Funding for this research was provided by:
Hunan Health Bureau for the project of "studying occupational health hazard of low level lead exposure"
Text and Data Mining valid from 2018-04-20
Received: 11 March 2017
Accepted: 17 April 2018
First Online: 20 April 2018
Ethics approval and consent to participate
: The written informed consent was obtained for all participants in this study. We have submitted a review application to Ethics Committee of Xiangya School of Public Health, Central South University and have obtained the approval. The approval number is: XYGW-2018-22.
: The authors declare that they have no competing interests.
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