Researchers at the University of Arizona have won a $1.4 million grant to study the occupational and environmental health effects of underground mining equipment that runs on biodiesel-blend fuels.

The university says mining operators are shifting from diesel to biodiesel-blend fuels in a bid to lower exposure to pollutants.

Biodiesel is made from vegetable oil or animal fat and can be added to diesel as a blend or used on its own.

The National Institute for Occupational Safety and Health awarded the grant to the university’s public health college and mining department.