There were three methods that could have been used to conduct
the survey: face-to-face interview, telephone interview, or mail
(Song et al., 2012a). Of these methods, we chose to use face-to-face
interviews with well-trained interviewers to accomplish our
research, because the quality of data obtained by such interviews
has been found to be the most complete, comprehensive and
meaningful. Due to the potential safety considerations as well as
accuracy, however, when we investigated the collection channels
(such as small retailers) and informal dismantling processes, we
posed as costumers asking for relevant information. In this manner,
a 100% participation level was realized for the questionnaire survey
in our study (Table 1).