Addressing air quality challenges: Comparative analysis of Barcelona, Venezuela, and Guayaquil, Ecuador.

This study presents a willingness-to-pay (WtP) questionnaire that was designed, validated, and applied to assess perceptions of air quality and self-reported health in two middle-income South American cities: Barcelona and its neighboring cities (Venezuela) and Guayaquil (Ecuador). These cities lack air quality monitoring and control measures. The questionnaire is a reliable tool to assess air quality based on citizens' perceptions, and the results reveal that both populations perceive low air quality and accurately identify emission sources and air pollutants (industrial emissions and particulate matter in Barcelona and vehicular emissions and carbon monoxide in Guayaquil). The study also evaluated the efforts made by both cities to improve air quality using the United Nations Environment Programme to strengthen air quality in South America. Based on this evaluation, strengths were identified for enhancing air quality in both cities. The study finds that in Barcelona and its surroundings, investment is needed to improve urban transport, waste management, and update the environmental legislation regarding air quality at the national level. In contrast, Guayaquil has already taken some measures to improve air quality, but more investment in public transport and measures to lower vehicle emissions are needed.

PM2.5 exceedances and source appointment as inputs for an early warning system.

Between June 2018 and April 2019, a sampling campaign was carried out to collect PM2.5, monitoring meteorological parameters and anthropogenic events in the Sartenejas Valley, Venezuela. We develop a logistic model for PM2.5 exceedances (≥ 12.5 µg m-3). Source appointment was done using elemental composition and morphology of PM by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). A proposal of an early warning system (EWS) for PM pollution episodes is presented. The logistic model has a holistic success rate of 94%, with forest fires and motor vehicle flows as significant variables. Source appointment analysis by occurrence of events showed that samples with higher concentrations of PM had carbon-rich particles and traces of K associated with biomass burning, as well as aluminosilicates and metallic elements associated with resuspension of soil dust by motor-vehicles. Quantitative source appointment analysis showed that soil dust, garbage burning/marine aerosols and wildfires are three majority sources of PM. An EWS for PM pollution episodes around the Sartenejas Valley is proposed considering the variables and elements mentioned.

Indicadores nutricionales en pacientes infectados con virus de inmunodeficiencia humana / Nutritional indicators in HIV infected patients

Para determinar la utilidad de los indicadores del estado nutricional y su asociación con el estado inmunológico se evaluaron 24 pacientes VIH positivo, en diferentes estadios de la enfermedad. Se utilizaron parámetros antropométricos, bioquímicos, e inmunológicos, 33 por ciento de los pacientes tenía estado nutricional normal y 67 por ciento presentó algún grado de desnutrición, 38 por ciento presentó pérdida de peso mayor al 10 por ciento, 60 por ciento tenían pliegue cutáneo del tríceps (PCT) menor a 12,5 mm, 54 por ciento circunferencia muscular del brazo (CMB) inferior a 25,3 cm, 33 por ciento índice de masa corporal (IMC) menor de 20 kg/m², 36 por ciento albúmina (ALB) menor a 3,5 g/dl, 48 por ciento transferrina (TF) menor a 2,0 g/L, 40 por ciento contaje linfocitario (CL) menor de 1500 cel/mmü y 76 por ciento con contaje de linfocitos CD4 menor de 500 cel/mmü. Los parámetros más sensibles fueron: pliegue cutáneo de tríceps, transferrina sérica y contaje CD4. Un 50 por ciento presentó CD4 menor de 200 cel/mmü, 25 por ciento entre 200-500 y 25 por ciento mayor de 500. Hubo diferencia significativa en peso, circunferencia media del brazo, índice de masa corporal, transferrina y contaje linfocitario entre los pacientes y controles, para diferenciar los controles de los desnutridos y estos entre sí, los mejores indicadores fueron porcentaje de pérdida de peso, IMC contaje linfocitario y de CD4 y los menos útiles fueron los bioquímicos. El comportamiento de las variables al comparar según estadío de la enfermedad por CD4 fue similar. Mientras más severo el daño nutricional y el estadío de la infección, mayor deterioro presentaron los parámetros antropométricos, bioquímicos e inmunológicos, lo cual permite su utilización para el seguimiento y evolución de la enfermedad