Introduction
Burkina Faso, like many countries, is confronted withvarious
issues among which food insecurity. In order to address this situation, the
level of fertility of the soils has been decreasing; the price of chemical
fertilizers is increasing on the marketas well as the weakness of the
pluviometry. Furthermore, the water resources are insufficient, because 44,15%
of rural population have not access of best water quality (DGRE, 2010).In
addition, there is theissue of an appropriate sanitation. According to WHO and
UNICEF, (2007) Joint Monitoring Program, access to improved sanitation in
Burkina Faso was about 17% on national scale (47% urban and 4% rural) in 2007.
The lower sanitation distribution is increasing the diseases from population
which constitutes a public health issue in Burkina Faso. Therefore, improvement
of the agriculture and sanitation is urgent task in the country.Faeces and
urine, as well as mixed sewage products, need to be seen as resources rather
than waste the resource oriented sanitation for sanitation or composting toilet
is an advantage for agriculture. In addition human excreta have traditionally
been used for crop fertilization in many countries. In Japan recycling of urine
and faeces was introduced in the 12th Century and in China human and
animal excreta have been composted for thousands of years (Höglund, 2001).
In human excreta, urine contains the major part of essential plant nutrients
(nitrogen, phosphorus and potassium). Concerning Faeces, apart from nutrients,
can contribute humus-like substances, thus improving soil fertilizer
(Schönning et al., 2007). In this case, thereuse of human excreta without
previous relevanttreatment in agriculture triggers a problem of public health
and remains health risk for farmers and consumers.Greywater reuse can alleviate
stress on depleted water resources while reducing water cost for residents
(Maimon et al., 2010). The reuse of greywater, however also can compromise
human and environmental health. Pathogens in greywater may cause diseases
through direct contact as well as through the consumption of contaminated
plants (Shuval et al., 1997 and Mara et al., 2007a).
However, hazards associated with the recycling of these
products include pathogens and pharmaceuticals as well as other micropollutants
and heavy metals (Höglund et al., 1998 and Schönning et al.,
2007).Thus, consumers can be exposedto diseases, when consuming the
contaminated products related to greywater and human excreta reuse in
agriculture especially if these products are not appropriately treated before
being used in agriculture (FAO and WHO, 2008). Therefore, in order to minimize
contamination of farmers and consumers due to the reuse of human excreta and
greywater in agriculture field, several studies were conducted on health risk
assessment related to urine, compost or greywater in agriculture field in the
world (Höglund et al., 2002; -Al-Hamaiedeh, 2010; Fidjeland, 2010 ;Gemmell
and Schmidt, 2011; and Nana O.B. Ackerson and Esi Awuah, 2012).
However, in Burkina Faso these kinds of study have not been
conducted yet according to our investigations, when we know that the majorityof
urban farming populations use wastewater to irrigate their crops which is not
necessarily treated before use to irrigate crops.In this context, the Japanese
International Corporation Agency (JICA) through the Ameli-EAUR project which
promotes the valorization of human excreta and greywater in family farming in
order to improve sustainable sanitation for rural populations tried to study
the health risk assessment related to the reuse of human excreta and greywater
in agriculture. It is in this context that a topic was suggestedto us within
the framework of our master's thesis. The topic is entitled «health risk
assessment associated with the reuse of compost, urine and greywater in
agricultural field in sahelian climate». The aim of this study isto assess
the health risks associated with the reuse of human excreta and greywater in
the agricultural field. It will, in a specific way, firstly, assess the health
risk forfarmers thatreuse human excreta and greywater in agriculture field; and
secondly assess the health risk for consumers of goods relating to the reuse of
human excreta and greywater in agriculture field.To meet these objectives, this
present dissertation includes the following parts: the state of the art on the
generality on health risk assessment which include the risk for farmers and
consumers, the material and methods which are used to do this study, then the
results and discussion issue following the different activities and
experimentations, and finally the conclusion and perspectives of this study.
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