44 research outputs found
Heat Waves: Health Effects, Observed Trends and Climate Change
According to climate change scenarios, the average annual temperature will increase by around 4°C if current trends continue. Maximum temperatures, however, have already registered higher values in different regions of the world, increasing the number, duration and intensity of heat waves. With the increase of maximum temperatures and the increase of significance of heat wave events, reports of mortality episodes due to heat effects have been increasing. According to the information from the Centre for Research on Epidemiology of Disasters (CRED), 5 of the 20 deadliest disasters between 1996 and 2015 were heat wave events. This chapter analyzes heat wave events, the criteria for determining dangerous temperature thresholds, as well as trends already observed, and those expected due to climate change. Heat wave events are correlated with observed increases on mortality rates, and recommendations are suggested to prevent their effects on human health
Efectos de los estrógenos como contaminantes emergentes en la salud y el ambiente
Los contaminantes emergentes son sustancias que tienen el potencial de dañar al ser humano, flora y fauna, y no están regulados por la legislación. Los estrógenos son parte de esta definición, es decir, contaminantes emergentes, que cuando incrementan su concentración en el ser humano o el ambiente causan daño. Los seres humanos están expuestos a concentraciones altas de estrógenos debido a su uso como parte de terapias de reemplazo hormonal o métodos anticonceptivos. Flora y fauna están expuestas a los estrógenos cuando se incorporan al ambiente por descargas de agua residual municipal, efluentes de plantas de tratamiento o por escurrimientos con desechos de la ganadería y otras actividades pecuarias. En este trabajo se presenta una revisión del estado del conocimiento sobre los efectos de los estrógenos en los seres humanos y la vida silvestre. Asimismo, se identifican el origen antropogénico, presencia y características de los estrógenos en el ambiente. Por último, se señalan algunos procesos de tratamiento para reducir o eliminar los estrógenos del agua
Characterization of Corrosion Behavior of Painted Galvanized Steel under Accelerated Conditions
In the present study three systems of carbon steel (1008) are evaluated, which were provide of two corrosion control methods, barrier and cathodic protection (painted and galvanized respectively) commonly used in the construction industry. They were evaluated under accelerated conditions exposed in fog chamber, according to ASTM B-117, which specifies continues exposition of sodium chloride at 5% and 35 °C. The main aim of the research was to characterize the corrosion resistance and to determine the degradation mechanism under test’s conditions. The results after 1080 and 3500 hours of exposure are presented, with adhesion measure (ASTM D-3359) and scratch resistance measure (D-1654) for each exposure time, as well as the characterization of corrosion attack through the mapping analysis of Scanning Electron Microscope / Energy Dispersive X-ray. According to the results it is proposed that the corrosion of the systems under study begins at galvanized – metal base interface. Later advances due to formation of porous layer of zinc hydroxi-chloride, which it’s characteristic of environments with chloride ions, forming zinc’s corrosion products like zinc oxide and zinc hydroxide on the porous layer until iron starts to dissolve, producing iron oxide and iron oxy-hydroxide on the zinc’s corrosion products and porous layer
Brief for GSDR - Emerging Contaminants in urban stormwater: Challenges and perspectives for sustainable water use
Emerging contaminants (ECs) are chemical compounds commonly present in water. It is only recently that this family of compounds is being recognized as significant water pollutants (. ECs include a wide variety of chemicals such as pharmaceutical and personal care products (PPCPs), pesticides, hydrocarbons and hormones, among others, that once released into the environment exert adverse impacts on the human and wildlife endocrine system. Natural attenuation and conventional treatment processes are not capable of removing these micro-pollutants detected in wastewater influent and effluent and surface and drinking water. The main challenges related with presence of ECs in stormwater in the context of reuse are: a) Development of suitable laboratory test methodologies and protocols for ECs identification and quantification b) Identification of the sources of ECs in the urban environment; c) Understanding their impacts on human and/or ecosystem health; and d). Development of cost-effective removal technologies which are appropriate for large as well as small-scale application
Engineered nanomaterials (ENMs) and their role at the nexus of Food, Energy, and Water
The use of engineered nanomaterials (ENMs) to improve food production, energy generation, and/or the removal of pollutants from water have changed several paradigms related with the way that the scientific community conceives the future of the respective fields. Nevertheless, the use of ENMs and their eventual release into the environment also generate concerns related with some undesirable effects that have been observed for ENMs once they enter the air, soil, or water. A significant amount of controversial results related with the role of ENMs and their potential side effects have been published, with the consequent lack of clarity and increased misinformation. This study is devoted to reviewing the role of ENMs at the nexus of food, energy, and water (FEW)—including some examples of their current applications and challenges specifically related with food production—as well as discussing their potential effects on the FEW nexus. Keywords: Engineered nanomaterials, Nexus, Food, Energy, Wate
Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV Irradiation
Iron-doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-ray Photoelectron Spectroscopy (XPS). The XPS evidenced that the ferric ion (Fe3+) was in the TiO2 lattice and unintentionally added co-dopants were also present because of the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radicals ((OH)-O-center dot) and estriol (E3) degradation. Fe-TiO2 accomplished E3 degradation, and it was found that the catalyst with 0.3 at.% content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV irradiation compared with TiO2 without intentionally added Fe (zero-iron TiO2) and Aeroxide (R) TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water
Temperature and Heat-Related Mortality Trends in the Sonoran and Mojave Desert Region
Extreme temperatures and heat wave trends in five cities within the Sonoran Desert region (e.g., Tucson and Phoenix, Arizona, in the United States and Ciudad Obregon and San Luis Rio Colorado, Sonoraand Mexicali, Baja California, in Mexico) and one city within the Mojave Desert region (e.g., Las Vegas, Nevada) were assessed using field data collected from 1950 to 2014. Instead of being selected by watershed, the cities were selected because they are part of the same arid climatic region. The data were analyzed for maximum temperature increases and the trends were confirmed statistically using Spearman's nonparametric test. Temperature trends were correlated with the mortality information related with extreme heat events in the region. The results showed a clear trend of increasing maximum temperatures during the months of June, July, and August for five of the six cities and statically confirmed using Spearman's rho values. Las Vegas was the only city where the temperature increase was not confirmed using Spearman's test, probably because it is geographically located outside of the Sonoran Desert or because of its proximity to the Hoover Dam. The relationship between mortality and temperature was analyzed for the cities of Mexicali, Mexico and Phoenix. Arizona