Kolkata, Feb 18 (IANS): Deploring the "inadequate" investment in India in the health sector, particularly sanitation, a top public health scientist Tuesday criticised politicians for not making sanitation a key political agenda.

K.J. Nath, president, Institution of Public Health Engineers, said though the central government is "working in the right direction" in securing water supply and sanitation facilities for the masses, the lack of attention to availability of sanitation facilities is a "paradox".

"If parties like the Aam Aadmi Party can campaign against corruption, then why can't sanitation be an issue? This is not yet a political agenda due to which the sanitation sector lags," Nath told reporters on the sidelines of an event here.

He was speaking at the launch of Information Education and Communication campaign on Safe Drinking Water and Sanitation in the state in collaboration with the United Nations International Children's Emergency Fund.

"Though the total expenditure on health is nearly four percent of the GDP (gross domestic product), investment in sanitation is very less... which shows that the government is hesitant in investment in this sector. This is a paradox," said Nath.

Finance Minister P. Chidambaram Monday allocated Rs.30,145 crore to the health ministry in the interim budget for 2014-15.

"Take out half of the defence budget and give it to health," Nath said.

Absence of integrated approach in tackling hygiene, sanitation and water supply also needs to be addressed, he said.