Mortality risk attributable to high and low ambient temperature in Pune city, India: A time series analysis from 2004 to 2012

CMIP6 models informed summer human thermal discomfort conditions in Indian regional hotspot

The frequency and intensity of extreme thermal stress conditions during summer are expected to increase due to climate change. This study examines sixteen models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) that have been bias-adjusted using the quantile delta mapping method. These models provide Universal Thermal Climate Index (UTCI) for summer seasons between 1979 and 2010, which are regridded to a similar spatial grid as ERA5-HEAT (available at 0.25° × 0.25° spatial resolution) using bilinear interpolation. The evaluation compares the summertime climatology and trends of the CMIP6 multi-model ensemble (MME) mean UTCI with ERA5 data, focusing on a regional hotspot in northwest India (NWI). The Pattern Correlation Coefficient (between CMIP6 models and ERA5) values exceeding 0.9 were employed to derive the MME mean of UTCI, which was subsequently used to analyze the climatology and trends of UTCI in the CMIP6 models.The spatial climatological mean of CMIP6 MME UTCI demonstrates significant thermal stress over the NWI region, similar to ERA5. Both ERA5 and CMIP6 MME UTCI show a rising trend in thermal stress conditions over NWI. The temporal variation analysis reveals that NWI experiences higher thermal stress during the summer compared to the rest of India. The number of thermal stress days is also increasing in NWI and major Indian cities according to ERA5 and CMIP6 MME. Future climate projections under different scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) indicate an increasing trend in thermal discomfort conditions throughout the twenty-first century. The projected rates of increase are approximately 0.09 °C per decade, 0.26 °C per decade, and 0.56 °C per decade, respectively. Assessing the near (2022-2059) and far (2060-2100) future, all three scenarios suggest a rise in intense heat stress days (UTCI > 38 °C) in NWI. Notably, the CMIP6 models predict that NWI could reach deadly levels of heat stress under the high-emission (SSP5-8.5) scenario. The findings underscore the urgency of addressing climate change and its potential impacts on human well-being and socio-economic sectors.

Investigation of the effects of temperature and relative humidity on the propagation of COVID-19 in different climatic zones

This study aims to evaluate the effects of temperature and relative humidity on the propagation of COVID-19 for indoor heating, ventilation, and air conditioning design and policy development in different climate zones. We proposed a cumulative lag model with two specific parameters of specific average temperature and specific relative humidity to evaluate the impact of temperature and relative humidity on COVID-19 transmission by calculating the relative risk of cumulative effect and the relative risk of lag effect. We considered the temperature and relative humidity corresponding to the relative risk of cumulative effect or the relative risk of lag effect equal to 1 as the thresholds of outbreak. In this paper, we took the overall relative risk of cumulative effect equal to 1 as the thresholds. Data on daily new confirmed cases of COVID-19 since January 1, 2021, to December 31, 2021, for three sites in each of four climate zones similar to cold, mild, hot summer and cold winter, and hot summer and warm winter were selected for this study. Temperature and relative humidity had a lagged effect on COVID-19 transmission, with peaking the relative risk of lag effect at a lag of 3-7 days for most regions. All regions had different parameters areas with the relative risk of cumulative effect greater than 1. The overall relative risk of cumulative effect was greater than 1 in all regions when specific relative humidity was higher than 0.4, and when specific average temperature was higher than 0.42. In areas similar to hot summer and cold winter, temperature and the overall relative risk of cumulative effect were highly monotonically positively correlated. In areas similar to hot summer and warm winter, there was a monotonically positive correlation between relative humidity and the overall relative risk of cumulative effect. This study provides targeted recommendations for indoor air and heating, ventilation, and air conditioning system control strategies and outbreak prevention strategies to reduce the risk of COVID-19 transmission. In addition, countries should combine vaccination and non-pharmaceutical control measures, and strict containment policies are beneficial to control another pandemic of COVID-19 and similar viruses.

Short-term effect of ambient temperature and ambient temperature changes on the risk of warts outpatient visits in Hefei, China: a retrospective time-series study

Concerns are growing about the adverse health effects of ambient temperature and ambient temperature changes. However, the association between ambient temperature and ambient temperature changes on the risk of warts outpatient visits is poorly understood. Our study used the distributed lag non-linear model (DLNM) aimed to evaluate the association between ambient temperature, ambient temperature changes (including temperature change between neighboring days (TCN) and diurnal temperature range (DTR)), and warts outpatient visits. We also performed subgroup analyses in order to find susceptible populations by gender and age groups. The maximum relative risk (RR) of low ambient temperature (0 °C) for warts outpatient visits was 1.117 (95% CI: 1.041-1.198, lag 04 days), and the maximum RR of high ambient temperature (32 °C) for warts outpatient visits was 1.318 (95% CI: 1.083-1.605, lag 07 days). The large temperature drop (TCN =  - 3 °C) decreased the risk of warts visits, with the lowest RR value at the cumulative exposure of lag 7 days (RR = 0.888, 95% CI: 0.822-0.959), and the large temperature rise (TCN = 2 °C) increased the risk of warts visits, with the highest RR value at the cumulative exposure of lag 7 days (RR = 1.080, 95% CI: 1.022-1.142). Overall, both low and high ambient temperatures and large temperature rise can increase the risk of warts visits, while large temperature drop is a protective factor for warts visits. However, we did not find any association between DTR and warts visits. Furthermore, subgroup analyses showed that males and the young (0-17 years old) were more sensitive to low and high ambient temperatures, and the elderly (≥ 65 years old) were more susceptible to TCN. The results may provide valuable evidence for reducing the disease burden of warts in the future.

High ambient temperatures are associated with urban crime risk in Chicago

Urban crime (UC) seriously affects the security and stability of the communities and society. However, the effects of external temperatures on the risk of UC are still confusing. We quantitatively estimated the effects of high and low temperatures on UC in Chicago. After controlling for the confounding factors, we found that high temperature has a positive promoting effect on UC, for non-domestic crime, the effect occurs at lag day 0 with a maximum risk of 1.40 (95%CI, 1.34-1.46) compared to a risk of 1 at temperature of -12.3 °C, and decreased as the lag day increased. The effect of low temperature is not significant for UC. Heat waves above the 99th percentile with a duration of 4.5-5.5 days exert a significant positive impact on non-domestic crime of UC. Our findings confirm the adverse promotion effect of high temperature on UC risk, and effective individual behavior guidance and administrative intervention are of great significance for reducing the risk of UC under specific high temperature environment.

Knowledge Gaps and Research Priorities on the Health Effects of Heatwaves: A Systematic Review of Reviews

Although extreme weather events have played a constant role in human history, heatwaves (HWs) have become more frequent and intense in the past decades, causing concern especially in light of the increasing evidence on climate change. Despite the increasing number of reviews suggesting a relationship between heat and health, these reviews focus primarily on mortality, neglecting other important aspects. This systematic review of reviews gathered the available evidence from research syntheses conducted on HWs and health. Following the PRISMA guidelines, 2232 records were retrieved, and 283 reviews were ultimately included. Information was extracted from the papers and categorized by topics. Quantitative data were extracted from meta-analyses and, when not available, evidence was collected from systematic reviews. Overall, 187 reviews were non-systematic, while 96 were systematic, of which 27 performed a meta-analysis. The majority evaluated mortality, morbidity, or vulnerability, while the other topics were scarcely addressed. The following main knowledge gaps were identified: lack of a universally accepted definition of HW; scarce evidence on the HW-mental health relationship; no meta-analyses assessing the risk perception of HWs; scarcity of studies evaluating the efficacy of adaptation strategies and interventions. Future efforts should meet these priorities to provide high-quality evidence to stakeholders.