Vol. 3, No. 1, 2014 ISSN 2350-8566 University Grants Commission, Nepal Sanothimi, Bhaktapur, Nepal Website: http://www.ugcnepal.edu.np E-mail: [email protected] Published by Post Box: 10796, Kathmandu, Nepal Phone: (977-1) 6638548, 6638549, 6638550 University Grants Commission Fax: 977-1-6638552 Nepal Vol. 3 No. 1 2014 The Journal of University Grants Commission Published by University Grants Commission Nepal Advisors Parashar Prasad Koirala Bhola Nath Pokharel Hridaya Ratna Bajracharya Editorial Board Krishna Chandra Sharma Pramod Kumar Jha Dev Raj Adhikari Anirudra Thapa Managing Editor Devendra Rawal Asst. Managing Editor Narayan Bhandari Contents 1. Heavy Metal Concentration in Household Dust in Kathmandu Metropolitan Area 1 Pawan Raj Shakya, Neena Karmacharya and Chirika Shova Tamrakar 2. Relationship between Foreign Trade and Economic Growth in Nepal: A Structural Break Analysis 11 Gautam Maharjan 3. Chemical Extraction of Heavy Metals in River Sediments of Karra River, Nepal 26 Sadhana Pradhanang 4. Biochemical Constituents in Some Edible Wild Fruits of Chitwan 35 Khaga Raj Sharma 5. Tense, Aspect and Modality (TAM) in Koyee 43 Tara Mani Rai 6. Mahatma Gandhi and the Sadharanikaran Model of Communication 63 Nirmala Mani Adhikary 7. Current Status and Recent Trends of Abortion Service Utilization in Two Facilities of Chitwan District 77 Dinesh Kumar Malla 8. A Conceptual Analysis of World Trade Organization (WTO) and its Impact on Nepalese Business 85 Dinesh Mani Ghimire 9. Adaptive Modulation in Multiple Input Multiple Output (MIMO) System 101 Rajeev Prajapati, Norsang Lama and Sabin Bhandari 10. Spatial Orientation of Angular Momentum Vectors of SDSS Galaxies having Redshift 1 × 10 -1 to 1.005 × 10 -1 117 S.N. Yadav, B. Aryal and W. Saurer 11. Evaluation of Crude Banana Powder as Formulation Additives and Comparison of its Mucoadhesive Property with Carbapol 934P 125 Sanjay K. Yadav, Lalit M. Pant, Gagan Paudel, Nabin Poudel and Rajan Shrestha 12. Survival and Efficiency of Bacillus thuringiensis in Waste Water for Biological Control of Mosquito Breeding 134 Upendra Thapa Shrestha and Vishwanath Prasad Agrawal 13. Pre-marital Sex Among Youth and Vulnerability in Contracting STI/HIV/AIDS in Nepal 140 Dhanendra Veer Shakya 14. Reading the Grammar of Visual Image: A Functional Analysis 150 Ram Chandra Paudel 15. Factors Associated with Anxiety Among Institutionalized Elderly in Kathmandu Valley 161 Rekha Timalsina, Pasang Doma Sherpa and Dan Kumari Dhakal 16. Factors Affecting Utilization of Postnatal Care in Selected Village Development Committees (VDCs) of Lalitpur District 169 Kamala Dhakal, Tara Acharya and Prajina Shrestha 17. Conflict between Humans and Urban Wild-life in Bhaktapur 181 Kamal Raj Gosai, Narayan Prasad Koju, Dikpal Krishna Karmacharya and Sarjina Basukala 18. Motivating Factors and Satisfaction Level of Visitors at Sagarmatha National Park, Solukhumbu, Nepal 186 Dul Raj Chimariya The Journal of University Grants Commission, Vol. 3, No. 1, 2014 Heavy Metal Concentration in Household Dust in Kathmandu Metropolitan Area Pawan Raj Shakya*, Neena Karmacharya 1 and Chirika Shova Tamrakar Department of Chemistry, Faculty of Science, Padma Kanya Multiple Campus Tribhuvan University, Bagbazar, Kathmandu 1Department of Botany, Faculty of Science, Padma Kanya Multiple Campus Tribhuvan University, Bagbazar, Kathmandu *Email: [email protected] Abstract: Dust samples have been collected from roadside houses of seven major locations in Kathmandu metropolitan area and trace element compositions have been determined by atomic absorption spectrophotometer (AAS). Results show significant content of Zn, Pb, Ni, Cr and Cd in the sampled household dusts as compared to the undisturbed (control) area. The mean concentrations of all the studied locations were found to be 76.2 mg/kg for Zn, 40.6 mg/kg for Pb, 29.9 mg/kg for Cr, 23.9 mg/kg for Ni and 8.2 mg/kg for Cd, respectively. Increases in these trace metals in the dust can most likely be attributed to rapid urbanization, increased vehicle emissions to the atmosphere and other anthropogenic sources. Elevated Zn abundances in household dust probably originate from traffic sources. Besides, the enrichment factor reveals that the household dust was most severely affected by Cd at almost all the locations. Also, correlations between metal levels in dust samples for all the metals were investigated. Keywords: Environment, heavy metals, household dust, Kathmandu. Introduction Solid matter, composed of soil, anthropogenic metallic constituents, and natural biogenic materials is called dust (Ferreira-Baptista & De Miguel, 2005). Dust is normally considered as household or street dust. It often contains a range of toxic metals with the composition and concentration being seldom constant (Fergusson & Kim, 1991). This is because of changes during weathering, the relatively short residence time in the environment, and also because the residence time is directly related to climate (Harrison et al., 1981; Al-Khashman, 2007). Of the three materials, soil, sediments and dust (which derive primarily from the earth's crust and with which human beings come into contact), dust is the most pervasive. It is also the material that is now recognized as a significant source of trace metals in the urban environment. In some instances, the dust may represent a significant pollutant source. Moreover, three main factors known to influence the levels of trace element in dust have been reported as road traffic (automobiles), industry and weathered materials. The effect of the road traffic on trace metal content of dust samples have been investigated for various purposes such as agricultural studies and various pollution studies (Balci & Kucuksezgin, 1994; Somer & Aydin, 1985). 2 The Journal of University Grants Commission, Vol. 3, No. 1, 2014 Kathmandu forms the core of the nation’s most populous urban region. Like many cities of the developing world, the city has been facing rapid population expansion including poor infrastructure and squatter settlements, with severe environmental consequences including air, water and other forms of pollution. The number of vehicles in the country has grown 15 times in the last two decades. According to Department of Transport Management (DoTM), the number of vehicles has reached 1126763 in the first eight months of 2011. Over 72 per cent of all the vehicles ply in the central development region (Himalyan News Service, 2011). Hence, the major polluting source of many trace elements in Kathmandu has become automobiles (Tamrakar & Shakya, 2011; Karmacharya & Shakya , 2012). Many of heavy metals such as Cr, Cd, Cu, Fe, Pb, Hg, Zn etc., are considered toxic to living organisms and even trace metals considered essential for life can be toxic when present at excessive levels that impair important biochemical processes and pose a threat to human health, plant growth and animal life (Morrison et al. , 1990). It has also been suggested that dust can be an important source of metal intake for young children due to inadvertent ingestion of the dust (Harrison et al., 1981; Fergusson & Kim, 1991). Consequently, in recent years, public and scientific attention has increasingly focused on heavy metal contamination and its effect on humans and other living creatures (Wang et al. , 2005). In the urban environment, such pollutants are commonly found in dust which can be potentially harmful to roadside vegetation, wildlife, and neighboring human settlements (Turer et al. , 2001). Considerable attention has been paid to the study of metal pollution in city air, roadside dusts and soils. However, there is a lack of concern of the presence of trace metals in household dust in the populous city of Kathmandu, where it has traditionally been assumed that such pollutants are rapidly dispersed by roadside dusts. This research, therefore, aims at quantifying the concentrations of heavy metals in household dust within the home environment in Kathmandu metropolitan area. Materials and methods Study area and sample collection: A total of 40 household dust samples (five replicates from each site) including those from undisturbed (control) area were sampled from seven major roadways of Kathmandu metropolitan area during a dry season (October to December). Sampling locations were selected keeping in view of traffic load, population density and anthropogenic activities. Offices and private residences, commercial buildings, shopping complexes, schools and hospitals were among the sources of sample collection. For the present study, sources of dust from such physical infrastructure except street dust were categorized as household dust unless and otherwise mentioned. A detailed description of the selected locations is given in Table 1. Heavy Metal Concentration in Household Dust 3 Table 1. Description of different sampling locations of Kathmandu metropolitan area Site Sampling locations Area Description of the nearby locations of sampling No. code households 1 Tinkune TKN Traffic load, densely populated and commercial area 2 Chabahil CBL Traffic load, densely populated and commercial area 3 Gongabu GGB Heavy traffic load; main bus station; densely populated and commercial area 4 Kalanki KLK Heavy traffic; sub station; densely populated and commercial area; main entry point to Kathmandu city 5 Thapathali THP Traffic load; densely populated and commercial area 6 Sahid gate SGT Heavy traffic; central sub station and commercial area 7 Ratna park RPK Heavy traffic, central sub station; densely