Human use pharmaceuticals in the estuarine environment: a survey of the Chesapeake Bay, Biscayne Bay, and Gulf of the Farallones

The assessment of emerging risks in the aquatic environment is a major concern and focus of environmental science (Daughton and Ternes, 1999). One significant class of chemicals that has received relatively little attention until recently are the human use pharmaceuticals. In 2004, an estimated 2.6 billion prescriptions were written for the top 300 pharmaceuticals in the U.S. (RxList, 2005). Mellon et al. (2001) estimated that 1.4 million kg of antimicrobials are used in human medicine every year. The use of pharmaceuticals is also estimated to be on par with agrochemicals (Daughton and Ternes, 1999). Unlike agrochemicals (e.g., pesticides) which tend to be delivered to the environment in seasonal pulses, pharmaceuticals are continuously released through the use/excretion and disposal of these chemicals, which may produce the same exposure potential as truly persistent pollutants. Human use pharmaceuticals can enter the aquatic environment through a number of pathways, although the main one is thought to be via ingestion and subsequent excretion by humans (Thomas and Hilton, 2004). Unused pharmaceuticals are typically flushed down the drain or wind up in landfills (Jones et al. 2001).

The coastal environment and human health: microbial indicators, pathogens, sentinels and reservoirs

Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.