The Centers for Disease Control'sMorbidity and Mortality Weekly Report probably isn't exciting reading for most people, but thankfully the Deep Sea News bloggers are scanning them and finding gems like the Delaware resident who discovered a chemical weapon in his new driveway:

In the first case a member of the public in Delaware had paved a driveway with a load of crushed clam shells and subsequently found a mysterious object protruding from the surface. The U.S. Air Force Explosive Ordnance Disposal (EOD) squad were called to remove the object, which appeared to be an artillery shell of some sort, and during transport to the Air Force base it oozed a black substance.  Two members of the EOD team later developed yellow blisters and one of the team had to be hospitalised. 

Turns out the shell was full of mustard gas, the nasty chemical agent used during World War I. But what was a tank of mustard gas doing in a batch of clamshells?

Well it turns out we put them there, and by "we" I mean the US Government through its armed forces, which prior to 1970 (when it became illegal) disposed of many unwanted munitions at sea, including both conventional and chemical varieties.