Sewage Sludge As Fertilizer May Alter Gender, Behavior in Lambs

[hatrack]

NEW warnings that a tiny amount of pollution can alter the gender of sheep have sparked fears that it could also affect human health .
Scientists at the government’s Macaulay Land Use Research Institute in Aberdeen have discovered that male lambs exposed to low-level environmental contamination start behaving like females. This has worrying implications, they warn. The toxic soup of industrial chemicals in the air may disrupt human hormones and make people more vulnerable to disease.

“If these results are confirmed by further studies, I believe humans have reason to be concerned about exposure to mixtures of pollutants, even at the very low concentrations present in the environment,” said Dr Stewart Rhind, one of the institute’s leading scientists. These results, combined with many other studies , suggest that exposure to low levels of a mixture of pollutants could result in subtle alterations to human and animal behaviour, and immune and reproductive function.”

People are exposed to small concentrations of thousands of synthetic chemical compounds in the air, in water and in food. Many of them are classed as gender-benders, or “endocrine disrupters”, because they can interfere with natural hormone cycles in the body.

EDIT

Rhind and Erhard stress that the contamination does not pose any “direct danger” to anyone who eats lamb. But they are worried it could have “adverse implications” for the reproductive and immune systems of humans, wildlife and domestic animals. Their study was funded by the Scottish Executive’s environment and rural affairs department and appears in the scientific journal Science Of The Total Environment. Although environmental groups approve of sewage sludge as a fertiliser, they are concerned about the “subtle contamination” of the land."

EDIT

http://www.sundayherald.com/46214

[donsu]

1. tick, tick, tick

nt

[noamnety]

2. It's time

The republicans need to embrace the "girlie men" label.

[kestrel91316]

3. Hmmmmmmmm.........................

toxic soup makes boy lambs into lambs that act like girl lambs? Wonder when somebody is going to figure out if toxic soup makes boys into boys that act like girls (gays)? Oh, nevermind, that would mean being gay is not a "lifestyle choice".

[Buzz Clik]

4. Blah.

That article was long on hysteria and short on facts. It would be interesting to dig into the Abderdeen study to see exactly what they did and how relevant it is to other areas.

Referring to sewage sludge as a "toxic soup" is an interesting way to see it. But, even if it's true, we all make our own little contributions to the soup, now don't we? Other than this exercise, what exactly are we doing to find a solution? What are we doing to demonstrate that the problems truly exist?

As environmentalists, we must be very careful in choosing our battles. Endocrine disruptors are nasty players, and we need as much information as possible to find out where they go and what they do. Then, we need to propose reasonable solutions. The article in the original post of this thread does nothing more than stir the pot, and that is NOT what we need.

[donsu]

5. the problem exists - worldwide

the hormones in meat and hormones used in other things (like hair oil) is in all ground water. it's changing fish, frogs, and yes human men and women. men are growing breasts (look around you) and little girls of 7 - 9 yrs. of age are starting their menses. in some species the males are turning into hermaphrodites. hermaphrodites happen in the human specie naturally but now are on the rise because of the hormones, etc. I could go on and on.

[amandabeech]

6. Too many pounds, unhealthy food and too little exercise

can also cause male breasts and early menses. We need more research in order to determine causation of many harmful developments.

[donsu]

7. being overweight as a child does not bring on sexual maturation

where ever did you hear that?

[amandabeech]

12. Various news outlets over the years.

I recall especially a documentary, I don't recall what channel. It clearly stated that time of menses was related at least in part to attaining a certain weight, I believe something in the low 100's to 110, depending on height, obviously. Extra pounds, at least according to that theory, can lead to earlier menses.

[NickB79]

8. Um, I'm not worried about excessive hormones from meat causing this

But what does worry me is thinking about the millions of women in the US who are on some form of contraceptive pill, and all the excess hormones being sent downstream by them. Hormone usage in cattle is fairly rare, restricted mainly to rBGH to increase milk production, and it is debatable as to whether or not rBGH can cause gender alterations. Beef cattle are not given growth hormones, as far as I know. Synthetic estrogen and progesterone in contraceptives, however, have long been known to alter gender, and are used much, much more widely and heavily than any given to cattle.

[midnight armadillo]

9. Sewage sludge

Sewage sludge includes much more than just feces, urine, and TP. It also includes a variety of industrial wastes (since we take all the useful shit and mix it in the sewage systems with whatever else comes down the drain) and often contains high levels of heavy metals and other nasties. So, yea, "toxic soup" is a pretty accurate description.

On top of that it's only party digested by microbes so when you dump it on your fields it continues to decompose and releases tons of toxic gas which afflicts those nearby. People get sick. There was a movement in Maine to prevent "free sludge" from being provided by waste treatment companies to farmers for fertilizer. I don't know how that worked out.

[NNadir]

10. Heavy metal contamination has been controlled in many municipal

sewage systems with interesting side effects.

When the city of Los Angeles (which BTW in many other respects has an awful sewage system) banned heavy metals sucessfully from its system, the result was that the system began to corrode much more rapidly.

Why? Many heavy metals, Mercury and Lead, for instance, form insoluble sulfides, even under relatively acidic conditions. Hydrogen sulfide is formed by many micro-organisms from the oxidation of proteins, in particular, proteins containing the amino acids cysteine and methionine. In sewage systems contaminated with heavy metals, the hydrogen sulfide would react with the metals to form insoluble metal sulfides. In the absence of these metals however, the sulfides would oxidize. The product of the oxidation of hydrogen sulfide is sulfuric acid, which is, of course, corrosive. As a result, the metal and concrete fixtures of the sewage system had their lifetimes significantly reduced.

(Please note that I am NOT advocating the re-inclusion of heavy metals into sewage treament systems, because such inclusion is uncontrolled; the heavy metals need not be balanced by hydrogen sulfide.)

The sulfide precipitation effect has not been totally removed by the banning of dumping Lead, Mercury, and other toxic elements into sewage systems. It is well understood that near the sewage outfall pipes there are significant deposits of copper and iron sulfide as well as silver sulfide. (This effect is very similar to the formation of such ores near undersea hydrothermal vents, which like outfall pipes, have considerable concentrations of hydrogen sulfide.)

It is true that under the best conditions of limiting what can be placed in sewage systems, the systems will still contain measurable concentrations of heavy metals. This is because the waste pipes in many homes and businesses are often lead pipes. In addition many solder, especially old solder which has not been replaced, contain lead. (It also contains silver which also has an insoluble sulfide.)

I am not certain of the analytical conditions under which heavy metal contamination of sewage sludge is measured. If the conditions are oxidizing, such as might be found in a ICP (Inductively coupled plasma) device for instance, then the metals will be detected, even if they are present only as relatively innocuous sulfides. It would be far more instructive to detect these metals in the crop plants grown in the presence of sewage sludge fertilizer.

Note that the elements Lead and Mercury, which are toxic, have always been present on earth. The reason that their toxicity has not been a problem with life (or prehaps more appropriately why life did not evolve to be indifferent to their presence or even to utilize their presence) is that these metals were precipitated as ores under reducing conditions, under which insoluble sulfides could form. Two relatively common ores containing these metals are cinnibar, Mercury sulfide, which has been used for thousands of years as an orange pigment, and Galena, Lead Sulfide, for which the city of Galena, Illinois is named. The real problem begins when these ores are oxidized, as takes place, say, in a coal fired power plant. Under these conditions, the sulfide ores are "roasted" and the sulfides are oxidized to sulfates, which are soluble. Thus the metals are then free to do their biological dirty work.

Interestingly, the toxicity of these metals is connected to their affinity for reduced sulfur. The compound, dihydrolipoamide, a key reactive agent in the citric acid cycle, where it activates acetate through the formation of a thioacetate ester, contains two sulfhydrl groups. When these two sulfhydrl groups are complexed by either Lead or Mercury, the citric acid cycle is arrested. Cells that are very dependent on dense high energy output and carbohydrate oxidation, in particular nerve cells, are deprived of energy and die.

Sewage is generally a hypoxic environment, meaning that it is reducing. Therefore the toxic metals found in sewage are often present as sulfides and are actually safe, just like the fields around Galena, Illinois are safe.

[struggle4progress]

13. I cannot agree that a sulfide such as cinnabar is of little or no concern.

Soil microenvironments exhibit, over small scales, heterogeneous redox conditions, so chemical reactions vary greatly over tiny distances. In cinnabar/soil admixtures, mercury complexes with the humic acids and thus ultimately can become mobilized.

Nor can I agree that the reduced forms of heavy metals are of relatively little concern: the Minamata catastrophe, for example, was caused by the reduced compound, methyl mercury.

[NNadir]

15. Really? "Heterogenous Redox Conditions?"

I'm really curious to see you describe the environmental chemistry of Mercury to us, especially because of your most curious reference to Methyl Mercury as a "reduced compound." It happens that neither Cinnabar nor methyl Mercury represent "reduced compounds." It is in fact it is Mercury its highest oxidation state. It also happens that Mercury in methyl mercury is also formally in the most oxidized state, since mercury is formally more electropositive than carbon. (The actual bonding interactions are best described as covalent, so this is a mere formalism, although in the synthesis of metal methyls starting from their elemental state, methyl mercury behaves as the formal oxidant.) The difference between methyl mercury involved in the Minimata matter - which you seemingly wish to erroneously ascribe as having some bearing on the chemistry of Mercuric sulfide in sewage - and Mercuric sulfide has to do with the relative solubility of these two very different compounds.

In particular, methyl mercury is a somewhat hydrophobic compound, and thus can concentrate in hydrophobic tissues, pass through membranes, etc. It is also fairly volatile. Methyl mercury is formed in the environment from the biological action of certain bacteria on oxidized, soluble Mercury. Cinnabar deposits have therefore been stable throughout geological history. In fact, many of these minerals formed in reducing atmospheres, conditions that have not existed for billions of years. This gives some insight to their stability. Mercuric sulfide is a rock.

It is true that many metal sulfides can be solubilized to some extent by treatment with acid. Mercuric sulfide though, is NOT among them. The solubility product of Mercury sulfide is on the order of 2E(-53). This one of the most insoluble compounds for which a solubility product is measurable. (The solubility product of Lead sulfide is on the order of 10^-28, it also is insoluble in acid solution.)

That's neither here nor there though. Whatever the chemistry, and however poor your understanding of it is, we have already nonetheless established that you are indifferent to Mercury pollution. In an earlier thread, you personally supported the use of coal which you prefer to nuclear energy. Coal has vastly more mercury than sewage sludge, accounting in fact for more than 40% of the man-made mercury released into the environment.

"According to the Environmental Protection Agency's 1999 National Emissions Inventory coal-fired electrical utilities are the largest source of anthropogenic mercury, releasing 40 percent of mercury from human sources, followed by industrial boilers (5 percent), hazardous waste incinerators (5 percent), and chlorine production (5 percent). Combustion of medical waste is no longer a significant sources. Mercury escapes from combustion points in gaseous form and is deposited back into soils and surface waters from the atmosphere."

http://www.enviroliteracy.org/article.php/693.html

Now how is that you're concerned with sewage sludge mercury which contains insoluble Mercury sulfide and completely unconcerned with coal's mercury, all of which is oxidized to the soluble sulfate in the coal incineration chambers? I suspect that the reason has more to do with validating preconceived notions with vague poorly constructed (and wrong) appeals to what you imagine might be "science" than it does with actually having a clue about what is actually happening.

[struggle4progress]

16. You assert above that reduced metallic ...

compounds (your example: cinnabar) are nontoxic because nonsoluble, in comparison to oxidized compounds. Now you wish to digress into a discussion of formal oxidation states, a construct so crude so as be be essentially worthless for toxicity discussions. And of course, the electronegativity of S does not differ very much from that of C. If we avoid the formal oxidation states completely, and pointless discussion of how relatively oxidized the metal nucleus is in various compounds, certainly you will agree that elemental mercury is reduced, and you know perfectly well that it is toxic by inhalation. This suggests that your proposed "oxidized = soluble = toxic" equation provides essentially no insight.

In thinking about what occurs in soils, it is important to remember that "averaged" conditions may not be at all typical of very small scale environments. It is well established that minerals such as cinnabar in soils will lead to humic acid complexes with Hg. I do not claim the actual mechanism leading to such complexation involved the direct attack of weak soil acids on the mineral; it may not be possible to understand the chemistry involved by considering the soil as if it were a homogeneous material. This is what I mean by "heterogenous redox conditions."

The view which you propose, that the toxicity of methyl mercury is associated with its solubility in <edit delete: hydrophilic><insert: hydrophobic> environments, has indeed sometimes been a common view, but it is not all clear that this view is widely accepted today. In particular, active transport mechanisms have attracted attention in recent years. You might want to consider getting up-to-date on current knowledge before making sweeping assertions about what you believe to be true.

[struggle4progress]

14. Incidently, your discussion of the mechanism for Hg neural toxicity ...

... may also be wrong. According to an NIEHS review article, adult neurotoxicity seems to result from inhibition of protein synthesis, in some (but not all) types of cells, rather than from any more general mechanism (such as the type of CAC poisoning you cite).

Cf Three Modern Faces of Mercury, Env Health Persp 110 Supp 1 (Feb 2002) 11-23.

[NNadir]

17. Really. I'm wrong about this? By what mechanism does Protein

Synthesis occur?

If you have read the article rather than simply cut and pasted the reference, maybe you will be able to tell us. More specifically, you will be able to delineate how Mercury interferes with this mechanism, much as I have explained how the structure of dihydroliponamide is responsible for the Mercury inhibition in the citric acid cycle, a fact which is reported in lots of undergraduate text books.

Now, sometimes I post lists of references that like you, I have not read, as you do below, to give some idea of the integrity of a particular report or scientific paper I am referencing. I am usually careful though to specify this when I do it however. Moreover I generally can indicate that I have read the relevant parts of primary papers or reports from whom such lists are obtained.

For instance, if I wanted to address your balderdash about humic soils and the alleged toxicity of Mercuric Sulfide, I might cite Chemical Reviews, 2000, Vol. 100, No. 7 pg 2727. Then I might elaborate the point I derive from the article: Mercuric Sulfide is demonstrably non-toxic because micro-organisms exist that detoxify methyl mercury by converting it to mercury sulfide. It is fair game to actually reproduce small excerpts of articles here at DU, and so I feel free doing something like this in the article referenced in the present case:

" The burning of fossil fuels
and the exhaust from manufacturing plants release
inorganic mercury into the earth’s atmosphere. In
addition, some microorganisms are capable of producing
small organic mercuric compounds, such as
methyl mercury, that can pollute aquatic environments
and eventually bioaccumulate...

...(i) Some strains of bacteria Enterobacter aerogenes
became resistant to mercuric compounds by reducing
permeability of the cells to mercuric ions. This
reduced permeability is due to two plasmid-encoded
proteins present in the cells.
(ii) Some microorganisms chemically modify the
more toxic forms of organic mercury to less toxic and
insoluble forms. Clostridium cochlearium T-2P contains
two plasmid-encoded enzymes that allegedly
catalyze the demethylation of methylmercury and
generates hydrogen sulfide in the cytosol. The demethylated
moiety is subsequently converted to insoluble
mercuric sulfide by reacting with the hydrogen
sulfide previously produced by the second enzyme.
(iii) In certain strains of the bacterium Desulfovibrio
desulfuricans, methylmercury levels within
the cells are maintained at nontoxic levels by an
enzyme-catalyzed reaction that produces hydrogen
sulfide, which is required for the conversion of
methylmercury its less toxic insoluble sulfide forms.
(iv) Certain soil and water bacteria are capable of
mercury methylation via series of enzyme-mediated
reactions. Although methylmercury is among the
more toxic forms of mercury, some plasmid- or
chromosome-borne enzymes are involved in the methylation
reaction to form methylmercury, which is
then effluxed from the cell by volatilization or is
sequestered into some other insoluble forms.
(v) In the vast majority of Gram-positive and Gramnegative
bacteria found throughout the world, the
most commonly encountered mercury resistance mechanism
involves the enzymatic reduction of the mercuric
ion to its elemental form and its subsequent
volatilization from the cell. The enzymes involved in
this mechanism are encoded by genes of the mer
operon.160,230
Of the previously mentioned resistance mechanisms
for mercury and mercury-containing compounds,
the latter one involving reduction of mercuric
ions is the best understood..."

This is somewhat different than simply reproducing a list of references and implying that the articles said list validate your statement position.

In the actual case, you don't give any evidence at all that you know what you are talking about.

Let us suppose that the article you reference and have not read indicates that in fact inhibition of protein synthesis as a mechanism for neural toxicity. This certainly is possible, if you understand the nature of metalloproteins. Does this also imply that I am "wrong," when I report the very, very, very well known dihydroliponamide-Mercury complex? Even if some effect onprotein synthesis is involved in apoptosis of nerve cells, is this mechanism exclusive of all others, ie does it's action negate other interactions?

Is it not entirely possible that both mechanisms are at work? Before you claim that I am wrong, you need to i) establish that the Mercury dihydroliponamide does not exist, ii) that the existence of this complex does not interfere with the citric acid cycle (it would be helpful if you can describe the mechanism by which dihydroliponamide participates in the citric acid cycle) or iii) establish that interruption of the citric acid cycle has no effect on the viability of neurological tissue. You can, in fact, do none of this.

To cite an example that causes me to place a very low value on your scientific insight, let us return again - as I will do repeatedly when exploring your environmental indifference - to the issue of burning coal. I say that burning coal is a bad idea because of Mercury toxicity. In so stating, I do NOT claim that this invalidates the idea that burning coal is a bad idea because of the output of benzodioxins. I do not claim the output of benzodioxins in coal combustion invalidates the idea that burning coal is a bad idea because of the output of carbon dioxide and its potential greenhouse effects. All of these mechanisms operate simultaneously to obviate to a scientifically literate person that coal is an unsustainable and unacceptable fuel.

So if you want to state that I am "wrong" you'd better learn some science. An introductory chemistry course at a good community college would be an excellent place to start.

[struggle4progress]

18. LOL! You think your excerpt shows "mercuric sulfide is demonstrably ...

... non-toxic because micro-organisms exist that detoxify methyl mercury by converting it to mercury sulfide"?

I'm assuming now that you're joking, because otherwise I could only say that you incautiously tend to draw sweeping misleading conclusions from the most minimal evidence.

Incidently, every serious scientist I've ever met knows how to use words like "may" and "might" --- and makes some effort to quote accurately when disagreeing.

Best wishes to ya!

[Name removed]

19. Deleted message

Message removed by moderator. Click here to review the message board rules.

[struggle4progress]

20. Unfortunately, in the case of cinnabar, use of the ...

formal solubility product will lead to underestimation of the amount of compound in solution.

[Name removed]

21. Deleted message

Message removed by moderator. Click here to review the message board rules.

[struggle4progress]

22. Tut tut! Is your understanding of the meaning of the solubility product ..

... limited to arithmetic manipulations with it? You must think! Think! What could possibly be missing from the definition that would not generally affect the usefulness of the construct but might in some circumstances? What is involved here is a common problem in the practice of science: the ideological purity of your idea is so compelling that it causes you to overlook reasons that your calculation may not reflect reality. The issue DOES, in fact, arise in the case of cinnabar, and what I said is actually correct: simple solubility product calculations will underestimate the amount of dissolved material. Yet another illustration of the important principle that even the most <edit:typo here> useful ideas have their limits and cannot be applied without caution ...


Incidently, insofar as you have pooh-poohed my suggestion supra that soils can release the Hg in cinnabar, here is a little snippet indicating that precisely this can indeed happen:

ENHANCED DISSOLUTION OF CINNABAR (MERCURIC SULFIDE) BY DISSOLVED ORGANIC MATTER FROM THE FLORIDA EVERGLADES
BY M. Ravichandran, G.R. Aiken, M.M. Reddy, and J. N. Ryan
U.S. GEOLOGICAL SURVEY
Organic matter isolated from the Florida Everglades caused a dramatic increase in Hg release (up to 0.35 mM Hgdiss) from cinnabar (HgS), an insoluble solid (log Ksp of -52.4) under most environmental conditions. <snip>
http://wwwbrr.cr.usgs.gov/projects/SW_corrosion/cinnabar/

[Name removed]

25. Deleted message

Message removed by moderator. Click here to review the message board rules.

[struggle4progress]

23. So confronted (say) with a situation in which increasing ...

... the sulfide concentration apparently promoted further dissolution of the cinnabar, rather than driving precipitation (as expected from a Ksp calculation, for example), your conclusion would be that the experimental result is so obviously wrong that no further inquiry would be warranted?

[struggle4progress]

11. Macaulay researchers have been studying sludge application for a while:

Erhard, H.W. and Rhind, S.M., (2004), Prenatal and postnatal exposure to environmental pollutants in sewage sludge alters emotional reactivity and exploratory behaviour in sheep., The Science of the Total Environment, 332, 101-108.

Rhind, S.M., Smith, A., Kyle, C.E., Telfer, G., Martin, G., Duff, E. and Mayes, R.W., (2002), Phthalate and alkyl phenol concentrations in soil following applications of inorganic fertiliser or sewage sludge to pasture and potential rates of ingestion by grazing ruminants., Journal of Environmental Monitoring, 4, 142-148.

Towers, W., Paterson, E. and Coull, M.C., (2002), Potential impact of draft proposals to revise the EC Directive (86/278/EEC) controlling sewage sludge applications to land. , Journal of the Chartered Institution of Water and Environmental Management, 16, 65-71.

Mitchell, D.S., Edwards, A.C. and Ferrier, R.C., (2000), Changes in fluxes of N and P in water draining a stand of Scots pine treated with sewage sludge., Forest Ecology and Management, 139, 203-213.

Rauret, G., Lopez-Sandez, J.F., Sahuquillo, A., Barahona, E., Lachica, M., Ure, A.M., Davidson, C.M., Gomez, A., Luick, D ., Bacon, J., Yli-Halla, M., Muntau., H. and Quevauviller, Ph., (2000), Application of the modified BCR sequential extraction (three-step) procedure for the determination of extractable trace meta l contents in a sewage sludge amended soil reference material (CRM 483)., Journal of Environmental Monitoring, 2, 228-233.

Baath, E., Diaz-Ravina, M., Frostegard, A. and Campbell, C.D., (1998), Effect of metal-rich sludge amendments on the soil microbial community., Applied and Environmental Microbiology, 64, 238-245.

MacLeod, F., McGaw, B.A. and Shand, C.A., (1998), Sequential extraction of selenium from four Scottish soils and a sewage sludge., Communications in Soil Science and Plant Analysis, 29, 523-534.

Towers, W. and Horne, P., (1998), The conflicts between sewage sludge recycling and livestock farming in the Strathclyde Region, Scotland., Livestock Farming Systems. More than Food Production. EAAP Publication No.89. Wageningen, 1997, Chapter 51, pp307-312.

Campbell, C.D., Warren, A., Cameron, C.M. and Hope, S.J., (1997), Direct toxicity assessment of two soils amended with sewage sludge contaminated with heavy metals using a protozoan (Colpoda steinii) bioassay., Chemosphere, 34, 501-514.

Quevauviller, P., Rauret, G., Rubio, R., Lopez-Sanchez, J.-F., Ure, A., Bacon, J. and Muntau, H., (1997), Certified reference materials for the quality control of EDTA- and acetic acid-extractable contents of trace elements in sew age sludge amended soils (CRMs 483 and 484)., Fresenius Journal of Analytical Chemistry, 357, 611-618.

http://www.mluri.sari.ac.uk/index.html

[Buzz Clik]

24. A couple of follow-up notes

I have no idea about the regulations for controlling contaminants in the UK, but the US has done a pretty fair job. Sewage sludge cannot be applied to soils if nitrogen, phosphorus, or toxic metals exceed certain guidelines. Before waste water can be discharged, it must meet strict standards (although, sadly, the Bush administration is backing off of enforcement).

One aspect of contamination that is under close scrutiny deals with the chemicals implicated in the opening article -- endocrine disruptors. Many, many contaminants can be classified as endocrine disruptors, and most of them are part of our everyday life. Personal care products often contain endocrine disruptors and are ubiquitous in sewage. The fraction that passes through waste water treatment or ends up in sewage sludge is not known with great certainty, but this is being studied carefully to help direct guidelines.

The key aspect of this is that endocrine disruptors can originate from products that nearly all of us use every day. If we find that these chemicals are a problem in sewage sludge, it is quite likely that the solution will be to reduce the mass of them entering in the waste stream in the first place -- exactly the strategy taken in reducing toxic metal loads in waste water.