Pandora's Poison

Chlorine, health, and a new environmental strategy

by Joe Thornton

MIT Press, second print, 2000, ISBN 0-262-20124-0


About the author

The book "Pandora's Poison", about the implications of organochlorines in health issues, was written by Joe Thornton, a former Greenpeace campaigner against PVC/chlorine. While he formally doesn't is a campaigner for Greenpeace anymore, he still (2001) works (occasionally?) for the Greenpeace Exeter (UK) unit. This should not have any relevance for his book, which is published by the prestiguous MIT press, if he should have used all knowledge that can be found in the literature and realistic numbers to prove what he wants to prove. But unfortunately, he uses the same tactics as when he was a campaigner: only citing these works which prove or suggests what he want to prove and ignoring any publications (even from governements and the UNEP) that prove the opposit.


Here follows an already long reaction on the first two chapters where the base assumptions for acting against organochlorines as a "class" are made. That will be widened with more facts as we find more flaws in Thornton's book in the coming months, depending on other time consuming activities... These reactions are far from complete, as a full reaction would consume as much paper as the book of Thornton itself (600 pages). That would be too much, as I still have a full time job to do…
There is also an addition from chapter 8, where Thornton makes such an incredible false statements about the factory where I work, that that alone proves that he has not made any changes in his Greenpeace attitude...

Parts of this page:

Comments on the chapters in the book:

Comments summary:

"God created 91 chemical elements, man more than a thousand and the devil created one: chlorine." [28]. That is the credo of Greenpeace for its anti-chlorine campaign and is the fundament of the book of Thornton, who still works for Greenpeace. There is no difference in methods used by Thornton as author of his MIT-based book and Thornton as (co)author of several brochures about chlorine/PVC as Greenpeace campaigner. There is only a difference in style, which makes it even more difficult for the average reader to know where the author is a little (?) economical with the truth. Or to say it with the words of the Hamburg (Germany) court in the case of Greenpeace e.V. vs. Engelbeen: "The reader understands from the actual context of the text that Greenpeace presents facts that are overstated or, even though they give true information about a fact, they do not give all the details, so that at the very least a false impression can be created in the mind of the person receiving the message.". That is what Thornton does again and again in his work.
The basic assumption that the introduction of chlorine in an organic molecule in general makes that molecule more toxic is true. But that this is also true for the introduction of oxygen, sulfur, nitrogen(oxides), phosphor(oxides), etc. is omitted. Every organochlorine that can be inhaled, ingested or can pass the skin is toxic, carcinogenic, mutagenic, hormone-disrupting, etc. at some dose. But that is also the case for all organics, whether these contain only carbon and hydrogen (as is especially the case for aromatics) or other elements like oxygen, sulfur, nitrogen,... Again that is omitted from the book. The introduction of chlorine makes a molecule more fat soluble, but that is similar to the addition of a CH3 group (an extra carbon with three hydrogen atoms) to such a molecule. Indeed some organochlorines are POPs (persistent organic pollutants), that means persistent and bio-accumulating and toxic. A few hundred of the more than 10,000 industrial and over 2,000 natural organochlorines can be found in human blood. With the today's analytical techniques, we can assume that most of the others are either not persistent enough, or don't bio-accumulate at all, or are released in such minute quantities that they can't be detected, which makes their environmental relevance rather questionable. But that also can be said of a few hundred of non-chlorinated materials like PAHs and nitro-PAHs. While their bio-accumulation is mainly at the lower end of the food chain, their impact is far higher than for organochlorines like dioxins, as they are released in quantities which are orders of magnitude higher and (nitro)PAHs are cancer inducers, while dioxins are cancer promoters at high levels, but cancer inhibitors at low levels...
One can write a similar book about the dangers of oxygen, sulfur, nitrogen, phosphor,... for all life on earth. That will be more difficult than for chlorine, for the simple reason that much less is known of the results of the introduction of these elements into organics. But what is known don't make them less suspect than organochlorines. And nature is not less toxic, carcinogenic, mutagenic,... than industry, to the contrary...
Thus if you believe that chlorine is invented by the devil, this is the book for you. If you are more critical, don't buy it, you can have the same "information" from Greenpeace for free...

General comment:

Much of Thornton's work on the toxicity of organochlorines is based on the study of Dietrich Henschler [65]. Henschler only studied the introduction of chlorine in relative harmless aliphates (organics with a straight-forward chain and/or side chains of carbon atoms) and more harmful aromatics (organics with ring-shaped forms of carbon atoms). There are no similar studies of the introduction of other elements in hydrocarbons, but the author implicitly says that the introduction of other electrophilic elements into alkanes also makes them more active (= more toxic):
"The electrophilic effect of chlorine augments - just like the other electrophilic elements (e.g. F, O, N, P) - the electrophily of the carbon atom where it is bound to...". The author also shows different pathways where different groups of organochlorines ultimately lead to mutagenic (cancer inducing) properties, but that is mainly for aliphates, not for chlorinated benzenes (which are - contrary to benzene itself -no carcinogens), nor for the lower chlorinated phenols (like 2,4 dichlorophenol, part and breakdown product of the herbicide 2,4-D) and not for a lot of chlorinated aromatics, ranging from DDT via PCBs to dioxins and furans [65].
Many chlorinated aromatics only show carcinogenic properties at very high doses, where severe damage to certain or several organs occurs. That is not because they are real carcinogens, but as result of the damage and the repair mechanism that makes a lot of new tissue (with the higher risk of growing a damaged cell). In these cases there exist a level where no extra cancer will occur - or even that the chemical blocks cancer, as is the case for vitamin A and TCDD-dioxin... [13].
About half of all chemicals (natural or not, chlorinated or not) ever tested at high doses in rodents are carcinogens [13]. Of course there are large differences in dose, where that occurs. But as good as some mainly human-made chemicals like dioxins and PAHs bind to specific receptors in the cells which can introduce cancer at some dose, that is the case for natural ones too. One helping of broccoli is about 1,500 times more toxic than the daily reference dose of TCDD by the EPA, taking into account the lower binding potential of IC (indole carbinol - the main toxin) and the residence time of one day of IC, compared to many years for TCDD [13]. But some natural toxins like aflatoxins made by the common house mold are ten times more toxic than TCDD at the same level of intake…


Detailed comment


page 3:
"Industry's electrical energy transforms salt's stable chloride ions into molecules of chlorine gas, a heavy, violently reactive, greenish gas that does not occur in nature."
This is clearly wrong. The amounts of sea salt in ambient air above the oceans, introduced by simple physical actions is estimated 6,000 million tons per year. Of that amount, some <100-800 million tons is estimated to be transformed into elementary chlorine as result of oxidation by sea-level ozone, nitrogen oxides, iodine and bromine compounds [66]. That has to be compared to the 40 million tons the chlorine industry produces (not emits!). This reactive chlorine is thought to help in the oxidation of organic compounds in the lower atmosphere, but in part forms organochlorines. It is also one of the origins of the nice green copper roofs in the neighborhood of the sea.

page 9:
"Moreover, pollution control devices merely shift pollutants from one place or environmental medium to another; they may reduce local pollution, but they do nothing to prevent global contamination."
There can be tremendous differences in local and global environmental impact of persistent pollutants like dioxins by using pollution control devices, together with pollution prevention measures. Prevention of dioxin formation in incinerators is directly related to design, and operation practices (not to chlorine content! See: chlorine input and dioxin output). These can reduce dioxin formation up to a 1,000-fold. Pollution control is done by injection of chemicals, precipitators, filters and end-of-pipe catalysts or absorbents. Catalysts destroy dioxins and absorbents like active carbon remove dioxins from the exhaust gases. The latter is incinerated (with a 99.99% dioxin reduction).
While much more dioxin is captured in waste solids from the precipitators and/or filters, this is completely irrelevant for global contamination, as that is secured in local dumps (or, like in The Netherlands, in part mixed with asphalt - an irrelevant yearly release of 0.6 g I-TEQ/year off the roads). Dioxin emissions into air are the most important sources of dioxin contamination in the food chain by incinerators. Thus any device that removes dioxins from the exhaust gases has a tremendous impact on the local and global dioxin burden.

Page 7--13: Risk paradigm vs. Ecological paradigm.
The Ecological paradigm by Thornton is mainly based on the "precautionary principle". While it is better to err at the side of safety, one still needs to address the risks of different processes to judge different products and/or processes to know which one is safer, including the status-quo. Assuming that non-chlorinated products and/or processes are safer by definition is contrary to the precautionary principle, as far more is known about the risks of chlorine products and processes than of the alternatives. And what is known of the alternatives is far from reassuring...
Further, 99% of the full class of (organo)chlorine products in The Netherlands were compared for human health and environmental impact with the total impacts of all products produced, as far as the latter impacts were known. Besides chlorine products which were already phased out or being phased out, the remainder had a lower impact on the environment (PVC far lower) than the average... (See: the Chlorine Chain). Thus there is not the slightest reason to phase out the remaining chlorinated products to pollute more...
Zero Discharge and Clean Production are nice intentions but impossible to fully obtain. There is no process on this earth where there is no pollution and/or where no toxic, carcinogenic, mutagenic... products are used or released at some part of the life cycle. Glass and concrete need sand (silicosis), steel uses coal (PAHs, sulfur, dioxins), wood dust causes cancer itself (and releases PAHs and dioxins when incinerated), plastics need crude oil (PAHs, benzene, dioxins...), and all fossil and bio-mass energy sources release PAHs, dioxins...

Page 15:
"Organochlorines account for the majority of known endocrine disrupters".
This is a clear untruth. Near all natural hormone disrupters and many man-made chemicals, known to interfere with hormones at some level, don't contain chlorine. Chlorine is not necessary at all. Instrumental seems to be a phenolic group (or a benzene ring that can be metabolized into a phenol) and a side chain: either a second phenyl/phenol or a medium-length alkyl chain. Except for DES, which was specifically been used as hormone influencing drug, the natural hormone disrupting chemicals in our food are far higher in amount and combined strength than man-made. Especially soy is notorious for its influence (both positive and negative) [67]. Further, the authors of the endocrine disruptor - sperm decline hypothesis specifically warned against pinpointing to any specific chemicals.

Page 18:
"As the German government's Council of Environmental Advisors concluded in 1991, 'The dynamic growth of chlorine chemistry during the 50s and 60s represents a decisive mistake in twentieth century industrial development, which would not have occurred had our present knowledge as to environmental damage and health risk due to chlorine chemistry then be available'".
While this was true for certain chlorinated products, the same Council has changed their opinion in 1998, after several of their advises were implemented [68]:

"The German Environmental Council does not wish to discuss here the issue of chlorine chemistry already discussed in its Special Report on Waste Management. It would, however, like to point out that it is aware of the fact that, as a result of interim developments in production and disposal technology (developments that are in part attributable to the German Environmental Council's recommendations), the environmental problems associated with PVC can no longer be used as a singular argument to justify rolling back the use of chlorine chemistry. The German Environmental Council is of the opinion that the health and environmental hazards engendered by PVC are not serious enough, in comparison with such substitutes as PET, PP, etc., as to warrant placing a ban or severe restrictions on its use. However, the German Environmental Council still intends to reassess the use of PVC from the point of view of whether materials that are environmentally persistent should be taken off the market because of this very property. It will deal with this issue when Sweden, as expected, formally proposes that EU environmental policy be revised along these lines."
The latter recommendation is rather curious, as that means that non-toxic persistent products, which have a long life-time and thus are very sustainable, like PVC, glass, brick, concrete,... should be banned?

Chapter 1: The Problem.

Page 27: Table 1.1
With the exception of carbon tetrachloride, the other pure chlorinated organics mentioned in the list have moderate lifetimes in air. Those with the longest lifetimes all contain fluorine, which makes the molecule extremely stable towards photo-degradation. It is unfair to call these "organochlorines". Further, even if TCDD-dioxin is formed from trichlorophenol by light, that is irrelevant as TCDD itself is completely destroyed by UV-light in a few weeks. And a lot of bulk produced organochlorines (for PVC) are readily destroyed by sunlight: VCM (a few hours), EDC (a few weeks). These are not included in the table. And some of the organochlorines in the table are produced (and emitted!) by nature in quantities, one to two orders of magnitude higher than industry. Methyl chloride (chloromethane): 99% natural, dichloromethane: 98% natural, chloroform: 98% natural, carbon tetrachloride: 95% natural [40]. Even Tri and Perc (dry cleaning compounds) have natural sources, be it that these account for app. 10% resp. 5% of the ambient atmosphere.
And as already mentioned before, elementary chlorine helps to clean the atmosphere from organics...

Page 29: Atrazine
Atrazine is one of the most widespread herbicides in the US. It is no wonder that it is found in groundwater and surface waters. But atrazine's action, while "chlorinated", is based on nitrogen. Atrazine is a member of the family of herbicides, called triazines. Moreover, the relative slow bio-degradation (app. 100 days in soil, several months to one year in water) is due to the triazine part, not to chlorine, as atrazine looses its sole chlorine atom very rapidly with soil bacteria [69],  forming hydroxyatrazine.

Trichloro acetic acid (and other organochlorines) is consistently present in rainwater, according to Thornton. But he forget to mention that known industrial organochlorines are 2-3 orders of magnitude lower present than most natural. And these that have higher levels (up to a few %), like the chloroacetic acids are as good from natural as from industrial sources [70]: Analyses of Antarctic snow that accumulated in the beginning of the 18th century has demonstrated that natural sources play a significant role in the global distribution of this group of compounds. The remaining bulk of organochlorines in rainwater is mainly, if not solely of natural origin.

Page 33: Table 1.2
The table shown has not the slightest reflection to real life. The half-lives are given for pure water, which is an inert medium for almost all organic materials, chlorinated or not. The pure chemical dechlorination (hydroxylation) process is a very slow process and depends of the chemical reactivity (bounding energy) of chlorine at a certain place in a molecule. Real life has to do with bacteria, fungi, plants and animals. And it are the bacteria which break down organochlorines, as good as in soil as in water and sediments... Bacteria break down over 98% of the organochlorines in waste water of PVC and herbicide production [71] in only three days, including 1,2-dichloroethane, which has a half-live of 72 years in pure water, according to table 1.2… Further, the break-down rate of organochlorines is comparable to figures for pure organics in the waste water treatment of petrol refining facilities.

Page 33/34: Chlorinated lignins and metabolites:
Chlorinated lignins, phenols, guaiacols, catechols and veratrols were formed by the – now nearly abandoned – use of elementary chlorine in paper manufacturing. But the industrial amounts of these components are by far exceeded by the natural decomposition of wood by fungi, making that the concentrations in remote, forested areas are higher than in rivers flowing through industrial areas [70]. And one has found a lot of organochlorines in 6,000 years old unspoiled aquifers…

Page 38: Whales.
"In the Gulf of St. Lawrence in eastern Canada, beluga whales, which feed primarily on eels from the Great Lakes, are contaminated with parts per million levels of chlorobenzenes, PCB's, and a host of organochlorine pesticides."
But the main contaminant of these whales are non-chlorinated PAHs:

"Transitional cell carcinoma among the belugas was first discovered during an autopsy of a carcass that had washed ashore in 1985. It was a particularly provocative finding because workers in nearby aluminum smelters, which release their wastes into the St. Lawrence, had also been found to have an elevated incidence of this type of bladder cancer… …Aluminum smelters and other industries lining the river basin have contaminated their waters with benzo[a]pyrene, a potent and well-known carcinogen… …The number of adducts attached to an organism's DNA is considered a useful measure of benzo[a]pyrene exposure. DNA from the brain tissue of stranded St. Lawrence belugas bore impressively high numbers of adducts… " [72]

Page 40-43: In our bodies and children.
While what is written is mainly true, that has little relevance for health, as humans only are living longer. Every child born today has a life time expectancy, about twice longer than was the case a hundred years ago…
And levels of persistent organochlorines are falling in breast milk, all over the Western world [51]

Thornton makes some speculation about the number of organochlorines vs. other/unknown contaminants: 190 vs. 700. How many of the "others" are organochlorines, how many non-chlorinated contaminants were found? How many of both are entirely natural? And most important, how toxic are they…
And the human white blood cells produce chlorine (bleach) to kill invaders like bacteria and viruses. How much organochlorines are formed by this chlorine production is totally unknown.
And, say 200 bio-accumulating organochlorines on a total of 10,000 industrial and over 2,000 natural organochlorines is a small portion which seems to be bio-accumulating. All the rest is either too volatile or too fast bio-degrading or too water soluble or produced in such minute quantities, that even after bio-accumulating they can not be detected by the todays extreme fine detection methods...
And there are at least the same number of non-chlorinated organics that have a bio-accumulating potential…

Page 45: PVC and dioxins.
'The Chlorine Chemistry Council and the Vinyl Institute argue that "dioxin in the environment has been falling," so restrictions on PVC plastic are unnecessary.'
This is not what the CCC and VI said. They say that PVC production is an insignificant source of dioxins in the environment. Many European and American government investigations prove that, see the UNEP world wide dioxin inventory [60]. And PVC is not the source of dioxins at incineration. And they point to the declining levels of dioxins in sediments since the seventies (now app. at the same level as in the fourties), while PVC production and use tripled in the same period.

Page 50-53: Local to global contamination.
Thornton is right that accumulation of POPs must be addressed as good as local (e.g. dioxins in the vicinity of an incinerator) as regional and global (intake via the food chain). But even in a Risk Paradigm, one can take that into account. That is e.g. the case in Flanders, where the total emission of all dioxin sources is related to the measured deposits and related to the human intake via the food chain. Total dioxin emissions are restricted to the maximum that gives not more than the WHO limits for daily intake. Thus Thornton is wrong if he asks for zero discharge of dioxins, as that not only means a tremendous amount of money to be invested, as all fossil fuel (except natural gas) burning must be ceased, all metal production stopped,… but also has no benefits for anybody's health.

Page 55: Table 1.3 POPs.
That the UNEP POPs list only contains organochlorines is a political question, not a matter of toxicity. One of the most important classes of POPs are PAHs, both in quantity as in toxicity. These are not included in the first POPs list…
The amounts of PAHs released in Flanders is 284 tons per year [59]. Or, with an underestimate of 1%, benzo-[a]-pyrene (BaP), the strongest carcinogen of all PAHs is emitted at 2.84 tons per year. Compare that to TEQ-dioxins: a total emission of 274 gram per year. The carcinogenic potential of dioxin to BaP is 20:1 in some strains of rats. The Ah-receptor binding (probably causing a lot of other non-cancer diseases) is app. 3-5:1…

Chapter 2: First-Class Poisons.

Page 57: Effects of Organochlorines.
Everything that Thornton says about the health effects of organochlorines can be said about organics in general and oxygenated, nitrogenated, sulfurated or phosphorilated organics. In each "class" of chemicals, there are members that cause cancer, damage to the DNA, immune suppression, hormone disrupting, dysfunction of the brain and nerves,…
The latter is even especially true for organophosphates. Thus only pointing to organochlorines is far from honest. Moreover, for all these health implications, the dose makes the poison…

Page 60-61: Table 2.1.
The table gives all the organochlorines classified by the IARC, as known, probable and possible carcinogens [*]. Further from the HSDB, organochlorines with a limited evidence of carcinogenity in animals.

What Thornton omits, is how many non-chlorinated organics are classified as known, probable and possible carcinogens. That can be illustrated by the figures of the German DfG (the German occupational health authority) [73]:
Of the 126 proven or probable human carcinogens at the workplace, 57 contain nitrogen (and many of these have a very high potency), 26 chlorine, 17 are metals or minerals, 15 contain oxygen, 6 are pure hydrocarbons, 5 contain sulfur and another 5 contain other halogens than chlorine. Thus organochlorines make some 21% of occupational carcinogens, while chlorine is used in some 60% of all chemical processes. That is remarkably low…

Page 63-65: The work of Henschler [65].
Henschler made a study of the introduction of chlorine into organics, in the first place simple alkanes and in the second place several aromatics. There is no comparable work of anybody about the introduction of other polar elements (N, P, O, S,…) into organics.
The work of Henschler is the base of the assumption of Thornton that the full "class" of organochlorines is more toxic than any other "class" of organics. But he forgets to mention that the introduction of nitrogen, sulfur, oxygen, and/or phosphor also enhances the reactivity (= toxicity) of simple alkanes and many aromatics. That is even mentioned by Henschler himself in his work:

 "The electrophilic effect of chlorine augments - just like the other electrophilic elements (e.g. F, O, N, P) - the electrophily of the carbon atom where it is bound to..."
If we look at the introduction of other elements than chlorine in simple aliphatics and aromatics, we can observe the following:

The introduction of oxygen into methane makes it far more toxic: methanol is a very toxic substance, causing nerve damage, even at low levels, blindness and death.
More oxygen makes formaldehyde, a very strong lung irritant and possible carcinogen. More oxygen makes CO, not an organic itself, but formed by incomplete combustion of organics. Causes app. 30 deaths per million per year.
More oxygen makes formic acid, a strong skin irritant and the cause of blindness when methanol is ingested and breaks down to formic acid.
The full class of aldehydes are strong lung irritants and possible carcinogens.
The introduction of oxygen into ethane makes in the first place ethanol, or common alcohol. This single organic has caused more problems than any other organic in the world. It is a strong nerve toxicant, reducing reaction times already at very low levels. That causes a high percentage of traffic deaths every day. And it causes more birth defects than all other toxicants together. And it is a known human carcinogen (although not officially).
The full class of alcohols are nerve toxicants and several are possible carcinogens.
Acetic acid and higher acids (with longer carbon chains) are basic foodstuffs (part of oils and fats), except for – especially if saturated – excess intake, they cause no problems.
But peroxy acetic acid is a probable carcinogen.
And another oxidized ethane: ethylene oxide is a probable carcinogen.
The full class of alkane oxides are probable carcinogens.
Introduction of oxygen in benzene makes phenol, which is more toxic, but elimiates its carcinogenic properties. That is true for the intake of phenols and cresols, which are very abundant in our food. These are conjugated (neutralized) in the liver and excreted via the urine, before they can do any damage. But the carcinogenic property of benzene is due to its oxidation to phenol at the wrong place, as that happens only partially in the liver. The rest is transformed mainly in the bone marrow, where it can interact with the DNA of growing cells, ultimately leading to leukemia…
The same problem of oxidation of many aromatics into more water soluble oxidants can be seen, with as ultimate problem the transformation of persistent, (partly) bio-accumulating PAHs into (epo)xidized products which directly damage DNA. Thus probable cancer initiators. Mixtures of PAHs as can be found in all pyrolyse products of organic material (tars of wood, coal, oil,…) are proven human carcinogens.
Almost all natural and a lot of synthetic materials that can mimic hormones are oxygen based: genistein, daidzein (soy), xanthohumol (hops), bisphenol A, alkylphenols (synthetic),…

Conclusion: the introduction of oxygen in organic materials in general makes them more toxic and in many cases leads to the formation of carcinogens, nerve toxicants, hormone disruptors and birth defects causing materials.

Nitrogen variants:
The introduction of nitrogen compounds into alkanes makes them far more toxic:
All alkylamines, di-alkylamines and tri-alkylamines are more toxic than the originals
Di-alkylamines are easily converted into nitrosamines (even in the stomach), which are extremely potent probable carcinogens…
The introduction of amines into aromatics nearly invariably makes them proven, probable or possible carcinogens. While (except for benzene), the original aromatics are not or less carcinogenic themselves.
The introduction of nitrate groups into all organics near invariably makes them proven, probable or possible carcinogens. The most extreme mutagens ever found are nitrated PAHs.
The introduction of nitrosamine groups makes all organics probable carcinogens.
The introduction of isocyanate groups makes all organics very to extremely toxic products and extreme lung irritants. And the aromatics are possible carcinogens.

Conclusion: the introduction of nitrogen in organic materials in general makes them more to extreme toxic and in many cases leads to the formation of carcinogens, nerve toxicants, and lung irritants at extreme low levels.

The introduction of a double bound:
The introduction of a double bound in any organic molecule invariably makes that molecule more active, thus more toxic. In the body, these double bounds in general are epoxidized, which leads to DNA damage and thus cancer initiation.

General comparison of the introduction of chlorine vs. other atoms:
If we look at the number of regulated carcinogens at the work place [73], half of them are nitrogen compounds, some of them, like nitrosamines, even at extreme low levels. That is twice as high in number than organochlorines, which are used in 60% of all chemical processes. Except for dioxins, most organochlorines with a carcinogenic potential have moderate levels of carcinogenity, comparable to the introduction of other elements.

General conclusion: there is more reason to ban nitrogenated organics as a "class" than of chlorinated…

Chapter 8: The Cause.

Page 306: PVC Plastic.
"When its entire life is considered, PVC appears to cause the formation of more extremely hazardous by-products than any other product, a fact that should come as no surprise, since more chlorine goes into vinyl than any other application."
This is not substantiated by any figure, as Thornton only points to PVC and doesn't take into account any life cycle for any alternative. Most alternatives for PVC are other plastics, mainly based on ethylene, propylene and/or benzene. In the manufacturing of ethylene/propylene, the main route is the cracking of naphtha, with a 70% yield, with as main byproducts benzene and other aromatics and PAH tars. The transformation of chlorine, ethylene and oxygen into EDC has an over 97% yield… Thus the production of PVC (57% chlorine, 43% ethylene) makes far less toxic byproducts than the production of any plastics alternative. The use of PVC in general needs less maintenance than any alternative. Dumping doesn't cause any problem and incineration doesn't add to more toxic waste. The toxicity of salt rests is zero if it is cleaned from heavy metals and if it is reused or dumped into brackish or seawater. See an example in Reggio Emilia (Italy).

Page 306-312: PVC production.
Dioxins were found in the chlor-alkali process, where graphite electrodes were used. No dioxins can be found in modern membrane electrolysis plants.
The releases of EDC/VCM which are mentioned by Thornton might be right, but miss any relevance to human and ecological health, as VCM has a half-live time in air of a few hours and is very volatile (vapor at normal temperature). EDC has a half-live time of a few days in air. The total air releases of an average VCM factory are comparable in carcinogenity to what one heavy diesel truck emits as carcinogenic soot at the same distance to houses of the neighbors… Within the fences, the risk for deadly accidents or a deadly cancer is comparable to people that work at home, without any more other health effects…
And Norsk Hydro and EVC, on which figures the calculation of Thornton are based are still doing better, year by year [74], as good as that is the case for all VCM factories world wide…

That one can find contamination within the boundaries of a factory (and sometimes out of the boundaries) is not unique for VCM factories. Thirty years ago, nobody cared when a valve – or even a tank – was leaking. One can find benzene beneath any petrol station… But nowadays, that is addressed by liquid tight floors in petrol stations and below tanks of EDC/VCM factories…

Indeed dioxins (and PCBs) are formed by the oxychlorination of ethylene and HCl to form EDC. Depending of the type of process and the type of catalyst: between 1 and 40 g I-TEQ per 100,000 tons of EDC. That has no relevance for the environment, as these follow the heavy ends (for organics) and water streams (for spent catalyst). Heavy ends are in most cases incinerated on site, waste water is purified from catalyst (with adhered dioxins). Thus the only important point for the environment, is how much is released to air from the incinerator(s) and to water after treatment. For the whole USA, that is 11 g I-TEQ to air, 0.6 g to water, 0.7 g to land and 3.1 g into product. These are maximum figures. Or a total of less than 0.06% for all dioxin emissions to air, water, land and product in the USA, see the Sources of dioxins.

The Dutch study by Evers, cited by Thornton, about the formation of dioxins [75] in EDC production was performed to give 1.5 gram (!) of EDC and compared that to 100,000 tons (!) of EDC production. The yield was 12%, compared to a factory with a 97% yield. Further 80% of the dioxins found were on the catalyst (which mostly stays on place in a factory). Thus that is far from comparable to a real life factory. The EDC/VCM-factory of Rovin (now Shin-Etsu) in The Netherlands, asked the researchers of the University of Amsterdam, where the experiment was done, to check the amounts of dioxin formed and released at their factory.
This was done and the results were: on a production of about 500,000 tons per year, about 4 g of dioxin were formed. That is already 500 times lower than what Thornton suggests. Of that amount, after cleanup in a biological waste water treatment and the incineration of the production wastes and the off-gases, only about 40 milligram of dioxins were released to air and about 10 milligram were released to water per year. That is 10,000 times less than what Thornton suggests and no ecological disaster, not even a problem. Again and again, as good as at the time he wrote his reports for Greenpeace, he confuses the reader between formation and emissions…

Some more false suggestions:
"In 1994 government scientists found dioxins at high concentrations (…) in sludges from a fully modernized EDC/VCM plant in Germany, refuting the claim that only outdated EDC/VCM technologies produce dioxin."
Nobody in the industry ever claimed that modern EDC/VCM plants don't produce dioxins, everybody claims that modern EDC/VCM plants don't emit significant amounts of dioxins…
Thornton himself gives the data of the German plant in one of his former works [1]:
Metal sludge: 409,270 ng/kg TEQ
Metals sludge cake: 413,790 ng/kg
Waste water treatment sludge: 7,199 ng/kg
Sediment near discharge pipe: 1.7-3.9 ng/kg
Mussels near discharge: 0.71-4.44 ng/kg
As all sludges either are properly disposed or incinerated, these are irrelevant for environmental contamination. And these figures simply prove that the facility is no treat to the environment, as even the sediments and mussels near the discharge pipe only have low levels of dioxins… Further, it seems remarkable that the mussels have not bio-concentrated the dioxins from the sediments. That proves that any residual contamination of sediments by the EDC/VCM factory is very local...

"…the ability of incinerators to destroy hazardous wastes completely has been drastically overestimated; in fact, incinerators are quite inefficient at destroying chemicals that are present in low concentrations, like the dioxins in EDC wastes".
With the real figures for a lot of VCM factories already published years before Thornton wrote his book, this is a complete distortion of the truth. The incinerators used to destroy liquid EDC/VCM wastes (tars) have a special design, which allows them to reach at least 1200 (up to 1500) ºC, far higher than any solid waste incinerator can reach. With a residence time of 2 seconds, all (chloro)organics are destroyed. After using some of the heat to fire a boiler, the off gases are quenched with diluted HCl (hydrochloric acid), that means cooled down in a fraction of a second, to below 200 degrees C, to prevent de novo dioxin formation. With this type of incinerator, no dioxin-like PCBs can be detected anymore (even not when PCBs are incinerated) and dioxins are destroyed with a 99.99% yield. The last remaining milligrams of dioxins per year nowadays can be captured by activated carbon, which reduces dioxin emissions to below detection limits…

"Not all of the by-products of EDC/VCM synthesis end up in the hazardous wastes; some escape directly into the environment. Dioxins have been detected in wastewater discharges and air emissions from a number of EDC/VCM plants,…".
What Thornton omits is to give the real amounts. These can be found in official surveys of dioxin emissions in a lot of Western countries. EDC/VCM facilities are below 0.4% to air in the USA and below 0.1% to air in Europe. Discharges to water are negligible, see Sources of dioxins.

"…severe dioxin contamination of sediments in Italy's Venice lagoon has been linked to an EDC/VCM manufacturing facility."
But the Greenpeace (!) report about that topic [76] concludes:

"The evidence thus supports the following conclusions:
that parts of the Lagoon are heavily polluted;
that at least some of the pollution can be attributed to EDC/VCM manufacturing;
that this contamination can be detected in parts of the Lagoon;
and that individuals who are exposed to higher than normal doses of dioxin are at increased risk of suffering impacts on their health."
Thus Greenpeace is a little more cautious than Thornton… For the rest, that there is historical contamination from the EDC/VCM factory can be true, but it is more important how much they emit today… And as not only organochlorines are found in the sediments, but also PAHs, heavy metals, radioactive materials,…

"In The Netherlands, levels of dioxins in sediment samples in the River Rhine jump dramatically just downstream from an EDC/VCM manufacturing plant; the levels are so high, in fact, that the majority of dioxins in Rhine sediments downstream from the plant, all the way to the river's mouth, and in the entire North and Wadden Seas, appear to be attributable to the facility."
This is very rude. In a report, made by Greenpeace International, "PVC-factories = dioxin factories" [77], Greenpeace "proves" that the only EDC/VCM-factory in The Netherlands, in Rotterdam, where I work, was the cause of a pollution with dioxin of the River Rhine at km 665. Because this was 10 km south of Cologne in Germany and the named factory was in Rotterdam at km 1015 in The Netherlands, this was impossible (dioxins don't swim upstream!). After some more investigation, the contamination is probably of the past, from a factory making chlorinated phenols, which has nothing to do with PVC and which was already closed for more than ten years. The error of the displacement was corrected by Greenpeace (without any apology) in a later work.
Thornton again uses this false claim while he should know of the error.
Evers, on whose work the claims of Thornton - except for the error - are based, is now working for the government in The Netherlands. He has made several claims about the contamination of the Rhine and the estuaries by EDC/VCM facilities. These are proven wrong. Not only doesn't match the "fingerprint" of the sediments, also the amounts discharged by the Rotterdam plant are not in the Rhine itself, but at a side arm of the Rotterdam harbor, and all dioxins deposit below the discharge pipe (where on can find historical contamination).
Moreover, the amounts of dioxins (and other contaminants) which are discharged, are openly published since 1989, and a copy of these environmental reports were sent to environmental groups, including Greenpeace. The discharges to water since 1986, when a biological waste water treatment was installed, were below 0.01 g I-TEQ per year. Nowadays even below detection limits as ultrafiltration should remove the last particulates where dioxins are adhered to.
The river Rhine at the German/Dutch border carries 66 g I-TEQ dioxins per year. At the outlet to the North Sea, it is 146 g. That can be read in the work of Evers. All industrial dioxin discharges to water in The Netherlands together are good for 1.3 g of that amount (of which 0.01 g was from the VCM factory where I work). That can be read in the dioxin inventory by TNO for the Dutch government [3], which is known by Greenpeace International, as I have had a very fierce discussion with the Greenpeace toxics campaigner Wytze van der Naald about the dioxin figures of the plant where I work. And it is extensively used by Greenpeace in their report on the Venice Lagoon [76]. As the TNO inventory was published in 1993 and the publication [1] of Thornton for Greenpeace was in 1994, he should have known that. Either the communication within Greenpeace is not that good (seems rather structural!) or Thornton doesn't like the figures and deliberately omitted its existence.
Further in the UNEP inventory of dioxin releases [60], many figures of several countries have the same message: the PVC industry is a negligible source of dioxins to the environment. That too should have been known by Thornton. This in itself discredits the whole book, as that is written with the same attitude as when he was a Greenpeace toxics campaigner, not as a scientist searching for a better understanding of the pro's and con's of chlorine use…

[*] The classification is as follows:
- Known carcinogen: sufficient evidence, both from animal trials and human epidemiologic studies.
- Probable carcinogen: sufficient evidence from animal trials and limited/inadequate evidence from human epidemiologic studies.
- Possible carcinogen: limited evidence from animal trials or based on theoretical mode of action, no evidence from human epidemiologic studies.



Thornton only mentions these works which support his prejudiced opinion. That was the normal Greenpeace strategy, which is a political one and that has nothing to do with science. This is - again - clearly the case for this work which - in our opinion deliberately - left out relevant information. The only difference is that this work was published by the prestigous MIT, which gives his work an aura of credibility, which it doesn't deserve.
As more examples of omissions will be found, this page will be updated...


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Created: Januari 1, 2002.

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