Regulators are denying the risks of widespread contamination of our drinking water with illicit drugs Prof Joe Cummins
Licit and illicit drugs
Until the mid-2000s, the emerging study of pharmaceuticals in the
environment inexplicably excluded illicit drugs. Illicit drugs are a
structurally diverse group of chemicals used in enormous quantities worldwide
that are very likely to affect humans and other non-target organisms; and just
like pharmaceuticals, can enter the environment via many pathways. It had been
known for decades that illicit drugs and their breakdown products are excreted
in urine, faeces, hair, and sweat; but this was ignored until 1999 when the United
Nations included illicit drugs in its scope of concern.
However, the United Nations drug control conventions still do not
recognize a distinction between licit and illicit drugs; they describe only use
to be licit or illicit. The term ‘illicit drugs’ designates drugs that are
under international control (and may or may not have licit medical purposes),
but are produced, trafficked and/or consumed illicitly .
The first published indication that illicit drugs might be
pervasive contaminants of our environment was a 1987 FBI study showing that
cocaine was present on money in general circulation. Later surveys found
illicit drugs in sewage wastewaters, surface waters, air, sewage sludge, and
drinking water. The illicit drugs commonly encountered in the urban environment
include codeine, morphine, methadone, amphetamine, methamphetamine, cocaine, tetrahydrocannabino (THC) and the primary metabolites of methadone.
Although widely detected in clinical and forensic drug screens, the occurrence
of heroin (diacetylmorphine) in the environment is limited primarily to banknotes,
because of its propensity to hydrolyse in water.
Illicit drugs in the environment
Illicit drugs and their metabolites in the environment and their
potential impact on the ecosystem is a growing concern. Cocaine, morphine,
amphetamine, and MDMA have potent pharmacological activities and their presence
as complex mixtures in water may well have adverse effects on aquatic organisms
and human health. However, there is no regulation over the presence of these pollutants
in treated wastewater, surface water, drinking water, or the atmosphere.
The concentrations (in ng/L) of illicit drugs in wastewaters and
surface waters from around the world are compiled in two categories: cocainics,
opioids, and cannabinoids; and amphetamine and ecstasy group compounds. The
range spans three to four orders of magnitude (see Table 1).
Table 1 Illicit Drugs in Water
Surface water ng/L
Cocainics, opioids, & cannabinoids
18.8 - 7 500
7.5 - 3 425
0.1 - 316
Amphetamine & ecstasy group
2.2 - 15 380
1.0 - 10 955
0.4 – 309
Extensive reviews from around the world reveal widespread pollution
of water by illicit drugs. The data provide information on drug abuse that cannot
be obtained from
conventional epidemiology. Even more importantly, they highlight the need for
remediation in order to restore the quality of urban drinking water .
drug consumption and sewage epidemiology
Drug consumption by wastewater analysis was carried out in Paris.
Cocaine and its metabolite, amphetamine, MDMA (ecstasy) and buprenomorphine were
compared in the areas around four water treatment plants. Drug consumption
differed in the four areas, being most prevalent during weekends. The estimated
illicit drug-taking in Paris were lower than in other countries such as Spain
and Italy . In Australia, wastewater analysis showed that in one year (from
2009 to 2010), the use of MDMA declined fifty fold with a rise in
methamphetamine use . Similar sewage epidemiology in the state of Oregon,
USA, showed that cocaine use was mainly in urban settings and low or absent in
rural areas . MDMA was used in less than half of the communities, mainly in
urban settings; while methamphetamine was used in all communities, whether
urban and rural .
Three unnamed Canadian cities were studied for the use of cocaine,
methamphetamine and MDMA. The highest methamphetamine use was in the largest
of the cities, while ecstasy and cocaine use was lowest in the smallest city
. The Canadian study violated a prime directive of
science reporting by failing to identify the cities and wastewater plants
studied; consequently, the experiments could never be repeated independently.
A study of surface waters from the Tagus River flowing through the
province of Toledo (downstream of Madrid metropolitan area) and drinking waters
in two nearby cities detected 12 out of 22 drugs of abuse at concentrations
ranging from 1.14 to 40.9 ng/L . Even as these relatively low
concentrations, effects on wildlife or human health cannot be disregarded,
especially in vulnerable populations
Cleansing drinking water polluted with illicit drugs
Drinking water polluted with illicit drugs has been deemed
acceptable by government agencies including the World Health Organization, the European
Union, the US Environment Protection Agency in clear violation of the precautionary
principle with regard to public health and safety.
A photo-Fenton process has been shown to be remarkably effective in
degrading the illicit drugs , and involves treating water with ferrous iron
and hydrogen peroxide in the presence of ultraviolet light.
A recent review includes removal of illicit drug pollutants by
conventional treatment technologies as well as advanced treatments such as
membrane bioreactors . Membrane bioreactor (MBR) technology is considered
the most promising development in microbiological wastewater treatment. Several
studies clearly outlined its strong potential for reducing ecological risks
associated with illicit drugs as well as other polar micro pollutants. Bank
filtration is a type of filtration that purifies water by passing the water
through the banks of a river or lake. It is then extracted by wells located
some distance away from the water body. Bank filtration does not guarantee the
complete removal of all potential illicit drug residues present in the water. It can
be regarded as a useful tool for the pre-treatment of raw water (wastewater,
surface water and reclaimed water), which then requires further purification to
produce drinking water.
are a new class of single-stranded DNA/RNA molecules selected from synthetic
nucleic acid libraries for molecular recognition  (see Aptamers for
Biosensing, Diagnosis, Drug Delivery and Therapy, SiS 56). A
novel aptamer column for removing trace drug pollutants in drinking water was
developed. Cocaine and diclofenac (an anti-inflammatory drug) were chosen as
model molecules to test the aptamer column. The removal of the illicit drug was
as high as 88-95% .
and ethical issues in sewage epidemiology
2012 report from Australia deals with some legal ramifications in the use of
site-specific wastewater analysis of illicit
drug use in prisons and or sites such as nightclubs or music festivals . The
article from a law journal concludes that producing anonymous, non-identifiable
data is essential for a number of reasons, including that the studies concern
illegal activities, namely drug possession and trafficking. It states that for
prison studies, it is important that publications do
not name the facilities at which the research was conducted. Aside from
alleviating concerns over negative media exposure, it is deemed important to
protect the anonymity of participating prisons to avoid stigmatizing inmates,
their families and prison staff.
disagree. The outlook of lawyers conflicts with the foundation of science that
research results should be reported fully and truthfully. Publications in
science journals should require that large anonymous samples such as those used
in sewage epidemiology should report the time and place of sample collection
and analysis. It is, further, a matter of public health, especially for those
who are forced to suffer the consequences of water pollution, without their
knowledge or consent.
growing pollution of surface and drinking water with illicit drugs and their by-products
is a matter of concern. Like pharmaceutical drug pollution, the levels observed
are sufficient to affect aquatic organism but claimed
to be of no major concern for humans according to regulatory authorities. Precaution
demands that the public be alerted to the growing threat to drinking water. The
locations where drinking water is polluted with illicit drugs should not be
withheld from the population affected.
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joe cummins Comment left 6th December 2012 18:06:05 Thank you Pete Brenton for the interesting question. The transgenic insecticidal protein (Cry1Ab) produced in GM maize has been found in streams and waterways in maize producing areas of USA and Canada. The protein has also been found in the blood of humans consuming the GM maize and drinking water polluted with the protein. Unfortunately regulators have ignored such toxins in setting regulations for drinking water pollution. Furthermore the biological drugs (mainly human gene products produced using GM microbes) have begun to make up a large part of prescription medicine in many countries . The widely used transgenic proteins such as vaccines, monoclonal antibodies, and therapeutic proteins are employed in humans and in veterinary practice. Probiotic bacteria have begun to be modified with human genes and the strategy to prevent them from entering the environment is far from failsafe. I personally take a daily injection of a biological drug used to treat type 2 diabetes and know other individuals whose diseases are treated with biological drugs. The point here is that many of these very potent drugs may be entering the water supply without any effort to monitor or regulate their presence. The pharmaceutical industry may be exerting influence on government bureaucrats to discourage public questioning of the potential pollution and its impact on people. It may be reminiscent of cigarette smoking and asbestos impact on human health which was suppressed for years by influential corporations.
Andy Smith Comment left 3rd December 2012 19:07:29 Is it better to do the research that demonstrates there is a problem, even though you are not at liberty to disclose locations, or to find that you are not allowed access to sites, or given the funding to do the work? Sometimes science must walk hand in hand with politics to get the job done. Science costs money, someone has to pay for it and if they set boudaries then either you don't do the science, get someone else to pay or accept them. Even though the specific locations aren't disclosed, we now know there is a problem and political pressure can be applied to take these studies further. Isn't this the right result for society?
sandy Comment left 3rd December 2012 19:07:07 Does reverse osmosis remove these chemicals?
joe cummins Comment left 4th December 2012 08:08:10 In reply to Andy Smith the foundation of science has always been that experimental results must be reported fully and truthfully. In my experience bureaucrats tend to be timid and retentive of information that implicates any aspect of human health or welfare. It seems to me that the editors of scientific journals should have required that the locations of all polluted sites should have been identified and published along with the scientific report. The failure to report the locations where polluted drinking water was found withheld information that would allow people with allergies or other health concerns to seek alternative sources of drinking water. Most people would likely demand that the information about illegal drugs in their drinking water be made available to them . Those such as athletes, airline pilots, police officers and others subject to random drug tests could be unjustly implicated by their drinking water.
joe cummins Comment left 4th December 2012 08:08:05 In reply to Sandy: Yes reverse osmosis does remove those chemicals.
Pete Brenton Comment left 5th December 2012 08:08:45 Is there any regulation over the presence of GMOs in drinking water?