A new study out of the Netherlands suggests increased levels of pharmaceutical residue found in the world’s lakes and rivers have become “potentially damaging” to the environment and could have an impact on antibiotic resistance.
The study -- released Friday in the journal Environmental Research Letters -- examined the levels of the anti-epileptic drug carbamazepine and the antibiotic ciprofloxacin in fresh water and found the environmental risks of these drugs in the water were 10 to 20 times higher in 2015 compared to 20 years prior.
The research is the first of its kind to create models on such a global scale and over a such a long period of time.
The environmental experts at Radboud University in Nijmegen blame the increased global use of ciprofloxacin by humans on the increased levels in the water and say the drug can have damaging effects on the ecosystem.
“There’s been an increase in the last 20 years in the concentrations of these pharmaceutics globally – and we predicted the concentration at least one of them to be higher than safe limits,” Rik Oldenkamp, lead author of the study, said in a phone interview with CTVNews.ca on Friday.
He adds these increased levels could have an impact on increasing antibiotic resistance -- which the World Health Organization calls “one of the biggest threats to global health.” However, the agency only refers to the problem as a misuse of prescription drugs, rather than bacteria developing a resistance to the drugs by being constantly exposed to them in a water source – which is what Oldenkamp suggests.
“From these predicted concentrations of antibiotics in the environment, we can try to link antibiotics to the emergence and development of antimicrobial resistance,” Oldenkamp said.
Oldenkamp added in a news release that there's “little awareness of the role of the environment in this problem … even though it becomes increasingly clear that the environment functions as a source of resistance for various pathogens.”
Although there’s been increase in antibiotic consumption all over the world in the last few decades, Oldenkamp said increased rates are the highest in “middle to lower-income countries, like those in Asia or Africa.”
The study outlines how concentrations of certain antibiotics in the water could be harmful for bacteria living there.
"These bacteria in turn play an important role in various nutrient cycles," Oldenkamp said in a news release. "Antibiotics can also have a negative impact on the effectiveness of bacteria colonies used in wastewater treatment."
Antibiotic concentration of the bacteria in water could also be affected by how dry a region is, Oldenkamp said. If there isn’t enough water to dilute the antibiotic residue, this could increase the concentration levels and be a problem to human health and the environment.
Oldenkamp is hoping their work opens the door for further research in the field.
"Getting an accurate picture of the environmental risks of pharmaceuticals around the world depends on the availability of data, which is limited," he said. "Our model predicts a relatively high environmental risk for ecoregions in densely populated and dry areas such as the Middle East, yet those are precisely the areas where there is little data on pharmaceutical use and concentrations in surface waters.”
In regions like the Middle East, where little data is available, the researchers predicted the levels by comparing drug consumption in other areas with various socio-economic differences between the two countries. They then looked at the area’s available water sources and the region’s access to sewage systems to estimate the level of pharmaceuticals that would be present in their water.
