Pharmaceuticals

Even after treatment, wastewater can contain pharmaceuticals, such as antibiotics, caffeine, nicotine, painkillers, antidepressants, and synthetic hormones (Meador et al., 2016; WHO, 2012). Recent field studies by Pusceddu and colleagues (2018) have shown that wastewater contaminated with pharmaceuticals can increase concentrations of antibiotics and painkillers in marine animal tissue and lead to subsequent declines in their health. Their studies demonstrated that sewage outflow off the coast of Brazil drastically increased concentrations of pharmaceuticals, including painkillers, resulting in higher concentrations of these same chemicals in filter-feeding clams and urchins. Their follow-up studies showed occurrence of these drugs in the tissues of young clams and urchins, which decreased their growth rates and altered their development. Similarly, antibiotics found in wastewater can impede coral growth by disrupting their microbiome, which plays a critical role in helping guard against disease (Glasl et al., 2016). Given the findings that pharmaceuticals found in wastewater suppress growth, development, and microbiomes of taxonomically diverse corals, clams, and urchins, it is very likely that these effects on marine organisms are more common than previously thought.