A rushed rinse, a reused knife, or unwashed hands can transfer microbes onto the peel and the cut face. Every extra step in a crowded kitchen is another chance for that transfer.

This does not mean every lemon wedge will make someone sick. Most people drink lemon water without any problem, and many restaurants keep clean boards, clean knives, and clean hands. The risk rises when standards slip under pressure—lunch rushes, short staff, or fruit cut hours ahead and left sitting. For people with weaker immune systems, even a small exposure can matter more than it would for someone healthy.

Skipping the lemon is a simple way to remove that uncertainty. If you want the flavor at home, wash the whole fruit well, use a clean knife and board, and add the slice yourself. You get the same taste with far more control. At a restaurant, plain water or a sealed bottle avoids the garnish that looks healthy and is only as clean as the last pair of hands that touched it.