Perhaps you should try some spelling variations:
"dioxin emissions" » "dioxide emissions", "down emissions", "union emissions"
"dioxide emission" » "dioxide emissions"
"toxic emissions" » "atomic emission", "voc emissions", "dioxide emissions"
"oxide emissions" » "dioxide emissions"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("toxic emissions") OR ("oxide emissions"))) OR ((("dioxin emissions") OR ("dioxide emission"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"toxic emissions\") OR (\"oxide emissions\"))) or (((\"dioxin emissions\") or (\"dioxide emission\"))))*".
• Removing quotes may allow a broader search: (((( toxic emissions ) OR ( oxide emissions ))) or ((( dioxin emissions ) or ( dioxide emission ))))*.