A 2011 analysis conducted by Earthjustice and Toxipedia showed that the dispersant could contain cancer-causing agents, hazardous toxins and endocrine-disrupting chemicals.[130] Environmental scientists expressed concerns that the dispersants add to the toxicity of a spill, increasing the threat to sea turtles and bluefin tuna. The dangers are even greater when poured into the source of a spill, because they are picked up by the current and wash through the Gulf.[131] According to BP and federal officials, dispersant use stopped after the cap was in place;[132][133] however, marine toxicologist Riki Ott wrote in an open letter to the EPA that Corexit use continued after that date[134] and a GAP investigation stated that "[a] majority of GAP witnesses cited indications that Corexit was used after [July 2010]."[135]