Size Distributions of Soil Particles Adhered to Children’s Hands
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The size distributions of the soil particles adhered to children’s hands were preliminarily investigated and compared with a cutoff soil particle size recently specified in the official analytical method in Japan. To facilitate fieldworks involving child participants, we tested a methodology using a laser scattering particle size distribution analyzer and validated it for field applications. The laboratory experiments using this method showed finer soil particles tended to be adhered more efficiently to human hands. Meanwhile, our preliminary field survey revealed large variations in mass (mean 26.2 mg/hand, median 15.2 mg/hand, max 162.5 mg/hand) and size distributions (particle mode diameter of 39 ± 26 μm) of the particles adhered to children’s hands after various playing activities. Even though the ways the particles adhered were noticeably varied under actual playing situations, the adhered particles were consistently and considerably smaller than the 2-mm cutoff diameter defined by the Ministry of the Environment, Japan. Since soil contaminant concentrations are generally higher for finer soil particles, measurement of contaminant concentrations for the soil fraction including the non-adherent millimeter particles may underestimate the risk of direct soil contaminant intakes.
KeywordsSoil Particle Human Hand Reference Soil Laser Transmittance Soil Contaminant
The authors thank Ms. O. Tsumashima as well as children of the Kawasaki City Nursery School for kindly providing us the sampling opportunity and participating in the field survey. Thanks are also due to Ms. M. Yoshikane and Y. Kanda of the National Institute for Environmental Studies for their assistance in the HORIBA LA-300 operation.
- Kissel JC, Shirai JH, Richter KY, Fenske RA (1998) Investigation of dermal contact with soil in controlled trials. J Soil Contam 7:735–752Google Scholar
- Ministry of the Environment, Japan (2001) Dojo no tyokusetsu- sessyoku niyoru risk hyouka ton nitsuite <http://www.env.go.jp/water/report/hl3-01/01.pdf> Accessed 5 May 2005 (in Japanese)
- Ministry of the Environment, Japan (2002) On the Dojo Osen Taisaku Hou <http://www.env.go.jp/water/dojo/law.html> Accessed 5 May 2005 (in Japanese)
- Ministry of the Environment, Japan (2003) Kokuji dai 19 gou. <http://www.env.go.jp/water/dojo/law/kokuji/04.pdf> Accessed 5 May 2005 (in Japanese)
- Sedman RM (1989) The development of applied action levels for soil contact: a scenario for the exposure of humans to soil in a residential setting. Environ Health Perspect 79:291–313Google Scholar
- U.S. Environmental Protection Agency (U.S. EPA) (1985) Development of statistical distributions or ranges of standard factors used in exposure assessments. Office of Health and Environmental Assessment. U.S. EP A/600/8-85/0 10, Washington, DCGoogle Scholar
- U.S. EPA (1997) Exposure factors handbook. Office of Research and Development. U.S.EPA /600/8-89/043, Washington, DC. <http://www.epa.gov/ncea/pdfs/efh/front.pdf> Accessed 5 May 2005