Africa Water, Sanitation & Hygiene January - February 2016 vol.11 no.1 | Page 21

Water Resources
“Microbes seem to be
making pharmaceuticals
out of what used to be
pharmaceuticals,” said
Benjamin Blair, the lead
author of a new study.
Blair and his team tested
wastewater before treatment
and after treatment at a plant near Milwaukee. “They
found that two drugs — the anti-epileptic carbamazepine
and antibiotic ofloxacin — came out at higher
concentrations than they went in. The study suggests
the microbes that clean our water may also piece some
pharmaceuticals back together,” Environmental Health
News reported.
“Pills 1,” e-Magine Art © 2010

Carbamzepine increased on average by 80 percent after
the treatment process. Ofloxacin increased by 120 percent.
“Such drugs, and their metabolites (formed as part of the
natural biochemical process of degrading and eliminating
the compounds), get into the wastewater by people taking
them and excreting them. Flushing drugs accounts for
some of the levels too,” the report said.
Other studies have yielded similar findings to Blair’s.
“Canadian researchers in Ontario found [comparable
results] when they tested water in a Peterborough plant.
It was not clear to the team why only two drugs of the
48 increased in the cleaning process,” The Independent
reported.
Drugs in water are on the government’s radar.
Pharmaceutical and personal care products (PPCPs)
are not regulated, but they are on the EPA’s list of
contaminants that may warrant more oversight.
The U.S. Geological Survey, a federal bureau, released
a study last year about the threat of drugs released
into the environment through wastewater. The study
found that treated municipal groundwater released back
into the rivers and streams can sometimes result in
groundwater carrying traces of pharmaceuticals and other
contaminants.

Greywater reuse for irrigation is safe,
study shows
Researchers at the Zuckerberg Institute for Water Research
at Ben-Gurion University of the Negev have determined
that treated greywater is safe for irrigation and does not
pose a risk for gastrointestinal illness or water-related
diseases.
The study, published in the online journal Science of the
Total Environment (Elsevier), determined that there was
no additional incidence of gastroenteritis or water-related
diseases caused by use of treated greywater in gardens,
even when compared to tap water and other irrigation
water sources.

Greywater includes any
wastewater generated in
households or office buildings
except for toilet wastewater.
According to the researchers,
“There is a growing interest
in greywater reuse from sinks,
bathtubs and laundry machines,
particularly in water-scarce
regions. New greywater
systems, including one
developed at the Zuckerberg
Greywater “towers” are used to
Institute, now make reuse
treat
and reuse greywater in the city
economically feasible on both
of Arba Minch, Ethiopia
a national and household
scale, provided it is handled
responsibly to eliminate potential environmental and
health risks.”
Study participants -- greywater users and the nongreywater-using control group -- were required to
complete a weekly health questionnaire for a year, as well
as a preliminary lifestyle questionnaire to assess their
exposure level to greywater or potable water used in
garden irrigation.
“This study showed that there was no additional incidence
of gastroenteritis found among treated greywater users
and practically no difference in the prevalence of waterrelated diseases between greywater and potable water
users,” explains BGU Zuckerberg Institute Prof. Amit
Gross, Ph.D. “In fact, the rate of illnesses was found to
be lower with the treated greywater than from the control
group at times, suggesting that the main exposure to
gastrointestinal disease-causing bacteria is not likely from
exposure to pathogens in greywater.”
The second study component compared the findings
to published results of health risks determined by
Quantitative Microbial Risk Assessment (QMRA), a
standard process used for measuring the risks from
exposure to known microbial pathogens or indicators in
water or food sources.
“Since the concentration of pathogens in the current
study was higher than QMRA risk levels, yet the
prevalence of water-related diseases between control and
greywater users was similar, we believe that QMRA can
be used as a conservative benchmark toward establishing
regulations governing greywater reuse,” Gross says.
Following this initial study, Prof. Gross recommends
further research involving a larger population to enhance
the statistical power of and enable elaboration on the
possible connections between gastrointestinal illnesses and
exposure to greywater.
Source: Zuckerberg Institute for