BACKGROUND: The objectives of the present study are to: (i) evaluate the effect of environmental and metabolic heat on heat-related illnesses in outdoor workers; and (ii) evaluate the effect of personal factors, including heat acclimation, on the risk of heat-related illnesses in outdoor workers. METHODS: We identified 47 cases of illnesses from exposure to environmental heat in outdoor workers in Korea from 2010 to 2014, based on review of workers' compensation data. We also obtained the information on location, time, and work environment of each heat-related illness. RESULTS: Our major results are that 29 cases (61.7%) occurred during a heat wave. Forty five cases (95.7%) occurred when the maximum estimated WBGT (WBGTmax) was equal to or greater than the case specific threshold value which was determined by acclimatization and metabolic rate. Twenty two cases (46.8%) were not acclimated to the heat. Thirty-seven cases (78.7%) occurred after tropical night (temperature above 25 °C), during which many people may find it hard to sleep. CONCLUSION: Personal risk factors such as heat acclimation as well as environmental factors and high metabolic rate during work are the major determinants of heat-related illnesses.
Acclimatization ; Extreme Heat* ; Hot Temperature ; Humans ; Infrared Rays ; Korea ; Risk Factors ; Workers' Compensation

OBJECTIVETo evaluate the impacts of air temperature on years of life lost (YLL) among the residents in Guangzhou and Zhuhai, Guangdong province.

METHODSDaily mortality and meteorology data in Guangzhou and Zhuhai were collected, and distributed lag non-linear model (DLNM) was used to evaluate the cumulative and delayed effects of daily air temperature on YLL of total non-accident mortality. The accumulative effect of air temperature on mortality under the extreme high temperature (0-1 days) and extreme low temperature (0-13 days) situation in Guangzhou and Zhuhai were analyzed respectively.

RESULTSThe average YLL was 1 928.0 in Guangzhou and 202.5 in Zhuhai. The exposure-response functions seemed to be non-linear. The hot effect seemed to be acute and reached the peak at the same day, while the cold effect reached the peak at 5(th) days and lasted for about two weeks. Low temperature had stronger gross effect than high temperature had. The cold effect among males was greater than that among females in Guangzhou. The hot/cold effect on YLL was greater in people aged ≥ 65 years than in people aged < 65 years and in people suffering from respiratory disease than in people suffering from cardiovascular disease in both Guangzhou and Zhuhai.

CONCLUSIONThe effects of high and low temperatures on YLL were obvious, and the impact of low temperature was greater. The elderly and people suffering from respiratory disease or cardiovascular disease are the vulnerable populations.

Aged ; Air ; Cardiovascular Diseases ; epidemiology ; China ; epidemiology ; Extreme Cold ; adverse effects ; Extreme Heat ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Mortality, Premature ; Nonlinear Dynamics ; Respiratory Tract Diseases ; epidemiology ; Time Factors

PURPOSE: To evaluate the effect of heat wave on emergency department (ED) visits due to heat related illness, we developed an ED based active surveillance system. We want to identify epidemiology of ED visits due to heat related illness and determine the effect of heat index on daily ED visits due to heat related illness. METHODS: We developed an ED based active surveillance system for adults who visited the ED due to heat stroke, heat exhaustion, heat syncope, heat edema, and heat cramp. We collected demographic and clinical variables, risk factors, and heat index by standardized registry on the webpage. We operated the surveillance into 16 emergency departments in Daegu City from June to September 2011. We analyzed epidemiologic variables descriptively and assessed the effect of heat index on the number of daily ED visits by multivariate Poisson regression analysis. RESULTS: During the study period, 34 cases were registered and nine cases were heat stroke. Heat stroke patients were older, and had more unemployment status than those with other heat related illness (p<0.05). More ED visits due to heat related illness were observed during the danger period than during the cool period, classified by heat index severity (Adjusted odds ratio: 1.72, 95% CI: 1.33-2.23). Increasing heat index by one degree caused more ED visits due to heat related illness (Adjusted incident rate ratio: 1.13, 95% CI: 1.07-1.19). CONCLUSION: We developed an ED based active surveillance system and observed more elderly persons and lower educational level in patients with heat stroke. In addition, increase in heat index significantly affected more daily ED visits due to heat related illness.
Adult ; Aged ; Daegu ; Edema ; Emergency Service, Hospital* ; Epidemiology ; Extreme Heat ; Heat Exhaustion ; Heat Stress Disorders ; Heat Stroke ; Hot Temperature* ; Humans ; Infrared Rays ; Odds Ratio ; Public Health Surveillance ; Risk Factors ; Syncope ; Unemployment