10.1021/es4006509.s001
Jerry E. Ongerth
Jerry E.
Ongerth
LT2 <i>Cryptosporidium</i> Data: What Do
They Tell Us about <i>Cryptosporidium</i> in Surface Water
in the United States?
American Chemical Society
2013
EPA
location
United States Federal regulation
water quality parameters
surface water source
sample
LT 2 Cryptosporidium Data
surface water
U.S
data
2013-05-07 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/LT2_i_Cryptosporidium_i_Data_What_Do_They_Tell_Us_about_i_Cryptosporidium_i_in_Surface_Water_in_the_United_States_/2417812
Beginning
in 2006 a United States Federal regulation required public
water suppliers using surface water serving more than 10,000 population
to analyze for <i>Cryptosporidium</i> in at least 24 consecutive
monthly samples from each surface water source. In July 2012, the
U.S. EPA released the resulting data consisting of ca. 45,000 records.
No <i>Cryptosporidium</i> were found in 93% of samples and
no <i>Cryptosporidium</i> were found in any samples analyzed
from over half of 1670 locations sampled. Nevertheless, at 250 locations
representing every region of the U.S., <i>Cryptosporidium</i> were found in sufficient numbers of samples to provide a picture
of their occurrence nationwide. Data from about 100 sites reporting
the highest numbers were examined in detail. Although analysis of
matrix spikes was required for quality control, the results do not
permit estimating organism concentrations. The data reported at each
of the individual sample locations were analyzed in the form of cumulative
probability distributions to describe key risk-related features of
median level and variability. Taken as a whole, the data describe
a spectrum of median <i>Cryptosporidium</i> occurrence in
surface waters of the U.S. ranging from ca. 0.005 to ca. 0.5 oocysts/L.
The variability at individual sites ranged from ca. 1 to 15 r.s.d.
Based on the LT2 positive data, comparison to measurements of other
water quality parameters, and independent means of estimating organism
production from watersheds reported in the literature, the hypothesis
is offered that <i>Cryptosporidium</i> may be found in surface
water anywhere worldwide continuously and within the spectrum defined
above.