Diclofanic contamination is the most common toxic in medical wast, but what Stefanos refer to be given more concern

Thank both of you for your answers. I can ask/search now more specifically for hot topics.

Hello Sandor,

a good starting point is the work of Klaus Kuemmerer, e.g. this review:

http://www.ncbi.nlm.nih.gov/pubmed/19261375

or this book, if available:

http://www.springer.com/environment/environmental+toxicology/book/978-3-540-74663-8

Best wishes

Christoph

Hello Cristoph, thank you for the links!

Metaprezoles antacids are the most common drug residues found in water

The Washington State Department of Ecology recently published a study of pharmaceuticals and personal care products in municipal wastewater discharging into Puget Sound:

https://fortress.wa.gov/ecy/publications/summarypages/1003004.html

The study also looked at removal efficiency of various chemicals at the treatment plants.

I participated in a project there the most used active pharmaceutical ingredients were evaluated based on the predicted concentration in fish based on bio-concentration and amount used compared to the known active concentration in humans.

Article Predicted critical environmental concentrations for 500 phar...

I think it differs from place to place but most of the waste water treatment plants are not capable of removing pharmaceutical wastes. In Kuwait marine environment we have noticed most of the prescribed medication in marine waters with exception to EDC, which is strange but probably pills are not much prevalent here.

Regarding the removal of pharmaceuticals in waste water treatment plants we found removal to different degree of more than half of 70 active pharmaceutical ingredients with and a third more than 50 %.

Article Occurrence and reduction of pharmaceuticals in the water pha...

Henrik this is right we have seen similar efficiencies. My experience is if the contact time is more, (if the activated sludge is left for a longer duration) the efficiencies of pharmaceutical removal.

I agree that the sludge age is an important factor for degradation of pharmaceuticals (as well as it is very important for optimizing the nitrogen removal).

We both found this is the survey I refereed in my previous answer as a clear difference between nitrifying and non-nitrifying sludge which is operationally distingiushed by the choice of sludge age. We also performed a study on degradation kinetic of pharmaceuticals by sludge that was collected from plants that used different sludge ages that showed this clearly.

Article Impact of solid retention time and nitrification capacity on...

I looked at this issue as part of a third year undergrad module. There is a fair bit of research out there. Try these two for starters

http://www.springerplus.com/content/2/1/24

http://www.mass.gov/eea/docs/dep/toxics/stypes/pharmh2o.pdf

It seems tricky to focus on the "toxic compunds" as suggested in parts of the discussion, as oftenly little is known about the "aquatic (side) effects" of most pharmaceuticals.. perhaps their side-effects in humans can be a good first indication.

Very good answers directing possible future research... thank you all!

It is dependent upon the specific location and the drugs that are prescribed in that area. Of course there are also illicit drugs to be found. Sulfamethoxazole is one prescribed drug that is quite common and also resistant to water treatment. Other common markers are ibuprofen, caffeine and non nutritive sweeteners like sucralose. Generally they are detected at extremely low concentrations of no public health concern. See: Therapeutic Dose as the Point of Departure in Assessing the Health Hazards from Drugs in Drinking Water and Recycled Municipal Wastewater. RJ Bull, J Crook, M Whittaker, JA Cotruvo. Regulatory Toxicology and Pharmacology. 60, 1-19, 2011.

Dear Joseph, no direct effects of antibiotics, might not exclude indirect public health risks, as in the case of multi-resistant bacterial strains emerging from WWTPs ? It is currently investigated if (and how) lower dose can contribute to the resistances.

I would disagree to mainly focusing on common markers, since much is known about them already, and I guess they are not meant with "medicinal". They can of course serve as a point of departure or for comparative purposes.

The consistent "medicinals" will be natural hormones like estrogens and androgens excreted by humans. The other chemicals will be site specific. Bacteria are certainly exchanging plasmids and some might randomly cause some antibiotic resistance. I doubt if antibiotics in the wastewater are significant relative to resistance. The antibiotic would have be there is sufficient quantity to altar the bacterial population. Resistant bacteria occur in patients taking the antibiotic. Resistance to antibiotics does not equate to resistance to disinfectants. So, if the downstream drinking water is properly treated there should not be concern about the risk from resistance bacteria, unless perhaps people are swimming downstream from the discharge.

I think your comment about human side effects being indicative of environmental effects is not likely. I think it is much more likely that waste discharges can have a greater environmental impact (fish) than human impact, because the fish live in the water and are more sensitive to environmental affects during early life stages. This has been demonstrated by studies of fish that were caged near sewage outfalls.

Wastewater plants are not specifically designed to remove pharmaceuticals, but they are part of a chain that includes wastewater chemical and biodegradation, environmental passage that includes adsorption, sedimentation, oxidation, hydrolysis, solar UV, then drinking water treatment that also includes sedimentation and oxidation. Chlorine converts some under drinking water treatment conditions, and ozone is even better. There are numerous studies of advanced water treatment processes for potable reuse purposes that indicate which few pharmaceuticals are refractory to the entire process train. Take a look at the citation in my earlier text. It gives some information , but there is a lot more in the literature in analytical studies by Drewes and Snyder and others.

The answer to the 2nd part of the question: Typically none of these compounds are tested for in source or finished drinking water. Many studies have been done, and they have all found pharmaceuticals. If you want to see whats "emerging" look no furthur than the top 100 pharmaceuticals sold. http://www.drugs.com/stats/top100/sales

In an area of concern, look at the most sold drugs and focus on those. Check also the shelves of shops and find out the most sold personal care products, this will lead to the most likely products to be found in the local wastewater.

Probably, phenolic compounds

Simple phenolics are degradable. The academic interest is in chemicals like triclosan ( a chlorinated phenolic) and DEET, as well as a few drugs that are not readily degraded or physically removed efficiently even by advanced treatments. The triclosan is persistent, but it and DEET are not very toxic. The prescribed drugs are very location specific. If there is reasonable wastewater and drinking water treatment there isn't much concern, although it is very annoying to know that some might be present. The real question is whether any of the human estrogens and androgens are getting through to the drinking water because they are quite potent at ppb doses. Unfortunately there are many locations that do not have any wastewater treatment.

Probably, the most important medicinal residue pollutants in effluent water: (i) the most consume (sold, prescribed); (ii) the most conservative and persistent (e.g. carbamazepine) and (ii) the most toxic as for human and environmental health.

The pollutants can be ranked by determined criteria and the top can be selected for the further research :)

Please see an article available on ResearchGate web of mine "Climate change and Contaminants" under pharmaceutical products (6) which reveals that about 20 most commonly detected pharmaceuticals in world environmental waters are: atenolol (beta blocker), benzafibrate (lipid regulator), carbamazepine (antiepileptic), clofibric acid (metabolites of clofibrate-lipid regulator), ciprofloxacin (antibiotic), diazepam (antidepressant), diclofenac (analgesic/ Non-steroidal anti-inflammatory drug, (NSAID), erythromycin (antibiotic), gemfibrozil (lipid regulator), ibuprofen (analgesic/NSAID), iopromide (contrast media), ketoprofen (analgesic/NSAID), mefenamic acid (analgesic/NSAID), metoprolol (beta blocker), norfloxacin (antibiotic), propranolol (beta blocker), roxithromycin (antibiotic), salicyclic acid (metabolite of aspirin), sulfamethoxazole (antibiotic), and trimethoprim (antibiotic)

How does the climate change affect pharmaceuticals in water? Actually it turns out that world temperatures have been flat for the last 17 years.

Increasing run-off due to climate change (extreme events such as higher rainfall, flooding, sea-level rise) would increase the amount of pharmaceutical inputs from municipalities dumping ground/ SWTPs etc. into surface waters and groundwater. Floods can lead to increased wash-off of chemicals from soils to water bodies. In addition, pharmaceutical compounds are generally polar and water soluble (high mobility in water). WWTP cannot completely remove pharmaceuticals as a consequence has been detected in groundwater, surface waters and even in drinking water. Some of pharmaceutical detected in treated drinking water: are Ethinylestradiol (EE2), Atenolol, Carbamazepine, Diazepam, Clofibric acid, Gemfibrozil (see Collier 2007- Pharmaceutical compounds in Potable Water: Potential concerns for pregnant women and children. EcoHealth 4, 164–171, 2007).

Thank you Golam for the valuable answers! Indeed climate change is not always global warming as used to call... increased temperature events and desertification can also increase the concentration of compounds of interest in soil.

Thank you Sandor

Regarding Golam's hypothesis of linkage between climate and pharmaceuticals---it seems to be a tenuous relationship. A better link would be if certain diseases increased and then more of certain drugs were consumed. That would lead to greater concentrations in ambient waters. Floods and runoff are quantum events and would not be continuous.

The frequency and intensity of extreme events such as heavy precipitation, floods, storms, and cyclones have increased and projected to increase over the coming years (IPCC reports). This will lead to more frequent contamination of water bodies with chemicals. For example, Hurricane Katrina (USA) caused contamination of flood water and sediments with hazardous chemicals (see references). In addition, floods may cause remobilisation of chemicals already in the environment.

J. Manuel. 2006. In Katrina’s Wake. Environmental Health Perspectives. 114 (1): 32-39.

D. D. Reible, C. N. Haas, J. H. Pardue, and W J. Walsh. 2006. Toxic and Contaminant Concerns Generated by Hurricane Katrina. Page: 5-13. National Academy of Sciences, USA.

E. Euripidou and V. Murray. 2004. Public health impacts of floods and chemical contamination. Journal of Public Health 26 (4): 376–383.

Golam, All three of those papers are out of date. Of course floods might remobilize chemicals in the environment---temporarily. That is hardly a scientific novelty, it is common sense. The recently released IPCC report has backed off significantly from their previous reports that started the global warming controversy. They had to face the reality that the models that they used (~1975 to 1998) were a snapshot in time and are now wrong, because there has been no net warming for 17 years. They even admitted that they could not attribute major storms etc to "global warming". Apart from that the primary sources of pharmaceuticals in the water environment are human sewage and animal feed lots.

Concerning the influence of the climate change, the behavior and input of pharmaceuticals can be dependent on the following factors: dilution (e.g. growing or decreasing of the concentration in water); solar activity (it can influence the degradation of certain compounds, e.g. ketoprofen), uptake (difficult to predict, but the climate change influence the health of people, e.g. adaptation of the organism to the climate change may need an additional medicaments, or other type of medicaments)...

The list of pharmaceuticals found in waste water and even drinking water is long and depends on the specific inputs and the sensitivity of the analytical method used. I agree with a previous post that the most often found compounds are combination between the most used drugs (ibuprofen, diclofenac... and even drugs of abuse) which are continuously replenished in the environment and the most recalcitrant ones (carbamazepine, gemfibrozil...) which have longer half lives. Due to very low concentrations, most drinking water plants are not equipped to eliminate those products. Concentrations will vary with dilution rates (season, water re-use rate), use rate (winter/summer) and regional input.

Returning to your initial question: pharmaceuticals in hospital waste water, is a bit more specific. In the particular case of hospital waste water, the bulk of pharmaceuticals found (usually over 60%) are contrast agents used in diagnosis (like iopramide). In hospital waste water the concentrations are higher than in surface waters and the waste water volumes are smaller and more economic to treat. The idea has been proposed and is actively discussed that it would make sense to encourage (or force!) the hospitals to treat their waste water before discharging it into municipal systems and compounding the problem by creating a large volume of very diluted waste which is very expensive to treat. This idea makes sense to me and, associated with measures already under way to collect old drugs and limit avoidable discharge (flushing your old medication down the toilet) may make a difference.

Thank you for your answer. Canada is always at the lead of environmental/health questions, as I noticed.

Apart from Diclofenac, carbamazepine is mostly researched since it is also widely detected and difficult to degrade. Check this link, http://www.sciencedirect.com/science/article/pii/S0043135403006419.

Checking the statistics of pharmaceuticals consumption would give you an idea of what could be possibly emerging right now. Hope this helps.