Mayor Giuliani reduced crime in New York. That is environmental justice. He made the city a better place to live. However, some would say he gave the NYPD a license to abuse. Regardless, New Yorkers universally agree that he made the city a safer place to live, work and play.
The former mayor also supports Indian Point nuclear power plant and nuclear power technology in general. The plant provides 30% of the electricity for the city (including the subway) and emits no smog forming or greenhouse gases. Harlem, The Bronx, Queens, Brooklyn and the rest of the region have clearner air and fewer asthmas because of the plant, so Giuliani gets EJ points for his support of the facility.
Of course, to our knowledge Giuliani has never directly addressed environmental justice. There was advancement at the state level during his administration but there were no Giuliani Environmental Justice Principles. Now that he is a candidate for president (still unannounced), maybe he will clarify his position on this issue.