Investigation of Heat Stress among Greenhouse Workers in Chhattisgarh, India

Abstract

Greenhouse cultivation is spreading as it offers the grower a higher net yield per hectare from high quality crops as it reduces the likelihood of yield decline. The greenhouse is kept at 30-40˚ C with a relative humidity of up to 70%, which could be ideal for plant growth, but is not suitable for workers. Heat exposure in the workplace causes discomfort to the human while working.   So, the main goal of conducting this research is to address the extent of heat stress and associated health issues for the greenhouse workers. The study was planned for 2022 in the Raipur district of Chhattisgarh. Prior to the assessment, a questionnaire survey was conducted among 50 greenhouse workers to learn perceptions of heat exposure, heat-related health issues and awareness of heat management. To get the heat exposure air temperature, wet bulb temperature, relative humidity, black globe temperature were measured on hourly basis. The wet bulb globe temperature (WBGT) was measured along with greenhouse workers' physiological parameters to quantify heat exposure. With the help of clock diagram showing Humidex Index (HI). The time period at which farmers most likely to suffer from heat stress was estimated. It was reported that in April, May, June, July, August and September WBGT index reaches varied between 30 and 34°C. According to ISO 7243 the recommended WBGT for comfortable workplace should be less than  31°C. Further study was conducted to get physiological responses of the 21 farm workers in three different type of greenhouses and at three time slots. It resulted that heart rate was maximum i.e. 156 bpm in walk in tunnel at 11 am to 1 pm. The average working heart rate was 20 % more than the open field condition. Hence, the study will help to make the strategies to reduce the exposure of heat stress conditions to the greenhouse workers.