Monday, July 10, 2006

Law of Contagion

Jaun, a regular commenter on this blog, left an interesting comment after my previous post (please excuse the minor expletives, -Jaun has a nice way with words!):

Well Stuart, if you dropped your knife in a pile of shit, would you clean it off and butter your bread? Would you wear your ring if it fell in the toilet full of crap? Would you brush your teeth if you dropped your toothbrush in the loo and cleaned it off? Would you wear your shirt with a poo stain on it in public? My point is, it doesn't matter how much you clean up sewage, it will always been seen that way. If anyone says Yes to any of the above questions, they are downright dirty people and should have no SAY in the debate. It's not a YUK factor we have to get over, it's just common sense to say NO!

In 2004, the WateReuse Foundation (USA) ran a workshop titled “Research Needs Assessment Workshop: Human Reactions to Water Reuse”. Social psychologist, Professor Paul Rozin (University of Pennsylvania) gave a presentation at the workshop. Dr Brent Haddad from the University of California wrote a report on the workshop, which was published by the WateReuse Foundation. The following paragraphs are transcribed directly from that report and describe some of the comments made by Prof Rozin (hence represent his professional views, rather than necessarily my own).

I expect that some readers may disagree with some of Prof Rozin’s comments (and are quite entitled to do so!). But while considering them, please try to remember that he is an international expert on social psychology and has studied this topic in detail. Dr Haddad’s description of Prof Rozin’s comments follow:

The “The Law of Contagion” suggests that when a pure object comes into physical contact with a contaminated object, the contamination is passed to the pure object. Thus, people will respond with revulsion to both things following their contact. The principle has the following properties:

  • Physical contact is required for contagion to operate. Examples include a cockroach touching a salad or Adolf Hitler wearing a sweater: people would want nothing to do with the salad or sweater no matter what scientific evidence could be produced to demonstrate that they are healthy/clean; and
  • The contagious effect is only slightly influenced by dose (degree of physical contact).

The perceived presence of contagion is often, though not always, permanent. For some people, nothing works to purify contaminated objects, but for the majority, there are two primary ways to reclaim them: for those using a physical-contact model of contagion, extreme measures of purification are often effective (eg, to get rid of HIV-related contagion in silverware, melting down the silverware into molten metal and then refashioning it into new silverware would actually work to purify it). For those using a “spiritual” (or non-physical) model, opposite contact could redeem the objects. Thus if a sweater was contaminated by contact with Hitler, then having Mother Teresa wear it could remove the contagion. In the case of water reuse, an endorsement from a “pure” pro-environment organisation such as Greenpeace, or a group such as La Leche League which endorses and provides advice to new mothers on breastfeeding, might serve as a purifying action.

Thus, psychological contamination is easy to accomplish, whereas psychological purification is difficult to achieve. This implies that extended discussions on the safety of indirect potable reuse are not able to move people’s feelings away from the sense that water from indirect potable reuse is contaminated.

A way to understand the law of contagion is to consider the thing's “essence”. People consider objects to have an essence that is not subject to the laws of physics. In addition to a thing’s physical nature, the history of it is part of what it is. Consequently, people associate purity with what has happened to a thing in the past, not just its current chemical profile. As a result, perceptions of recycled water include what is in it as well as where it has been and what it once was. However, the historical aspects that are included in a discussion of indirect potable reuse do not have to dwell on its prior urban use since all water has a very long history. The public perception of the essence of water from indirect potable reuse can change if the public understanding of history of the water changes.

I must admit that the references to Adolf Hitler, Mother Teresa, Greenpeace and the La Leche League are a bit foreign to my way of thinking (and perhaps yours too?), but I can quite relate to comments about cockroaches and salad!

Contrary to Jaun’s assertion that “it's not a YUK factor we have to get over”, I suggest that the difficulties that he has described are precisely a manifestation of this so-called “YUK factor”. This is perfectly natural and we all experience it to some degree. I also suggest that this “YUK factor” serves us humans very well in the absence of more precise scientific information regarding true chemical (or hygienic) quality.

Whadda you reckon?


Jaun said...

Well Sturart I ask you this, why do dentist, doctors destroy their equipment (this includes, tubes, drills, knifes, needles and other sharp objects) if they can be reused in the manner you speak of.

The YUK factor is still there, but also health concerns, the same reason why people won't accept recycled effluent.

Dentists destroy the equipment they use on you, because of the MINOR risk of contamination to the next patient. It's not a YUK factor, its common since and it's the same reason why police don't reuse or clean breath testing mouth pieces. (And do not tell me they are recycled, I know they are NOT!)

Boil it all up and it comes down to the health risk, not the YUK factor. Most people will look beyond the YUK factor to get the truth, something this city is doing.

My point, which you so kindly had to quote, was a point that people won't accept something where there is doubt and a simple term of YUK involved.

Shit has always been a term of YUK, and when scientist try and tell us they can recycle it and use it's bi products, people will be in doubt, and nothing will change their mind, just like some people don't believe in God!

You must also consider that effluent is not just shit and water, but chemicals, poisons, hormones and a horde of other contaminations.

The day majority of people accept we need to recycle effluent for drinking, is when the oceans dry up. For those who think it's a viable solution to desal plants and other sources of water, should then think about the people they are stepping over. People like farmers who feed them, people that cloth them and those who pay their wages.

Water is a valuable resource, and a price should not be put on its head and the cheapest option selected, like the Toowoomba council have done.

25% to 1% is a big difference, and NO WHERE has tested this much, so there can be no evidence to prove it is safe. But 100% could be used for non-domestic use, which would benefit this city far greater then only 25% for drinking.

This is my final point on this subject. I don't care what people vote, but a Yes will do more damage then good. Why, because the dams will still continue to drop, and the council will be thinking this solution to be the all and end all fix to our water problem.

If the drought continues, they will end up implementing one of the other options they have already dismissed, so why can't they use them now!

This is no longer a fight over recycled effluent, but the intelligence of our political parties and their decisions, and they look pretty dumb to me.

I can only hope the world leaders OUTLAW recycled effluent for drinking.

Hope your cup of sewerage isn’t too strong.

Stuart Khan said...

Hi Jaun, I appreciate your comments.

No scientist would deny that water recycling involves potential risks to public health. So does the use of any other water source, as well as eating, swimming and breathing. The important thing is that we are able to put in place satisfactory measures to manage these risks.

Dentists and doctors dispose of disposable equipment as a component of risk management. Some items (syringe needles, scalpel blades, etc) are simply more cost-effective to destroy and replace than it would be to implement satisfactory (in terms of effectiveness and reliability) resterilisation procedures.

As a society, we have tried to adopt the same approach for water. We use it once and then discharge it, kidding ourselves that the water is gone forever and can be replaced with new pristine sources. This is a comparatively simplistic approach to public health risk management (compared to incineration of syringe needles), but in Australia it appears to be working sufficiently in the vast majority of circumstances.

However, as I’m sure you are aware; water is an increasingly scarce resource in some parts of Australia. Therefore, we are being encouraged to reconsider the short-sightedness of our approach with an aim to maximising the use that we can attain from a limited supply. This may mean that we need to look more closely at our urban water cycles and in many cases, improve our risk management practices. One way of doing this is to implement increased levels of water treatment and monitoring. Destroying water forever (like a disposable syringe needle) is not an option worth considering.

But I agree with you, -people will not accept something which poses a real increased risk to human health. I count myself firmly among such people. One of the great challenges to scientists, planners and regulators is to effectively communicate the fact that intentionally recycled water can be managed just as safely as any other supply. A second great challenge is to overcome some of the psychological barriers described in this post. Many of us may have difficulty distinguishing between the two and this makes the job even harder.

Anonymous said...

Stuart, have you never heard the expression “Flagging A Dead Horse”??? Recycled water will never happen in this country while most sustainable and safer options are available. People like you should admit defeat and get a life!!!

john c said...

It's interesting how the Toowoomba debate has moved passed the yuck factor. Sure plenty of people voting on 29/7 will vote no because of the yuck factor. But the debate is really about concealment of other viable options by a Council whose councillors are the subject of multiple CMC investigations.

TCC has run a campaign of lies and deceptions - they will say anything to try to get a yes vote. Their latest message is - vote yes even if you don't want to drink the water because we need it. Last ditch tactics from a campaign going under.

Stuart Khan said...

Thanks John C,

Yes, I agree and acknowledge that there are numerous more significant issues being debated than the “yuck factor” in Toowoomba at the moment. My post was an attempt to specifically address an issue that was raised in the comments section of my blog. I am following the other issues that you mention with great interest and I am sure that there will be plenty of important lessons to learn from them.

Jaun said...


No scientist would deny that water recycling involves potential risks to public health.

But they are, they have come hear educate people it is 100% safe. So if 100% of it is safe, why do they deny it!

You stating this proves my own personal opinion about recycled effluent, IT ISN'T SAFE!

People will walk over the DEAD to make money; recycled effluent is just that, A MONEY MAKING SCHEME.

There can be no other outcome for its use other then destruction, unless it's used sensibly.

Stuart Khan said...

Hello Jaun,

Just because something involves ‘risk’ doesn’t mean it can’t be ‘safe’. If that were the not case we would have to regard all of the examples listed above (drinking any water supply, eating, swimming and breathing) to not be safe. The important thing is that the risks are low and manageable.

Jaun said...

A persons health and well being is not a low risk, it's extremely high. Why else would we have laws to govern speeding, murder, stealing etc? Because the risk to the persons involved are HIGH and unnecessary.

If recycled effluent is so safe, then tell me why doesn't every country in the world use it, and why people tell you to NOT DRINK the water when in London.

As I mentioned before, you wouldn't wash you hands in the toilet then eat dinner. Not because it seems YUK, but because of the RISK involved. No sensible person is going to play with their life, why should scientist and political parties be allowed to.

Scientist can't say something is 100% safe when nothing in this world is without risk, driving, walking, eating even sleeping are all a risk (I agree), but it's our choice to take that risk, not a forced one like imposing recycled effluent into a cities water supply. With that we have only 2 choices, LIVE WITH IT AND TAKE THE RISK or MOVE OUT OF TOWN, not much of a choice is it.

You really need to get a grip with life Stuart and think of other people instead of yourself and your beliefs.

paul said...

Read the other side of the Toowoomba water debate:

Clive Berghofer's Newspaper

Jaun said...

Paul, couldn't agree a more, Clive should have written the NO case for us and he back's the use of recycled water for NON-DOMESTIC use 110%. It's a pitty other people have a disgusting view!

Anonymous said...

Dear Anonymous,
It's called "FLOGGING a dead horse", not 'flagging'. Just an aside.

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