Starting in the mid-1960s, ecologists and toxicologists began to express concern about the potential adverse effects of pharmaceuticals in the water supply, but it wasn't until a decade later that the presence of pharmaceuticals in water was well documented. Studies in 1975 and 1977 found
clofibric acid and
salicylic acids at trace concentrations in treated water. Widespread concern about and research into the effect of
PPCPs largely started in the early 1990s. Until this time, PPCPs were largely ignored because of their relative solubility and containment in waterways compared to more familiar pollutants like
agrochemicals, industrial chemicals, and
industrial waste and byproducts. Since then, a great deal of attention has been directed to the ecological and physiological risk associated with pharmaceutical compounds and their metabolites in water and the environment. In the last decade, most research in this area has focused on
steroid hormones and antibiotics. There is concern that steroid hormones may act as
endocrine disruptors. Some research suggests that concentrations of
ethinylestradiol, an estrogen used in oral contraceptive medications and one of the most commonly prescribed pharmaceuticals, can cause endocrine disruption in aquatic and amphibian wildlife in concentrations as low as 1 ng/L. • What is the effect of exposure to low levels of PPCPs over time? • What is the effect of exposure to mixtures of chemicals? • Are the effects acute (short-term) or chronic (long-term)? • Are certain populations, such as the elderly, very young, or immuno-compromised, more vulnerable to the effects of these compounds? • What is the effect of PPCPs on bacterial, fungal, and aquatic life? • Are the levels of antibiotics in the aquatic environment sufficient to promote antibiotic resistance? • What is the effect of exposure to steroid hormones on animal and human populations?
Pharmacoenvironmentology Pharmacoenvironmentology is an extension of pharmacovigilance as it deals specifically with the environmental and ecological effects of drugs given at therapeutic doses. Pharmacologists with this particular expertise (known as a pharmacoenvironmentologist) become a necessary component of any team assessing different aspects of drug safety in the environment. Pharmacoenvironmentology is a specific domain of pharmacology and not of environmental studies. This is because it deals with drugs entering through living organisms through elimination. According to the EPA, pharamacovigilance is science aiming to capture any adverse effects of pharmaceuticals in humans after use. However, ecopharmacovigilance is the science, and activities concerning detection, assessment, understanding, and prevention of adverse effects of pharmaceuticals in the environment which affect humans and other animal species. There has been a growing focus among scientists about the impact of drugs on the environment. In recent years, we have been able to see human pharmaceuticals that are being detected in the environment which most are typically found on surface water. The importance of ecopharmacovigilance is to monitor adverse effects of pharmaceuticals on humans through environmental exposure. Due to this relatively new field of science, researchers are continuously developing and understanding the impacts of pharmaceuticals in the environment and its risk on human and animal exposure. Environmental risk assessment is a regulatory requirement in the launch of any new drug. This precaution has become a necessary step towards the understanding and prevention of adverse effects of pharmaceutical residue in the environment. It is important to note that pharmaceuticals enter the environment from the excretion of drugs after human use, hospitals, and improper disposal of unused drugs from patients.
Ecopharmacology Ecopharmacology concerns the entry of chemicals or drugs into the environment through any route and at any concentration disturbing the balance of ecology (ecosystem), as a consequence. Ecopharmacology is a broad term that includes studies of "PPCPs" irrespective of doses and route of entry into environment. The geology of a karst aquifer area assists with the movement of PPCPs from the surface to the ground water. Relatively soluble bedrock creates sinkholes, caves and sinking streams into which surface water easily flows, with minimal filtering. Since 25% of the population get their drinking water from karst aquifers, this affects a large number of people. A 2016 study of karst aquifers in southwest Illinois found that 89% of water samples had one or more PPCP measured. Triclocarban (an antimicrobial) was the most frequently detected PPCP, with gemfibrozil (a cardiovascular drug) the second most frequently detected. Other PPCPs detected were trimethoprim, naproxen, carbamazepine, caffeine, sulfamethoxazole, and fluoxetine. The data suggests that septic tank effluent is a probable source of PPCPs.
Fate of pharmaceuticals in sewage treatment plants use physical, chemical, and biological processes to remove
nutrients and contaminants from waste water.
Sewage treatment plants (STP) work with physical, chemical, and biological processes to remove
nutrients and contaminants from waste water. Usually the STP is equipped with an initial mechanical separation of solid particles (cotton buds, cloth, hygiene articles etc.) appearing in the incoming water. Following this there may be filters separating finer particles either occurring in the incoming water or developing as a consequence of chemical treatment of the water with flocculating agents. Many STPs also include one or several steps of biological treatment. By stimulating the activity of various strains of microorganisms physically their activity may be promoted to degrade the organic content of the sewage by up to 90% or more. In certain cases more advanced techniques are used as well. The today most commonly used advanced treatment steps especially in terms of
micropollutants are •
membranes (which may be used instead of the biological treatment), •
ozonation, •
activated carbon (powdered or granulated), •
UV treatment, • treatment with
potassium ferrate and •
sand filtration (which is sometimes added as a last step after the aforementioned). PPCPs are difficult to remove from wastewater with conventional methods. Some research shows the concentration of such substances is even higher in water leaving the plant than water entering the plant. Many factors including environmental pH, seasonal variation, and biological properties affect the ability of an STP to remove PPCPs. Recent computational studies have also examined emerging two-dimensional materials such as Si₂BN nanoflakes for the adsorption and detection of persistent pharmaceutical pollutants, including carbamazepine. Several research projects are running to optimize the use of advanced sewage treatment techniques under different conditions. The advanced techniques will increase the costs for the sewage treatment substantially. In a European cooperation project between 2008 and 2012 in comparison four hospital waste water treatment facilities were developed in
Switzerland,
Germany,
The Netherlands and
Luxembourg to investigate the elimination rates of concentrated waste water with pharmaceutical "cocktails" by using different and combined advanced treatment technologies. Especially the German STP at Marienhospital
Gelsenkirchen showed the effects of a combination of membranes, ozone, powdered activated carbon and sand filtration. But even a maximum of installed technologies could not eliminate 100% of all substances and especially
radiocontrast agents are nearly impossible to eliminate. The investigations showed that depending on the installed technologies the treatment costs for such a hospital treatment facility may be up to €5.50 per m3. Other studies and comparisons expect the treatment costs to increase up to 10%, mainly due to energy demand. It is therefore important to define best available technique before extensive infrastructure investments are introduced on a wide basis. The fate of incoming pharmaceutical residues in the STP is unpredictable. Some substances seem to be more or less eliminated, while others pass the different steps in the STP unaffected. There is no systematic knowledge at hand to predict how and why this happens. Pharmaceutical residues that have been conjugated (bound to a bile acid) before being excreted from the patients may undergo de-conjugation in the STP, yielding higher levels of free pharmaceutical substance in the outlet from the STP than in its incoming water. Some pharmaceuticals with large sales volumes have not been detected in the incoming water to the STP, indicating that complete metabolism and degradation must have occurred already in the patient or during the transport of sewage from the household to the STP. == Regulation ==