Researchers at the University of Bath, Bath, U.K., “mined” wastewater for biophysico-chemical indicators (BCIs) and found a direct link between the size of a city or town and the quantity of harmful chemicals and biological agents released naturally into the environment after passing through people’s bodies, or directly discharged via various activities such as showering and dish washing.
The researchers studied five cities and towns in the country’s southwest, each with very different characteristics including population size, industry presence and socioeconomic status. They looked for BCIs in rivers and wastewaters associated with each location to determine their impact on the environment. The researchers particularly focused on industrial chemicals such as bisphenol A found in plastics; personal care products, including UV filters and preservatives in cosmetics; pesticides, illicit drugs; lifestyle chemicals such as caffeine and nicotine; prescription medicines; and genetic material such as antibiotic-resistance genes.
“We found that wastewater represents an excellent fingerprint of a city’s use of a complex mixture of substances of biological and chemical origin,” says Barbara Kasprzyk-Hordern, professor at Bath’s department of chemistry and lead researcher on the study.
The biggest offenders identified were painkillers and medications used for heart disease, mental health conditions, and epilepsy; antibiotics — known to contribute to the prevalence of antibiotic resistance; lifestyle chemicals such as caffeine; and substances produced when these compounds are broken down by the body.
“Each of us needs to start considering our lifestyle as a factor contributing to deterioration of environmental health,” she advises. “First, we need to acknowledge that we are responsible, through the way we live, for water contamination, and then we need to start finding solutions,” she adds.
“It’s often more sustainable to remove the problem at [the] source, for instance via social interventions, than to invest in end-of-pipe, energy-intensive wastewater treatment processes that do not necessarily help reduce society’s carbon footprint or provide wider environmental benefits,” counsels Ruth Barden, director of environmental solutions at Wessex Water, Bath, U.K., which collaborated on the research.
The researchers hope the study’s findings, recently published in the Journal of Hazardous Materials, will give local governments the impetus to establish policies that will better support the health and resilience of their city environments; they suggest several social interventions to target pharmaceuticals — for example, awareness campaigns to highlight the correct disposal of unused pharmaceuticals, which does not include flushing or trashing, but instead returning medicines to pharmacies. Green prescribing is another. Here, if several medicines of equal therapeutic benefit exist, doctors prescribe the one with the least environmental impact. Another alternative is social prescribing in which doctors refer patients to local, non-clinical services offering activities known to improve health and wellbeing; patients considered not-at-risk are prescribed medicine as a last resort.
“Most of us are unaware of this impact because each use of a product results in small parts-per-billion quantities of toxic waste that can’t be seen with a naked eye, but when taken together, these tiny quantities create a complex chemical cocktail in our rivers that might have detrimental effects on the wider environment, especially aquatic creatures,” emphasizes Kasprzyk-Hordern.
This latest study builds on research conducted by the same group and published last year in Environmental Science & Technology. It concluded down-the-drain disposal of pharmaceuticals remains an overlooked and unrecognized source of environmental contamination that requires non-technological “at source” solutions.
In this study, 31 pharmaceuticals were monitored over seven days at five wastewater treatment plants (WWTPs) serving the same five towns and cities in southwest U.K. It revealed down-the-drain co-disposal of six pharmaceuticals to three WWTPs: carbamazepine and propranolol in city A; sildenafil in city B; and diltiazem, capecitabine and sertraline in city D.
The study also revealed a one-off record co-disposal of an estimated 253 pills (40 g of carbamazepine) and an estimated 96 pills (4 g of propranolol) in city A which accounted for their ten-fold and three-fold respective increases in wastewater daily loads over that of “normal” bodily-excretion-only days.
As a result, the researchers urge reducing these down-the-drain disposals, noting such disposals were double that of a previous study performed in 2005.
“This may be due to the lack of information and messaging that informs people to dispose of unused medicines at pharmacies. Media campaigns that inform the public of how to safely dispose of medicines are key to improving rates of return and reducing pharmaceutical waste in the environment. The environment is a key motivator for returning unused medicines to a pharmacy and so messaging should highlight environmental risks associated with improper disposal,” they concluded.