title: Removal of Diethylhexyl Phthalate from Hands by Handwashing: Evidence from Experimental N-of-1 and Crossover Designs.
abstract: Phthalate exposure through skin is often neglected due to the small quantity and limited dermal absorption rate. However, free phthalate can be ingested by hand-to-mouth action or by contact with food. To evaluate the effectiveness in removing phthalate exposure on hand, we compare here the removal efficiency of di-(2-ethylhexyl)phthalate (DEHP) on hands by handwashing with soap-and-water versus water-only. In two three-day N-of-1 trials, residual DEHP was measured in a single female adult who washed exposed hands with soap-and-water or water-only. Subsequently, a crossover study was performed by randomly assigning another 28 subjects equally to wash with soap-and-water or with water-only, and then each one received the other treatment 24 hrs later. In the N-of-1 trials, mean DEHP removal rates range from 95.9% (SD = 0.1%) to 97.0% (SD = 2.5%) for soap-and-water handwashes, and 1.8% (SD = 0.1%) to 7.0% (SD = 0.3%) (n = 3) for water-only. In the crossover study, mean removal rate was 94.6% (SD = 6.5%) for handwashing with soap-and-water (n = 28) and 8.7% (SD = 5.7%) for water-only (n = 28). We concluded that handwashing with soap-and-water removes 80% more DEHP than handwashing with water alone, and may be a cost-effective way of removing other endocrine disruptors from hands.
authors.affiliation: Kaohsiung Medical University, Department of Public Health, Kaohsiung, 807, Taiwan.|Kaohsiung Medical University, Research Center of Environmental Health, Kaohsiung, 807, Taiwan.|Harvard T.H. Chan School of Public Health, Department of Environmental Health, Boston, 02115, USA.|Kaohsiung Medical University, Department of Pharmacy, Kaohsiung, 807, Taiwan.
authors.forename: Pi-I D
authors.initials: PD
authors.lastname: Lin
authors.affiliation: Kaohsiung Medical University, Department of Public Health, Kaohsiung, 807, Taiwan.
authors.forename: Chia-Fang
authors.initials: CF
authors.lastname: Wu
authors.affiliation: Kaohsiung Medical University, Department of Pharmacy, Kaohsiung, 807, Taiwan.
authors.forename: Hwang-Shang
authors.initials: HS
authors.lastname: Kou
authors.affiliation: Kaohsiung Medical University, Department of Public Health, Kaohsiung, 807, Taiwan.
authors.forename: Tzu-Ying
authors.initials: TY
authors.lastname: Huang
authors.affiliation: National Sun Yat-Sen University, Department of Chemistry, Kaohsiung, 807, Taiwan.
authors.forename: Jentaie
authors.initials: J
authors.lastname: Shiea
authors.affiliation: Kaohsiung Medical University, Department of Public Health, Kaohsiung, 807, Taiwan. e_encourage@yahoo.com.|Kaohsiung Medical University, Research Center of Environmental Health, Kaohsiung, 807, Taiwan. e_encourage@yahoo.com.|Kaohsiung Medical University Hospital, Department of Family Medicine, Kaohsiung, 807, Taiwan. e_encourage@yahoo.com.|Kaohsiung Municipal Hsiao-Kang Hospital, Center of Environmental and Occupational Medicine, Kaohsiung, 807, Taiwan. e_encourage@yahoo.com.
authors.forename: Ming-Tsang
authors.initials: MT
authors.lastname: Wu