Radiation health hazard and risks assessment among greenhouse farmers in Egypt, seasonal study

Objectives Greenhouses have been rapidly developing in Egypt in the recent years so as to overcome the problem of water shortage required for agriculture because agriculture in protected houses provides about 20-40% of the water consumption from agriculture in open lands. Greenhouses are widely used to cultivate different kinds of plants. Greenhouses are considered spacious, enclosed areas, in close contact with airtight and soil. They have been the main radon source for a long time. Radon and its progeny are released and trapped in the vacant space of greenhouses, causing health hazards for the farmers who work in them. Taking this into consideration, seasonal radon concentration levels have been monitored and measured in 8 greenhouses located at the city of Alexandria and Rosetta, Egypt. Materials and methods Passive closed-and-open can techniques are mainly used to calculate these concentrations. Each can has an attached CR-39 polymeric nuclear track detector as a detector material. For a period of 1 year inside the chosen greenhouses, the dosimeter has been exposed to the local for four seasons, 3 months each. Results The average annual radon concentration in those greenhouses varies between the lowest radon concentration value of 310 +/- 86 Bqm(-3) in the glass greenhouse in Alexandria, and the highest concentration value of 543 +/- 88 Bqm(-3) in the plastic greenhouses in Rosetta, with a total average annual value of 476 +/- 68 Bqm(-3). A remarkable variation in the seasonal radon concentrations in the greenhouses is observed. Also, in the research at hand, the radon radiation dose received by a farmer working in the greenhouses is calculated according to the ICRP. The occupants' greenhouse exposure rate varies from 1.38 mJ h m(-3) (0.39 WLM) in the plastic greenhouses to 2.42 mJ h m(-3) (0.683 WLM) in the glass ones, with an average value of 1.68 mJ h m(-3) (0.55 WLM) during that year. The workers' estimated effective dose per annum ranges between 1.94 mSv and 3.39 mSv with an average dose of 2.73 mSv. Conclusion In all the examined greenhouses in the Egyptian cities of Alexandria and Rosetta, the estimated effective dose per year is in the lower limit range of the action level (3-10 mSv) recommended for greenhouse workers by the ICRP, and it does not exceed the ICRP's upper limit. If the farmers work for a long number of years in the greenhouses, the occupational exposure to radiation doses due to radon concentration must be taken into consideration.