Administrative Information
‫المعلومات االدارية‬
Project Title - ‫عنوان المشروع‬
and health risks of nitrates dynamics in the soil- :‫بلغة اجنبية‬
groundwater-food chain
‫السلسلة الغذائية‬-‫المياه الجوفية‬-‫ المخاطر الصحية والبيئية لتراكم النترات في التربة‬:‫باللغة العربية‬
Environmental
Principal Investigator - ‫الباحث الرئيسي‬
‫رقم الهاتف‬
‫العنوان االلكتروني‬
‫العنوان‬
Telephone
e-mail
Address
04 409845 tdarwich@cnrs.edu.lb ،‫المنصورية‬
‫لبنان‬
‫الوظيفية‬
Post
‫المؤسسة‬
Institution
‫االسم‬
Name
‫طالل‬
‫المجلس الوطني للبحوث‬
‫درويش‬
‫مركز االستشعار‬/‫العلمية‬
Talal
‫ عن بعد‬Darwish
CNRS-CRS
‫مدير أبحاث‬
Director
of
Research
Co-Workers - ‫الباحثون المشاركون‬
‫العنوان االلكتروني‬
e-mail
therese.atallah@ul.edu.lb
safaa.baydoun@liu.edu.lb
‫المؤسسة‬
Institution
‫كلية الزراعة‬/‫الجامعة اللبنانية‬
‫معهد الفنون والعلوم‬/‫الجامعة اللبنانية الدولية‬
Two years (2009-2010)-‫سنتان‬
2.
3.
4.
5.
6.
Safa Baydoun
: Duration -‫المدة التعاقدية للمشروع‬
Scientific Information
‫العلمية‬
‫المعلومات‬
ّ
1.
‫االسم‬
Name
Therese Atallah
Objectives - ‫الهدف‬
Identify the main cropping systems in Central Bekaa and chose two or three sites with
different cropping systems and polluting level for further monitoring of the fate of
applied nitrates.
Study the current agricultural practices and the environmental impact of cropping
pattern and fertilization level.
Follow the fate of applied nitrates which move toward the groundwater as a result of
excess irrigation and rainfall.
Collect soil, water and plant samples from the sites and analyze for nitrate level.
Consult the food consumption pattern in adult urban population established by
Nasreddine (2005) and adapt to the consumption habits of Bekaa population through
screening a representative sample of local inhabitants.
Analyze food entering into the Lebanese diet for nitrates content to assess the overall
dietary consumption of nitrates by adult population.
7. Organize a field demonstration experiment consisting of applying no nitrogen from
fertilizers with reliance on N from the soil and irrigation water pools.
Achievements -‫أالنجازات المحققة‬
1. The contribution of major agro systems of the Central Bekaa to the soil-groundwater
contamination with nitrates was determined. Four plots on the farmer’s fields were monitored:
potato-wheat, potato-salad-wheat, permanent mint and grape production.
2. Soil samples were collected at two month interval and groundwater samples collected at one
month interval and analyzed for nitrate content.
3.; The surplus of nitrogen input to the soil-groundwater system in the intensive vegetable and
field crop production was assessed.
4. Both bad and good agricultural practices were emphasized through a demonstration plot
experiment on the farmer’s field to show the possibility of the reliance on nitrogen provided by
the soil and irrigation water. Therefore, a quantification of the saved money spent on additional
nitrogen fertilizers and the associated reduction of nitrate leaching to the groundwater was
implemented.
4. One workshop was organized in the Bekaa on December 03, 2009 with the participation of
LRA, LIU, LU and local stakeholders to raise people awareness on the ecological and health
risks of nitrates mismanagement in the soil-groundwater-food chain. Another workshop is
planned during March 2010.
5. The food habits of 500 people were studied and the nitrate content in locally produced
vegetables was analyzed
6. Health risk associated with nitrate dietary intake from the consumption of locally produced
fresh vegetables was determined and population exposure assessed.
7. Results were presented on one local and two international conferences and published in three
abstracts.
8. Basic maps and derived maps were produced showing the nitrate spatial and temporary
distribution and content in the groundwater.
Perspectives - ‫آفاق البحث‬
1. Agriculture as major no point source of pollution characterized according to the input and
level of intensification. The possibility of reducing N input as based on available soil and
ground water pools was demonstrated and shall be followed to protect the natural resources.
2. Management practices leading to nitrate accumulation in the soil-groundwater system and
food chain determined. Bad agricultural practices must be replaced by good economically
justified and environmentally sound practices
4. Average adult population nitrate intake assessed in relation to the health risks and
international norms. Need to control vegetable quality to reduce nitrate risks.
5. Awareness campaign among farmers and consumers must keep on to correct and to create
conditions favoring the improved agricultural practices and healthy food.
Publications & Communications - ‫المنشورات والمساهمات في المؤتمرات‬
1. One paper was published in the proceedings of the 5th Int. Conf. on Land Degradation, BariItaly, 18-22 September 2008. Book of Abstracts, Vol II: 499-503.
2. One abstract was published on the 9th International Water Week, Stockholm, 17-23 August
2008. Abstract Volume: 70-71.
3. One oral presentation was presented on the 16th International Scientific Conference of the
Lebanese Association for the Advancement of Science. Beirut Arab University. November 13 15, 2009.
4. One abstract was published in the International Workshop, UNESCO, Paris 10-11 December,
2009. Abstract: page 21 (attached).
Abstract in Arabic - ‫موجز باللغة العربية عن نتائج البحث‬
Agriculture in Lebanon is concentrated mainly in the fertile Bekaa plain, where intensive
agricultural practices prevail. Due to weakness of policies and extension service, farmers apply
excessive chemical fertilizers notably nitrogen. Consequently, ecological and health problems
are suspected due to nitrate accumulation in the soil-groundwater-food chain. We have
monitored the status of soil and GW quality in Terbol area located in Central Bekaa Plain. Soil
and water samples were collected between July 2007 and July 2009. The aim was to assess
current agricultural practices, soil vulnerability to nitrate leaching and to study soil and
groundwater exposure to nitrate pollution. Nitrate dietary exposure from the consumption of
main vegetable was evaluated. After excluding extreme cases, the estimation of nitrates and
nitrites daily dietary exposure was based on food frequency study of 419 individuals from the
same region. Soil samples were taken in four representatives plots under four different existing
agriculture practices (leafy vegetable monoculture, potato-lettuce rotation, wheat-potato rotation
and grape fields). GW samples were systematically taken from 25 wells water is used for
irrigation, industrial and domestic purposes. Analytical water results show alarming levels of
nitrate concentration in a number of wells mainly in the central part of the plain reaching 517.7
-1
mg NO3 L . Soil data show large accumulation of nitrates towards the end of the cropping
-1
season in the topsoil layer reaching 102 mg Kg soil. Due to nitrate leaching by intensive
irrigation, higher amounts of nitrates are found at deeper layers which could not be detected
from the root zone after one winter season. Results were confirmed using Cl tracer technique.
A GIS soil model based on soil properties affecting soil infiltration, like soil depth, soil texture,
soil structure type and strength, organic matter content, pore abundance and size, was
elaborated to assess soil vulnerability to leaching. Results show medium and high vulnerability
in the larger area of the Central Bekaa plain, with very high vulnerability in the foot slope due
to larger porosity and infiltration rates. The drawn soil and GW maps are useful tools for
decision makers and local stakeholders including consumers delineating critical areas where
special care must be applied to control N input and balance in the soil-GW system and food
chain.
Our results show an average intake of 3363.6 Calories/day and daily intakes of potatoes,
tomatoes, lettuce, spinach and parsley to be 140.78, 50.45, 37.07, 20.13 and 40.12 g/day,
respectively. The consumption of only these vegetables showed an exposure of 3.32 mg/kg
bw/day of nitrates. This dose is on the upper boarder line of the Acceptable Daily Intake (ADI)
of 0-3.7 mg/kg bw/day evaluated by the Joint FAO/WHO Expert Committee on Food Additives
(JECFA). Ecological and health risks imply further assessment studies and the implementation
of tools and strategies to control agricultural practices and the excessive use of fertilizes in
Lebanon.
Key words: Soil, Groundwater, Nitrate accumulation, Nitrate leaching, nitrate exposure