Physiological Equivalent Temperature Index Research Articles

Associations between Short-Term Exposure to Particulate Matter and Ultrafine Particles with Lung Function in Schoolchildren from the German CorPuScula Study

BACKGROUND AND AIM: Short-term exposure to particulate matter (PM) has been associated with impaired lung function, but exposure to ultrafine particles (UFP) has been less well examined in children. METHODS: We analyzed data from 50 schoolchildren (ages 6-10) at an elementary school from the German CorPuScula study conducted from 2001 to 2002. Spirometry (VC, FEV1, MEF25-75) and body plethysmography (specific airway resistance) were performed to assess lung function. PM exposure (diameter ≤10 µm; µg/m (PM10), diameter ≤2.5 µm; µg/m³ (PM2.5)) was measured at school over the full study period, and UFP exposure was measured for six months. Mean exposures during the day of examination (9-21h) as well as one- and two-day lags were assessed. Further, individual mean UFP (1- and 3-h), and PM10 (3-, 12- and 24-h) exposures before examination were calculated. Associations between short-term air pollution and lung function were assessed using generalized estimating equation models with an autoregressive correlation matrix, adjusted for day of the week, study day and physiological equivalent temperature index using splines. Two-pollutant models adjusted for centrally-monitored NO2 were performed. RESULTS:For PM, median PM10 levels were 17.4 µg/m³ (nobs=961, average of 20 tests/child). For UFP, median UFP concentration was 21,826 particles/mL (nobs=421, average of 8 tests/child). PM and UFP showed mixed associations with spirometry outcomes. For PM, we observed weak positive associations with airway resistance for 12-h and 24-h PM10 (e.g. 7.4 % [95% CI: 1.9%; 13.3%] increase in airway resistance per 24.9 µg/m³ increase in 12-h PM10) and weak inverse associations for the two-day lag. While results for 12-h and 24h PM10 before testing were robust to NO2 adjustment, inverse associations for two-day lags disappeared. For UFP, no associations with airway resistance were visible. CONCLUSIONS:We observed mixed results for spirometry outcomes. PM10 was associated with increased airway resistance. No associations were visible for UFPs. KEYWORDS: Short-term exposure, Particulate matter, Respiratory outcomes

Thermal Comfort Analysis of Residential Home in Coastal City Based on Physiological Equivalent Temperature (PET) Index and Operative Temperature Zone

Hot and humid tropical conditions in the coastal city have specific problems with the building thermal comfort. An important fact in creating thermal comfort is strongly influenced by two main factors that are the thermal environment and thermal balance of the human body. The differences in physical adaptation, physiological adaptation, behavior, and expectation of each human make thermal comfort varied as well. This research aim is to find out the level of thermal comfort for living home in the coastal city based on physiological equivalent temperature (PET) index and operative temperature zone. The research used simulation methods with RayMan software to analyze the thermal comfort of outdoor space and CBE Thermal Comfort to analyze the thermal comfort of indoor space. There are 4 (four) different subjects simulated in this research. The results showed that the condition could be categorized as comfortable if the thermal sensation is in a neutral position with a PET index of 20.5 – 27.0 and operative temperature zone at 22.8-28.8°C. Effective thermal comfort only happened in a short period. The 2nd floor is more comfortable for activity, and old female subjects need special attention to reach thermal comfort.

Summer outdoor thermal benchmarks in Melbourne: Applications of different techniques

In urban planning, sustainability is often synonymous to urban livability. Urban livability seeks to improve living conditions of current and future outdoor users and hence it has become a key priority for cities authorities. Melbourne, as the world second most livable city, sets out to improve its urban life quality through various policies and initiatives. One area of improvement is the creation of sustainable outdoor spaces that provides comfortable thermal conditions for its residents. The relevant strategies to create such spaces are supported by the knowledge of human thermal comfort requirements, particularly during the summer thermal conditions. Hence, this study aims to develop comprehensive thermal comfort benchmarks for Melbourne during the summer. This study builds on 4717 subjective survey responses collected in seven urban environments with different settings. Data collection was performed in Melbourne's summer from 2012 to 2015. Physiological Equivalent Temperature (PET) was used to predict thermal comfort conditions. The results were based on four thermal comfort measures (neutral temperature, preferred temperature, acceptable thermal range and thermal comfort range). The analysis' outcomes suggested that Melbourne's summer acceptable thermal range is between 11.3 °C and 20.3 °C, the preferred temperature value is 21.5 °C, the neutral temperature value is 16.1 °C. Furthermore, PET index was calibrated against thermal responses collected from the surveys. The results would help to inform policies aiming to create sustainable outdoor spaces that are pleasant to outdoor users in Melbourne.

Summer thermal comfort in Russian big cities (1966-2015)

The main goal of the study is the assessment of modern bioclimatic conditions (1966-2015) for determining the level of comfort in large Russian cities based on the observations at the meteorological stations, including Physiological Equivalent Temperature (PET) for the main extent of thermal comfort. According to the distribution of thermal stress events (calculated for meteorological fix hours, 8 times per day) the authors created the comfort diagram for each city during daytime heat wave period and evaluated their comfort conditions. In the current research we are operating with WMO climatic data for eleven biggest cities of the Russian Federation: from the European part (Moscow, Saint-Petersburg, Ekaterinburg, Voronezh, Volgograd, Kazan, Nizhny Novgorod, Perm, Ufa) and from Siberia (Omsk and Krasnoyarsk). The most interesting result of the comparison of the long-period (50 years) urban trends (PET-index and Air Temperature) in different parts of Russia is its extraordinary cross-shaped form in Moscow (in other cities the trends lines are practically parallel to each other). It means that at the level of the average annual values, only in Moscow the PET index (and, hence, potentially the thermal stress) grows faster than the regional climate warms. In other cities this tendency is much weaker (N.Novgorod) or not significant. This interesting tendency is caused by both Moscow related urban planning dynamics in post-USSR period and by regional climate dynamics.

The effect of kharkhona on outdoor thermal comfort in Hot and dry climate: A case study of Sistan Region in Iran

Few, if any, studies have researched the effects of vegetation, water and shading on outdoor thermal comfort in the hot and dry climate. This study identified and examined the effect of kharkhona as an architectural element of Sistan Region, which is often used in closed spaces, on outdoor thermal comfort in the hot and dry climate of Sistan during the summers of 2019 and 2020 with the aim of improving the unfavorable climatic conditions of the region via building on a technique devised by the residents of Sistan. To this end, a kharkhona was designed, built and evaluated in an open urban space. Physiological equivalent temperature index, which has been shown to be highly associated with the sensation of thermal comfort, was used as the indicator for evaluation of outdoor thermal condition. The findings showed that kharkhona can reduce the PET index by 9.34 °C in the space inside kharkhona compared to the environment outside the construct and moderate the “hot” and “very hot” heat sensation of the space outside kharkhona to “warm” and “slightly warm” in the inner space of the construct. Kharkhona can be used as a reference model for designing natural ventilation and is a viable strategy for modification of outdoor thermal comfort since it can provide better comfort conditions than vegetation.

Health risk for older adults in Madrid, by outdoor thermal and acoustic comfort

Cities must adapt to aging populations and mitigate the effects of climate change and urbanization on health. This study analyses the outdoor thermal and acoustic comfort of older adults in public spaces in Madrid. We compared the subjective perception with real environmental conditions measured in-situ and two thermal comfort indices Physiological Equivalent Temperature (PET) and Universal Thermal Index (UTCI). Additionally, use and stay of older people in those public spaces was assessed. Results showed that older adults represent 26.35% of the users, environmental variables such as mean radiant temperature, air temperature, and noise levels are the most relevant variables for them to decide to stay in these places. Although most of the 413 interviewees perceived the environment as comfortable, this research shows that in dense urban areas there is a significant health risk due to noise pollution and extreme temperatures. Average noise levels measured exceed the maximum threshold recommended by the World Health Organization and according to PET and UTCI indices around 73% of the interviewees would be in risk of thermal stress in winter and 98.2% in summer. The need for further research to find strategies to mitigate the environmental risks of older people in public spaces is evident.

The physiological equivalent temperature (PET) Index and non-accidental and cardiovascular respiratory disease mortality in Ahvaz, Iran

Background: Climate change may be associated with human morbidity and mortality through direct and indirect effects. Ahvaz is one of the hottest cities in the world. The aim of this study was to investigate the relation between Physiologically Equivalent Temperature (PET) and non-accidental, cardiovascular and respiratory disease mortality in Ahvaz, Iran. Methods: Distributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to investigate the effect of PET on deaths. In this study the effect of time trend, air pollutants (NO2, SO2 and PM10), and weekdays were adjusted. Results: The results showed that in cold stress (the PET index, 1st percentile (2.7 CO) relative to 25th percentile (11.9 CO)) the risk of non-accidental mortality in men and the 65-74 year olds; and also total respiratory mortality, respiratory mortality in men, in people under 65 and the 65-74 year olds; significantly decreased in the cumulative lags of 0, 0-2, 0-6 and 0-13. In contrast, heat stress (the PET index, 99th percentile (44.9 CO) relative to 75th percentile (43.4 CO)) significantly increased the risk of total cardiovascular mortality (CVD), cardiovascular mortality in men and the elderly, ischemic heart disease and cerebrovascular disease mortality in lags 0 and 0-2. Conclusions: It seems that high PET values increase the risk of cardiovascular mortality, while low PET values have a protective effect on mortality, especially respiratory mortality in Ahvaz.

Calculation of comfortable thermal conditions for Mersin urban city planning in Turkey

Computer models that evaluate the formulas of these indices together with environmental factors and human characteristics have been created. Physiological equivalent temperature index and classification summer calculation model used for bioclimatic comfort calculations by obtaining monthly data of General Directorate of State Metrology Stations between 1972 and 2018 in Mersin city center. The results, comfortable monthly intervals, were determined and necessary suggestions were made for the people of Mersin city center in a month. In the calculations, the meteorological parameters such as surface-and-air temperature, wind speed, and relative humidity were taken into consideration. Monthly results show the bioclimatically comfortable area in September and May. There are conditions in Mersin that lead to comfortable perceptions in summer. During the cold period, different levels appear and warm and comfortable thermal conditions are observed. GIS analysis was used to determine the development of thermal perceptions over time. It was calculated between 1972 and 2018. According to these coefficients, there is a tendency to increase in PET values in the regions close to the water in Mersin and to decrease in Mersin, which is the station in rural areas, as a city station.

Quantifying the cooling effect of rain events on outdoor thermal comfort in the southern coastal stations of the Caspian Sea.

Pleasant outdoor thermal conditions depend on a wide range of climatic elements. The impact of rainfall events, as important climatic elements, on providing thermal comfort, has been less explored in the available literature. The work presented herein investigates the impact of Rainy Days as well as a Day Prior to (Dprior) and a Day Post rain (Dpost) events on thermal conditions in the southern coastal region of the Caspian Sea. In this study, rainfall events during 1961-2017 observational period were categorized based on their intensity. Then, human thermal comfort during non-rainy (sunny) and rainy days was estimated and compared by using the radiation-driven Physiological Equivalent Temperature (PET) index, Universal Thermal Climate Index (UTCI) and Perceived Temperature (PT) index. Furthermore, difference between the average of thermal conditions in rainy days compared to a day prior and a day post rain events was calculated separately for comfort, cold and heat stress thresholds of each bioclimatic index. Finally, the correlation between the average of indices for rainy days and the frequency of rainfall events of each specific year was computed. Results suggested that overall average of studied indices for all rainy days is lower than the average for days prior and post the rain events. PET index has shown to be most impacted and reduced as a result of rain events and therefore more indicative of a cool ing effect. The observed difference in total average of PET in rainy days compared to non-rainy days were 8.30°C, 5.86°C and 8.85°C for Babolsar, Rahst and Gorgan stations, respectively. Generally, the cooling effect of rain events on the temperature for a day prior rain events is higher than a day post rainfall. Finally, the trend analysis on rainy days in the studied period revealed that the average of bioclimatic indices in western stations (Babolsar and Rasht) are increasing whereas a decreasing trend was observed for Gorgan as more of an eastern station.

Human thermal climate of the Carpathian Basin

AbstractA human body–clothing–atmosphere environment system energy balance model is constructed to evaluate individual human thermal climates in the Carpathian Basin. The analysis is performed in terms of clothing resistance and operative temperature for the period 1971–2000. The model's main strength is that it simulates the metabolic activity rate M as simply as possible taking into account interpersonal variations. Non‐sweating, walking humans are considered in natural outdoor conditions at a walking speed of 4 km⋅h−1. Atmospheric data are used from the CarpatClim dataset; human data are taken from a Hungarian human dataset. The dataset reveals that the interpersonal variations of M of walking humans can reach 40–50 W⋅m−2. According to the results, the variability of individual human thermal climates can be significant. This variability increases towards cold climates and is less in the comfortable thermal zone, when the operative temperature is between 23 and 28°C. It should be mentioned that summer is thermally neutral in the Little Hungarian Plain, the Great Hungarian Plain and in larger parts of the Transylvanian Plateau, irrespective of the person considered. The warmest areas in the Carpathian Basin can be found in Bačka and Banat. In terms of thermal sensation, the results obtained agree well with the results referring to the human considered in the Physiological Equivalent Temperature index model.

Human thermal sensation over a mountainous area, revealed by the application of ANNs: the case of Ainos Mt., Kefalonia Island, Greece.

Mt. Ainos in Kefalonia Island, Greece, hosts a large variety of plant species, some of them endemic to the region. Because of its rich biodiversity, a large portion of the mountain area is designated as National Park and is protected from human activities such as hunting or logging. Therefore, the area presents a lot of opportunities for ecotourist activities, such as trekking, birdwatching, and mountain climbing. In order to estimate its touristic activities potential, it is essential to assess the mountain's biometeorological conditions. To achieve that, the human thermal index PET (physiologically equivalent temperature) was used, which is based on a human energy balance model. However, it is difficult to get the specific meteorological data over mountainous areas (air temperature, humidity, wind speed, and global solar radiation), appropriate as input variables for PET modeling. In order to overcome this limitation, artificial neural networks (ANNs) were developed for the estimation of PET index in ten sites within the Ainos National Park. In the process, the spatiotemporal distributions of the PET thermal index were illustrated, taking into consideration the ANN modeling. The findings of the performed analysis shed light that Mt. Ainos offers the greatest touristic opportunities from May to September, when thermal comfort conditions appear. The study also proves that the highest frequency of thermal comfort appears within the aforementioned time period over the highest altitudes, while on the contrary, slightly warm class appears as the altitude decreases on both sides of the mountain.

خنک سازی محیطهای شهری و تأثیر آن بر تغییرات اقلیمی در محلات سنتی و سکونتگاههای غیررسمی از طریق آسایش حرارتی بیرونی (نمونه موردی محلات عاملی ، قلعه ساختمان و شهرک حجت شهر مشهد)

خنک سازی محیطهای شهری و تأثیر آن بر تغییرات اقلیمی در محلات سنتی و سکونتگاههای غیررسمی از طریق آسایش حرارتی بیرونی (نمونه موردی محلات عاملی ، قلعه ساختمان و شهرک حجت شهر مشهد)

Thermal Sensation in Courtyards: Potentialities as a Passive Strategy in Tropical Climates

Climate change will bring changes to our living conditions, particularly in urban areas. Climate-responsive design strategies through courtyards can help to moderate temperatures and reduce the thermal stress of its occupants. Thermal response inside courtyard is affected not only by its morphological composition but also by subjective factors. Thus, standardized thermal scales may not reflect the stress of the occupants. This study investigated the impact on thermal attenuation provided by a courtyard located in a tropical climate under extreme cold and hot synoptic conditions by means of local thermal sensation scales. Microclimatic variables were monitored, simultaneously with the application of a thermal comfort questionnaire, by using weather stations installed outside and inside the courtyard. The Modified Physiological Equivalent Temperature Index (mPET) was utilized to predict the heat stress. Calibration was conducted using linear regression to attribute particular thermal sensation votes to correspondent mPET values. It was found that thermal sensation can be affected by factors such as psychological, behavioral, and physiological. The courtyard’s form provides a passive cooling effect, stabilizing interior thermal sensation, with attenuation peaks of 6.4 °C on a cold day and 5.0 °C on a hot day. Courtyards are an alternative passive strategy to improve thermal ambience in tropical climate, counterbalancing climate change.

Post-occupancy evaluation of outdoor thermal comfort in hot arid zone

Abstract Human comfort and healthy environments lie at the core of every debate about outdoor spaces nowadays. Thermal comfort is a vital concern for planners and designers in order to produce a healthy and thermally comfortable environment, since the influence of different climates and user groups has been found to greatly alter the range of responses for thermal comfort calculations. This requires Post-Occupancy Evaluation (POE) with an integration of the appropriate outdoor thermal comfort (OTC) index. This paper presents the results of a detailed assessment for the OTC in hot arid zone (HAZ) using the most suitable thermal index. A case study was selected from Effat Campus, Jeddah, Saudi Arabia, to represent the HAZ. Subjective assessment employed the physiological equivalent temperature (PET) and the predictive mean vote (PMV) thermal indices in analysing the results of online and self-directed questionnaires while objective assessment employed a hand-held anemometer that was used to measure wind speed, whereas the wet bulb globe temperature (WBGT) SD Card Logger with a black globe thermometer 75 mm in diameter and emissivity of 0.95 was used to measure the globe temperature. The physical measurements were later used to calculate the mean radiant temperature (MRT) and consequently the PET index using RayMan Software. The results confirmed the significance of the shading strategy on OTC. The study revealed that there is no percentage as shading is permitting people to use the space; otherwise, in hot arid zone, the space would be completely unusable under the sun while the PET is more suitable than the PMV index.

Is Physiological Equivalent Temperature (PET) a superior screening tool for heat stress risk than Wet-Bulb Globe Temperature (WBGT) index? Eight years of data from the Gothenburg half marathon

BackgroundThe Wet-Bulb Globe Temperature (WBGT) index is a common tool to screen for heat stress for sporting events. However, the index has a number of limitations. Rational indices, such as...

The effect of physiological equivalent temperature index variations on mortality in Urmia (The Northwest of Iran)

The effect of physiological equivalent temperature index variations on mortality in Urmia (The Northwest of Iran)

Evaluation of tourism climate conditions at three stations of Noshahr, Ramsar and Rasht using the physiological equivalent temperature and average predicted polling index

Provinces located on the southern shores of the Caspian Sea are one of the most important northern places in the country that have always attracted a great deal of tourists in different seasons of the year due to their various natural, human and historical attractions. Every year, they welcome different tourists. These beaches, while having attractive features for tourists, can also play a vital role in the sustainable development of the natural scenery and conservation area. One of the steps to reach sustainable development is tourism planning. The first step in this area is to assess the tourism climate in the country. In this study, in order to evaluate the conditions of the northern climate of Iran's climate, the meteorological data of synoptic stations of Noshahr, Ramsar and Rasht have been used in a 30-year statistical period divided into three decades of age. The method used to assess the climate of comfort, the physiological equivalent temperature index, and the predicted mean of the survey. The results of this study show that the highest climatic conditions for spending leisure time and tourism activities in this region are two separate periods in the middle of spring (May and June) and the beginning of the fall season (October). The continuation of average heat stress from July to August and cold stress from different periods from November to the end of the winter season is a factor for tourism constraints during these months. For other months, they have relatively good weather conditions in terms of temperature and humidity in a little warm and slightly cool thermal condition. Also, changes over the decades indicate climate change and impact on thermal comfort.

The impact of green space structure on physiological equivalent temperature index in open space

Planting vegetation in urban areas can tilt the heat balance in favor of cooler temperatures. For this reason, studying the extension and intensity of the cooling effect of vegetation and the factors which can influence these two parameters is significant in open space design. In this regard, the purpose of the present study was to analyze the different thermal behaviors of green spaces at the micro scale and explain the reason of different extensions and intensities of the cooling effect in spaces which have vegetation. The region of Sistan (Zabol), situated east of Iran, was selected as the study area. Data analysis and study of the parameters affecting physiological equivalent temperature index indicated that the highest impact of green space on this index is related to air temperature and mean radiant temperature among all microclimatic parameters. It was revealed that in stations with vegetation, mean air temperature was lower by 1 °C, mean radiant temperature was lower by 6 °C and PET index was lower by 7 °C in comparison to stations without any vegetation. Analysis of the relation between PET and spatial variables which form the structure of green space, indicated that flooring type has a significant relation with physiological equivalent temperature.

Thermal discomfort analysis using UTCI and MEMI (PET and PMV) in outdoor environments: case study of two climates in Iran (Arak & Bandar Abbas)

AbstractObjectivesThe aim of this study was to analyse the thermal discomfort of outdoor environments in two climates of Iran using physiological equivalent temperature (PET), predicted mean vote (PMV) indices and Universal Thermal Climate Index (UTCI).MethodsIn this study, the meteorological data recorded by the meteorological organisation in a 15‐year period, including temperature, air velocity, cloudiness, relative humidity and water vapour pressure, in two different climates of Iran were surveyed. According to classification of the Köppen, Arak as a representative of a semi‐arid and cold climate and Bandar Abbas as a representative of a hot and dry climate were used to calculate thermal indices. The PMV index was based on the ASHRAE 7‐point thermal sensation scale, and the values of PMV and PET indices were extracted using Rayman1.2 software. The values of the UTCI were calculated using BioKlima 2.6 software.ResultsThe results showed that the maximum and minimum temperatures in two climates were related to July and January, respectively. In Arak, the means of the UTCI, PET and PMV indices were 14.41 ± 11.5, 15.81 ± 1.23 and −0.77 ± 2.15, respectively. In Bandar Abbas as well, the mean of the UTCI, PET and PMV indices were 22.56 ± 9, 22.73 ± 7.7 and 0.73 ± 7.7, respectively. In Arak, there was moderate heat stress to moderate cold stress in this region, whereas in Bandar Abbas, the days had a strong heat stress to low cold stress. There are very strong correlations between the indices used for two different climates.ConclusionThe bioclimatic comfort indices used were able to demonstrate the comfort and discomfort of people during different months of the year in two surveyed climates, and despite trivial differences, they provided relatively uniform representations of climate comfort for surveyed cities. Using thermal comfort indices, high‐risk areas can be identified, and appropriate measures can be adopted to reduce the effects of the changes.

Study on Environment Regulation of Residential in Severe Cold Area of China in Winter: Base on Outdoor Thermal Comfort of the Elderly

Overwhelming evidence shows that the harsh climate conditions are affecting urban residents who are living in severe cold areas of China in winter, particularly affecting the frequency and length of outdoor space usage of the elderly. This study aims (1) to establish the modified model which is suitable for the harsh climate region, (2) to verify whether the physiological equivalent temperature (PET) index can be evaluated for the outdoor thermal comfort of older adults in severe cold areas of China in winter, (3) to draw the thermal comfort map that is based on the former conclusions. In this study, the outdoor environments in typical residential areas for the elderly of Changchun, China, has been investigated by using field measurement, questionnaire survey, and Computational Fluid Dynamics (CFD) simulation. The results show that the wind direction is the important aspects of model modification and quite possibly one of the most neglected. In addition, it is convenient to evaluate outdoor thermal comfort of the elderly on the basis of the PET index and the neutral PET temperature of elderly people who live in severe cold areas of China in winter is −0.5 degrees Celsius. According to the thermal comfort map, the park green land of urban residential is the best area for the elderly.