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Subject: use of compost as an absorbant
From: Edo McGowan <[log in to unmask]>
Reply-To:IOBB E-Seminar: Biodegradation of Lubricating oil contaminated soil (08-31 May)" <[log in to unmask]>
Date:Mon, 22 May 2006 16:26:17 +0000
Content-Type:text/plain
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text/plain (160 lines)


To: Jackie Foo
Re: Suggestion for using engineered microbes or sewer sludge as adsorbant 
and then feed stock for composting oil spills.
Fm: Dr Edo McGowan

SUBJECT:  "IOBB E-Seminar: Biodegradation of Lubricating oil contaminated 
soil (08-31 May)" <[log in to unmask]>
Sent : 	May 22, 2006 12:45:30 PM
To : 	[log in to unmask]
Subject : 	[BIODEGRADATION] DIGEST 3.3. Discussion with Kenneth Yongabi (CM) 
et al.

Jackie---some time ago, I think it was on this list serve, there was some 
discussion of spreading or incorporating sewer sludge into land were there 
had been oil spills. While at first glance this seems like a plausible 
solution to a process that would mix two undesirables into a viable solution 
to a problem, it is not without side effects such as the spread of 
antibiotic resistance, hence public health implications.

Also with incorporation of engineered microbes, there may accompanying 
spread of antibiotic resistance from the methods used in the engineering 
processes that develop these microbes. In this latter case, antibiotic 
resistant sections of genetic material are incorporated into the microbe’s 
structure. These organisms can then be selected out because they are now 
resistant to an antibiotic challenge, but the markers are left within the 
final product.

Exposure to heavy metals and toxins for example, will also select for 
resistance, and this resistance can cross to that capable of  supplying 
resistance to antibiotics. The cellular machinery developed for one is 
similar to that needed for the other.

Recent articles in the press have noted that there is the development of 
“superbugs”, i.e. germs or  pathogens that have become resistant to even the 
most potent currently available antibiotic. This may bring in an era where 
infections are unstoppable. This thought is not new and this same idea was 
introduced to the U.S. Congress by the World Health Organization’s head of 
infectious disease several years ago. The WHO has for some time noted that 
antibiotic resistance amongst these superbugs or professional pathogens has 
been rapidly increasing and has now reached a global crisis. This is 
actually a preparedness issue, especially if there is a major infectious 
disease epidemic.

As to antibiotic resistance, the medical community may be tuned in, the 
average citizen is not, especially where health care systems are 
oversubscribed to non-existent as in many of the developing nations. In this 
case there is no preparedness. Lets look at some reasons for the development 
of supebugs and their antibiotic resistance. In scientific and medical 
circles, much of the underlying cause is well known but this information 
fails to reach the average citizen. Thus citizens are unable to prepare.

Two decades ago, superbugs were mainly confined to hospitals and other 
facilities where large numbers of very sick people were maintained on 
antibiotics. The fecal material and urine were often merely flushed into the 
local sewer and thus enter sewer works in large numbers. A very good 
coverage of this is found within the writings of Vikrant Chitnis of India. 
These super bugs or professional pathogens are now emerging outside of the 
hospital and are found increasingly within the local communities across this 
and other nations. This problem is augmented by over prescribing or over use 
of antibiotics, especially for viral infections since antibiotics have 
essentially no effect on viruses. In many countries, there is no need for a 
doctor’s prescription as one can just go to the local pharmacy and buy what 
is felt to be needed. Additionally, many drug manufacturers are setting up 
business in countries where there are lax environmental regulations. Studies 
on discharge to rivers down stream from such plants have often found 
astonishingly large numbers of highly resistant organisms. Another reason we 
are seeing the spread of antibiotic resistance is the excessive use of drugs 
within feeds used to raise food-animals. This is seen within these large 
operations where antibiotics are used not for disease control but merely for 
rapid weight gain. These drugs are added to feed mixes in small but constant 
amounts. This creates antibiotic resistance, which is found in the manure 
and also in the finished raw product. The derived product carrys these 
resistant microbes and the resistant pathogens are later transferred to the 
consumer, usually by heavily contaminating the kitchen surfaces. Once thus 
contaminated, these surfaces are extremely hard to disinfect.

Another way for the spread of antibiotic resistance, but seldom discussed, 
is the inadequate treatment of sewage. As now operated, sewer plants across 
the world’s nations are manufacturing billions of antibiotic resistant 
pathogens and discharging them into the environment.

Part of this problem accrues from people in the more affluent nations 
flushing unused and dated antibiotics into the sewer.

Part of the excess flushing of antibiotics is also from nursing homes, at 
least in the United States. In the U.S. the federal Drug  Enforcement 
Administration, mandates that dated and unused drugs to be dumped into the 
toilet. This adds very impressive volumes of unused and dated drugs into the 
toilets each year, which wind up in the sewer works. The problem is that 
sewer plants were never designed to deal with these inputs.

Sewer plant designs have been recently under review for just such reasons 
but unfortunately the main agency responsible for their operation in the 
United States, for example, is the U.S. EPA with demonstrably poor staffing 
in the areas of emerging and communicable disease. The EPA has steadfastly 
refused to seriously look into this issue, especially the issue of 
antibiotic resistance.

As the sewage is processed from the moment it enters a treatment plant and 
then courses through the sewer works, there is increased survival pressure 
placed on bacteria and other pathogens. In response to this increased 
selective pressure, the microbes utilize all their acquired skills 
attempting to survive. Some are amazingly gifted in this area, yet others 
can freely share their genetic information with those that are totally 
unrelated. The end result is that those who survive, and there are billions 
of them, are now far more potent and far more resistant than when they first 
arrived at the sewer plant. Most wind up in the sewer sludge (now termed 
biosolids because it sounds better) which is then applied to our farmlands.

In 2002, the National Academy of Sciences produced a major report on the 
land application of sewer sludge, the solids that are separated from the 
discharged wastewater. That report admonished the U.S. EPA to look at sewage 
generated antibiotic resistance. Most of this sewer sludge,  classified 
technically as hazardous waste, is dumped on agricultural lands or sprayed 
(top-dressed) onto pasture lands. The controls over what can be raised on 
this land or when the animals can be returned are presumed to be well 
addressed within the EPA regulations. Unfortunately, there is 
characteristically poor compliance and the regulations are often flaunted. 
Worse, in the U.S. these regulations apply only to those spreading the 
sludge but not the farmer upon whose land the material is applied----a big 
loophole. Recognizing this flaw some of the major processed foods and canned 
goods manufacturers in the U.S. refuse to allow product raised on sludge 
applied lands to be used in their brands.

As to the preparedness issue, sewer sludge and sewer effluent are major 
transport mechanisms for disease. The following example may help the reader 
appreciate all this. In Toronto, there was a recent major out-break of SARS. 
The death rates were astonishingly high and the whole of Toronto was placed 
under strict public health quarantine. The economic impact was thus 
devastating. Health care workers in contact with patients died along with 
their patients. The people and their movements were carefully followed by 
the health authorities. The epidemic’s quarantine was finally stopped and 
this was now believed to have been premature based on business pressures 
against the health authority. The health authority released statements that 
all was well. The second epidemic of SARS then promptly broke out and now 
people and their movements were really tightly controlled.

SARS is transmitted by sewage and air droplets. When a toilet is flushed, an 
astonishingly high level of aerosolized material escapes, especially with 
the new air-assisted toilets. No one was apparently aware of this situation 
although there are several reports in the literature discussing this. 
Further, as  an easily aerosolized disease organism, the virus, once flushed 
entered the local sewer plants. Sewer plants have high rates of aerosol 
generation. From these plants the wastewater containing viable SARS virus 
was sent to the lakes and the sludge was transported across the U.S border 
to Michigan to be used on agricultural areas. No one thought the worse of 
any of this, actually these pathways were not even considered by the 
regulators.

Thus when engineered microbes or sewer sludge are offered for remediation, 
there is a need to look to the wider impacts from such activities. I doubt 
that much of this is apparent to planning and policy-makers or elected 
officials. Nonetheless, without a better perspective on how antibiotic 
resistance and disease is passed around, the implications addressed above 
for preparedness---or more accurately the apparent lack of preparedness and 
thus public health implications, the citizens of a community may not be 
being well served. Without further knowledge, it seems it would be reckless 
to continue the current situation, absent a through analysis of how sewer 
plant operations or how the use of engineered microbes may impact currently 
emerging infectious diseases and antibiotic resistance.

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