New Delhi, Jul 15 (PTI) Demands to raise royalty on coal, roll back of steep hike in airfares between Kerala and Gulf region and government intervention to help release fishermen captured by Pakistan were among issues raised during the Zero Hour in Rajya Sabha on Monday. Amar Patnaik (BJD) said the rate of royalty paid to state governments on coal produced in states was last changed in April 2012 and as per rule was due to be revised in April 2015 but was not done. The issue was placed before the GST Council but is yet to be approved, he said, adding instead a cess was imposed which goes to indivisible pool that is not devolved to states. He demanded that royalty on coal should be raised to 20 per cent from the current 12 per cent. K K Ragesh (CPM) demanded roll back in steep hike in airfares in the Kerala-Gulf sector which, he said, was a "loot" by airlines by exploiting migrant workers. While the Calicut-Dubai flight costs Rs 6,000, a Dubai to Calicut flight costs Rs 40,000, he said, adding airfares are jacked up during festive seasons and holidays when migrant workers seek to return to their hometown. Jairman Ramesh (Congress) asked the Environment and Forest Ministry to reject clearance to building of a mega port complex in North Chennai which, he said, poses danger to the fragile ecosystem in the region and livelihood of thousands of fishermen. Raising the issue of fishermen languishing in Pakistan jails, V Vijayasai Reddy (YSR-Congress) said 46 fishermen were captured by Pakistan maritime security agency in October- November last year after illegally entering into Indian waters. According to Pakistan, as many as 483 fishermen are languishing in its jails, he said, adding 22 out of the 46 fishermen captured in October/November 2018 were from Andhra Pradesh who had gone to Gujarat for working on fishing trawlers. "What was the Indian Coast Guard doing when Pakistan intruded into Indian waters," he asked. He said when the issue was first raised, the then External Affairs Minister Sushma Swaraj had promised to get consular access. "But neither the fishermen were released nor consular access given to families," he said, asking the Government to urgently intervene to get families consular access. Harnath Singh Yadav (BJP) raised the issue of supply of drinking water which is high in fluoride, nitrate and iron in 336 out of 719 districts in the country and is leading to disorders in humans and animals as well as affecting land infertility. Shanta Chhetri (TMC) raised the issue of death of a person after his hand got stuck between two sliding doors of the Kolkata Metro on Saturday last. She alleged passenger safety was being compromised with by the Railway Ministry and demanded immediate allocation of funds for proper maintenance and upgrade of the metro rail. Satyanarayan Jatiya (BJP) raised the issue of inter- linking of rivers to solve problem of drought. A K Selvaraj (AIADMK) raised a similar demand. .