Sir

Contrary to the claim reported in your News story, “Herbicide critic dropped from pollution conference” (Nature 432, 136; 2004doi:10.1038/432136a), an official of the US Environmental Protection Agency (EPA) did not “instigate” the “uninvitation” of Dr Tyrone Hayes in the conference sponsored by the Minnesota Pollution Control Agency. The EPA had no involvement in this decision. When Minnesota state officials contacted the EPA about this conference, the EPA only provided them with web links where interested parties could read about the EPA's exhaustive evaluation of atrazine.