Many of you have asked a very important question: is the Hudson River safe to paddle and swim in?
The July 24, 2008 edition of the New York Times features an article which discusses the health of the City's rivers, including the Hudson.
Reading the River and Its Contents, With an Eye on Its Health
You can also check out the Riverkeeper's report. Swimmable River, based on regular samples from 67 test sites between New York Harbor and Troy, updated monthly and provides something closer to real-time conditions.