title: Implications of polarity of unipolar ionisers on reduction of effective dose attributable to thoron progeny.
abstract: Negative ionisers have been proved to be effective in reducing indoor particulates in general and activity concentrations due to radon and thoron (220Rn) decay products in workplace environments in particular. However, in comparison, there exist few studies on the effect of positive ions for mitigation. In the present work, particle and activity concentration reduction has been compared for three experimental conditions (two for positive ions and one for negative) in an unoccupied room with elevated (220)Rn levels. The negative ioniser configuration provided a better concentration reduction factor of 4.59 with smallest characteristic depletion time. A theoretical estimate of the dose reduction factor is found to be 3.96 and 3.74, respectively, for positive and negative ioniser configuration.
authors.affiliation: Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. mjoshi@barc.gov.in
authors.forename: Manish
authors.initials: M
authors.lastname: Joshi
authors.forename: B K
authors.initials: BK
authors.lastname: Sapra
authors.forename: Pallavi
authors.initials: P
authors.lastname: Kothalkar
authors.forename: Arshad
authors.initials: A
authors.lastname: Khan
authors.forename: Rajni
authors.initials: R
authors.lastname: Modi
authors.forename: Y S
authors.initials: YS
authors.lastname: Mayya
mesh_terms: D000390:Air Ionization; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D052918:Environmental Restoration and Remediation; D006801:Humans; D007477:Ions / Q000627:therapeutic use*; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D017687:Radon Daughters / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D007477:Ions; D017687:Radon Daughters; D011886:Radon