Citing such past tragedies as the poisonous gas leak in Bhopal, India, that killed at least 7,000 people, the United Nations called yesterday for stronger safeguards on the production and storage of hazardous chemicals in developing countries. The call to action came during a U.N. Environment Programme conference held in Cartagena, Colombia, and attended by delegates from 120 countries. In recent decades, chemical manufacturing has increasingly shifted from developed to developing nations, heightening concerns about the potential for industrial and environmental accidents. The U.N. hopes to attract international funders for programs to increase poor countries’ knowledge of hazardous chemicals management, crack down on illegal trade in banned chemicals, prevent dumping of substances, and conduct regular health and environmental checkups.