Human Health Risk
Cryptosporidium
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drinking water recreational water
Ecological Risk
Socioeconomic Risk
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Cryptosporidum is an intestinal parasite that infects humans and animals. Infections in
healthy people can result in relatively minor and self-limiting symptoms including nausea,
cramps, diarrhea, and vomiting. In those with weakened immune systems, severe and
potentialy life-threatening illness may occur. Egg stage organisms are excreted in the
feces of infected individuals and animals, and are found in virtually all lakes, rivers, and
streams. Able to resist most forms of chemical disinfection, large numbers of
Cryptosporidium in public drinking water supplies caused widespread illness in the City of
Milwaukee in 1993.
What’s at risk?
What are the human health impacts in New
Jersey?
There have been no confirmed reports of outbreaks due to drinking water in New Jersey since
1976. However, it is difficult to estimate how many
people are affected by a waterborne illness because
not everyone exposed will develop symptoms and
many cases go unreported. In healthy populations,
the increased number of cases of minor gastrointestinal illness may be as many as 19,000 or as
few as 300 per year. Estimates for the subpopulation of immune-compromised people range from
less than 1 death per year to a high-end estimate of
5-10 additional deaths per year. There was a single
documented case of Cryptosporidium infection
from recreational bathing in New Jersey in 1994
with 135 cases reported.
What are the socioeconomic impacts to
New Jersey?
Costs associated with Cryptosporidium (doctor’s
visits, lost time) are relatively insignificant given
the expected low frequency of illness, and while
the possibility of an outbreak may cause concern, the psychological impacts associated with
this stressor are also judged to be relatively
minimal.
What’s being done?
All public water supplies in New Jersey are
filtered; filtration results in significant reduction
in the number of organisms, to an average
concentration of below 0.0001 organism per
liter. Drinking water treatment technologies exist
that would provide further protection, but these
are not likely to be employed on a widespread
basis because of the high costs involved.
Cryptosporidium is not regulated in waters used for
recreational purposes, except where they also
serve as sources of drinking water.
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Final Report of the New Jersey State Comparative Risk Project
STRESSOR SUMMARIES
Three million of New Jersey’s eight million
residents get their drinking water from surface
water sources that could potentially be contaminated with harmful levels of Cryptosporidium.
People may also become exposed while swimming, or coming in contact with the feces of
infected individuals. Wildlife can also be exposed
and infected, but ecological impacts are negligible.