Anthropic pollution in aquatic environment: development of a caffeine indicator.

This study aimed to evaluate the co-occurrence of caffeine and the extent of its influence front to other traditional water quality parameters (microbiological indicator data) in way to characterize it as an efficient pollution indicator of anthropogenic origin in urban aquatic environments. Caffeine is a constituent of a variety of beverages (coffee, tea and caffeinated soft drinks) and of numerous food products (chocolate, pastries and dairy desserts). Although the human body is efficient at metabolising this stimulant, between 0.5 - 10% is excreted, mostly in urine. In addition, caffeine from domestic use may find its way directly into the sewer system due to the disposal of unconsumed drinks. The analysis of samples from Leopoldina Hydrographic Basin and Guanabara Bay revealed a significant difference areas not commonly affected by nutrient enrichment or sewage inputs versus areas chronically influenced by sewage discharges. Monitoring caffeine will be fundamental in urban-stressed aquatic environments where frequent accidental ruptures of sewage lines, pump station overflows or elevated numbers of inefficient septic tank systems are common.