Electric two-wheelers in China produce net environmental, safety and mobility/accessibility impacts and overall, they provide huge mobility gains at a low safety and environmental cost, especially compared to some of the less sustainable transport modes. A problem with these bikes is the huge amount of lead (Pb) being introduced into the environment. There are some more sustainable battery technologies that can be employed, but some economic incentives need to be put in place to encourage their adoption.

URL: http://www.ce.berkeley.edu/~cherry/Publications/full_dissertation-committee_final-2007.pdf