The Yodo River flows through urban areas and is typical for Japan in that its water
is recycled. The three water works are on the lower reaches of the river. One task of the
water works is to examine water samples for Cryptosporidium parvum and Giardia
intestinalis (lamblia). This study examined raw water sampled at three water treatment plants of Osaka Prefectural Water Works for these organisms every
month from December 1999 to March 2001. In addition, water was sampled
summer and winter at 28 locations in the watershed of the Yodo River for the pinpointing of the sources of these microorganisms. There were
more raw-water samples containing one or both of the organisms in winter than in
other seasons. Of the 48 samples, 19 (40%) contained C. parvum; the maximum
number of oocysts was 14/10 liters. The mean number of oocysts for all samples
was 1.7/10 liters. In the watershed samples, detection rates for both organisms
were greater in winter than in summer. Twenty (71%) of the 28 winter samples contained C. parvum; there was a maximum of 32 oocysts/10 liters, and the winter
mean number of oocysts was 5.1/10 liters. These values for G. intestinalis were 23
(82%) of 28, 380 cysts/10 liters, and 40 cysts/10 liters, respectively. Many cysts
and oocysts of these species were detected at four watershed locations along four
tributaries receiving effluents from different sewage treatment plants. These
catchment areas were residential zones where most households have a septic tank.
Waste from the livestock industry was not a factor, as livestock are not kept in the
area. Includes 8 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.7 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 09/22/2002 |
