Final answer:
A food handler sneezing without proper hygiene poses a risk for viral contamination since a small number of virus particles, like those from Norovirus, can transfer to food and cause sickness.
Step-by-step explanation:
When a food handler sneezes and then returns to work without following proper hygiene practices, this poses a risk for viral contamination of food. Sneezing can expel virus particles into the air and onto a food handler's hands. Without thorough handwashing, these particles can be transferred to the food being prepared. A classic example is the Norovirus, which is a common culprit in foodborne diseases and can be easily transmitted through contaminated hands. Given that a minute amount, fewer than 20 particles, of this virus can cause illness, the risk of contamination is significant. Furthermore, maintaining good hygiene practices such as handwashing is crucial in preventing the spread of microbes that can cause illness when they enter the body through the mouth, nose, or eyes.