Elution and adsorptive concentration of Japanese cedar (Cryptomeria japonica) pollen allergen in environmental water.

Elution of Japanese cedar pollen allergens (Cry j I and others) from pollen grains and its adsorptive concentration onto hydrophobic and hydrophilic surfaces were investigated using the surface plasmon resonance technique. Results showed that the allergen elution was obviously enhanced when the ion concentration was higher than that within the human body, indicating that the pollen tend to release its allergen in environmental water having a high ion concentration. However, higher adsorption capacity was observed on hydrophobic surface than hydrophilic surface. These results indicate that water puddles on roadsides beside heavy traffic including large amounts of ion compounds and hydrophobic diesel exhaust particles (DEPs) are a pollen allergen-DEP complex generator. DEPs are easily absorbed into the living body; therefore these mechanisms may be responsible for causing the highest incidence of pollinosis among residents living alongside roads with heavy automobile traffic.

Numerical modelling of the petroleum oil penetration into sandy beach sediments.

A numerical model describing the penetration of petroleum oil into sandy beach sediments was developed to assess the behavior of stranded oil at tidal zone as a result of tanker accidents, and so on. To understand the penetration behavior, penetration rate of three species of petroleum oil (two species of fuel oil C and one species of crude oil) was observed experimentally with artificial tidal zone equipment. As a consequence, two types of oil were distinguished from the viewpoint of penetration rate. One (fuel oil C-1) kept its homogeneity in composition and showed relatively rapid penetration, the other (fuel oil C-2 and crude oil) became heterogeneous and slow in penetration. Considering this aspect as the adsorption of polar compounds (i.e. asphaltenes) on the sediment surface, a numerical model that described oil penetration into sandy beach was developed. As a result, the difference in penetration rate between these two types of oil could not be replicated sufficiently only by consideration of the adsorption. However, the change of a parameter value which represents the apparent viscosity of oil led to good agreement with observations. Simulation results indicated that when fuel oil C or crude oil used in this study was stranded at a sandy beach located in Hiroshima Bay, Japan, 2 to 39% of total stranded oil might penetrate into the deeper zone (> 3 cm in depth) over 50 days.