High Altitude Cities Research Articles

Erythemal weighting function adjustment for a correct calculation of UV index in high-altitude cities

Abstract Andean cities are mostly characterized, and appreciated, by their high elevation. Commonly above 2500m above the sea level. However, a more subtle feature is their proximity to the Equator. These two characteristics provide these cities with unique climatological conditions. Complementary to this, the main autoethnography of the zone is “mestizo”, which is characterized by its type of skin (namely types III and IV). These kind of skins are highly adapted to radiation intensity (and atmosphere density) of the equatorial zone. We use measurements of radiation from sensors located at Quito in order to provide a novel method to computing the local ultraviolet-index range risk, taking into account an action spectrum of skin types III and IV, and the recommendations of the World Health Organization. The results of this study could be applied directly to cities with climatological conditions, and with population with skin types, similar to those from the Andean region.

Oxidative potential of particulate matter and its association to respiratory health endpoints in high-altitude cities in Bolivia

Exposure to particulate matter (PM) pollution is a significant health risk, driving the search for innovative metrics that more accurately reflect the potential harm to human health. Among these, oxidative potential (OP) has emerged as a promising health-based metric, yet its application and relevance across different environments remain to be further explored. This study, set in two high-altitude Bolivian cities, aims to identify the most significant sources of PM-induced oxidation in the lungs and assess the utility of OP in assessing PM health impacts. Utilizing two distinct assays, OPDTT and OPDCFH, we measured the OP of PM samples, while also examining the associations between PM mass, OP, and black carbon (BC) concentrations with hospital visits for acute respiratory infections (ARI) and pneumonia over a range of exposure lags (0–2 weeks) using a Poisson regression model adjusted for meteorological conditions. The analysis also leveraged Positive Matrix Factorization (PMF) to link these health outcomes to specific PM sources, building on a prior source apportionment study utilizing the same dataset. Our findings highlight anthropogenic combustion, particularly from traffic and biomass burning, as the primary contributors to OP in these urban sites. Significant correlations were observed between both OPDTT and PM2.5 concentration exposure and ARI hospital visits, alongside a notable association with pneumonia cases and OPDTT levels. Furthermore, PMF analysis demonstrated a clear link between traffic-related pollution and increased hospital admissions for respiratory issues, affirming the health impact of these sources. These results underscore the potential of OPDTT as a valuable metric for assessing the health risks associated with acute PM exposure, showcasing its broader application in environmental health studies.

Health impacts of a cold wave and its economic loss assessment in China’s high-altitude city, Xining

ObjectiveAmidst climate change, extensive research has centered on the health impacts of heatwaves, yet the consequences of cold spells, particularly in cooler, higher-altitude regions, remain under-explored.MethodsAnalyzing climatic data and non-accidental mortality in Xining, China’s second-highest provincial capital, from 2016 to 2020, this study defines cold spells as daily mean temperatures below the 10th, 7.5th, or 5th percentiles for 2–4 consecutive days. A time-stratified case-crossover approach and distributional lag nonlinear modeling were used to assess the link between cold spells and mortality, calculating attributable fractions (AFs) and numbers (ANs) of deaths. The study also examined the impact of cold spells over different periods and analyzed the value of a statistical life (VSL) loss in 2018, a year with frequent cold spells. Stratified analyses by sex, age, and education level were conducted.ResultsA significant association was found between cold spells and non-accidental mortality, with a relative risk of 1.548 (95% CI: 1.300, 1.845). The AF was 33.48%, with an AN of 9,196 deaths during the study’s cold period. A declining trend in mortality risk was observed from 2019–2020. The 2018 VSL was approximately 2.875 billion CNY, about 1.75% of Xining’s GDP. Higher risks were noted among males, individuals aged ≥ 65, and those with lower education levels.ConclusionThe findings underscore the vulnerability and economic losses of high-altitude cities to cold spells. Implementing interventions such as improved heating, educational programs, and community support is vital for mitigating these adverse health effects.

Impacts of future urbanization and rooftop photovoltaics on the surface meteorology and energy balance of Lhasa, China

Little attention has been given to possible future urban expansion and its potential impacts in high-altitude cities of the Tibetan Plateau. This study predicts the future urban expansion of Lhasa using a metacellular automata method and investigates the change in the surface thermal environment under projected urbanization and rooftop photovoltaic (RPV) scenarios using numerical simulations. Until 2035, Lhasa will further expand along the Lhasa River Basin to the east, west, and south, most prominently to the south. Such urban expansion contributes to an increase in daily average surface air temperature of 0.63 ± 0.16 °C and a decrease in relative humidity of 1.89 ± 0.43% under cloudless weather conditions, with more significant nighttime impacts. An increase of 34.89 ± 7.69 W•m−2 in sensible heat flux and a decrease of 40.92 ± 8.02 W•m−2 in latent heat flux are shown to coincide with the urban expansion areas. In addition, it is found that the city-scale RPV scenario results in a decrease in surface sensible heat flux of 3.02 ± 1.54 W•m−2 but has little influence on latent heat and surface meteorological elements, especially in the daytime.

Impact of High-Flow Nasal Cannula Use in Subjects With COVID-19 ARDS at High Altitudes: Clinical Presentation and Prognostic Factors.

High-flow nasal cannula (HFNC) reduces the need for intubation in adult subject with acute respiratory failure. Changes in hypobaric hypoxemia have not been studied for subject with an HFNC in ICUs at altitudes > 2,600 m above sea level. In this study, we investigated the efficacy of HFNC treatment in subjects with COVID-19 at high altitudes. We hypothesized that progressive hypoxemia and the increase in breathing frequency associated with COVID-19 in high altitudes affect the success of HFNC therapy and may also influence the performance of the traditionally used predictors of success and failure. This was a prospective cohort study of subjects >18 y with a confirmed diagnosis of COVID-19-induced ARDS requiring HFNC who were admitted to the ICU. Subjects were followed up during the 28 d of HFNC treatment or until failure. One hundred and eight subjects were enrolled. At admission to the ICU, FIO2 delivery between 0.5-0.8 (odds ratio 0.38 [95% CI 0.17-0.84]) was associated with a better response to HFNC therapy than oxygen delivery on admission between 0.8-1.0 (odds ratio 3.58 [95% CI 1.56-8.22]). This relationship continued during follow-ups at 2, 6, 12, and 24 h, with a progressive increase in the risk of failure (odds ratio 24 h 13.99 [95% CI 4.32-45.26]). A new cutoff for the ratio of oxygen saturation (ROX) index (ROX ≥ 4.88) after 24 h of HFNC administration was demonstrated to be the best predictor of success (odds ratio 11.0 [95% CI 3.3-47.0]). High-altitude subjects treated with HFNC for COVID-19 showed a high risk of respiratory failure and progressive hypoxemia when FIO2 requirements were > 0.8 after 24 h of treatment. In these subjects, personalized management should include continuous monitoring of individual clinical conditions (such as oxygenation indices, with cutoffs adapted to those corresponding to high-altitude cities).

Thermal bridges in buildings of consolidated contexts in high-altitude cities. Case study: Ambato, Ecuador

This research work has been centered on the study of thermal bridges in the urban area of the city of Ambato, this city is located at an altitude of 2570m with an average temperature of 15°C throughout the year, the construction systems used in the study area mostly consist of a layer of material either clay brick or concrete block and exterior and interior finishing’s. The objective is to diagnose the points where thermal leaks can be found in consolidated environments and to provide possible solutions in different construction elements. The methodology used is based on a mixed study, which analyzes the urban context, the buildings present, the construction materials used, their relationship with the current climate of the area and the quantification of latent temperatures for further simulation. The results were obtained through a calculation software where the diagnosis and the improvement plan were simulated to increase the ambient temperature of the houses from 15-17°C to the range of 20-24°C within the comfort temperature range for interior spaces. This study concluded that it is possible to significantly improve the thermal performance of buildings in consolidated contexts with specific interventions.

Mental Disorders and Level of Resilience in Eight High-Altitude Cities of Peru during the Second Pandemic Wave: A Multicenter Population-Based Study.

COVID-19 has led us to take preventive measures, such as social isolation, to reduce the high transmissibility of the disease. This could have affected the mental health of various population groups and the development of resilience as a mitigator. A cross-sectional analytical study was conducted with 700 participants from eight cities. The dependent variables were depression, anxiety, and post-traumatic stress disorder (PTSD). The independent variable was resilience. Generalized logistic regressions were used to identify the associations between the variables. The population consisted mostly of university students (65.0%); the rest of the population was distributed among workers of public or private institutions, housewives, and others (35.0%). High prevalences of anxiety (72.7%), depression (64.1%), and PTSD (15.1%) were found, as well as a median (interquartile range) resilience score of 24 points was determined. Factors associated with a high prevalence of PTSD were having lost employment and having a family member who died from COVID-19. For depression, associated factors were severe food insecurity and hypersomnia. For anxiety, associated factors were were having a deceased family member with COVID-19 and mild food insecurity. Our results show that, during the pandemic, the general population had a higher prevalence of mental disorders. In addition, anxiety was the most prevalent of the dependent variables. Special attention should be paid to the factors influencing the development of mental disorders and mental health prevention and promotion programs should be established.

Modelling the impact of climate change on dengue outbreaks and future spatiotemporal shift in Pakistan.

Climate change hasasignificant impacton the intensity and spread ofdengueoutbreaks. The objective of this studyis to assessthe number of dengue transmission suitable days (DTSD) in Pakistan for the baseline (1976-2005) and future (2006-2035, 2041-2070, and 2071-2099) periods under Representative Concentration Pathway (RCP4.5 and RCP8.5) scenarios. Moreover, potential spatiotemporal shift and future hotspots of DTSD due to climate change were also identified. The analysis is based on fourteen CMIP5 models that have been downscaled and bias-corrected with quantile delta mapping technique, which addresses data stationarity constraints while preserving future climate signal. The results show a higher DTSD during the monsoon season in the baseline in the study area except for Sindh (SN) and South Punjab (SP). In future periods, there is a temporal shift (extension) towards pre- and post-monsoon. During the baseline period, the top ten hotspot cities with a higher frequency of DTSD are Karachi, Hyderabad, Sialkot, Jhelum, Lahore, Islamabad, Balakot, Peshawar, Kohat, and Faisalabad. However, as a result of climate change, there is an elevation-dependent shift in DTSD to high-altitude cities, e.g. in the 2020s, Kotli, Muzaffarabad, and Drosh; in the 2050s, Garhi Dopatta, Quetta, and Zhob; and in the 2080s, Chitral and Bunji. Karachi, Islamabad, and Balakot will remain highly vulnerable to dengue outbreaks for all the future periods of the twenty-first century. Our findings also indicate that DTSDwould spread across Pakistan, particularly in areas where we have never seen dengue infections previously. The good news is that the DTSD in current hotspot cities is projected to decrease in the future due to climate change. There is also a temporal shift in the region during the post- and pre-monsoon season, which provides suitable breeding conditions for dengue mosquitos due to freshwater; therefore, local authorities need to take adaption and mitigation actions.

Physical activity in the post-COVID-19: AEROBICOVID project design and perspectives

During the COVID-19 pandemic, several late-onset impairments have been observed, affecting the health and functionality of those involved. On the other hand, lower SARS-CoV-2 infection rates and severity of symptoms were observed in high-altitude cities. In this sense, the AEROBICOVID project was developed with the hypothesis that exercise would be an important opportunity for health improvement and that hypoxia would promote additional benefits in the recovery process. The cohort was about 84 participants with approximately 30 days since the COVID-19 symptoms recovery, 25 in the control group, and 59 divided into three moderate physical training groups. The project had good results in teaching, research, and extension, but also faced difficulties in operationalization. This experience is the basis for future proposals through an extension project at the University of São Paulo and in a Family Health Unit, besides a research project that will develop a new low-cost hypoxia technology.

Contribution of urban expansion to surface warming in high-altitude cities of the Tibetan Plateau

Contribution of urban expansion to surface warming in high-altitude cities of the Tibetan Plateau

Prevalence and factors associated with food insecurity in eight high-altitude cities in Peru during the second wave of the COVID-19 pandemic: a retrospective, cross-sectional study

BackgroundFood insecurity has increased during the COVID-19 pandemic, affecting an estimated 260 million people. However, little evidence is available on how pandemic-related characteristics influence food security in a high-altitude population. The objective of this study was to assess factors associated with food insecurity in high-altitude Peruvian cities during the second epidemic wave of COVID-19.MethodsA retrospective, cross-sectional study was conducted in eight Peruvian cities over 1,500 m above sea level. An online survey measuring food security, presence of anxiety & depressive symptoms, sleep quality, post-traumatic stress disorder (PTSD), resilience, and sociodemographic characteristics was disseminated through social networks between December 2020 and February 2021. Generalized linear models were used to identify an association between the study variables.ResultsOf 700 participants, the median age was 23 years, and more than half were female (56.7%). The prevalence of food insecurity was 37.1%. Anxiety symptoms, depressive symptoms, and PTSD were present in 72.7%, 64.1%, and 15% of respondents, respectively. The prevalence of food insecurity was higher in people with fair (PR: 1.60, 95% CI: 1.23–2.07) and very bad perception of their health (PR: 4.06, 95% CI: 2.63–6.26), individuals seeking mental health support (PR: 1.42, 95% CI: 1.25–1.62), and in those who lost their job due to the pandemic (PR: 1.82, 95% CI: 1.62–2.04). Having moderate (PR: 1.52, 95% CI: 1.26–1.83) and moderate to severe depressive symptoms (PR: 1.58, 95% CI: 1.11–2.27) also increased the prevalence of food insecurity.ConclusionDuring the pandemic, the prevalence of food insecurity has increased in the Peruvian high-altitude population, revealing the need for preventive strategies. Identification of pandemic-related characteristics that influence food insecurity can guide interventions in at-risk individuals and reduce the long-term impact of this problem on overall health and quality of life.

Web-Based Data to Quantify Meteorological and Geographical Effects on Heat Stroke: Case Study in China.

Heat stroke is a serious heat‐related health outcome that can eventually lead to death. Due to the poor accessibility of heat stroke data, the large‐scale relationship between heat stroke and meteorological factors is still unclear. This work aims to clarify the potential relationship between meteorological variables and heat stroke, and quantify the meteorological threshold that affected the severity of heat stroke. We collected daily heat stroke search index (HSSI) and meteorological data for the period 2013–2020 in 333 Chinese cities to analyze the relationship between meteorological variables and HSSI using correlation analysis and Random forest (RF) model. Temperature and relative humidity (RH) accounted for 62% and 9% of the changes of HSSI, respectively. In China, cases of heat stroke may start to occur when temperature exceeds 36°C and RH exceeds 58%. This threshold was 34.5°C and 79% in the north of China, and 36°C and 48% in the south of China. Compared to RH, the threshold of temperature showed a more evident difference affected by altitude and distance from the ocean, which was 35.5°C in inland cities and 36.5°C in coastal cities; 35.5°C in high‐altitude cities and 36°C in low‐altitude cities. Our findings provide a possible way to analyze the interaction effect of meteorological variables on heat‐related illnesses, and emphasizes the effects of geographical environment. The meteorological threshold quantified in this research can also support policymaker to establish a better meteorological warning system for public health.

Leadcare® II Comparison with Graphite Furnace Atomic Absorption Spectrophotometry for Blood Lead Measurement in Peruvian Highlands

Peru is one of the countries with the highest lead contamination in the world. Biological monitoring has limitations due to the shortage of laboratories with validated methodologies for the measurement of blood lead, and it is necessary to use alternative methods for its measurement in high-altitude cities. We aimed to compare the blood lead levels (BLL) measured by the LeadCare II (LC) method and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). We measured the BLL of 108 children from the city of La Oroya. The mean and median BLL for GF-AAS were 10.77 ± 4.18 and 10.44 µg/dL, respectively; for the LC method, the mean was 11.71 ± 4.28 and the median was 11.60 µg/dL. We found a positive linear correlation (Rho = 0.923) between both methods. Notwithstanding, the Wilcoxon test suggests a significant difference between both methods (ρ = 0.000). In addition, the Bland–Altman analysis indicates that there is a positive bias (0.94) in the LC method, and this method tends to overestimate the BLL. Likewise, we performed a generalized linear model to evaluate the influence of age and hemoglobin on BLL. We found that age and hemoglobin had a significant influence on BLL measured by the LC method. Finally, we used two non-parametric linear regression methods (Deming and Passing-Bablok regression) to compare the LC method with the GF-AAS. We found that these methods differ by at least a constant amount, and there would be a proportional difference between both. Although in general there is a positive linear correlation, the results of both methods differ significantly. Therefore, its use in cities located at high altitudes (higher than 2440 m.a.s.l.) would not be recommended.

High Altitude Pulmonary Edema, High Altitude Cerebral Edema, and Acute Mountain Sickness: an enhanced opinion from the High Andes- La Paz, Bolivia 3,500m.

Traveling to high altitudes for entertainment or work is sometimes associated with acute high altitude pathologies. In the past, scientific literature from the lowlander point of view was primarily based on mountain climbing. Sea level scientists developed all guidelines, but they need modifications for medical care in high altitude cities. Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema are medical conditions that some travelers can face. We present how to diagnose and treat acute high altitude pathologies, based on 51 years of high altitude physiology research and medical practice in hypobaric hypoxic diseases in La Paz, Bolivia (3,600m; 11,811ft), at the High Altitude Pulmonary and Pathology Institute (HAPPI- IPPA). These can occasionally present after flights to high altitude cities, both in lowlanders or high-altitude residents during re-entry. Acute high altitude ascent diseases can be adequately diagnosed and treated in high altitude cities following the presented guidelines. Treating these high-altitude illnesses, we had no loss of life. Traveling toa high altitude with sound medical advice should not be feared as it has many benefits. Nowadays, altitude descent and evacuation are not mandatory in populated highland cities, with adequate medical resources.

System dynamics-based prediction of municipal solid waste generation in high-cold and high-altitude area: The case of Lhasa, Tibet

The ecological environment in high-cold and high-altitude area is fragile and sensitive, which raise higher claim for municipal solid waste (MSW) management. In the high-cold and high-altitude area, there are problems, such as the mismatch between the actual amount of MSW generated and the scale of transportation and treatment facilities, and the inefficiency of MSW management. In terms of MSW forecasting methods, it is also difficult to forecast due to the lack of data. This study is the first to propose a system dynamics-based method for predicting the amount of MSW generated in high-cold and high-altitude area, and apply it to Lhasa. The research results show that the total amount of MSW generated in Lhasa is small, but the growth rate is fast. Through dynamic simulation, it is found that the synergistic consideration of gross domestic product (GDP) growth rate, urban construction policy and tourism development policy can significantly reduce the growth trend (14% emission reduction in 2030). In addition, strengthening supervision and restraint, publicity and education in high-cold and high-altitude area can produce better waste sorting effects, minimise the pressure on treatment facilities, and improve resource utilisation. Finally, the policy implications are suggested, for example, in the process of MSW management, the impact of economy, urbanisation, tourism and so on, should be taken into account and comprehensively adjusted. It is anticipated that this model and policy implications can be applied to other high-cold and high-altitude cities to provide data support and policy reference for the whole-process management of MSW.

Prediction of Blood Viscosity Based on Usual Hematological Parameters in a Clinically Healthy Population Living in a High-Altitude City.

Huamaní, Charles, William Sarmiento, Golda Córdova-Heredia, Luz Cruz-Huanca, Paulina Damián-Saavedra, and Dario Antonio. Prediction of blood viscosity based on usual hematological parameters in a clinically healthy population living in a high-altitude city. High Alt Med Biol. 23:78-84, 2022. Background and Aims: Variations in blood viscosity are mainly determined by the hematocrit level, but in residents of high-altitude cities, the hemoglobin levels and blood viscosity values are often high. We aimed to determine the blood viscosity values in clinically healthy chronic hypoxia-acclimatized individuals and establish a predictive model based on the hematocrit level and other common hematological parameters. Methods: A prospective observational study was conducted in asymptomatic young adults living in Cusco (a city located at 3,399 m). Venous blood samples were collected to determine the hemoglobin, hematocrit, and albumin and serum protein levels and blood viscosity values. Results: Altogether, 253 volunteers were included, of whom 147 (58.1%) were women. The hematological values were mean values of hemoglobin, 16.32 ± 2.0 g/dl; hematocrit, 48.12% ± 5.24%; triglycerides, 130.68 ± 90.64 mg/dl; globulin, 3.07 ± 0.36 g/dl; and mean blood viscosity, 6.17 ± 0.94 centipoises. The prediction model with the highest explained variance (R2 = 68.07%) and parsimony conservation comprised hematocrit, globulin, and triglycerides [blood viscosity = hematocrit × (0.176) + globulin × (0.595) + triglycerides × (1.77/1,000) - 4.13]. Conclusions: In a population living at high altitude, the blood viscosity level is extremely high and mainly determined by the hematocrit level. This population has chronic high blood viscosity levels, which can be predicted using other blood elements.

The relationship between the altitude and the simulations of ozone and NO2 by WRF-Chem for the Tibetan Plateau

Simulations of the spatiotemporal distribution of air constituents such as ozone and NO2 on the Tibetan Plateau (TP) can be affected by many factors such as the altitude of the observational site. In the present study, we used a mesoscale meteorological model coupled with chemistry (WRF-Chem) with two different anthropogenic emission inventories (MEIC and MEIC + EDGAR), to investigate the association of the simulation accuracy of ozone and NO2 on TP with the altitude of the observational sites. Statistical parameters such as the correlation coefficient (r) and the index of agreement (IOA) were also calculated to evaluate the model performance in capturing the concentration change of these two air constituents (i.e., ozone and NO2). The results revealed that when only the MEIC emission inventory is implemented, the deviation between the model simulations and the observations becomes larger with the increase of the altitude of the city. Moreover, it was also found that when the EDGAR emission inventory was added into the model (i.e., MEIC + EDGAR scenario), the negative dependence of the simulation accuracy of ozone on the altitude becomes weaker than that using only MEIC inventory, due to the change in ozone simulations in high-altitude cities. In contrast, simulation results of NO2 using two different emission inventories were found to be similar to each other.

Using an Eigenvector Spatial Filtering-Based Spatially Varying Coefficient Model to Analyze the Spatial Heterogeneity of COVID-19 and Its Influencing Factors in Mainland China

The COVID-19 pandemic has led to many deaths and economic disruptions across the world. Several studies have examined the effect of corresponding health risk factors in different places, but the problem of spatial heterogeneity has not been adequately addressed. The purpose of this paper was to explore how selected health risk factors are related to the pandemic infection rate within different study extents and to reveal the spatial varying characteristics of certain health risk factors. An eigenvector spatial filtering-based spatially varying coefficient model (ESF-SVC) was developed to find out how the influence of selected health risk factors varies across space and time. The ESF-SVC was able to take good control of over-fitting problems compared with ordinary least square (OLS), eigenvector spatial filtering (ESF) and geographically weighted regression (GWR) models, with a higher adjusted R2 and lower cross validation RMSE. The impact of health risk factors varied as the study extent changed: In Hubei province, only population density and wind speed showed significant spatially constant impact; while in mainland China, other factors including migration score, building density, temperature and altitude showed significant spatially varying impact. The influence of migration score was less contributive and less significant in cities around Wuhan than cities further away, while altitude showed a stronger contribution to the decrease of infection rates in high altitude cities. The temperature showed mixed correlation as time passed, with positive and negative coefficients at 2.42 °C and 8.17 °C, respectively. This study could provide a feasible path to improve the model fit by considering the problem of spatial autocorrelation and heterogeneity that exists in COVID-19 modeling. The yielding ESF-SVC coefficients could also provide an intuitive method for discovering the different impacts of influencing factors across space in large study areas. It is hoped that these findings improve public and governmental awareness of potential health risks and therefore influence epidemic control strategies.

Altitude conditions seem to determine the evolution of COVID-19 in Brazil

COVID-19 is spreading rapidly in Brazil, a country of continental dimensions, but the incidence of the disease is showing to be very heterogeneous, affecting cities and regions differently. Thus, there is a gap regarding what factors would contribute to accentuate the differences in the incidence of COVID-19 among Brazilian cities. This work aimed to evaluate the effect of altitude on the incidence of COVID-19 in Brazilian cities. We analyzed the relative incidence (RI), the relative death rate (RDR) of COVID-19, and air relative humidity (RH) in all 154 cities in Brazil with a population above 200 thousand inhabitants, located between 5 and 1135 m in altitude. Pearson's correlation analysis was performed to compare a relationship between altitude with RI and RDR, and between RH with RI and RDR. Altitudes were classified into three classes [low (altitude ≤ 97 m a. s. l), middle (97 < altitude ≤ 795 m a. s. l), high (795 < altitude ≤ 1135 m a. s. l)] for the RI, RDR, and RH variables. To compare the three classes of altitude, analysis of variance (ANOVA) and Tukey test were used to compare averages (p < 0.05). Our epidemiological analysis found that the RI, RDR, and RH were lower in cities located in high altitudes (795 < altitude ≤ 1135 m a. s. l) when compared to the middle (97 < altitude ≤ 795 m a. s. l) and low (altitude ≤ 97 m a. s. l) cities altitudes. Furthermore, our study shows that there is a negative correlation between the incidence of COVID-19 with altitude and a positive correlation with RH in the cities analyzed. Brazilian cities with high altitude and low RH have lower RI and RDR from COVID-19. Thus, high altitude cities may be favorable to shelter people at risk. This study may be useful for understanding the behavior of SARS-CoV2, and start point for future studies to establish causality of environmental conditions with SARS-CoV2 contributing to the implementation of measures to prevent and control the spread of COVID-19.

RETRACTED: Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema: A view from the High Andes

Travelling to high altitude for entertainment or work is sometimes associated with acute high altitude pathologies. In the past, scientific literature from the lowlanders' point of view was mostly based on mountain climbing. Nowadays, descent is not mandatory in populated highland cities. We present how to diagnose and treat acute high altitude pathologies (hypobaric hypoxic diseases) based on 50 years of experience in both: high altitude physiology research and medical practice as clinicians, in La Paz, Bolivia (3,600 m; 11,811 ft), at the High Altitude Pulmonary and Pathology Institute (HAPPI - IPPA). Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema are medical conditions faced by some travelers. These can occasionally present after flights to high altitude cities, both in lowlanders or in high altitude residents during re-entry, having spent more than 20 days at sea level. Traveling to high altitude should not be feared as it has many benefits; Acute high altitude ascent diseases can be adequately diagnosed and treated without descent.