The government is considering an independent evaluation of plants of cola majors - Coke and Pepsi - in the vicinity of the Yamuna river to check whether there is any adverse environmental impact due to the functioning of these units.

The issue has been taken up with the companies after it was alleged that the sludge generated in Coke's plant in Kerala had toxins that could affect human health.

"Based on the allegations made in Kerala, we have asked these companies to furnish details of sludge generated in their plants near Yamuna. This can then be forwarded for an independent, third-party evaluation regarding health and ecological safety," officials of the Upper Yamuna River Board said on Friday.

They added that Coke officials have already communicated to the River Board authorities that the sludge did not contain toxins like cadmium and lead beyond permissible limits, and that their plants were environmentally safe.

The board has, in turn, asked company officials to substantiate their contentions with data.