Yamasue E. (a), Duc Huy T.(b), Duc Quang N.(b), Oguchi M.(c), Okumura H.(a) and Ishihara, K.N.(a)
a) Kyoto University, Kyoto, Japan
b) Hanoi University of Science and Technology, Hanoi, Vietnam
c) National Institute for Environmental Studies, Tsukuba, Japan
Keywords: Vietnam; lifetime; electronic devices; questionnaire survey.
Abstract: For sustainable treatment of e-waste in Vietnam, the lifetimes and possession ratios of various electronic devices (colour television, refrigerator, washing machine, air conditioner and personal computer) have been investigated through interview investigation. It was found that almost all of the electronic devices were made in Japan or Korea in 2007. Especially, the ratio of Korea was relatively high in the case of TV, while Japan was high in cases of washing machine and refrigerator. The number of possessions per household is increased with the increase in household income for all devices investigated. The average lifetimes assuming Weibull distribution were estimated 7.3, 6.2 7.2 and 10 years for TV, refrigerator, washing machine and air conditioner, respectively, which are relatively smaller than the estimation in Japan. It is found, however, that since the second hand market is active in Vietnam, total lifetime is estimated to be about 1.8-2.5 as long as those in Japan when considering repeated use of the devices.
In the last few years in Vietnam, a trend for prices to go down was drastic and therefore many electronic devices become more affordable for even the low-income people in rural areas. This trend brings about a shortage in their lifetime, leading to an increase in the number of end-of-life products. Since any special treatments such as appropriate recycling are hardly made in Vietnam at this moment, problems such as public health and resource security are about to become probable in near future. Thus, it is of great importance to figure out the lifetime of various appliances, but less attention has been paid so far. Thus, the purpose of this study is to estimate the lifetimes of various electronic devices in Vietnam.
Television, phone, personal computer, refrigerator, washing machine, and air conditioner, etc. were selected as target products. For the estimation of lifetime, questionnaire investigations were carried out mainly in Hanoi city in 2007 and 2012. As for the former, the survey was done at two Universities: Hanoi Industrial University and Hanoi National University. The questionnaires were distributed to 1,904 students. Students took questionnaires back to their family during the Tet holiday (traditional Vietnamese new- year holiday) and completed it before returning. Some inappropriate answers were excluded from analyses. The other survey, using the same answer sheet was also conducted to 184 households in Hanoi area. The households were selected first from high-educated relatives and friends with the complete explanation, and then those interviewees continued to ensure that their reliable relatives and friends fill in the questionnaires and so on.
Results and discussion
Figure 1 shows distribution of manufacturer for television, washing machine, refrigerator and air conditioner in Vietnam in 2007 (Nguyen, Yamasue, Okumura, & Ishihara, 2009).
It is found that almost all of home appliances were made in Japan or Korea in 2007. Especially, the ratio of Korea was relatively high in case of TV, while Japan was high in cases of washing machine and refrigerator.
Figure 2 shows the estimated possession ratio for color TV, refrigerator, washing machine, computer and air conditioner in Vietnam in 2007. It was found that the possession ratio is increases with an increase in household income. But it is still less than 80 % for air conditioner even for the highest income group.
The estimated lifetime based on Weibull distribution for the four home appliances is shown in Figure 3.
The lifetimes are shorter than those seen in Japan. It is also found that there are differences not only in lifetime but also in possession ratio between the urban area of Hanoi and Ho Chi Minh cities.
It is found that Vietnamese people tend to sell end-of-life products or to keep them in their house rather than to bring them to a collecting agent. This would be due to: (1) their nationality, (2) benefit from end-of-life products, (3) lowness of normative consciousness, (4) lack of the proper legislation system that can force the stakeholders to obey the law, and (5) the living standard is still not high enough to eliminate uncontrolled markets. This has been the situation since at least 2006.
In order to consider repeated use, a Markov chain model using transition probability matrix has been applied (Nguyen, Yamasue, Okumura, & Ishihara, 2008). As the results show, it was found that TV, refrigerator, washing machine and air conditioner are used for 19.7, 18, 18.3 and 27.1 years for their entire life cycle, respectively. This indicates that although their used lifetime from brand new is shorter than those in Japan, active second-hand market contributes to increase in their entire life time 1.8-2.5 as long as those in Japan.
The lifetimes and possession ratios of various electronic devices (colour television, refrigerator, washing machine, air conditioner and personal computer) were investigated. The number of possession per household is increased with increase in household income for all devices investigated. The average lifetimes assuming Weibull distribution were estimated 7.3, 6.2 7.2 and 10 years for TV, refrigerator, washing machine and air conditioner, respectively, which are relatively smaller than the estimation in Japan. It was found, however, that since the second hand market is active in Vietnam, total lifetime is estimated to be about 1.8-2.5 as long as those in Japan, when considering repeated use of the devices.
Nguyen, D. Q., Yamasue, E., Okumura, H., & Ishihara, K. N. (2008). Evaluation of Recycling System for Electronic Appliances in Vietnam. Development Engineering, 14, 1-13.
Nguyen, D. Q., Yamasue, E., Okumura, H., & Ishihara, K. N. (2009). Use and disposal of large home electronic appliances in Vietnam. Journal of Material Cycles and Waste Management, 11(4), 358-366.