沙漠研究 19-1, 305- 308 (2009 )Journal of Arid Land Studies“Desert Technology IX ”
Refereed Paper

Water Pollution in the Rivers of Northern Central Mongolia
Caused by Human Activity
Yoshiko KAWABATA1, Tsend Ayush MUNKHJARGAL2, Kunio SHIRAISHI3,
Masahiro NAGAI4, Yukio KATAYAMA5
Abstract: Major ion and heavy mental concentrations in the river water in northern central
Mongolia were investigated. Ammonium and manganese concentrations in the Tuurl River
exceeded the Maximum Acceptable Concentrations prescribed by the Surface Water Quality
Standard of Mongolia. Allowable zinc concentrations were also exceeded at many sampling
locations. It is therefore of concern that the quality of drinking water sourced from rivers isaffecting people living around Ulaanbaatar.
Keywords: Ammonium, Mongolia, River, Water pollution, Zinc

1. Introduction
Access to safe drinking water is essential for people’s health. It is a component of effective healthpolicy and is also a development issue at national, regional and local levels.
Mongolia is considered as a country with relatively poor water resources. The water volume andflow discharge in the basin of Mongolia have decreased owing to numerous reservoirs built for mining,
agricultural irrigation, and hydropower generation activities. As a negative consequence of the activity,
the ability of the soil to hold water has been reduced and water runs off the soil surface. For the same
reason, many streams and lakes have dried up and the water quality has deteriorated.
The exploitation of natural resources has been Mongolia’s most important industry and the nation’ssingle most reliable source of revenue since 1992, when the former Soviet Union ceased its raw materials
assistance to the livestock industries in Mongolia. The government began exploring natural reserves tosustain the country’s economy, and several regions are considered to have potential reserves (Myagmarjavand Davaa, 1999). However, the reserves are mostly close to rivers or river beds, and thus exploitation
imposes an immediate threat to the environment. Inadequate technologies used by growing mining
companies include the excessive extraction of gold-bearing gravels and sands, poorly designed pumps andwash plants and unsuitable settling ponds. The mining operations and locations, management of tailings
and topsoil storage, river diversions, environmental protection plans and reclamations are also unsuitable.
The population of the capital city Ulaanbaatar increases year by year and the quality of drinking waterin the city is a problem. This research was conducted to evaluate the change in water quality in northern
central Mongolia.
2. Materials and Methods
The sampling sites are shown in Figure 1. Water samples were collected from 31 locations on theOrkhon River and its tributaries, the Yeroo, Shariin, Kharaa, Boroo and Tuul Rivers, in Mongolia fromMarch to April 2007. The position of each sampling location was determined using an eTrex Legend
portable Global Positioning System (Garmin Ltd., Japan). Water samples for ion measurements werefiltered through a 0.45 μm Millipore filter (Millipore Corporation) and collected in polypropylene bottles.
Na+, NH4+, K+, Mg2+, Ca2+, Cl– and SO42– concentrations were determined using an LCA-10A ion
chromatographic analyzer (Shimadzu Corporation, Japan). The accuracy and precision of the analyticalmethods used here were tested using Anion Mixed Standard Solution IV and Cation Mixed Standard II forion chromatography (Kanto Chemical Corporation, Japan) and shown to be satisfactory with 2–5% error.
1

Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan, E-mail: yoshikok@cc.tuat.ac.jp
United Nation Development Programme, Partizan’s Street-6, Ulaanbaatar, Mongolia, E-mail: Moogii.san@gmail.com
3
National Institute of Radiological Science, Inage, Chiba, 263-8555, Japan, E-mail: k_shirai@nirs.go.jp
4
University of Human Environments, Okazaki, Aichi, 444-3505, Japan, E-mail: nagai@ uhe.ac.jp
5Toyohashi University of Technology, Toyohashi, Aichi, 441-8580, Japan2306Fig. 1. Location of study areas.

Mn, Cu, Zn, Sr, Cd, Cs and U concentrations in water were determined with a Hewlett Packard
inductively coupled plasma mass spectrometer (ICP-MS) using In as an internal standard to compensate forthe sensitivity fluctuation. The standard solution was prepared from Spex XSTC-469. The accuracy andprecision of the analytical methods used here were tested using Spex XSTC-469 (Spex CertiPrep Inc.) andshown to be satisfactory with 1–5% error.
3. Results and Discussion
The ion concentrations for the sampling locations are given in Table 1.
Of the 12 rivers including the small streams sampled, the Tuul River passing through Ulaanbaatar
showed a noticeably distributed and high concentration of ammonium, especially at the T6 observation
point downstream, owing to the urbanization and growth of industrial activity in the capital. However, at
the T8 observation point near the headstream of the Selbe River, a tributary 32 km north of the Tuul River,the ammonium concentration was 58.8 times the Maximum Acceptable Concentration (MAC) prescribedby the Surface Water Quality Standard of Mongolia. It may have resulted from human impact andtraditional livestock breeding life-style near to this area.
The T6 observation point had a concentration of manganese 1.66 times the MAC and 4.16 times theWorld Health Organization guideline level for drinking water (2006). Manganese poisoning has been
linked to impaired motor skills and cognitive disorders (WHO, 1973). Bolormaa (2006) demonstrated themanganese concentrations along the Boroo River were higher downstream. However, the concentrations
recorded in the present study were not higher than the MAC. The manganese contamination of the Boroo
River needs to be investigated in more detail.
Kelderman and Batima (2006) stated that rivers in Mongolia can generally be classified as “clean” or“of acceptable quality” with the exception of the Tuul River, which is classified as “acceptable” toTable 1. Ion Concentration in River Water.

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“moderately polluted”. Khazheeva et al. (2002) demonstrated the concentrations of zinc and chromiumin the arms of the Selenge River exceeded MAC values. Bolormaa (2006) demonstrated theconcentrations of heavy metals of Mn, Fe, Ni, Zn and As along the Boroo River were higher downstream,
which can be explained by dilution, precipitation, adsorption to sediments and local anthropogenic input.
Our results show the same trends as for the former studies, but our trends are more serious.
4. Conclusions
This study showed that ammonium, zinc, and manganese concentrations in rivers in northern central
Mongolia were higher than MAC values prescribed by the Surface Water Quality Standard of Mongolia.
Water pollution was more serious than that found in previous studies. It is therefore of concern that thequality of drinking water sourced from rivers is affecting people living around Ulaanbaatar.
Acknowledgement
This work was supported by a Grant-in-Aid for Science Research from the Ministry of Education,
Culture, Sports, Science and Technology of Japan, 2004 (Monbusho International Scientific Research
Program No. 16405003, represented by Kawabata, Y.).
Reference
Mongolian National Standards (1992): Surface Water Quality General Requirements. MNS90-92. (in Mongolian)
Myagmarjav B., Davaa G. (1999): Surface water of Mongolia. National Agency for Meteorology, Hydrology and Environment
Monitoring Institute of Meteorology and Hydrology, Ulaanbaatar, Mongolia (in Mongolian)
Kelderman P., Batima P. (2006): Water Quality Assessment of Rivers in Mongolia. Water Science & Technology, 53: 111-119.
Khazheeva Z.I., Urbazaeva S.D., Bodoev N.V., Radnaeva L.D., Kalinin Y.O. (2002): Heavy Metals in the Water and Bottom
Sediments of the Selenge River Delta. Water Resources, 31: 64-67.
WHO (1973): Trace elements in human nutrition: Manganese. Report of a WHO Expert Committee, Technical Report Service, 532.
World Health Organization.
WHO (2006): Guidelines for Dinking-water Quality, 3rd edition. World Health Organization.