The study was praised as offering "an important insight into potential effects of cell phone radiation on the human brain" by Renee Sharp, director of the Environmental Working Group California office.
After quitting a job as an executive director in the fixed-income group in the London office of Goldman Sachs, Sulger, now 33, moved to Shanghai knowing no Mandarin.
Mark Schonfeld, director of the New York office, said his group wanted to make a "broad sweep" of the companies that seem to be targeted in the e-mails and heighten public awareness.