Chad Clark's Open Journal : 2007-09-25

1) Bacteria and the human immune system are affected by space travel.

The Globe and Mail article reads:

  Bacteria that cause food poisoning on Earth get stronger in space, says a
  team of researchers that sent dozens of carefully packaged vials of
  salmonella on a 2006 shuttle mission.
  
  After 12 days in orbit, the shuttle bugs were nearly three times more
  deadly to mice.
  
  ...
  
  Dr. Nickerson said there is evidence that fluids flow over the outer
  membranes of bacteria differently in low gravity, and that this may
  trigger changes. Fluid flows over bacteria in different ways in the human
  body as well - for example, in the bloodstream - but scientists don't
  know what impact this has on them.
  
  ...
  
  As well as injecting mice with either the stay-at-home or the
  space-travelling bacteria, they did a genetic analysis, and studied the
  proteins that both sets of micro-organisms produced. They found that
  space travel altered the way 167 genes functioned.


2) Fertilizer run-off is linked to amphibian deformities.

The Rocky Mountain News article reads:

  In 1995, Minnesota schoolchildren noticed that more than half the frogs
  in a pond had missing limbs or too many limbs.
  
  Scientists since then have figured out that a parasite plays a key role.
  
  The more nitrogen, phosphorus or cattle droppings in a pond, the more
  algae forms, said Johnson.
  
  The algae boosts the population of snails, which host a microscopic
  parasite known as a trematode.
  
  The snails release the parasites into the ponds, which then get into
  tadpoles and form cysts in their developing limbs.