at the national and global levels of analysis. The implications of these findings for environmental policy and education in the countries of this region are also discussed.

El presente estudio explora las evaluaciones realizadas por los habitantes de ocho países de América Latina en relación con su percepción sobre el estado actual del medio ambiente a escala local, nacional y mundial, así como las expectativas hacia el futuro del ambiente y la asignación de responsabilidades en cuanto a la gestión del futuro ambiental. Participaron un total de 944 personas de ocho países, hombres y mujeres de más 18 años con diferentes niveles de educación. Se aplicó la Escala de Futuros Ambientales a la que se le añadieron dos ítems pertinentes para evaluar el medio ambiente en la región y los ítems correspondientes a la Escala de Responsabilidad Ambiental. Los resultados muestran diferencias entre los países, aunque en general son pesimistas sobre el estado actual y futuro del medio ambiente a nivel local, nacional y mundial, con la excepción de Brasil. Igualmente en general, y con la excepción de Brasil, en los diferentes países encuestados las personas asignan un alto nivel de responsabilidad a los agentes sociales externos en los diferentes niveles, siendo más grande la responsabilidad asignada en los ámbitos nacional y mundial. También se discuten las implicaciones de estos hallazgos para la política del medio ambiente y las implicaciones para la educación en los países de esta región.