碩士 / 高雄醫學大學 / 公共衛生學研究所 / 101 / Recent incidence on phthalate contamination in food products and daily wares alerted the public about the adverse health impact of phthalate use. Phthalate esters are widely use in daily life; studies had confirmed that long term exposure to phthalate will result in chronic health symptoms. Phthalate esters are classified as toxic chemical substance by the Environmental Protection Administration, Executive Yuan, ROC. Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly found phthalate in our daily life with the highest toxicity.
There is a universal exposure to a small concentration of DEHP via dermal contacts, inhalation, and ingestion every day. Strict regulations are imposed on the use of DEHP in daily products, and a Tolerable Daily Intake (TDI) limit is set at 50μg/kg bw/day. However, dermal exposure to DEHP is hard to estimate thus its risk to our health is often neglected. DEHP can be directly absorbed by the skin; DEHP can also be ingested by hand-to-mouth behavior and hand-to-food contacts.
Hand washing is a simple way to practice good hygiene. Washing hands before eating can reduce the amount of dermal exposure to phthalate and other chemicals, and thus, reduce the level of exposure in our body. Current knowledge on dermal exposure to DEHP is limited and no published study has been found to investigate the removal efficiency of DEHP on skin. This study aimed to understand the removal efficiency of dermal exposure to DEHP by hand washing with phthalate-free soap.
The study employed N-of-1 study design for the pilot study. One subject was recruited to mimic DEHP exposure on hands at a concentration comparable to real life situation, the subject then receive Treatment (hand washing with phthalate-free soap) and Placebo (washing with water only) interventions in order to study the removal efficiency of DEHP on hand surface.
The pilot study showed that the Treatment had removal efficiency of 99.40±13.70%；whereas Placebo only had 5.11±4.85%. The study was then expanded to a field study using a randomized controlled crossover study design. A total of 16 subjects with 8 females and 8 males were randomly assigned to the Treatment or Placebo group. After one week washout, crossover was performed and each subject received the other intervention.
The result showed that the Treatment intervention had removal efficiency of 91.42±5.78%；Placebo had 10.64±6.54%. Using phthalate-free soap can significantly remove 90% or higher dermal exposure to DEHP on hands, and the efficiency was significantly higher than washing with water alone. The study also found that although water wash had lower removal efficiency, the DEHP left on hands unable to be washed off by water-only can be successfully removed if an additional soap washing step was added. Males and females had significantly different hand sizes; however, no difference in the removal efficiency across genders was observed in the study. This study suggested that using proper hand washing technique and improving understanding and familiarity on hand washing can also increase the removal efficiency on dermal exposure to DEHP.
| Identifer | oai:union.ndltd.org:TW/101KMC05058004 |
| Date | January 2013 |
| Creators | Pi-i Debby Lin, 林碧憶 |
| Contributors | Ming-Tsang Wu, 吳明蒼 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 88 |
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