Avoidable heat risk under scenarios of carbon neutrality by mid-century.

To prevent anthropogenic warming of the climate system above dangerous thresholds, governments are required by the Paris Agreement to peak global anthropogenic CO2 emissions and to reach a net zero CO2 emissions level (also known as carbon neutrality). Growing concerns are being expressed about the increasing heat stress caused by the interaction of changes in temperature and humidity in the context of global warming. Although much effort has been made to examine future changes in heat stress and associated risks, gaps remain in understanding the quantitative benefits of heat-risk avoidance from carbon-neutral policies, limited by the traditional climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Here we quantify the avoided heat risk during 2040-2049 under two scenarios of global carbon neutrality by 2060 and 2050, i.e., moderate green (MODGREEN) and strong green (STRGREEN) recovery scenarios, relative to the baseline scenario (FOSSIL), based on multi-model large ensemble climate projections from a new climate model intercomparison project (CovidMIP) that endorsed by CMIP6. We show that global population exposure to extreme heat stress increases by approximately four times its current level during 2040-2049 under the FOSSIL scenario, whereas the heat exposure could be reduced by as much as 12 % and 23 % under the MODGREEN and STRGREEN scenarios, respectively. Moreover, global mean heat-related mortality risk is mitigated by 14 % (24 %) under the MODGREEN (STRGREEN) scenario during 2040-2049 relative to the FOSSIL scenario. Additionally, the aggravating heat risk could be mitigated by around a tenth by achieving carbon neutrality 10 years earlier (2050 versus 2060). In terms of spatial pattern, this heat-risk avoidance from low-carbon policies is typically greater in low-income countries. Our findings assist governments in advancing early climate change mitigation policy-making.

Exploring the Influence of Summer Temperature on Human Mobility During the COVID-19 Pandemic in the San Francisco Bay Area.

Studies on the relationship between temperature and local, small scale mobility are limited, and sensitive to the region and time period of interest. We contribute to the growing mobility literature through a detailed characterization of the observed temperature-mobility relationship in the San Francisco Bay Area at fine spatial and temporal scale across two summers (2020-2021). We used anonymized cellphone data from SafeGraph's neighborhood patterns data set and gridded temperature data from gridMET, and analyzed the influence of incremental changes in temperature on mobility rate (i.e., visits per capita) using a panel regression with fixed effects. This strategy enabled us to control for spatial and temporal variability across the studied region. Our analysis suggested that all areas exhibited lower mobility rate in response to higher summer temperatures. We then explored how several additional variables altered these results. Extremely hot days resulted in faster mobility declines with increasing temperatures. Weekdays were often more resistant to temperature changes when compared to the weekend. In addition, the rate of decrease in mobility in response to high temperature was significantly greater among the wealthiest census block groups compared with the least wealthy. Further, the least mobile locations experienced significant differences in mobility response compared to the rest of the data set. Given the fundamental differences in the mobility response to temperature across most of our additive variables, our results are relevant for future mobility studies in the region.

A Preliminary Study of Mild Heat Stress on Inflammasome Activation in Murine Macrophages.

Inflammation and mitochondrial-dependent oxidative stress are interrelated processes implicated in multiple neuroinflammatory disorders, including Alzheimer's disease (AD) and depression. Exposure to elevated temperature (hyperthermia) is proposed as a non-pharmacological, anti-inflammatory treatment for these disorders; however, the underlying mechanisms are not fully understood. Here we asked if the inflammasome, a protein complex essential for orchestrating the inflammatory response and linked to mitochondrial stress, might be modulated by elevated temperatures. To test this, in preliminary studies, immortalized bone-marrow-derived murine macrophages (iBMM) were primed with inflammatory stimuli, exposed to a range of temperatures (37-41.5 °C), and examined for markers of inflammasome and mitochondrial activity. We found that exposure to mild heat stress (39 °C for 15 min) rapidly inhibited iBMM inflammasome activity. Furthermore, heat exposure led to decreased ASC speck formation and increased numbers of polarized mitochondria. These results suggest that mild hyperthermia inhibits inflammasome activity in the iBMM, limiting potentially harmful inflammation and mitigating mitochondrial stress. Our findings suggest an additional potential mechanism by which hyperthermia may exert its beneficial effects on inflammatory diseases.

Knowledge regarding heat stress and practice of personal protective equipment use among healthcare workers during the COVID 19 pandemic

Introduction: The need for healthcare workers (HCWs) to wear personal protective equipment (PPE) during the coronavirus disease 2019 (COVID-19) pandemic heightens their risk of thermal stress. Objective(s): To determine knowledge regarding heat stress and practice of PPE among HCWs during the COVID-19 pandemic. Material(s) and Method(s): A cross-sectional observational study was done among 115 HCWs using a self-designed questionnaire to identify their thoughts on heat stress caused by PPE wear during the COVID-19 pandemic. The ambient temperature, relative humidity (RH), and dew point in their respective locations were recorded using data loggers (EL-USB-2-LCD+, Lascar Electronics, Salisbury, UK). R version 3.6.2 was used to examine the frequency and descriptive statistics from the survey findings. Pearson's chi-square was used to determine associations. A p value of <0.05 was considered statistically significant. Result(s): The average wet bulb globe temperature (WBG) reported was 30.0oC (IQR 29.1-31.8oC) according to the heat exposure data. The majority of the 115 HCWs were involved in medical consulting (39%), followed by nursing (29%). The researchers discovered that 50% of the workers (n=57) were wearing 5-6 PPEs and had a fourteen-fold increased risk of developing an undesirable thermal health symptom (95 % CI: 0.77 to 280.24;p=0.0737). In addition, 36% of the participants (n=42) worked between 8 and 10 hours every shift with little or no rest. It was also important to note that 76% (n=88) of them worked in non-air-conditioned environments, and 33% (n=38) of them had excessive workloads, which could add to the employees' heat burden. More than half of them agreed that wearing PPE is extremely inconvenient, and they avoided taking breaks to maintain infection control. The impression of thermal stress was reported by 96% of the participants (n=111), and it was found to be substantially linked with the job they were engaged [OR 0.0654 (95% CI: 0.003- 1.246) P=0.001]. More than half of the participants strongly agreed that appropriate rest and hydration before work could help them lower their thermal stress. Conclusion(s): HCWs are cognizant of the effects of heat stress but might not adopt best practices due to various constraints. Ice slurry ingestion could be a practical and effective method for promoting thermal comfort. Adverse effects of heat stress on productivity and judgment of HCWs warrant further investigation.

OCCUCON 2022 Abstracts

The proceedings contain 40 papers. The topics discussed include: respiratory hypersensitivity profiling among farmers with pesticide exposure: field- based, cross-sectional study;requirements of prescription safety eye wear;Covid-19 and comorbidities: deleterious impact on infected patients;knowledge regarding heat stress and practice of personal protective equipment use among healthcare workers during the Covid 19 pandemic;arrhythmia burden in Covid-19 patients from industrial workforce evaluated by remote patient monitoring technology;a qualitative perspective of construction site migrant workers' plight during covid-19 lockdown in Bhavnagar (Western India);elimination of volatile organic compound VOCs exposure at chemical testing laboratory: through effective OHIH assessment;and perceived morbidity, its risks and catastrophic health expenditure among construction workers: a cross sectional observation from Ahmedabad.

Thermoregulation and subjective thermal perception of N95 respirator users: Influence of significant workloads

Working under a significant metabolic rate while wearing an N95 mask increased the heat stress that users of protective clothing experienced. This study investigated in a climatic chamber preset at 25 degrees C and a relative humidity of 65% the changes in thermoregulation and thermal perception of 13 men and 12 women when performing exercises involving different metabolic consumption for 60 min first without wearing an N95 mask for 30 min and then donning a mask. The physiological parameters include the metabolic rate, tympanic temperature, heart rate, skin temperature, skin moisture, and transepidermal water loss (TEWL). Thermal perceptions, including thermal sensation, humidity sensation, thermal comfort, and thermal acceptance were surveyed. The results show that both N95 mask use and exercising contributed to vigorous thermoregulation, particularly in women. The tympanic temperature was between 35.5 degrees C and 36.5 degrees C during the experiment for both sexes. Skin temperature during the exercise with or without donning a mask was not influenced by the change in workload, indicating a balance in heat exchange between the body and ambient air. Skin moisture increased by 58.91% and 49.99% when the users of masks performed exercises involving moderate and very high metabolic rates, respectively, compared to levels when a mask was not worn. The TEWL of women and men when wearing a mask and jogging increased by 16.35% and 14.89%, respectively, compared to when not wearing the mask. These results suggests a potential thermal stress from using N95 masks and working in a warm environment when the users are not acclimatized.

Biostimulants for greenhouse and nursery crops. (L'Accademia per il post Covid-19.)

The market for biostimulants is rapidly growing and many companies are expanding their portfolio with the introduction of these products, which are increasingly used to improve the management of crop systems and increase their sustainability. In fact, biostimulants, if properly used, can increase crop yields and quality, reducing fertilizer inputs and increasing plant tolerance against abiotic stresses.

A Successful Heat Wave Prevention in Ahmedabad Calls for Segregated Health Record: Highlights from Existing Heat Action Plan

South Asia is one of the hot-spots of extreme heat events and associated health risks. As heat waves continue to get harsher due to climate change, South Asia's exposure to them is probably going to increase. After a heatwave in 2010, Ahmedabad implemented South Asia’s first heat action plan (HAP). The Ahmedabad HAP can serve as a model for other cities across South Asian nations interested in intervention strategies against excessive heat. In recent years, 2020 and onwards, Ahmedabad’s healthcare system faces an extreme COVID-19 crisis which resulted in severe negligence of heat wave-influenced mortality and morbidity cases. Though the city continued to disseminate the necessary information for public heat preparedness from the existing heat action plan, there was no record made separately for COVID-19 and heat stress-related mortality/morbidity by the health department. Thus, due to a lack of heat-related health records, we were unable to track the HAP intervention effect in 2022.

Remote Sensing-Based Evaluation of Heat Stress Damage on Paddy Rice Using NDVI and PRI Measured at Leaf and Canopy Scales

Extremely high air temperature at the heading stage of paddy rice causes a yield reduction due to the increasing spikelet sterility. Quantifying the damage to crops caused by high temperatures can lead to more accurate estimates of crop yields. The remote sensing technique evaluates crop conditions indirectly but provides information related to crop physiology, growth, and yield. In this study, we aim to assess the crop damage caused by heat stress in paddy rice examined under elevated air temperatures in a temperature gradient field chamber from 2016 to 2019, using remote-sensed vegetation indices. A leaf-spectrometer, field-spectrometers, and a multi-spectral camera were used to monitor the conditions of paddy rice. Although, in the leaf- and canopy-scales, the values of normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) decreased after the heading of rice under normal conditions, the decreasing sensitivity of NDVI and PRI was different depending on the degree of physiological heat stress by high temperature conditions. The NDVI after the heading under extremely high air temperature was not dropped and remained the value before heading. The PRI decreased at all air temperature conditions after the heading;the PRI of the plot exposed to the elevated air temperature was higher than that under ambient air temperature. Further, the relative change in NDVI and PRI after the heading exhibited a strong relationship with the ripening ratio of paddy rice, which is the variable related to crop yield. These remote-sensing results aid in evaluating the crop damage caused by heat stress using vegetation indices. [ FROM AUTHOR] Copyright of Agronomy is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Heat acclimation does not attenuate hepcidin elevation after a single session of endurance exercise under hot condition.

PURPOSE: We sought to determine the effects of heat acclimation on endurance exercise-induced hepcidin elevation under hot conditions. METHODS: Fifteen healthy men were divided into two groups: endurance training under hot conditions (HOT, 35 °C, n = 8) and endurance training under cool conditions (CON, 18 °C, n = 7). All subjects completed 10 days of endurance training (8 sessions in total), consisting of 60 min of continuous exercise at 50% of maximal oxygen uptake ([Formula: see text]) under their assigned environment condition. Subjects completed a heat stress exercise test (HST, 60 min exercise at 60% [Formula: see text]) to evaluate the exercise-induced thermoregulatory and hepcidin responses under hot conditions (35 °C) before (pre-HST) and after (post-HST) the training period. RESULTS: Core temperature during exercise in the post-HST decreased significantly in the HOT group compared to pre-HST (P = 0.004), but not in the CON group. The HOT and CON groups showed augmented exercise-induced plasma interleukin-6 (IL-6) elevation in the pre-HST (P = 0.002). Both groups had significantly attenuated increases in exercise-induced IL-6 in the post-HST; however, the reduction of exercise-induced IL-6 elevation was not different significantly between both groups. Serum hepcidin concentrations increased significantly in the pre-HST and post-HST in both groups (P = 0.001), no significant difference was observed between both groups during each test or over the study period. CONCLUSION: 10 days of endurance training period under hot conditions improved thermoregulation, whereas exercise-induced hepcidin elevation under hot conditions was not attenuated following the training.

Workers' Perception Heat Stress: Results from a Pilot Study Conducted in Italy during the COVID-19 Pandemic in 2020.

Many workers are exposed to the effects of heat and often to extreme temperatures. Heat stress has been further aggravated during the COVID-19 pandemic by the use of personal protective equipment to prevent SARS-CoV-2 infection. However, workers' risk perception of heat stress is often low, with negative effects on their health and productivity. The study aims to identify workers' needs and gaps in knowledge, suggesting the adaptation of measures that best comply with the needs of both workers and employers. A cross-sectional online questionnaire survey was conducted in Italy in the hottest months of 2020 (June-October) through different multimedia channels. The data collected were analyzed using descriptive statistics; analytical tests and analysis of variance were used to evaluate differences between groups of workers. In total, 345 questionnaires were collected and analyzed. The whole sample of respondents declared that heat is an important contributor to productivity loss and 83% of workers did not receive heat warnings from their employer. In this context, the internet is considered as the main source of information about heat-related illness in the workplace. Results highlight the need to increase workers' perception of heat stress in the workplace to safeguard their health and productivity. About two-thirds of the sample stated that working in the sun without access to shaded areas, working indoors without adequate ventilation, and nearby fire, steam, and hot surfaces, represent the main injuries' risk factors.

Assessing the Climatological Relationship between Heatstroke Risk and Heat Stress Indices in 47 Prefectures in Japan

This study provides a decade-long link between summer heatstroke incidence and certain heat stress indices in 47 prefectures of Japan. The results for each prefecture were determined from the age-adjusted heatstroke incidence rate (TRadj) with heatstroke patients transported by ambulance, as well as from the daily maximum temperature (TEMPmax), maximum wet-bulb globe temperature (WBGTmax), and maximum universal thermal climate index (UTCImax) recorded from July to September of 2010–2019. The UTCImax relatively increased the vulnerability in many prefectures of northern Japan more distinctly than the other indices. In the following analysis, the ratio of the TRadj of the hottest to coolest months using the UTCImax was defined as the heatstroke risk of the hottest to coolest (HRHC). Overall, the HRHC varied approximately from 20 to 40 in many prefectures in the past decade. In contrast, for the same analysis performed in each month, HRHC ratios in July and August fell within 2–4 in many prefectures, whereas in September, the average and maximum HRHC ratios for all prefectures were 7.0 and 32.4, respectively. This difference can be related to the large difference in UTCImax between the maximum and minimum for a decade.

Reversible Hydration Composite Films for Evaporative Perspiration Control and Heat Stress Management.

Donning of personal protective equipment (PPE) in the healthcare sector has been intensified by the on-going COVID-19 pandemic around the globe. While extensive PPE provides protection, it typically limits moisture permeability and severely hinders the sweat evaporation process, resulting in greater heat stress on the personnel. Herein, a zinc-poly(vinyl alcohol) (Zn-PVA) composite film is fabricated by embedding a super-hygroscopic zinc-ethanolamine complex (Zn-complex) in the PVA matrix. By attaching the Zn-PVA composite film, the relative humidity (RH) inside the protective suit decreases from 91.0% to 48.2%. The reduced RH level, in turn, enhances evaporative cooling, hence bringing down the heat index from 64.6 to 40.0 °C at an air temperature of 35 °C, remarkably lowering the likelihood of heat stroke. The American Society for Testing and Materials tests conducted on a sweating manikin have also proven that the Zn-PVA composite films can significantly reduce the evaporative resistance of the protective suit by 90%. The low material cost, facile fabrication process, and reusability allow the Zn-PVA composition films to be readily available for healthcare workers worldwide. This application can be further extended to other occupations that are facing severe thermal discomfort and heat stress.

Enhanced personal protective equipment can cause acute kidney injury in health care workers during COVID-19 pandemics

Introduction: Enhanced personal protective equipment (PPE) can expose health care workers (HCWs) to high heat stress and dehydration. The objective of this study was to assess the risk of acute kidney injury (AKI) among HCWs during the pandemic. Material and Methods: We recruited 52 HCWs worked on the mobile COVID-19 screening bus in the summer of 2021. We measured the body water content, pulse, core body temperature, blood pressure, creatinine, and urinary analysis before and after the work shift. We obtained the amount of water intake, environmental and personal measurements of temperature, humidity, and heat stress index during the work shift. Physicians interviewed the study subjects to confirm their medical history. Paired sample t-tests were used to test the pre and post-measurements. Results and Conclusions: After excluding 18 subjects who did not wear PPE in the pilot study, 34 HCWs were used in the analyses (male: 11.8%;female: 88.2 %). Most of them were nurses, with a mean age of 30.53 years old (SD 6.82). After a work shift, 14.7% of the subjects had incident AKI (1.5 times reference value or increase≧0.3 mg/dl). Core body temperature increased 0.27 degree (95% confidence interval [CI]: 0.16 to 0.38), creatinine level increased 0.161 mg/dl (95% CI: 0.11 to 0.22, p<0.001). The estimated glomerular filtration rate (eGFR) showed a significant decline in renal function (-16.82 ml/min/1.73m2, 95% CI: -22.47 to -11.17, p<0.001). There was a protective effect of hydration (p= 0.09). In conclusion, wearing enhanced PPE can cause kidney injuries. There is an urgent need to develop regulations to prevent AKI among HCWs.

Mask wearing behavior in hot urban spaces of Novi Sad during the COVID-19 pandemic.

Urban overheating (due to climate change and urbanization) and COVID-19 are two converging crises that must be addressed in tandem. Fine-scale, place-based, people-centric biometeorological and behavioral data are needed to implement context-specific preventative measures such as mask-wearing. This study collected local biometeorological measurements in diverse urban spaces (square, urban park, river quay) in Novi Sad, Serbia on hot sunny summer days (27-30 August 2020) during the COVID-19 pandemic. Observations were supplemented by an online survey asking questions about thermal sensation, comfort, and concurrent protective behavior of the local population. Biometeorological measurements show that the main square in the city center was the most thermally uncomfortable area. According to the survey, it was also perceived as the least safe space to not contract the virus. The urban park was perceived as the most thermally comfortable area in the morning and during midday. It was also considered the safest urban space for outdoor activities. In the evening, the river quay was the most thermally comfortable area in the city. Intra-urban differences in Physiologically Equivalent Temperatures were highest during midday, while differences in air temperatures were highest in the evening. More than 70% of the respondents did not wear face masks when it was hot because of breathing issues and feeling warmer than without mask. Most people wearing a mask felt "slightly warm" in the morning and evening, while the majority of respondents felt "hot" during midday. Only 3% of the respondents felt comfortable while wearing a mask, while 97% experienced some degree of discomfort (from slight discomfort to very uncomfortable). Our study shows that fine scale temporal and spatial urban biometeorological data and population surveys should be included in decision-making processes during the pandemic to develop climate-sensitive health services that are place-based, people-centric, and facilitate planning towards green, resilient, and inclusive cities.

Animal Welfare Risks in Live Cattle Export from Australia to China by Sea.

There are long-standing and ongoing concerns about the welfare of animals in the Australian live export trade by sea. However, scrutiny of animal welfare on board vessels is generally hindered by a lack of independent reporting. Cattle voyages from Australia to China have concerned animal welfare advocates due to their long duration and lack of consistent veterinary oversight. In April 2018, following a media exposé of animal cruelty and declining public trust, the Australian government installed Independent Observers on some live export voyages. Summaries of Independent Observer (IO) reports by the Department of Agriculture and Water Resources (DAWR) provided a new and independent source of information about management of animals in the live export trade. The IO summaries on live cattle export voyages to China for the period July 2018 to December 2019 (n = 37) were reviewed. The IO summaries detailed voyages that carried 147,262 slaughter, feeder or breeder cattle which included both dairy and beef breeds. The long-haul voyages averaged 20 days in duration, generally departing the ports of Fremantle and Portland and discharging at ports in northern China. Key animal welfare risk factors identified in the IO summaries included: hunger, thirst, exposure to extreme temperatures, poor pen conditions, health issues, absence of veterinarians, rough seas, poor ship infrastructure, mechanical breakdown and mismanagement at discharge.

A pilot study of core body temperatures in healthcare workers wearing personal protective equipment in a high-level isolation unit.

Personal protective equipment used by healthcare workers to mitigate disease transmission risks while caring for patients with high-consequence infectious diseases can impair normal body cooling mechanisms and exacerbate physiological strain. Symptoms of heat strain (e.g., cognitive impairment, confusion, muscle cramping) are especially harmful in the high-risk environment of high-consequence infectious disease care. In this pilot study, the core body temperatures of healthcare workers were assessed using an ingestible, wireless-transmission thermometer while performing patient care tasks common to a high-level isolation unit setting in powered air purifying respirator (PAPR)-level. The objective was to determine the potential for occupational health hazard due to heat stress in an environmentally controlled unit. Maximum core temperatures of the six participants ranged from 37.4 °C (99.3 °F) to 39.9 °C (103.8°F) during the 4-hr shift; core temperatures of half (n = 3) of the participants exceeded 38.5 °C (101.3 °F), the upper core temperature limit. Future investigations are needed to identify other heat stress risks both in and outside of controlled units. The ongoing COVID-19 pandemic offers unique opportunities for field-based research on risks of heat stress related to personal protective equipment in healthcare workers that can lead to both short- and long-term innovations in this field.

Hot days and Covid-19: Online survey of nurses and nursing assistants to assess occupational heat stress in Germany during summer 2020.

Objectives: Our aim was to identify if working during hot days while wearing Covid-19 related personal protective equipment causes occupational heat stress for nurses and nursing assistants in Germany. Design: Using an online survey, we assessed the impact of hot weather on nurses and nursing assistants working with personal protective equipment. Respondents were recruited by distributing the link to the survey via personal communication, email and various social media channels to nursing staff from hospitals, nursing homes and outpatient care. Results: There were in total 428 participants (18.2% male, 82.5% female), mostly (30.5%) aged between 45 and 55 years. Half of respondents (48.3%) had more than 20 years of experience in nursing. Cardiac, pulmonary, or other pre-existing conditions were reported by 46.2%.Nurses and nursing assistants working in personal protective equipment during hot days were exposed to occupational heat stress. Work was found exhaustive by 96.5% of the participants during those days. 93.0% reported breathing problems and 85.8% reported difficulties with focusing on their work. Many workplaces did not provide adequate heat protection, with distinct differences concerning the amount of prophylactic and heat mitigating measures across institutions. There were significant differences across institutions when it comes to the number of drinks served (p < 0.001), the availability of room thermometers (p < 0.001), the use of mobile cooling devices (p < 0.001) and fans (p < 0.05). Conclusions: Results suggest employers must make more of an effort to provide adequate heat protection for their nursing staff. In order to ensure patient care, there is a need for action; in particular, attention must be paid to the pre-existing health conditions of the nursing staff.