Survey on Radon Level, Environment and Workers Health in Greenhouse in Lanzhou

OBJECTIVES①To investigate radon level and its affecting factors in greenhouse in suburb of Lanzhou, and then estimate the annual effective dose exposed to radon absorbed by growers. It was expected to provide measures for controlling indoor radon pollution.②To investigate indoor ambient in greenhouses and its effect on the Health of greenhouse workers in Lanzhou.METHODS 1 Spot investigation:①Three greenhouses were chosen to detect indoor temperature, relative humidity and radon concentrations by Model 1027 type radon monitor during nearly three months.②Two greenhouses were chosen randomly to detect indoor temperature, relative humidity, CO₂ and NH₃ concentrations during nearly three months. 2 Questionnaire: a questionnaire was carried out for 120 greenhouse workers and 100 controls to clarify the possible correlation between the greenhouse ambient and the workers Health.RESULTS 1 Spot investigation:①An average radon concentration of 132.77 Bq/ m³ in local greenhouses was observed, which is 3.38 and 5.60 times higher than local average indoor radon level and country average indoor radon level, respectively. Soils and rocks under and around the greenhouse as well as wall body are main source of indoor radon. High temperature and low humidity probably facilitated the movement of radon into greenhouses. Meanwhile, a diurnal fluctuation in indoor radon concentration was observed. Furthermore, the annual effective dose exposed to radon absorbed by growers was estimated. Thus, the results showed that growers in greenhouses absorbed much higher effective dose than other residents.②The indoor concentrations of CO₂ and NH₃ were 0.20±0.02% （0.15～0.24%） and 0.65±0.45mg/m³ （0.05～1.50 mg/m³）, respectively. Higher indoor humidity and temperature differences were also observed. 2 Questionnaire: The greenhouse ambient has many adverse effects on joints, eyes and respiration for long-term growers.CONCLUSIONS①High radon exposure is probably potential health risk ifconsidering combined effects of other adverse Environmental factors in greenhouses.②Higher ammonia level is observed in greenhouses besides temperature andhumidity. More attention should be focused on negative impact of greenhouseambient on growers health.