�Palestinian and German scientists have recommended to the authorities in the Gaza Strip that they take immediate measures to combat excessive nitrate levels in the drink water. 90 per cent of their water samples were establish to moderate nitrate concentrations that were between iI and eighter from Decatur times higher than the limit recommended by the World Health Organization (WHO), say the researchers from the University of Heidelberg and the Helmholtz Centre for Environmental Research (UFZ) writing in the medical specialist journal Science of the Total Environment.
Over the long term they recommend that the best protection would be provided by quality direction for groundwater resources. Groundwater is the only source of imbibing water for the majority of mass living in the Gaza Strip. In babies jr. than six-spot months, nitrate can steer to methaemoglobinaemia, to looseness and to acidosis. The WHO hence recommends keeping nitrate levels to 50 milligrams per litre or less.
According to unpublished research, half of the 640 infants tested were already display signs of methaemoglobinaemia. The new Palestinian-German study confirms earlier water analyses and is the first study to pinpoint a source of the contamination. With the facilitate of isotope analyses, the researchers were able to demonstrate that the nitrate pollution tin can be traced back to manure used in farming and to wastewater.
With over 2600 people per square km, the Gaza Strip is one of the most densely populated areas on earth. Because of their isolation, the inhabitants of this country between the Mediterranean, Egypt and Israel are reliant on organism self-sufficient.
The fields are mostly fertilized with gallus gallus and cow dung. Artificial fertilizers account for only around a quarter of the fertiliser used. Because of the area's geology and the semi-arid climate, it is fairly easy for impurities to ooze down from the earth's surface into the aquifier system. Organic fertilizers and wastewater are the main causes of the nitrate taint in the groundwater, followed by sewerage sludge and artificial fertilizers. This was revealed by the isotope ratios of nitrogen (15N/14N) and o (18O/16O) in the nitrate.
Isotopes are variations of the same chemical element that have a different number of neutrons in their nuclei. 18O and 15N ar stable, i.e. nonradioactive, isotopes that are heavier than "normal" oxygen (16O) or atomic number 7 (14N) and can therefore be measured using a mass spectrometer. "The lower 15N nitrogen isotope values in the sewage sludge indicate that the nitrate in the Gaza groundwater comes in the main from manure used as fertilizer," explains Dr Karsten Osenbr�ck of the UFZ. Between 2001 and 2007 the scientists took h2O samples from 115 municipal wells and 50 individual wells on seven occasions. They measured nitrate concentrations of 'tween 31 and 452 milligrams per l. Only 10 of the 115 municipal wells examined were found to bear a nitrate level below the WHO guideline note value.
The state of affairs with the private wells was equally serious: apart from tierce, all the wells were found to have nitrate levels that were betwixt five and seven times higher than the WHO recommendations.
Publication:
Basem Shomar, Karsten Osenbr�ck, Alfred Yahya:
"Elevated nitrate levels in the groundwater of the Gaza Strip: Distribution and sources."
Science Of The Total Environment 398 (2008) 164-174
Click here to perspective abstract online
This research was funded by the Federal Ministry of Education and Research,BMBF, Germany.
At the Helmholtz Centre for Environmental Research (UFZ) scientists enquiry the causes and consequences of far-reaching environmental changes. They written report water resources, biological diversity, the consequences of climate change and adaptation possibilities, environmental and biotechnologies, bio energy, the behaviour of chemicals in the environment and their effect on health, as well as modelling and social science issues. Their guiding research principle is supporting the sustainable habit of natural resources and helping to secure these basic requirements of life over the long term under the influence of global change. The UFZ employs 900 people at its sites in Leipzig, Halle and Magdeburg. It is funded by the German government and by the states of Saxony and Saxony-Anhalt.
The Helmholtz Association helps solve major, pressing challenges facing fellowship, science and the economic system with summit scientific achievements in six research areas: Energy, Earth and Environment, Health, Key Technologies, Structure of Matter, Transport and Space. With 25,700 employees in 15 inquiry centres and an annual budget of around EUR 2.3 billion, the Helmholtz Association is Germany's largest scientific organisation. Its work follows in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894).
Source - Doris Boehme
Helmholtz Association of German Research Centres
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