Integration of magnetism and heavy metal chemistry of soils to quantify the environmental pollution in Kathmandu, Nepal
スポンサーリンク
概要
- 論文の詳細を見る
Soil profiles of Kathmandu urban area exhibit significant variations in magnetic susceptibility (χ) and saturation isothermal remanence (SIRM), which can be used to discriminate environmental pollution. χ can be used to delineate soil intervals by depth into normal ( < 10^[-7] m^3 kg^[-1]), moderately enhanced (10^[-7] to <10^[-6] m^3 kg^[-1]) and highly enhanced (≥10^[-6] m^3 kg^[-1]). Soils far from road and industrial sites fall commonly into 'normal' category. Close to a road corridor, soils at several cm depth possess highest χ, which remains high within the upper 20 cm interval, and decreases with depth through 'moderately magnetic' to 'normal' at ~30-40 cm. Soils in the upper parts profiles in urban recreational parks possess moderate χ. Soil SIRM has three components of distinct median acquisition fields (B_[1/2]): soft (30-50 mT: magnetite-like phase), intermediate (120-180 mT: probably maghemite or soft coercivity hematite) and hard (550-600 mT: hematite). Close to the daylight surface, SIRM is dominated by soft component implying that urban pollution results in enrichment by magnetite-like phase. Atomic absorption spectrometry of soils from several profiles for heavy metals (HM) reveals remarkable variability (ratio of maximum to minimum contents) of Cu (16.3), Zn (14.8) and Pb (9.3). At Rani Pokhari, several metals are well correlated with χ as shown by linear relationship between the logarithmic values. At Ratna Park, however, both χ and SIRM show significant positive correlation with Zn, Pb and Cu but poor and even negative correlation with Fe (Mn), Cr, Ni and Co. Such differences result from a variety of geogenic, pedogenic, biogenic and man-made factors, which vary in time and space. Nevertheless, for soil profiles affected by pollution (basically traffic-related), χ exhibits significant linear relationship with a pollution index based on the contents of some urban elements (Cu, Pb, Zn), and therefore it serves as an effective parameter for quantifying the urban pollution.
- 2005-12-01
著者
-
Gautam Pitambar
北海道大学理学部地質学鉱物学教室
-
Appel Erwin
Institute Of Geosciences University Of Tubingen
-
Blaha Ulrich
Institute Of Geosciences University Of Tubingen
-
GAUTAM Pitambar
COE for Neo-Science of Natural History, Graduate School of Science, Hokkaido University
-
Gautam P
Hokkaido Univ. Sapporo Jpn
-
Gautam Pitambar
Coe For Neo-science Of Natural History Graduate School Of Science Hokkaido University
-
Gautam Pitambar
Hokkaido Univ.
-
Gautam Pitambar
Division Of Earth And Planetary Sciences Graduate School Of Science Hokkaido University
関連論文
- Magnetism and granulometry of Pleistocene sediments of Dhapasi section, Kathmandu (Nepal) : implications for depositional age and paleoenvironment
- Integration of magnetism and heavy metal chemistry of soils to quantify the environmental pollution in Kathmandu, Nepal
- Magnetic susceptibility of dust-loaded leaves as a proxy of traffic-related heavy metal pollution in Kathmandu city, Nepal
- 西南北海道洞爺湖東方の鮮新-更新統について : 堆積相・花粉層序・古地磁気層序
- Recent Advances in Research on Terrestrial and Marine sequences from the mid-Cretaceous Oceanic Anoxic Events (OAEs).
- Preface
- Environmental magnetic approach towards the quantification of pollution in Kathmandu urban area, Nepal
- Two Metamorphic Events of the Nepal Himalayas Prior and Posterior to India-Eurasia Collision
- Magnetic-polarity stratigraphy of Siwalik Group sediments of Tinau Khola section in west central Nepal, revisited
- Magnetic Properties of some late Paleozoic to Tertiary Sedimentary Rocks of Tansen Area, Lesser Himalaya, Nepal
- On the Nature of Remanence in the 1985 Andesitic Pumice with Self-Reversed Magnetization from Nevado del Ruiz, Colombia
- 513 Remanent magnetism and fission-track ages of some rocks from the Ampipal massif, the Lasser Himalaya, Nepal
- Paleomagnetism of the Northwestern Part of the Mahabharat Synclinorium, Lesser Himalaya, Nepal
- A Paleomagnetic Reconnaissance of some late Precambrian to Early Paleozoic Rocks of Tansen Area, Lesser Himalaya, Nepal
- Magnetic minerals and magnetic properties of the Siwalik Group sediments of the Karnali river section in Nepal
- Mapping of subsurface karst structure with gamma ray and electrical resistivity profiles : a case study from Pokhara valley, central Nepal
- Depositional chronology and fabric of Siwalik group sediments in Central Nepal from magnetostratigraphy and magnetic anisotropy
- Magnetic polarity stratigraphy of Siwalik Group sediments of Karnali River section in western Nepal
- Magnetostratigraphic dating of the prime-time sedimentary record of Himalayan tectonics and climate: new age constraints (13-10 Ma) from the Siwaliks of the Tinau Khola north section, Nepal
- Reflection of cross-disciplinary research at Creative Research Institution (Hokkaido University) in the Web of Science database: appraisal and visualization using bibliometry