Mumbai, Sept. 18 -- Acting on a complaint by a city-based environment group, the Maharashtra Pollution Control Board (MPCB) on Thursday sent a notice to the Brihanmumbai Municipal Corporation (BMC) asking it to stop spraying herbicides containing glyphosate in Powai lake to control the growth of water hyacinths, until further notice. MPCB also asked BMC to "submit any technical say towards use of this herbicide in the lake area"....