[M-ZZ51] 環境汚染・環境毒性と生物

[MZZ51-04] Immobilization of lead in soil by chicken manure and its efficacy on a mouse model

*Nyein Chan Soe^1,2、Takamitsu Ohigashi³、Hokuto Nakata¹、Chikae Tatsumi³、Yoshitaka Uchida⁴、Walubita Mufalo⁵、Mayumi Ito⁶、Tsutomu Sato⁶、Toshifumi Igarashi⁶、Yared B Yohannes^1,7、Yoshinori Ikenaka^1,8,9,10、Mayumi Ishizuka¹、Shouta MM NAKAYAMA^1,11 (1.Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, 060-0818, Japan、2.Department of Pharmacology and Parasitology, University of Veterinary Science, Yezin, Nay Pyi Taw, 15013, Myanmar、3.Graduate School of Global Food Resources, Hokkaido University, Sapporo, 060-8589, Japan、4.Global Center for Food, Land and Water Resources, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060- 8589, Japan、5.Graduate School of Engineering, Hokkaido University, Sapporo, 060- 8628, Japan、6.Faculty of Engineering, Hokkaido University, Sapporo, 060- 8628, Japan、7.Department of Chemistry, College of Natural and Computational Science, University of Gondar, Ethiopia、8.Translational Research Unit, Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan 、9.One Health Research Center, Hokkaido University, Japan、10.Water Research Group, School of Environmental Sciences and Development, North-West University, South Africa、11.Biomedical Sciences Department, School of Veterinary Medicine, The University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia)

キーワード：Immobilization, lead, tissues distribution, soil, manure

Lead (Pb) is the historical pollutant due to the anthropogenic activities and weathering. Its high concentration in soil and dust still impacts the adverse effect on the health of human, animals and environment especially around mining area. Organic amendments such as animal manure can reduce the bioavailability of Pb in soil. This study aimed to evaluate the effect of chicken manure which is amended into the Pb spiked soil on tissue distribution of Pb in mice under environmentally relevant circumstance. C57BL/6 mice (six mice per group) were reared on Pb spiked soil (3000 mg/kg) for 98 days. Chicken manure (27%) was applied as the immobilizer on Pb spiked soil. Soil physiochemical properties such as pH, total organic carbon (TOC) %, moisture content and soil particle distribution were analyzed from the experimental soil and Pb spiked soil. Blood, brain, lungs, trachea, small intestine, kidneys, liver and bone were collected from each mouse at day 30 and day 98, respectively. The concentration of Pb in blood and tissues were analyzed by using inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. pH and TOC% in chicken manure amended soil were higher than those in Pb spiked soil. Moisture content and soil particle distribution were similar between groups. There was no significant difference in blood lead level between groups at both day 30 and 98. Pb concentration in brain, kidneys and lungs were significantly different (p < 0.05) when chicken manure was used as the immobilizer in Pb spiked soil at day 30. The reduction percentages in brain, kidneys and lungs were 28.58, 26.63 and 25.62, respectively. Though there was no significant difference in other tissues, concentration of Pb in trachea, small intestine, liver and bone were reduced to 25.01%, 30.34%, 6.25% and 19.23%, respectively at day 30. However, there was no significant difference (p > 0.05) in tissues at day 98. Similar reducing phenomenon was observed in most tissues at day 98 except in lungs, trachea and small intestine which show slightly high in the treatment group. The reduction percentage in brain, kidneys, liver and bone were 11.82, 4.63, 29.87 and 14.54, respectively at day 98. Pb accumulation ratios in the lungs of Pb exposed group with liver were 0.47 and 0.33 at day 30 and 98, respectively. Moreover, those ratios of chicken manure with Pb spiked soil group were 0.38 and 0.44 at day 30 and 98, respectively. It indicated that the inhalation pathway would share the important route of Pb exposure along with the ingestion pathway. It was concluded that chicken manure as the immobilizer for Pb might have the potential to reduce the Pb concentration in tissues when it was contaminated by accidental ingestion and inhalation of Pb contaminated soil or dust.