[4] Khan served as the chief engineer of International Centre for Diarrhoeal Disease Research, Bangladesh from 1988 to 1998.

[6] On 21 October 2019, his comments saying WASA water in 100 percent pure were criticized in parliament by the parliamentary standing committee on public undertakings.

According to Muhibur Rahman Manik, a member of the committee, Khan was criticized for the water not being safe and his comments.

The court had directed WASA to close all sewage lines flowing to the river to reduce pollution in 2011.

According to WASA executive engineer Badrul Alam, Taqsem stepped down due to health issues.