JeffB wrote:
Still not enough info on the subject. Sure, the chemicals are bad. I'll give you that. But how much of those chemicals are used in the liners? How much actually leaches out into the water, if any? How much of that is absorbed by the fish and/or plants, if any? And how much of that actually gets into a person's system, if any? All completely unanswered questions.
At the end of the day, however, there are people successfully using vinyl lined containers for AP and aquaculture and so far I haven't found a single negative article where someone got ill or suffered negative effects as a result. So although the vinyl liners 'may' cause a problem, there doesn't seem to be any evidence out there that supports it actually causes a problem. Just a whole heap load of maybe without any concrete science to back it up.
Look it depends on your attitude to risk. I'm an avid student of history. One of the things I've learnt from that is how arrogant people almost always are. For example peope look back at historical mistakes and so often ask themselves the question "how could they have been so dumb".
Examples that are relevant to this discussion include the attitudes of governments to DDT, asbestos, lead, mercury infact almost all industrial chemicals and their now known and now obvious adverse health effects. At the time these chemicals and substances were thoroughly tested by the standards of the day and found to be safe.
Many people look at the litany of public health issues caused over the decades and blame the deaths and sickness caused by industry to be the result of greed, the capitalist system, uncaring government and to a certain extent they are right. Many of todays politicians, civil servants and industrialists blame their forbears while saying with utmost confidence that things are better now and to a certain extent they are also right. However, apathy, ignorance and arrogance are just as much to blame and are just as prevalent today as they were when lead was added to petrol and asbestos used as insulation.
There has been a body of evidence growing for at least two decades that this group of chemicals have serious effects on the human body that are at best poorly understood. When this field evidence started being developed the field of epigenetics didn't even exist and that is where some of the biggest concerns are. More immediate concerns are how these chemicals are implicated in the disruption of the endocrine systems of many organisms not just humans.
Now you may find it easy to dismiss a body of evidence that you haven't seen or read, that is understanable. You may find it easy to dismiss my opinion the ease of which would be based on your opinion of me, which again would be understandable. The thing is that opinions don't change facts. My opinion on the real risks that these products pose to human and environmental health may be wrong. Then again it may not. There is no way for me or anyone else to prove it one way or another. However, you have been told about the risk and if in 10 or 20 years it turns out that the body of evidence has grown to the extent that governments start to regulate the exposure and emission of these chemicals to the environment and to the populace you will bare the responsibility for the exposure that you have subjected others to from this point on.
I find that the guilt from hindsight is always worse when it turns out I should have known but didn't act.
Now you and others may find this far fetched but I'll bring to your attention an issue that is in the Australian media right now.
In the 60's a number of scientists started raising concerns about asbestos and its potential adverse health effects. Despite repeated warnings to companies and governemnt bodies no action was taken.
20 years ago in Canberra a whole stack of houses were known to be contaminated with an asbestos product called "Mr. Fluffy". It turns out that before this product was used numerous people had advocated that it be banned because of the risk it posed to human health. 20 years ago the government now being aware or rather acknowledging the risks there was a government program at the time to remove this product from affected houses. At the time the government was adivsed two things. 1-that all the houses that had this product installed had not been identified and 2 that the measures taken to remove the product from houses were insufficient to decontaminate affected houses.
Now it has come to light that all the houses from which the asbestos has been removed are still contaminated and more houses which haven't been attempted to be decontaminated have come to light.
From a purely financial point of view all the effected houses need to be deomlished and all the people that have lived in those houses over the last 20 years need to have their health monitored and those that develop asbestos related cancers cared for.
From a human perspective, enough people knew at the time what needed to be done but it wasn't due to people dismissing the evidence of the real risk posed to human health and as a consequence not being prepared to wear the cost. As a result of whole new generation of Canberra residents have been exposed to this cancergin, the cost will be magnified as a result not to mention the human anguish, suffering and life sentence of living under the threat asbestos related cancers.
Backyard Aquaponics
