Do Pharmaceuticals Pose a Threat to Primary Producers?

Trace amounts of pharmaceuticals have been reported in aquatic environments worldwide, and their toxicity to nontargeted organisms is of increasing concern. Algae are primary producers in aquatic food chains, and as such are very sensitive to external disturbance. While data are available on the toxicity of a variety of pharmaceuticals to algal species, there has been no attempt to synthesize and make sense of these data. Here, we discuss the importance of algae and summarize the available data on the ecotoxicity of pharmaceuticals to algal species. We then use the data to assess the potential risks of pharmaceuticals to algae. These data indicate that some antibiotics in aquatic environments could pose a potential threat to algal species with blue-green algae being particularly sensitive. Some of these pharmaceuticals could pose a risk that is equivalent to some compounds used as herbicides. However, there are significant gaps in the understanding of the risks of pharmaceuticals to algae and many research questions on the topic still need to be addressed.