Chinese environmental groups say local manufacturers are polluting the environment while making products for U.S. technology giant Apple.

The Beijing-based Institute of Public and Environmental Affairs has issued a report charging that dozens of Apple’s suppliers have released toxic gases and heavy metal waste into the areas surrounding their factories. It says the discharges are endangering the health of local residents.

Apple responded in a statement Thursday saying it is committed to “driving the highest standards of social responsibility” throughout its supply base. The company said it has contacted the institute to request direct talks in order to discuss the charges in the report.

The institute says it compiled its report over the course of five months of research and field investigations. Apple does not identify its Chinese suppliers, but many of its popular iPods and iPads are assembled at massive plants run by Taiwan-owned Foxconn.