The United Nations Environment Programme will for the first time survey mercury emissions at waste dump sites in developing countries.
UNEP officials say waste containing mercury, such as used fluorescent lights and batteries, is often incinerated without proper treatment in developing nations in Asia and Africa.
This is raising concern about environmental contamination and health problems.
The UNEP will launch the study in July with support from Japan's Environment Ministry.
This year's survey will cover Indonesia, Iran and Myanmar.
Officials will measure the concentration of mercury in the atmosphere, water and hair samples collected from dump-site workers and nearby residents.
They will investigate the people's health through interviews.
The project also involves teaching locals how to conduct such a survey.
The UNEP plans to report part of the results at a meeting of signatories to the Minamata Convention on Mercury which will be held in Switzerland in November.