[Spatiotemporal Variations in Areca Nut Consumption in Haikou and Wuzhishan Cities Based on Wastewater Monitoring]

Areca nut is a legal but addictive substance. Its consumption is rising in China and is closely linked to various diseases. This has raised widespread concern. It is crucial to develop real-time monitoring methods for areca nut consumption. Wastewater-based epidemiology is a low-cost， timely， and accurate method. It has been widely used to monitor addictive substances. However， research on areca nut remains limited. Based on the background above， areca nut biomarkers from the biomarkers of 19 wastewater treatment plants in Haikou and Wuzhishan over a six-month period were collected and analyzed. The results revealed clear spatiotemporal patterns of areca nut consumption. Areca nut biomarkers were consistently present in city sewage. Per capita load was higher in winter than in summer， with noticeable increases during holidays. The concentration of these biomarkers was markedly higher in domestic sewage compared to that in industrial or agricultural sewage. Furthermore， the composition ratios of four areca nut biomarkers showed little variation over time or across locations within Haikou. In contrast， the proportions of arecoline and N-methylnipecotic acid notably were lower than those observed in Wuzhishan. This reflects differences in areca nut consumption habits between the two cities. In conclusion， wastewater-based epidemiology of areca nut biomarkers can effectively reflect local consumption levels and habits. This provides a reliable tool for monitoring areca nut use.