Health Canada August 16, 2010 [2,4-D is safe on lawns]– Canadian Health Measures Survey: Summary of the Biomonitoring Results and Government Actions

2,4-D is not detected in urine of Canadians from 6 to 79 years of age from 2007-2009
Health Canada refers readers to the 2008 Reevaluation Decision on 2,4-D. 2,4-D is safe to use on your Lawn.

Phenoxy Herbicide
2,4-D urine 2007–2009 6–79 yrs. μg/L — Below LOD

Below LOD: Below the limit of detection. The lowest concentration of a chemical that can be reliably measured. Refer to Health Canada, 2010; CDC, 2009; CDC, 2010 for further details.

Here are the August 16th Results from Health Canada’s Website:

http://www.hc-sc.gc.ca/ewh-semt/contaminants/human-humaine/chms-ecms_bio-eng.php