Eco-efficiency of the transport sector is a novel idea of high importance for reduced environmental pollution and sound resource use in Nairobi City. An assessment of transport eco-efficiency of the 11 sub-counties of the city was carried out for the period between June 2019 and May 2020 by examining the overall transport eco-efficiency levels, specific sub-regional variability in the efficiency and factors affecting efficiency. To realize this, a combined PCA-DEA-MLR approach is applied. The empirical results of the study indicate that the overall transport eco-efficiency of the 11 sub-counties is 0.67, with only Makadara sub-county being optimally efficient while most being moderately efficient to highly inefficient. This result indicates that the development of the transport sector in the city significantly harms the environment and human well-being. The findings also show that the amount of wage and number of employees had a noteworthy positive impact on transport eco-efficiency while fuel consumption, traffic volume, transport share of the Gross County Product (GCP) and transport attributed particulate matter pollution had a notable negative impact on transport eco-efficiency of sub-counties in the city. Several factors that affect transport eco-efficiency were noted and recommendations made for enhancing the transport eco-efficiency thus higher quality of life for Nairobi City residents and overall sustainable development.
Cite this paper
Muge, A. K. , Jia, Q. , Wang, Y. and Li, F. (2020). Exploring the Eco-Efficiency of Transport-Related Particulate Matter Pollution in Nairobi City, Kenya. Open Access Library Journal, 7, e7067. doi: http://dx.doi.org/10.4236/oalib.1107067.
Raje, F., Tight, M. and Pope, F.D. (2018) Traffic Pollution: A Search for Solutions for a City like Nairobi. Cities, 82, 100-107.
https://doi.org/10.1016/j.cities.2018.05.008
Gaita, S.M., Gatari, M.J., Pettersson, J.B.C. and Janh?ll, S. (2014) Source Apportionment and Seasonal Variation of PM2.5 in a Sub-Saharan African City: Nairobi, Kenya. Atmospheric Chemistry and Physics, 14, 9977-9991.
https://doi.org/10.5194/acp-14-9977-2014
Gichuru, M., et al. (2017) High Airborne Black Carbon Concentrations Measured near Roadways in Nairobi, Kenya. Transportation Research Part D: Transport and Environment, 68, 99-109.
Mbandi, A.M., et al. (2019) Estimating On-Road Vehicle Fuel Economy in Africa: A Case Study Based on an Urban Transport Survey in Nairobi, Kenya. Energies, 12, 1177. https://doi.org/10.3390/en12061177
UNEP (2020) Used Vehicles and the Environment: A Global Overview of Used Light Duty Vehicles: Flow Scale and Regulation. United Nations Environment Programme, Nairobi.
Fan, Y.P., Qiao, Q., Kang, P., Zhang, Y. and Guo, J. (2017) Study on Eco-Efficiency of Industrial Parks in China Based on Data Envelopment Analysis. Environmental Management, 192, 107-115. https://doi.org/10.1016/j.jenvman.2017.01.048
Yu, C., de Jong, M., Shi, H., et al. (2015) From an Eco-Industrial Park towards an Eco-City: A Case Study in Suzhou, China. Journal of Cleaner Production, 102, 264-274. https://doi.org/10.1016/j.jclepro.2015.04.021
Liu, J., Fu, Z.B., et al. (2017) Tourism Eco-Efficiency of Chinese Coastal Cities-Analysis Based on the DEA-Tobit Model. Ocean & Coastal Management, 148, 164-170. https://doi.org/10.1016/j.ocecoaman.2017.08.003
Suh, S., Ha, S.S., et al. (2005) Eco-Efficiency for Pollution a Prevention in Small to Medium-Sized Enterprises: A Case from South Korea. Journal of Industrial Ecology, 9, 223-240. https://doi.org/10.1162/108819805775247918
Bohne, R.A., Bergsdal, H., et al. (2008) Dynamic Eco-Efficiency Projections for Construction and Demolition Waste Recycling Strategies at the City Level. Journal of Industrial Ecology, 12, 52-68. https://doi.org/10.1111/j.1530-9290.2008.00013.x
Lam, C.-M., Hsu, S.-C., et al. (2016) Eco-Efficiency Analysis of Sludge Treatment Scenarios in Urban Cities: The Case of Hong Kong. Journal of Cleaner Production, 112, 3028-3039. https://doi.org/10.1016/j.jclepro.2015.10.125
Ren, Y.F., Lin, X.Q., Sun, S., Li, G.D., Fan, B.L., et al. (2019) Evaluation of the Eco-Efficiency of Four Major Urban Agglomerations in Coastal Eastern China. Journal of Geographical Sciences, 29, 1315-1330.
https://doi.org/10.1007/s11442-019-1661-7
Huang, Y., Yu, Y.T., et al. (2018) Does Urban Cluster Promote the Increase of Urban Eco-Efficiency? Evidence from Chinese Cities. Journal of Cleaner Production, 197, 1307-1316. https://doi.org/10.1016/j.jclepro.2018.06.251
Li, Z., Du, K.R., Zhao, Y., et al. (2017) Does Government Transparency Contribute to Improved Eco-Efficiency Performance? An Empirical Study of 262 Cities in China. Energy Policy, 110, 79-89. https://doi.org/10.1016/j.enpol.2017.08.001
Li, D.Z., Leung, B.Y.P., Li, X.M., Xing, X., et al. (2010) A Methodology for Eco-Efficiency Evaluation of Residential Development at City Level. Building and Environment, 45, 566-573. https://doi.org/10.1016/j.buildenv.2009.07.012
Beltrán-Esteve, M. and Picazo-Tadeo, A.J. (2015) Assessing Environmental Performance Trends in the Transport Industry: Eco-Innovation or Catching-Up? Energy Economics, 51, 570-580. https://doi.org/10.1016/j.eneco.2015.08.018
Park, Y.S., et al. (2018) Environmental Efficiency Assessment of US Transport Sector: A Slack-Based Data Envelopment Analysis Approach. Transportation Research Part D Transport and Environment, 61, 152-164.
https://doi.org/10.1016/j.trd.2016.09.009
Chen, X., et al. (2020) Assessing Eco-Performance of Transport Sector: Approach Framework, Static Efficiency and Dynamic Evolution. Transportation Research Part D: Transport and Environment, 85, Article ID: 102414.
https://doi.org/10.1016/j.trd.2020.102414
Iqbal, A., Afroze, S., et al. (2017) Analysis of Transport Eco-Efficiency Scenarios to Support Sustainability Assessment: A Study on Dhaka City, Bangladesh. Environmental Monitoring and Assessment, 189, 366.
https://doi.org/10.1007/s10661-017-6078-0
Song, S. (2018) Assessment of Transport Emissions Impact and the Associated Social Cost for Chengdu, China. International Journal of Sustainable Transportation, 12, 128-139. https://doi.org/10.1080/15568318.2017.1337833
van Zanten, H.H.E., Mollenhorst, H., Klootwijk, C.W., van Middelaar, C.E. and de Boer, I.J.M. (2015) Global Food Supply: Land Use Efficiency of Livestock Systems. The International Journal of Life Cycle Assessment, 21, 747-758.
https://doi.org/10.1007/s11367-015-0944-1
Beames, A., Heijungs, R., Lookman, R., Boonen, K., Van Geert, Y., Dendoncker, K., Seuntjens, P., et al. (2015) Accounting for Land-Use Efficiency and Temporal Variations between Brownfield Remediation Alternatives in Life-Cycle Assessment. Journal of Cleaner Production, 101, 109-117.
https://doi.org/10.1016/j.jclepro.2015.03.073
Vogtl?nder, J., Brezet, H., et al. (2002) Communicating the Eco-Efficiency of Products and Services by Means of the Eco-Costs/Value Model. Journal of Cleaner Production, 10, 57-67. https://doi.org/10.1016/S0959-6526(01)00013-0
Wang, Y.T., Hansson, L., Zhang, K., Wang, R.Q., et al. (2011) Implementing Stricter Environmental Regulation to Enhance Eco-Efficiency and Sustainability: A Case Study of Shandong Province’s Pulp and Paper Industry, China. Journal of Cleaner Production, 19, 303-310. https://doi.org/10.1016/j.jclepro.2010.11.006
Liu, Y., Li, X.Q., Zhang, G.Q., et al. (2010) Eco-Efficiency of Urban Material Metabolism: A Case Study in Xiamen, China. International Journal of Sustainable Development & World Ecology, 17, 142-148.
https://doi.org/10.1080/13504501003603223
Cerutti, A., Bagliani, M., Donno, D., Bounous, G., et al. (2013) Multifunctional Ecological Footprint Analysis for Assessing Eco-Efficiency: A Case Study of Fruit Production Systems in Northern Italy. Journal of Cleaner Production, 40, 108-117.
https://doi.org/10.1016/j.jclepro.2012.09.028
Lenzen, M., et al. (2001) A Modified Ecological Footprint Method and Its Application to Australia. Ecological Economics, 37, 229-255.
https://doi.org/10.1016/S0921-8009(00)00275-5
Barath, L. and Ferto, I. (2015) Heterogeneous Technology, Scale of Land Use and Technical Efficiency: The Case of Hungarian Crop Farms. Land Use Policy, 42, 141-150. https://doi.org/10.1016/j.landusepol.2014.07.015
Robaina-Alves, M., Moutinho, V. and Macedo, P. (2015) A New Frontier Approach to Model the Eco-Efficiency in European Countries. Journal of Cleaner Production, 103, 562-573. https://doi.org/10.1016/j.jclepro.2015.01.038
Tone, K. (2001) A Slacks-Based Measure of Efficiency in Data Envelopment Analysis. European Journal of Operational Research, 130, 498-509.
https://doi.org/10.1016/S0377-2217(99)00407-5
Lin, J.Y., Wang, W., Cui, S.H., Wei, X.H., et al. (2010) An Eco-Efficiency-Based Urban Sustainability Assessment Method and Its Application. International Journal of Sustainable Development & World Ecology, 17, 356-361.
https://doi.org/10.1080/13504509.2010.493070
Yin, K., An, Q.X., Yao, L., Liang, J., et al. (2014) Using Eco-Efficiency as an Indicator for Sustainable Urban Development: A Case Study of Chinese Provincial Capital Cities. Ecological Indicators, 36, 665-671.
https://doi.org/10.1016/j.ecolind.2013.09.003
Yu, Y., Huang, J. and Zhang, N. (2019) Modeling the Eco-Efficiency of Chinese Prefecture-Level Cities with Regional Heterogeneities: A Comparative Perspective. Ecological Modelling, 402, 1-17. https://doi.org/10.1016/j.ecolmodel.2019.03.012
Ji, X., Zhu, Q.Y., Sun, J.S., et al. (2019) Using a Hybrid Heterogeneous DEA Method to Benchmark China’s Sustainable Urbanization: An Empirical Study. Annals of Operations Research, 278, 281-335. https://doi.org/10.1007/s10479-018-2855-6
Huang, J.H., et al. (2019) Eco-Efficiency Convergence and Green Urban Growth in China. International Regional Science Review, 42, 307-334.
https://doi.org/10.1177/0160017618790032
Zhou, J.G., et al. (2016) Provincial Eco-Efficiency Research in Eastern China Based on Super Efficiency DEA and Malmquist Index. 2016 3rd International Conference on Economic, Business Management and Educational Innovation (Ebmei 2016), Prague, Czech Republic, 10-11 May 2016, 5.
Chen, J.H., et al. (2016) Operational Efficiency Evaluation of Iron Ore Logistics at the Ports of Bohai Bay in China: Based on the PCA-DEA Model. Mathematical Problems in Engineering, 2016, Article ID: 9604819.
https://doi.org/10.1155/2016/9604819
McNabola, A., Broderick, B.M. and Gill, L.W. (2009) A Principal Components Analysis of the Factors Effecting Personal Exposure to Air Pollution in Urban Commuters in Dublin, Ireland. Environmental Science and Health Part A—Toxic/Hazardous Substances & Environmental Engineering, 44, 1219-1226.
https://doi.org/10.1080/10934520903139928
Ahmad, M., et al. (2020) Chemical and Source Characterization of PM2.5 in Summertime in Severely Polluted Lahore, Pakistan. Atmospheric Research, 234, Article ID: 104715. https://doi.org/10.1016/j.atmosres.2019.104715
Azid, A., et al. (2014) Prediction of the Level of Air Pollution Using Principal Component Analysis and Artificial Neural Network Techniques: A Case Study in Malaysia. Water Air and Soil Pollution, 225, 2063.
https://doi.org/10.1007/s11270-014-2063-1
Abdul-wahab, S., Bakheit, C. and Al-Alawi, S. (2005) Principal Component and Multiple Regression Analysis in Modelling of Ground-Level Ozone and Factors Affecting Its Concentrations. Environmental Modelling & Software, 20, 1263-1271.
https://doi.org/10.1016/j.envsoft.2004.09.001
ESCAP (2009) Eco-Efficiency Indicators: Measuring Resource-Use Efficiency and the Impact of Economic Activities on the Environment. United Nations Economic and Social Commission for Asia and the Pacific.
https://www.unescap.org/sites/default/files/publications/eco%20efficiency%20indicators%202009.pdf
Poldaru, R. and Roots, J. (2014) A PCA-DEA Approach to Measure the Quality of Life in Estonian Counties. Socio-Economic Planning Sciences, 48, 65-73.
https://doi.org/10.1016/j.seps.2013.10.001
António Afonso, S.F. (2008) Assessing and Explaining the Relative Efficiency of Local Government. Socio-Economics, 37, 1946-1979.
https://doi.org/10.1016/j.socec.2007.03.007
Lars Otto, P.B. (2010) Benchmarking with DEA, SFA, and R. International Series in Operations Research & Management Science, Vol. 157, Springer Science & Business Media, Berlin.
Zhu, J. (2014) Quantitative Models for Performance Evaluation and Benchmarking: Data Envelopment Analysis with Spreadsheets. 3rd Edition, International Series in Operations Research & Management Science, Vol. 213, Springer, Berlin.
Abdullah, S. and Ismail, M. (2018) Identification of Air Pollution Potential Sources through Principal Component Analysis (PCA). International Journal of Civil Engineering and Technology, 9, 1435-1442.
Papamanolis, N. (2015) The Main Characteristics of the Urban Climate and the Air Quality in Greek Cities. Urban Climate, 12, 49-64.
https://doi.org/10.1016/j.uclim.2014.11.003