Blood from 10 umbilical cords was analyzed. In this report the EWG found an average of 200 industrial chemicals and toxins in cord blood. They tested for 287 chemicals, and we already know what 180 of them cause cancer, and more cause development problems.
See the full report for a breakdown on types of chemicals and how many were found. Even this small sample size means more study is important.
Environmental Working Group Report, 2005.