[Monthly variation of viable count and coliforms count of sandpits in parks]

Field and experimental microbiological investigations of samples from sandpits from 5 parks were performed 2 times a month for 1 year, January-December 1990. Total viable count from the sandpits was highest in the surface layer sample than the inner layer throughout the year. However, there was no such tendency in the number of Coliforms and Enterobacter, Escherichia coli, Citrobacter. The number of bacteria on the surface and inner layer was high from April to June, and in September and October, while it was low in July and August. The proportion of Coliform bacteria represented in the total viable count ranged from 2.1 to 8.9% in the surface layer and from 1.6 to 19.6% in the inner layer. There was a significant correlation between the numbers of bacteria on the surface and inner layer. Relationships between the total viable count and Coliform count and between Coliform count and E. coli, Enterobacter and Citrobacter were also observed. In view of the results it can be concluded that park sandpits are not, from a hygienic point of view, to be an ideal environment for children to play in.