Researchers are worried about growing levels of drug-resistant pathogens in our environment

Some drugs, used by people and livestock, leave residue in our wastewater systems.

Pathogens -- viruses, bacteria and parasites -- exposed to this residue can become drug-resistant.

Auckland University researcher Naresh Singhal says drug-resistant pathogens pose a serious threat to New Zealanders' health.

He says illnesses caused by drug-resistant pathogens are becoming harder to treat.