In Buffalo, panic arrived in the form of a powdered doughnut.
In Washington, a crumbly muffin did the trick.
And all around the country, police have chased after anthrax scares that turned out to be everything from drywall dust to talcum powder.
In light of it all, authorities urge Americans to calm down. They say the odds of the average American encountering anthrax are minuscule -- while the odds of overtaxing already-strained emergency response systems are great.
The FBI's Buffalo office received 125 false anthrax reports between Sunday and Wednesday alone and had to investigate many of them. Special Agent Paul Moskal, an agency spokesman in Buffalo, said that represents just a fraction of the anthrax calls to local authorities.
"It's been overwhelming," said Dean Messing, deputy commissioner for disaster preparedness at the Erie County Department of Emergency Services, which has responded to hundreds of such false alarms this week. "The calls are getting to be ridiculous. . . . They're running us ragged."
Each call gets investigated by some level of law enforcement, with the FBI or hazardous materials teams called in on the most serious cases.
So far, though, each threat proved to be about as threatening as the powdered doughnut that left sugar on an office floor in Buffalo, prompting an office worker to call the authorities, Messing said.
Similarly, in Washington, a man attending a conference ate a muffin, later found crumbs in his conference materials, and alerted authorities. Coffee creamer prompted scares in both Buffalo and Long Island.
Amid all the panic, Erie County Health Commissioner Anthony Billittier IV said: "People need to re-evaluate their take on anthrax."
Granted, when inhaled in sufficient quantities, anthrax is almost always fatal. It has already killed one man and infected eight others in media and political offices in Florida, New York and Washington. In each of those cases, the anthrax arrived in the mail.
But the odds of the average citizen getting anthrax in the mail "right now would appear to be between slim and none," said Clinton Van Zandt, a former FBI agent who drew up psychological profiles of terrorism suspects.
"The person who is doing this is taking on the powerful," Van Zandt said. "He's probably given us his best shot."
And that best shot is by no means likely to reach vast numbers of people.
In the current anthrax cases, it appears that there was some effort to refine the bacteria to make it more likely to waft through the air. Doing so is difficult, said Charles Haas, a professor of environmental engineering at Drexel University in Philadelphia. If refined too finely, the bacteria dies.
For that reason, Haas doubts that anthrax will be used in a more widespread attack.
"I haven't done anything out of the ordinary," Haas said. "I'm not going to go out and get a gas mask."
Even if you're in a building exposed to a letter containing anthrax, the risk of dying from the disease is small, said John E. Vena, professor of social and preventive medicine at the University at Buffalo.
That's because the bug is unlikely to infect everyone in the building, and because those who get exposed can be treated with antibiotics if doctors catch the infection in time.
Those facts apparently aren't reassuring enough for some people. Newsday said a junior high school in Long Island was evacuated after someone discovered chalk dust on a teacher's desk. Talcum powder elicited a scare on a jet in Indianapolis. And a Buffalo bakery called the FBI to report a suspicious shipment that turned out to be flour.
Authorities, for their part, are getting a little worn out by it all.
Buffalo-area FBI agents have been working 12- to 14-hour shifts six days a week ever since the Sept. 11 terrorist attacks, chasing leads in that case and 2,000 others on the docket. And now agents are forced to deal with calls that Moskal, the agency spokesman, called "inappropriate."
"It's good for the public to have a heightened sense of awareness, but that has to be blended with good judgment," Moskal said.
Of course, truly suspicious packages should not be ignored. The Centers for Disease Control and Prevention's anthrax health advisory said that if you receive an odd package, you should put it in a plastic bag or cover any contents that might have spilled out. Then you should leave the room and close the door, wash your hands and call the police.
Strangely, though, many of the anthrax false alarms don't involve packages. They involve everyday substances that suddenly evoke terror.
"Because this threat is so new, people just don't know how to think about it," explained Baruch Fischoff, a cognitive psychologist at Carnegie Mellon University in Pittsburgh.
That being the case, there's a run on Cipro, the antibiotic that's usually used to treat anthrax. Doctors nationwide say patients are calling, begging for the drug. Others are rushing to Web sites such as CiproPharmacy.com.
Physicians such as Lewis H. Biben are having none of it. A Rochester native who has practiced in Washington for 40 years, he's refusing to prescribe Cipro to patients who want it even though they haven't been exposed to anthrax.
"It's unnecessary," he said. "There's not enough to go around. . . . And there are side effects. With young people, it can cause complications with your joints and bones."
Other experts warn that Cipro causes severe stomach troubles, all because it's so strong that it kills good bacteria that the stomach uses in the digestive process.
People are demanding the drug anyway, all because the anthrax threat is new, mysterious and -- in a worst-case scenario -- potentially catastrophic.
"We really don't know a lot about this," said David Ropeik, director of risk communication at Harvard University's Center for Risk Analysis. "Who are the bad guys? What are they going to do next? Our uncertainty is almost complete, and that increases the fear."
The uncertainty also makes it impossible to compare the risk of anthrax to other public health threats, Ropeik said. Nevertheless, experts suspect that the risk is far less than with all sorts of other threats that people take for granted every day.
While only one person has died of anthrax in America this year, 41,804 died in car crashes in 2000. Billittier, the Erie County health commissioner, pointed out that's the equivalent of the number of lives that would be lost if a passenger jet crashed every day for a year.
Americans also appear to stand a far greater chance of drinking themselves to death than they do of dying from anthrax. Alcohol claimed more than 30,000 lives last year, and that doesn't count alcohol-related auto fatalities.
Another 12,000 or so Americans die in falls every year, and about 2,000 die from the flu -- an illness most could prevent if they'd only get a flu shot, said Vena, of UB.
Ironically, Ropeik said, many of those other public health threats become more serious when people are under long-term stress -- such as what many are encountering now in wake of the terrorist attacks.
"Stress suppresses the immune system, which makes us more vulnerable to disease," he said. "So, in that way, fear produces a physical risk."
That's why physicians and other experts urge Americans to take it easy. Asked what Americans should do if they really want to protect their health amid the anthrax threat, Vena urged people to stop smoking, wear seat belts when driving and exercise regularly.
Washington bureau assistant David J. Hill contributed to this report.