For years the EPA, U.S. States and U.S. territories have issued health advisories warning people not to consume fish caught from certain lakes and rivers and even oceans, due to pollution. The contaminants of most concern in many areas are mercury, polychlorinated biphenyls (PCBs) and dioxins, as in North Carolina, for example. Usually the bigger the fish, the more poison it contains due to bioaccumulation (bigger fish eat smaller contaminated fish).
More recently there is serious concern over another contaminant, one that not only poisons fish and the waters where they swim, but one that has the capacity to eliminate fish altogether. In May, 2019, The Guardian reported on this newly investigated source of water contamination worldwide – antibiotics.
The testing found Africa’s waters, overall, to be the most contaminated, with some rivers in Kenya so riddled with antibiotics that “no fish can survive” in them. Europe’s second largest river, the Danube, is its most polluted, and eight percent of Europe’stested sites were found to exceed safe limits. Even England’s Thames River, considered to be one of Europe’s cleanest, was found to contain high levels of five antibiotics – those often used to treat respiratory, skin and urinary tract infections.
Interviewed by The Guardian, University of Exeter microbial ecologist William Graze explains the gravity of these findings. This kind of environmental bacteria, he notes, contributes to the current global emergency of human resistance to life-saving medicines. Because, in many cases, these antibiotics are being detected at unsafe levels, “…resistance is much more likely to develop and spread.” And, he added, the levels don’t have to be high to create this threat.
These antibiotics get into the earth’s waters via human and animal waste, often through leaks at drug manufacturing plants and from wastewater facilities. Sometimes the waste is dumped directly into rivers and not always illegally or by accident—but by permit. The higher concentrations of contamination are most often found in poorer countries where wastewater treatment facilities lack the technology needed to filter out the drugs.
To ameliorate what has become a global threat to all of us, it will be necessary to help low-income countries improve their health and hygiene services, says Water Aid’s health and hygiene analyst Helen Hamilton.
The research team that did the testing is now planning to assess the impact of this antibiotic pollution on animal and plant life. Hopefully The Guardian and other major news sources will keep us posted on the findings, what must be done to end this threat and what we individuals can do in the meantime to protect ourselves.
For The Guardian’s complete report, go to
For information on fish advisories in the United States, go to: