[DanBC]

Drinks at a bar would be using unwaxed lemons.

It's possible to buy organic unwaxed lemons, so people who worry about what's put on lemons and sealed in with wax can still enjoy zest.

For this post let's assume that all lemons are sprayed with pesticides and fungicides, and then they're waxed. And that the wax is removed by alcohol, allowing the pesticide and fungicide to come off into the drink.

A slice of lemon in a gin and tonic is going to give you a tiny dose. I'd be interested to see if there's any evidence that the pesticides and fungicides are doing any harm. (Especially in comparison to the alcohol.)