From the excellent blog on the excellent site stats.org comes this plea for greater public safety from our ever-vigilant public health officials:

Dihydrogen monoxide is a persistent environmental chemical, it’s present in most of the food we eat, and absorbing too much of it can cause hyponatremia, a condition where cells lose their salt content, which is associated with congestive heart failure, liver failure, renal failure as well as brain edema (swelling). Acute hyponatremia, which happens when the serum salt level is less than 105 mEq/L, has a mortality rate over 50 percent.

 More here, and I highly recommend spending about an hour browsing on stats.org.