Subject: [permaculture] pharmaceuticals, hormones, composting toilets, etc.
Date: Tue, 27 May 2008 21:35:56 -0500
from page 15 of Guidelines on the Use of Urine and Faeces in Crop
Production by ECOSANRES
Håkan Jönsson, Swedish University of Agricultural Sciences – SLU
Anna Richert Stintzing, VERNA Ecology, Inc
Björn Vinnerås, Swedish University of Agricultural Sciences – SLU
Eva Salomon, The Swedish Institute of Agricultural and Environmental
Engineering (JTI)
A large proportion of the hormones produced by our bodies and the
pharmaceuticals that we
consume are excreted with the urine, but it is reasonable to believe
that the risk for negative
effects on the quantity or quality of crops is negligible. All mammals
produce hormones and,
during the course of evolution, these have long been excreted in
terrestrial environments.
Thus, the vegetation and soil microbes are adapted to, and can degrade,
these hormones.
Furthermore, the amount of hormones in manure from domestic animals is
far larger than the
amount found in human urine. Thus, even though theoretical estimations
based on tests with
fish have indicated a risk of ecotoxicity from oestradiol
(Ambjerg-Nielsen et al., 2004) when
applying urine, both fertilizer experiments and evolutionary history
strongly indicate that there
is no real risk.
By far the majority of all pharmaceutical substances are derived from
nature, even if many
are synthetically produced, and they are thus found and degraded in
natural environments with
a diverse microbial activity. This has been verified in ordinary
wastewater treatment plants,
where the degradation of pharmaceutical substances improved when the
retention time was
prolonged from a number of hours to a number of days. Urine and faecal
fertilizers are mixed
into the active topsoil, which has a microbial community just as diverse
and active as that in
wastewater treatment plants, and the substances are retained for months
in the topsoil. This
means that there is plenty of time for the microbes to degrade any
pharmaceutical substances
and that risks associated with them are small.
Concerning both hormones and pharmaceutical substances, it thus seems
far better to recycle
urine and faeces to arable land than to flush them into recipient
waters. Since the aquatic
systems have never before been exposed to mammal hormones in large
quantities, it is not
surprising that the sex development of fish and reptiles is disturbed
when they are exposed to
wastewater effluent. Furthermore, the retention time of the wastewater
in the treatment plants
is far too short for many pharmaceutical substances to degrade and
recipient waters are also
usually connected to water sources. Thus, it is not surprising that
pharmaceutical substances
have been detected for decades, not only in e.g. the recipient waters of
Berlin but also in the
groundwater, which is Berlin’s source of drinking water (Herberer et
al., 1998).
Guidelines on the Use of Urine and Faeces in Crop Production
9
There are many indications that the possible risk from pharmaceutical
substances in the
agricultural system is small and far smaller than the risks associated
with the present system.
One such indication is that in many countries the human consumption of
pharmaceuticals
is small compared to that by domestic animals, as in most countries most
commercial feeds
contain antibiotic substances, added as growth promoters. Furthermore,
the human use
of pharmaceutical substances is small compared to the amount of
pesticides (insecticides,
fungicides, bactericides and herbicides) used in agriculture, which are
just as biologically
active as pharmaceutical substances.
[permaculture] pharmaceuticals, hormones, composting toilets, etc.,
George Anna Clark, 05/27/2008