Association of self-perceived work ability with worksite temperature as modified by relative humidity and air velocity: a cross-sectional study of poultry workers in Thailand

Abstract

The combined association of self-perceived work ability with ambient temperature, relative humidity, and air velocity in the poultry industry has not been described. We asked 286 poultry workers in Thailand regarding their perceived work ability and regressed the data on worksite temperature, relative humidity, air velocity, interactions, workers’ characteristics, and work-related factors. The mean age of the workers was 32.7 years (range, 18–57 years), and 166 (58 %) were men. The average worksite temperature, relative humidity, and air velocity were 3.7 °C (range, −21.6–23.0 °C), 46.6 % (range, 27.0–72.0), and 0.44 m/s (range, 0.01–3.00 m/s), respectively. The mean work ability score was 8.29 (range, 4–10), and 68 participants (23.8 %) reported poor work ability (≤7). At cold and humid sites (temperature <2.0 °C; relative humidity >50 %), the prevalence of poor work ability increased with falling temperature (23.0 °C to −21.6 °C), by up to 94.2 % percentage points at the highest air velocity and highest relative humidity. At warmer and drier sites (temperature ≥2.0 °C; relative humidity <35 %), the prevalence of poor work ability increased from cold to warm sites (−21.6 °C–23.0 °C), by up to 70.5 % percentage points at sites with the lowest relative humidity and lowest air velocity. Workers at cold and humid sites (19.6 %) and those at warm and dry sites (17.8 %) suffer from poor work ability and need preventive actions. These groups require advice to minimise work hazards for various combinations of temperature, humidity, and air velocity.