"There is no question that for a woman with severe hot flashes, sleep disturbance and an annoyingly dry vagina, nothing else works as well as estrogen," Savard wrote. "But the risks of breast cancer, stroke and blood clots from estrogen are hard to ignore... So once again, women are asked to balance the benefits of hormones with the risks and make the best decision for them."
After the collapse of the World Trade Center in 2001, five people died after inhaling anthrax bacteria sent through the mail.
But the public at large had little to fear from a tainted envelope.
"That was obviously not a major health problem but a significant problem for a small number of people who have been getting exposed," said Schwartz. "I think the primary concern was this might be being used to kill some people."
Senators Tom Daschle of South Dakota and Patrick Leahy of Vermont, among other public figures, had letters mailed to their offices containing anthrax.
No one was ever convicted of sending the letters, but the Federal Bureau of Investigation reportedly planned to charge government researcher Bruce Ivins in the case before he committed suicide in the summer of 2008.
As cell phones became more popular this past decade, concerns over the radiation they emit -- and what effect they might have on human health -- have proliferated. Some have worried that their use may be linked to the development of brain tumors.
Thus far, however, most research suggests there is little to worry about.
Animal studies have shown that magnetic fields can affect melatonin levels, so while radiation only shows up in low levels, it's unclear what effect it has on humans. And a Scandinavian study released last week in the Journal of the National Cancer Institute confirmed what many have been saying about cell phone safety, showing no increase in brain cancer among cell phone users.
"Whether they do something worth worrying about, that's another question," said Schwartz. Similar questions are raised about high-voltage power lines, but Schwartz urged calm. "It seems to be an issue where it hasn't completely resolved, but I would say the evidence is that if something is going on it's not that big."
Of course, cell phones present an unquestioned safety hazard to Americans, but not for reasons related to radiation. Studies have shown that their use while driving poses a very real hazard.
"That's pretty clear -- talking on a cell phone and driving is like driving drunk," said Schwartz. "The radiation effects -- that doesn't look like that's a major public health issue. That doesn't look very compelling."