Up to a quarter of the volume of medical waste from hospitals and healthcare organizations worldwide could present a serious health hazard to patients, medical workers and anybody who comes in contact with it, a U.N. human rights advocate said on Wednesday.

“Some 20 to 25 per cent of the total waste generated by health-care establishments is regarded as hazardous and may create a variety of health and environmental risks if not managed and disposed of in an appropriate manner,” said Calin Georgescu in a report.

The medical waste problem is increasing in developing countries, where health care services are expanding to meet demands. The waste includes a variety of hazardous materials like infectious, anatomical and pathological waste, radioactive materials and discarded used medical instruments.

Mr. Calin Georgescu, who works for the U.N. Human Rights Council in Geneva, warned that the threats to human beings can come also from incomplete waste destruction in incinerators, ash disposal and dioxins emissions. His report on medical waste included also recommendations to ensure proper disposal in environmentally friendly methods.