“…The odor threshold concentration (OTC, the odorant concentration that 50% of the population can smell) is influenced by many factors, including genetics, , age, , gender, , odor memory or prior exposure experiences, ,− regional water quality, and methodology to determine the odor threshold . For a specific odorant, individual OTC can even vary by more than 100-fold . Thus, odor threshold of human population is best described by a range rather than a single value .…”