Tag: pollution

Pissing or flushing: Pharmaceuticals in drinking water

What happens when I flush a pill down the toilet? And why should I care?

[Finnish version: click here]

Trace amounts of medications have been found in drinking water in various places. Are there effects on health? Some media are alarmist, but the most accurate answer basically is that we simply do not know yet (WHO,CWA, CBS, New Scientist).

Although it is only human to be worried about humans, the effects on the wider ecosystem may be much larger. A small amount in purified water means a larger amount in the non-purified source water. Again, there are alarming case studies where large amounts of medicine-related hormones have had biological effects on fish populations. However, on the whole no one really knows how much contamination there is, nor what its overall effects are, nor who is causing it (USGS).

There are relatively few possible sources of contamination. Pharmaceutical manufacturers may cause some very high contamination peaks, but the question is controversial (NBC). Antibiotics in agriculture are also a major source (WCP). However, it is clear that some of the contamination is coming from ordinary consumers.

How much?  I don’t know. Rather than getting involved in a big-picture controversy on which we don’t have enough data, I decided to hone in on a small concrete detail. We, ordinary consumers, are contaminating the sewer system with our medications. Whether the effect is serious, we cannot know yet. But there is one question that we can try to answer. What is the mechanism that causes it? Or, to put it in a more earthy manner:

Is the contamination caused by pissing, or by flushing?

There are two ways to get a drug into the sewer system. A person can eat the pill and later excrete any excess medicine in his urine or feces. Or he may dispose of old medications by flushing them down the toilet.

I want to know whether the flushing is causing most of the overall contamination. This is an eminently practical question at the grassroots level. People will take the medications they need, whatever the environmental effect. But there are steps that can be taken against flushing, like information campaigns, creating better incentives to return the medications, or good take-back systems.

Finland has a strong take-back system. All aged medications can be returned to pharmacies free of charge, no questions asked. (The waste is then disposed of as hazardous waste). But even in Finland, flushing happens anyways.

I am trying to find a single number that would allow consumers to get an intuitive feel of the damage they cause by flushing. I may have found it in the inverse of the excretion rate. I am calling it the flush rate. This needs a little explanation.

Whenever a medicine is taken, a complex process occurs (ADME).  Some drugs are broken down almost entirely. Sometimes these byproducts are as harmful as the drug itself, but typically they are much less bioactive. Thus, passing a drug through a human is a good way to clean it up.

However, it is not a perfect way, and some of the drug passes unchanged directly into the urine or feces. If the body breaks up 98% of the drug, the person still urinates 2%. The flush ratio is the inverse of this, or 50. This means that if the person throws just one pill into the toilet, he causes as much contamination as he causes by eating 50 of those pills.

Some typical values for some drugs are shown below. These must be treated skeptically, as variations can be huge and closely related drugs may have completely different excretion rates. Also added is an estimate of the cost per pill, since this information has an effect on how the medication is likely to be treated.

  • Paracetamol, Aspirin (painkiller): Less than 2% excreted. Flush ratio is therefore 1/2%, or  about 50. Cost is ~1 cent per pill
  • Atorvastatin (anti-cholesterol): <2%. Flush ratio ~50, ~50 cnt per pill
  • Carbamazepine (epilepsy medication):  2-3%. Flush ratio ~40, ~20 cnt
  • Prozac (antidepressant): ~15%. Flush ratio ~6, ~1 EUR
  • Oxycodone (strong painkiller): ~19%. Flush ratio ~5, ~4 EUR
  • Cetirizin (anti-histamine): 30%. Flush ratio ~3, ~1 EUR
  • Antibiotics: Huge variations. 40-80% of some antibiotics (NIH). Flush ratio ~2, ~1 EUR/pill (for penicillin)
  • Lisinopril: (hypertension): 100% (Not metabolized at all by the body). Flush ratio ~1, ~30 cnt/pill.
  • Birth control pills (COCP): Special case. The metabolites are hormones which have an environmental effect. Flush ratio not known, but probably low. ~1 EUR/pill

The society-level impact of flushing of course requires knowledge of things like the toxicity of the drug, the speed at which it decays, and the number of people taking the drug. However, a list like the one above does give some indication of where to focus.

My hunch (it is no more than that) is that a low-cost high-flush-ratio over-the-counter (OTC)  medicine has the highest contamination risk. People can buy as much medication in reserve as they want, and the low price means they do not have much incentive to make sure the medication does not age (it is much easier to just buy new pills). In addition, people buy these painkillers like candy. Large amounts will go to waste.

My hunch that people are careless with aspirin is supported by one study (LHWMP): aspirin contamination was found in 24% of tested streams. Aspirin can be toxic for example to cats (Manning), although the levels found in the water were in practice far below this toxicity level.

Thus, if I were to prioritize things based on these figures alone, I would target aspirin. The amounts may be tiny, but the point it that there is no reason for them to be there in the first place. Without flushing, the concentration would be close to zero. SInce the aspirin is not passed into the urine, people could take all the aspirin they want, as long as they disposed of the rest correctly.

I can also think of practical things that could follow from the priorization. Why not put extra notifications specifically on aspirin packages to encourage users to dispose of them correctly?  If such warnings are put indiscriminately on all medications, they may lose their effect. Focus them where the impact is the greatest.

I emphasize that the analysis above has too little data and too few parameters to be reliable. Aspirin may be a problem, but given that antibiotics and hormones have more severe biological effects, they may be much more serious problems. Someone should try to calculate this; I do not really have the competence.

I feel that this kind of analysis has psychological value, if nothing else. Arguments on environmental issues tend to become heated and repetitive. Sometimes it is worthwhile to look at things from a completely different perspective.

 

Open monitoring: Can citizens be trusted?


Many citizens to distrust the authorities when it comes to monitoring pollution from industry.  Here is a reverse question that few ask but many should: why should the authorities place any more trust on the citizens?

Self-monitoring by industry is criticized, but is self-monitoring by citizens any more credible? I have been driving for “citizen monitoring” of pollution, and this question needs to be asked brutally.  Here is what I claim: if we require independence and transparency from the authorities, then we need to require it from ourselves also. I am thinking of some ways to make this possible.

At the grassroots level, I have been following the plans to build a new waste incinerator in Turku, fairly close to where I live. It is a heated local topic, which is no surprise. No sane person specifically WANTS to live next to an incinerator (personally, I am neutral about it, but then it’s not quite in my backyard even though it is close). This NIMBY effect is well documented everywhere.

What seems less well documented is the POSITIVE potential of people who live next door to these things. The people here have had decades of experience with the old incinerator, and they have local knowledge of both the surroundings and the incinerator itself. From persistent monitoring, they know what parts of the incineration process cause the worst emissions. They have followed the color of the snow and the water in closeby streams. They have made measurements of the pH levels in the emissions.  They know what environmental conditions cause the worst smells.

The authorities turn a blind eye to these results. And — I hate to put it this way — perhaps that is the right thing to do. Even if one fully trusts the people, the scattered measurements simply do not fulfill scientific criteria. Since they are not fully documented, it is impossible to audit the results for credibility.

To me, the fundamental problems lie with confirmation bias. Locals are likely to measure only when something has happened, for example there is a particularly bad smell. Few people think of photographing the color of the snow on days when there are no problems. Or to mark down days on which there are no smells. These citizen measurements certainly give an indication of what the situation is on the worst days, but they are not calibrated and do not give much of an indication about average conditions.

This is NOT conscious manipulation! It is a psychological necessity. On those days when things are fine, it is important to forget the problems. Constant worry is more likely to lead people to early graves than any pollution.

To face these problems, I have two suggestions, one trivial and one less trivial.

A. Trivial suggestion

The trivial suggestion is to automate everything as far as possible. However, even with improvements in technology, there are major limits to what can be done. Real air quality measurements, for example, are expensive and difficult to make accurately.

A suitable user interface for odor measurements? Picture: YLE / Karoliina Hult

In cases where an accurate measurement cannot be made, for example with smells, there could be clever ways to measure near-automatically. One solution I am thinking about is to use “like buttons” next to peoples’ front doors (see picture). The face corresponds to subjective air quality.  Pressing the correct button will take half a second. The process would very quickly become automatic. And once the process is automatic (nearly sub-conscious) it will start creating credible time series of odor levels. These can be correlated with micrometeorological weather data measured by a weather station in a neighbor’s yard.

B. Non-trivial suggestion

The second, less trivial suggestion is that the people doing the analysis should be more or less indifferent about the results. In other words, any analysis of the data needs to be done at a completely different location than the measurements, preferably so that there is no personal contact between the observers and the analysts. Emotions should not exist.

There is a clear precedent for this in the human rights arena: Amnesty International members generally do not work on human rights issues in their own countries. This improves the impartiality of the organization (and also the personal safety of the members).

In exactly the same way, citizen monitoring of industry should be scattered geographically, and there should be a firewall between the people who measure and the people who analyze. The firewall cannot be perfect in practice, as each location is different, and the locals are best aware of the things that should be measured. Locals thus need to be involved in setting up the measurement systems, and they of course need to do the actual measurements, but they should be cut off from the analysis.

This suggestion goes against human nature in just about every possible way. Locals should agree to be lackeys of someone else, and measure what is asked without knowing why? They should potentially pay for instruments without knowing what they are used for? And they should trust that someone “out there” knows and will do right? I personally cringe at the idea.

However, it could be doable. In Finland, analysis of the Turku incinerator could be done from Lappeenranta, which has a university that specializes in waste management — perhaps student labor could be used? And conversely, locals from Turku could help set up the measurements in Vaasa, since Turku locals have the most experience on incinerators (the old Turku incinerator was for many years the only one in the country). People here could absolutely have the competence to know what to measure.

I suspect that the psychological obstacles may be the biggest obstacle. Local observers are motivated to monitor local conditions, since it is their environment and their health that is at stake. If someone is already stressed and exhausted about the situation in Turku, why would he care about the situation in Vaasa?

And what about the money, the resources, the leadership, the responsibility? I have no idea. The technology is not the chokepoint (challenging though it is). Human and political issues are.

More on open monitoring: here.

When trash burns wrong, part 1

To take Zygomatica beyond the realm of academic speculation, I have decided to hitch myself to a concrete issue which I have little competence in. A municipal solid-waste incinerator is being planned in Turku, quite near where I live. In any human activity, things can always go haywire. How can things go wrong with the incinerator, and how can we prepare for them?  [Click here for Finnish version]

This first blog is simply a summary of what I have learned in some days of browsing. I think I have most of the facts right.  Concretely, I am a member of the Turku section of the Finnish Association for Nature Conservation, and have helped comment the Environmental Impact Assessment of the planned incinerator. Being a member of the Association helps find information, but also allows me to affect things rather than just theorizing about them. All views and opinions expressed here are absolutely my own, however.

Trash incineration is a difficult issue politically, ethically, environmentally, and technically. I don’t actually know my opinion yet. I live quite close to the planned incinerator, but am not automatically against it. In this series I will take a laser focus which is the same whether I end up being for or against the incinerator: I will focus on the possibility of major accidents, how to prepare for them, how to inform the population, and how to  recover from them. My essential interest is in the finding and disseminating of information.

In one sentence: an incinerator is a huge furnace. The waste from trucks is dumped into silos and fed into the incinerator (Figure 1). The temperature needs to be at least 800 degrees in order to break up the toxic materials. The process can generate both heat and electricity. The burning produces flue gases which need to be cleaned (Figure 2). The clean-up residue (5% or the original mass) is considered toxic waste. The bottom ash weighs about 15% of the original mass. If the incineration was successful, the bottom ash can be used for example in landfills and construction.


Figure 1: The furnace system. (Source: TSJ:n YVA-dokumentti).

Figure 2: The cleaning system. (Source: TSJ:n YVA-dokumentti).

In Turku, the planned amount of waste would be 150,00 tons per year (one dump truck an hour). About 8,000 tons of toxic waste will be produced (one dump truck per day), and 25,000 tons of non-toxic bottom ash (a few dump trucks per day).

Before the 1980’s, little attention was paid to environmental matters. Incinerators produced significant amounts of dioxins and toxic heavy metals. When reality struck, incinerators disappeared from Finland; for many years, Turku had the only functioning incinerator in the country. In new incinerators, the emission levels have been set lower than for other energy-producing plants. If everything works correctly, the emission levels are considered acceptable (whether they really are acceptable is an issue which I will not get into here).

However, one thing is pure common sense: if a plant operates for thirty years, everything will not work correctly all the time. Something will happen: fires, failures of the filtering system, industrial actions, accidental contamination by toxic wastes, unexpected chemical reactions, failed maintenance, human errors…. If an accident can happen, it will happen, somewhere, eventually.

This common sense should ideally be supported by facts. And there is the catch: facts are hard to come by, at least from easily available public sources. Manufacturers and operators do not report malfunctions automatically. Accident reports can occasionally be found, but not systematically. That, then, is the theme of this series. Based on the limited information that is available, I will try to determine what can go wrong in an incinerator, and how the locals can deal with such malfunctions.

I feel no hysteria. Even if a fire is set off, it will end when there is nothing more left to burn. An explosion like the Flixborough disaster is not possible. Even in the (theoretical) case of an explosion, the shock wave is not an issue. The release of hazardous substances is the core issue; right now, I have no real idea how much and what types of materials might be released.

It is certainly possible that I will find nothing dramatic. In that case, I will report that nothing dramatic was found. Time will tell.

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