A Suitable Thermal Stress Index for the Elderly in Summer Tropical Climates

A Web Survey to Evaluate the Thermal Stress Associated with Personal Protective Equipment among Healthcare Workers during the COVID-19 Pandemic in Italy

The pandemic has been afflicting the planet for over a year and from the occupational point of view, healthcare workers have recorded a substantial increase in working hours. The use of personal protective equipment (PPE), necessary to keep safe from COVID-19 increases the chances of overheating, especially during the summer seasons which, due to climate change, are becoming increasingly warm and prolonged. A web survey was carried out in Italy within the WORKLIMATE project during the summer and early autumn 2020. Analysis of variance (ANOVA) was used to evaluate differences between groups. 191 questionnaires were collected (hospital doctor 38.2%, nurses 33.5%, other healthcare professionals 28.3%). The impact of PPE on the thermal stress perception declared by the interviewees was very high on the body areas directly covered by these devices (78% of workers). Workers who used masks for more than 4 h per day perceived PPE as more uncomfortable (p < 0.001) compared to the others and reported a greater productivity loss (p < 0.001). Furthermore, the study highlighted a high perception of thermal stress among healthcare workers that worn COVID-19-PPE and this enhances the need for appropriate heat health warning systems and response measures addressed to the occupational sector.

A human-centred assessment framework to prioritise heat mitigation efforts for active travel at city scale

Hot weather not only impacts upon human physical comfort and health, but also impacts the way that people access and experience active travel options such as walking and cycling. By evaluating the street thermal environment of a city alongside an assessment of those communities that are the most vulnerable to the effects of heat, we can prioritise areas in which heat mitigation interventions are most needed. In this paper, we propose a new approach for policy makers to determine where to delegate limited resources for heat mitigation with most effective outcomes for the communities. We use eye-level street panorama images and community profiles to provide a bottom-up, human-centred perspective of the city scale assessment, highlighting the situation of urban tree shade provision throughout the streets in comparison with environmental and social-economic status. The approach leverages multiple sources of spatial data including satellite thermal images, Google street view (GSV) images, land use and demographic census data. A deep learning model was developed to automate the classification of streetscape types and percentages at the street- and eye-view level. The methodology is metrics based and scalable which provides a data driven assessment of heat-related vulnerability. The findings of this study first contribute to sustainable development by developing a method to identify geographical areas or neighbourhoods that require heat mitigation; and enforce policies improving tree shade on routes, as a heat adaptation strategy, which will lead to increasing active travel and produce significant health benefits for residents. The approach can be also used to guide post COVID-19 city planning and design.

The Impact of Non-optimum Ambient Temperature on Years of Life Lost: A Multi-county Observational Study in Hunan, China

The ambient temperature–health relationship is of growing interest as the climate changes. Previous studies have examined the association between ambient temperature and mortality or morbidity, however, there is little literature available on the ambient temperature effects on year of life lost (YLL). Thus, we aimed to quantify the YLL attributable to non-optimum ambient temperature. We obtained data from 1 January 2013 to 31 December 2017 of 70 counties in Hunan, China. In order to combine the effects of each county, we used YLL rate as a health outcome indicator. The YLL rate was equal to the total YLL divided by the population of each county, and multiplied by 100,000. We estimated the associations between ambient temperature and YLL with a distributed lag non-linear model (DNLM) in a single county, and then pooled them in a multivariate meta-regression. The daily mean YLL rates were 22.62 y/(p·100,000), 10.14 y/(p·100,000) and 2.33 y/(p·100,000) within the study period for non-accidental, cardiovascular, and respiratory disease death. Ambient temperature was responsible for advancing a substantial fraction of YLL, with attributable fractions of 10.73% (4.36–17.09%) and 16.44% (9.09–23.79%) for non-accidental and cardiovascular disease death, respectively. However, the ambient temperature effect was not significantly for respiratory disease death, corresponding to 5.47% (−2.65–13.60%). Most of the YLL burden was caused by a cold temperature than the optimum temperature, with an overall estimate of 10.27% (4.52–16.03%) and 15.94% (8.82–23.05%) for non-accidental and cardiovascular disease death, respectively. Cold and heat temperature-related YLLs were higher in the elderly and females than the young and males. Extreme cold temperature had an effect on all age groups in different kinds of disease-caused death. This study highlights that general preventative measures could be important for moderate temperatures, whereas quick and effective measures should be provided for extreme temperatures.

Uso de sistemas modulares vegetados para promoção da saúde urbana e atenuação do estresse térmico

RESUMO O processo de urbanização possui efeitos significativos no microclima local, resultando no surgimento das ilhas de calor e comprometimento das condições térmicas no interior de habitações. A aplicação de sistemas modulares vegetados em telhados ou coberturas surge como alternativa à melhoria das condições térmicas no interior de habitações, dispensando, algumas vezes, a climatização artificial e promovendo melhores condições de salubridade no ambiente. A avaliação da atenuação do estresse foi realizada por meio da comparação entre duas habitações protótipos idênticas em que uma possui telhado e paredes vegetadas, e a outra, não. O estresse térmico foi avaliado com base no Índice de Calor, que considera os efeitos combinados da temperatura e umidade relativa. O sistema modular vegetado exerceu papel importante na atenuação do estresse térmico nas habitações, melhorando os parâmetros das condições de salubridade ambiental e minimizando riscos associados à saúde. Os Índices de Calor máximos registrados nos protótipos não vegetado e vegetado foram 57,5°C e 49,2°C respectivamente. Em termos de atenuação do estresse térmico, a adoção dos sistemas vegetados diminui o tempo de exposição de condições térmicas referentes às condições de 'perigo' a 'perigo extremo' de 17,3% para 5,4%.

Quantifying the effect of rain events on outdoor thermal comfort in a high-density city, Hong Kong

Rainfall events often cause a modification to atmospheric conditions. The impact of this phenomenon on human thermal comfort has however been less well studied. Therefore, this paper quantifies the effect of rainfall events on human thermal comfort in a hot-humid subtropical city, Hong Kong. Firstly, rainfall events were categorized based on time of occurrence, i.e., morning (on or before 11:00 LST), afternoon (12:00-15:00, LST), early evening (16:00-18:00), and all-day events. Thereafter, human thermal comfort on typical non-rainy (sunny) days and rainy days was estimated and compared by using the radiation-driven physiological equivalent temperature (PET) and non-radiation-driven temperature-humidity index (THI) and compared. Results revealed variable and stable hourly patterns of PET and THI thermal classification, respectively under different rainfall event category. The insensitivity of THI values could be due to the retained strong contribution of both input parameters (air temperature and relative humidity) on both rainy and non-rainy (sunny) days. An understanding of the mechanism of thermal changes before, during, and after rainfall events based on statistical analysis suggests a strong interplay between moisture content and air temperature as determinants of thermal comfort in the hot-humid city and not necessarily the radiation parameter. This finding suggests that while PET clearly shows the impact of rain-event; it is principally due to the strong contribution of the lowered radiant temperature in its calculation while in reality, the critical determinants of thermal comfort in such period in a hot-humid subtropical environment like Hong Kong are the moisture content and ambient temperature. Finding from the study could enhance occupational health and safety management of outdoor workplaces.