Workplace heat exposure, health protection, and economic impacts: A case study in Canada.

BACKGROUND: Occupational heat exposure is a serious concern for worker health, productivity, and the economy. Few studies in North America assess how on-site wet bulb globe temperature (WBGT) levels and guidelines are applied in practice. METHODS: We assessed the use of a WBGT sensor for localized summertime heat exposures experienced by outdoor laborers at an industrial worksite in Ontario, Canada during the warm season (May-October) from 2012 to 2018 inclusive. We further examined informed decision making, approximated workers' predicted heat strain (sweat loss, core temperature), and estimated potential financial loss (via hourly wages) due to decreased work allowance in the heat. RESULTS: Significantly higher worksite WBGT levels occured compared with regional levels estimated at the airport, with an upward trend in heat warnings over the 7 years and expansion of warnings into the fall season. The maximum WBGT during warnings related strongly to predicted hourly sweat loss. On average, 22 hours per worker were lost each summer (~1% of annual work hours) as a result of taking breaks or stopping due to heat. This amount of time corresponded to an average individual loss of C$1100 Canadian dollars (~C$220,000 combined for ~200 workers) to workers or the company. The additional losses for an enterprise due to reduced product output were not estimated. CONCLUSIONS: Worksite observations and actions at the microscale are essential for improving the estimates of health and economic costs of extreme heat to enterprises and society. Providing worksite heat metrics to the employees aids in appropriate decision making and health protection.

What do we know about the healthcare costs of extreme heat exposure? A comprehensive literature review.

Exposure to extreme heat can lead to a range of heat-related illnesses, exacerbate pre-existing health conditions and cause increased demand on the healthcare system. A projected increase in temperature may lead to greater healthcare expenditure, however, at present the costs of heat-related healthcare utilization is under-researched. This study aims to review the literature on heat-related costs for the healthcare system with a focus on ED visits, hospitalization, and ambulance call-outs. PubMed, Scopus, and Embase were used to search relevant literature from database inception to December 2017 and limited to human studies and English language. After screening, a total of ten papers were identified for final inclusion. In general, the healthcare costs of heat extremes have been poorly investigated in developed countries and not reported in developing countries where the largest heat-vulnerable populations reside. Studies showed that exposure to extreme heat was causing a substantial economic burden on healthcare systems. Females, the elderly, low-income families, and ethnic minorities had the highest healthcare costs on a range of health services utilization. Although a few studies have estimated heat healthcare costs, none of them quantified the temperature-healthcare cost relationship. There is a need to systematically examine heat-attributable costs for the healthcare system in the context of climate change to better inform heat-related policy making, target interventions and resource allocation.

Correlates of Occupational Heat-Induced Illness Costs: Case Study of South Australia 2000 to 2014.

OBJECTIVE: To investigate the profile of occupational heat-induced illness costs in South Australia and to examine the association with high temperature. METHODS: Workers' compensation claim data were used to quantify the associations between maximum temperature (Tmax) and occupational heat illness (OHI)-related costs, using time-series analysis after controlling for confounding factors. RESULTS: Four hundred thirty-eight OHI claims in 2000 to 2014 resulted in total medical costs of AU$6,002,840 and 5,036 work days lost. Relatively higher OHI burdens were found in men, those aged 25 to 44 years, new workers, medium-size businesses, and those employed in the mining industry. A 1 °C increase in Tmax above about 33 °C was associated with a 41.6% increase in medical costs and a 74.8% increase in days lost due to OHI, respectively. CONCLUSIONS: The cost profile of OHI may be used to justify interventions for particular industries, occupations, and worker categories.

Heatwave and elderly mortality: An evaluation of death burden and health costs considering short-term mortality displacement.

BACKGROUND: A heatwave can be a devastating natural disaster to human health, and elderly people are particularly vulnerable. With the continuing rise in earth's surface temperature alongside the world's aging population, research on the mortality burden of heatwave for the older population remains relatively sparse. The potential magnitude of benefits of averting such deaths may be considerable. OBJECTIVES: This paper examined the short-term mortality displacement (or "harvesting") of heatwave, characterized the heatwave-mortality relationship, and estimated death burden and health costs attributable to heatwave among the elderly in Australia. METHODS: We collected daily data on the temperature and deaths of people aged ≥75 years in the five largest cities of Australia (Sydney, Melbourne, Brisbane, Perth and Adelaide), totaling 368,767 deaths in different periods between 1988 and 2011. A total of 15-tiered heatwave definitions, based on intensity (95th to 99th percentiles of temperature distribution) and duration (two or more consecutive days), were used to quantify heatwave effects, using time-series regression and random-effects meta-analysis. We calculated attributable deaths for each city and by different types of heatwave. Potential economic benefits in monetary terms were also estimated, considering that heat-related deaths are avoidable. RESULTS: Among the Australian elderly population, we found significant associations between heatwave and deaths, with raised mortality immediately in the first few days followed by lower-than-expected mortality. In general, heatwave was associated with an average death increase of 28% (95% confidence interval: 15% to 42%), and greater increases were mostly observed for more intense heatwaves across multiple megacities. During the study period, there were dozens to hundreds of deaths attributable to heatwave for each city, equating to an economic loss of several million Australian dollars every year. Although the estimated attributable deaths varied by heatwave intensity and duration, the pattern was not consistent across cities. CONCLUSIONS: Heatwave caused harvesting effects on mortality in the elderly population of Australia, and contributed to a substantial amount of death burden and indirect financial costs. To lessen the health impacts of heatwave in the affected regions, effective heatwave early warning systems and interventions targeted at the elderly population could be beneficial, both now and in the future.

Willingness to Pay for Measures of Managing the Health Effects of Heat Wave in Beijing, China: a Cross-sectional Survey.

OBJECTIVE: There are evidences that heat wave events cause deaths and emergency cases. This article used the contingent valuation method to find the willingness to pay for the protective measures and investigated the factors that influence the willingness to pay. METHODS: A cross-sectional face-to-face household survey was completed by 637 urban long-term residents and 591 rural long-term residents aged 15-79 in Beijing, China. Binary logistic regression was used to identify factors that influenced the payment rate or payment amount for the protective measures, including independent variables for district, gender, age, education, income, air conditioner ownership, heat wave experience, and chronic non-communicable disease. RESULTS: The payment rate was 41.1% for protective measures provided by the government and 39.5% by measures provided by the market. Most of the respondents were willing to pay 40 CNY per capita annually for measures provided by the government or the market. The factors influencing willingness to pay were district, gender, income, air conditioner ownership, heat wave experience, and chronic non-communicable disease.. CONCLUSION: Protective measures for heat waves need to be provided immediately. More attention should be paid to the situation of vulnerable groups, such as people who live in urban areas, those without air conditioning, and those who have experienced a heat wave in the past.

Economic feasibility of cooling dry cows across the United States.

Heat stress during the dry period reduces milk yield in the subsequent lactation of dairy cows. Our objectives were to quantify the economic losses due to heat stress if dry cows are not cooled and to evaluate the economic feasibility of dry cow cooling. We used weather data from the National Oceanic and Atmospheric Administration to calculate the number of heat stress days for each of the 50 US states. A heat stress day was declared when the daily average temperature-humidity index was ≥68. The number of dairy cows in each state in 2015 was obtained from the USDA-National Agricultural Statistics Service. We assumed that 15% of the cows were dry at any time, a 60-d dry period, and a calving interval of 400d. Only cows in their second or greater parity (65%) benefitted from cooling during the dry period of the previous parity. Milk yield decreased by 5kg in the subsequent lactation (340d) if the cow experienced heat stress during the dry period based on a review of the literature. The default marginal value of milk minus feed cost was $0.33/kg of milk. The investment analysis included purchases of fans and soakers and use of water and electricity. Investment in a dry cow barn was considered separately. The average US dairy cow would experience 96 (26%) heat stress days during the year if not cooled and loses 447kg of milk in the subsequent lactation if not cooled when dry. Annual losses would be $810 million if dry cows were not cooled ($87/cow per yr). For the top 3 milk-producing states (California, Wisconsin, New York), and Florida and Texas, the average milk losses in the subsequent lactation were 522, 349, 387, 1,197, and 904kg, and reduced profit per cow per year would be $101, $68, $75, $233, and $176, respectively. The average benefit-cost ratio and payback periods of cooling dry cows in the United States were 3.15 and 0.27 yr (dry cow barn already present) and 1.45 and 5.68 yr (if investing in a dry cow barn) in the default scenario. To reach positive net present values, 6d (barn is present) and 55d (barn investment necessary) of heat stress annually were necessary (default assumptions). Other benefits of cooling, such as increased health and more productive offspring, were not considered. In conclusion, cooling of dry cows was profitable for 89% of the cows in the United States when building a new barn is required (under default assumptions) and very profitable when construction of a dry cow barn is not required (except for Alaska).

Economic Burden of Hospitalizations for Heat-Related Illnesses in the United States, 2001-2010.

Understanding how heat waves affect morbidity and mortality, as well as the associated economic costs, is essential for characterizing the human health impacts of extreme heat under a changing climate. Only a handful of studies have examined healthcare costs associated with exposures to high temperatures. This research explores costs associated with hospitalizations for heat-related illness (HRI) in the United States using the 2001 to 2010 Nationwide Inpatient Sample (NIS). Descriptive statistics of patient data for HRI hospitalizations were examined and costs of hospitalizations were reported using the all-payer inpatient cost-to-charge ratio. Costs were examined using a log-gamma model with patient and hospital characteristics included as fixed effects. Adjusted mean costs were then compared across racial groups. The mean costs of HRI hospitalizations were higher among racial/ethnic minorities compared to Whites, who accounted for almost 65% of all HRI hospitalizations. Observed differences in costs based on income, insurance, and gender were also significant. These results suggest that these populations are suffering disproportionately from health inequity, thus, they could shoulder greater disease and financial burdens due to climate change. These findings may have important implications in understanding the economic impact public health planning and interventions will have on preventing hospitalizations related to extreme heat.

Impact of Arm Immersion Cooling During Ranger Training on Exertional Heat Illness and Treatment Costs.

UNLABELLED: Ranger training includes strenuous physical activities and despite heat mitigations strategies, numerous cases of serious exertional heat illness (EHI) occur. We developed an Arm Immersion Cooling (AIC) system that is not logistically burdensome and may be easily employed in training environments. PURPOSE: To examine the effect of AIC on EHI incidence, severity, and treatment costs during Ranger School. METHODS: The training program was standardized for physical exertion and heat stress factors throughout the study period. AIC was employed summer months of 2010-2012 (n = 3,930 Soldiers) and Control (CON; n = 6,650 Soldiers) data were obtained for summer months of 2007-2009. Descriptive characteristics of all EHI casualties were obtained, including hospitalization status (treated and released [Treat], evacuated [Evac] or admitted [Admit] to the hospital), which served as proxy indicator of illness/injury severity. Medical cost savings were calculated from hospital records. RESULTS: Incidence rates were not different (CON 4.06 vs. AIC 4.00/1,000 person-days). Treat increased during AIC (18.43 vs. 4.84/1,000 person-days) accompanied by marked but non-significant decreases in Evac and Admit rates. AIC use was associated with a medical cost savings of $1,719 per casualty. CONCLUSIONS: AIC implementation during strenuous physical training in summer months can reduce EHI severity and associated medical treatment costs.

Heat-related illness in Washington State agriculture and forestry sectors.

BACKGROUND: We sought to describe heat-related illness (HRI) in agriculture and forestry workers in Washington State. METHODS: Demographic and clinical Washington State Fund workers' compensation agriculture and forestry HRI claims data (1995-2009) and Washington Agriculture Heat Rule citations (2009-2012) were accessed and described. Maximum daily temperature (Tmax) and Heat Index (HImax) were estimated by claim date and location using AgWeatherNet's weather station network. RESULTS: There were 84 Washington State Fund agriculture and forestry HRI claims and 60 Heat Rule citations during the study period. HRI claims and citations were most common in crop production and support subsectors. The mean Tmax (HImax) was 95°F (99°F) for outdoor HRI claims. Potential HRI risk factors and HRI-related injuries were documented for some claims. CONCLUSIONS: Agriculture and forestry HRI cases are characterized by potential work-related, environmental, and personal risk factors. Further work is needed to elucidate the relationship between heat exposure and occupational injuries.