Experimental study on human physiological responses and labor safety under salt spray exposure in high-temperature and high-humidity environments

To assess the combined human physiological responses and labor safety impacts of salt spray aerosol in a high-temperature and high-humidity environment, 88 healthy male participants are tested under conditions of a temperature of 36 ℃ and a relative humidity of 50%, with the salt spray concentrations of 0, (6.41±1.95), (9.60±0.72), and (12.90±0.77) mg/m3. Oral temperature, heart rate, and dehydration rate are continuously monitored, and the safe labor time (SLT) is calculated. The results show that the exposure to salt spray concentrations of (6.41±1.95), (9.60±0.72), and (12.90±0.77) mg/m3 results in reductions of SLT by 23%, 27%, and 23%, respectively (p<0.05). The labor safety index (LSI), developed based on the above physiological indicators, demonstrates good consistency with the classical physiological strain index (PSI). The logistic regression prediction model developed to predict high-risk individuals (SLT<60 min) achieves an area under curve (AUC) of 0.788 and an overall accuracy of 71.6%.