ArticlePDF Available

A preliminary bacterial study of Egyptian paper money



The objective of this study was to investigate the extent of contamination of some of the most used paper denominations of the Egyptian currency (25 PT). Sixty-nine bills in circulation were collected from November 2003 through January 2004. A swab from each bill was cultured on nutrient agar and incubated at 37 degrees C for 48 h. Results showed that over 65% of these bills had a bacterial count above 5.0 cm2. A preliminary identification of organisms present on these paper notes was done using selected Petri dishes with well-defined colonies.
A preliminary bacterial study of Egyptian paper money
Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo, Egypt
The objective of this study was to investigate the extent of contamination of some of the most used paper
denominations of the Egyptian currency (25 PT). Sixty-nine bills in circulation were collected from
November 2003 through January 2004. A swab from each bill was cultured on nutrient agar and
incubated at 378C for 48 h. Results showed that over 65% of these bills had a bacterial count above
5.0 cm
. A preliminary identification of organisms present on these paper notes was done using selected
Petri dishes with well-defined colonies.
Keywords: Egyptian paper money, bacterial contamination, Staphylococcus aureus,Staphylococcus
albus,Klebsiella pneumoniae
Paper currency is exchanged for goods and services worldwide (Pope et al. 2002). Even
though these bills are made of a rugged mix of 75% cotton and 25% linen (Gadsby 1998),
they offer more surface area for bacteria and microorganisms to reside on both sides. Coins,
on the other hand, offer less residing time for microorganisms and bacteria on their faces
(estimated at 9 11 days) (Bonifazi 2002; Craig 2002). Moreover, the presence of an
appreciable amount of Cu coined metal alloys seems to be the limiting factor for bacterial
survival on coins in general (Bonifazi 2002). On the other hand, the older the paper notes
become, the more space they offer for germs and microorganisms (pathogenic and non-
pathogenic) to accumulate (Brown 2003). Accordingly, this increases the amount of bacteria
circulated and distributed among its handlers.
In a recent study, 94% of 68 US one-dollar bills were found to be contaminated with
potentially pathogenic or pathogenic microorganisms (Pope et al. 2002). Studies on Chinese
currency (China) after the outbreak of SARS in Asia found some banknotes carried over one
hundred thousand types of bacteria and 9500 E. coli-like organisms (Brown 2003). Newer
banknotes from the Hong Kong area carried a lower count than in those in China; however,
banknotes from Northern Korea were almost bacteria free. Older notes studied in China,
Hong Kong, India, Pakistan, Cambodia and the Philippines carried overwhelming amount of
bacteria on both surfaces. Some of these organisms found were considered potentially
Correspondence: Farida M. S. El-Din El-Dars, 3 Kabool Street, Madinet Nasr, Cairo 11371, Egypt. E-mail:
International Journal of Environmental Health Research
June 2005; 15(3): 235 – 239
ISSN 0960-3123 print/ISSN 1369-1619 online ª2005 Taylor & Francis Group Ltd
DOI: 10.1080/09603120500105976
dangerous to healthy humans and may infect the body through scratches on the hands or
when the hand touches the mouth or nose (Siddique 2003).
In Egypt, certain paper bill denominations have become more used than others in recent
years. One of these denominations is the quarter of a pound or the 25-piaster (PT) paper bill.
This bill represents the minimal change handled for services such as in public transportation,
phone calls and buying newspapers or bread. Also, it may be given to street handlers and
beggars. Therefore, it has precedence in circulation over the 5 and 10 PT coins or bills, two
denominations that significantly lost their true value after the global surge in prices. Thus, the
objective of this study is to investigate the status of contamination of some of the circulated 25
PT paper denominations during the early part of 2004.
Materials and methods
An equivalent of 17.5 LE worth of twenty-five PT paper bills were collected randomly from a
number of services during the period November 2003 January 2004. The bills were sorted
according to date of mint, grouped and each bill was preserved in sterile plastic file-bags in
order to avoid further contamination. Bacterial examination was carried out at the Biology
Department at the American University in Cairo during April 2004. Other denomination
notes (100, 50, 10, 5 and 1 LE) were also collected during the examination date from
university students and staff and were examined.
In a sterile chamber, individual paper bills were first introduced. The surface of each bill was
wiped using a sterile cotton swab pre-dipped in sterile distilled water. The swab was cultured
on a sterile nutrient agar in a 5-cm
petri dish; one petri dish was used for each individual
paper bill. Each dish was coded according to the order of work and a photo was taken of both
dish and paper bill before incubation at 378C for 48 h. After 48 h, the dishes were transferred
to a fridge for 72 h. A bacterial count was conducted thereafter and newer photos were
recorded for each dish accordingly. For the general identification of microorganisms
contaminating these 25 paper bills, 12 cultured dishes with well-defined colonies covering the
three-mint years span were selected for this undertaking.
Table I provides the bacterial count obtained during examination of the coded petri dishes
according to mint date (2001, 2002 and 2003, respectively). Bills dated in 2001 represented
58% of the collected sample in circulation followed by those from 2002 (33%) and then by
those from 2003 (9%). For the year 2001, 65% of the paper bills had bacterial colony counts
ranging between 5.0 – 11.1 cm
. This percentage increased for the 2002 and 2003 bills to
69% and 100%, respectively. There was one case where no infection detected on a sample
dating from 2001. Bacterial count for other denominations is shown in Table II. The data
reveals that the 1, 5 and 50 LE banknotes (all minted in 2002) had a bacterial count of
10 cm
, which was equivalent to the 25 PT bills. The 10 and 100 LE bills had average counts
of 5.5 and 4.3 cm
, respectively. Table III shows the types of organisms isolated from the
selected 12 cultured petri dishes and the number of isolates. From these results, three types of
microorganisms were identified, namely: Staphylococcus aureus, Staphylococcus albus and
236 F. M. S. El-Din El-Dars & W. M. H. Hassan
Klebsiella pneumoniae. The more virulent aureus was isolated from 8 dishes; the relatively
harmless albus (S. epidermidis albus) was isolated from 5 dishes and K. pneumoniae was isolated
in 6 of the selected cultured dishes. In addition to the bacteria identified, observations
concerning the cultured petri dishes showed that 38 dishes (55%) developed significant fungal
Table I. Bacterial colony count on 25 PT paper bills after incubation at 378C for 48 h.
No of bills
Date of mint (mm/yy)
Colony count /cm
08/01 & 12/01 01/02 01/03
10.0 – 11.1 4 1 2
9.0 – 9.9 3 4 1
8.0 – 8.9 6 4 0
7.0 – 7.9 1 1 2
6.0 – 6.9 7 3 0
5.0 – 5.9 5 3 1
4.0 – 4.9 3 0 0
3.0 – 3.9 5 3 0
2.0 – 2.9 1 3 0
1.0 – 1.9 3 1 0
0.1 – 0.9 1 0 0
No infection 1 0 0
Total number sampled 26 + 14 = 40 23 6
Table II. Bacterial colony count on a variety of paper bill denominations collected randomly from university students
and staff during April 2004.
Currency denomination Date of mint Colony count/cm
100 LE January 2000 4.3
50 LE June 2002 10
10 LE No date 5.5
5 LE December 2002 10
1 LE March 2002 10
Table III. Organisms isolated from 12 cultured Petri dishes.
Organisms Number of isolates
Staphylococcus aureus 8
Klebsiella pneumoniae 6
Feebly or non-pathogenic
Staphylococcus albus 5
Total isolates 19
Bacterial study of Egyptian paper money 237
Until recently, the studies concerning the contamination of paper banknotes and coins have
been few and rather limited (Bonifazi 2002; Pope et al. 2002). However, after the outbreak of
some transmissible diseases such as SARS in Asia, these studies have gained some serious
consideration (Siddique 2003; Brown 2003; Podhajny 2004). The reason behind this is that
money is thought to play a role (direct or indirect) in spreading disease. Both paper banknotes
and coins offer ample surface areas to harbor bacteria and microorganisms. However, due to
the difference between the textures of these paper notes compared to the metal alloys used for
coins, paper notes can accommodate a variety of contaminants and for longer periods
(Gadsby 1998; Brown 2003).
The more the paper bill stays in circulation, the more opportunity there is for it to become
contaminated (Gadsby 1998; Brown 2003). In effect, the wear and tear on these older notes
offers more hiding space for germs to reside. Studies in some Asian countries revealed that
these older notes carry an overwhelming number of bacteria (Brown 2003). The rugged
texture of these paper notes was found to accommodate chemicals as well as germs within
(Gadsby 1998). A study concerning the one US dollar found that drug particles accumulate
by being easily squeezed into the fiber matrix (Gadsby 1998).
In this study, most of the 25 PT paper notes provided positive indications of bacterial
contamination. On the 2001 notes (58% of the total sample), the maximum bacterial count
obtained was 11.1 cm
and the minimal was 0.64 cm
. Only one note from this year group
showed no signs of infection. Results for the 2002 notes revealed a bacterial count range
between 1.6 cm
and 10 cm
. However, the crisper notes from 2003 had a comparatively
higher range from 5.0 to 10 cm
. The higher bacterial count for the 2001 notes may be
attributed to the fact that they have been in circulation for almost two and a half years and by
appearance, they were already worn out. The 1, 5 and 50 LE notes had similar maximum
bacterial counts of 10 cm
followed by the 10 LE (5.5 cm
) and the 100 LE (4.3 cm
). This
may be an indication that the first group of currency denominations may be more frequently
used as they represent the other common paper denominations exchanged when using a 100
LE bill. It could mean that smaller change may be required to render or receive more services.
The Egyptian currency denominations showed similar bacterial counts comparable to those
reported for some US currency denominations. In 2000, it was reported that the one-dollar
bill had an 8.2 cm
bacterial count, the five dollar 7.9 cm
, the ten dollar 5.8 cm
and, finally,
the twenty-dollar bill 5.4 cm
(Chase 2000).
Concerning the general identification of microorganisms contaminating these 25 paper
bills, the three types of microorganisms identified (namely: Staphylococcus aureus,
Staphylococcus albus and Klebsiella pneumoniae), were similar with those identified on US
one-dollar bills (Gadsby 1998; Leutwyler 2001; Bonifazi 2002; Pope et al. 2002). The more
virulent aureus is a potential pathogen present on hands, normal skin, nasal cavities and
suppurative lesions of man (Wilson & Miles 1957) as well as on the skin of people suffering
from eczema (Gadsby 1998). This organism can survive outside a living host for prolonged
periods (Pope et al. 2002). The relatively harmless albus (Staphylococcus epidermidis albus)is
feebly pathogenic or non-pathogenic organism present on skin, in the hair and in abscesses
after suturing of operation wounds as well as in the air, water and dust (Wilson & Miles 1957).
Pneumoniae is another virulent organism that is isolated from the respiratory tract of man and
animal (Wilson & Miles 1957). It causes both community and hospital acquired infections
(Pope et al. 2002).
In conclusion, this study helped to quantify the extent of contamination of one of the most
circulated banknote denominations used in Egypt. At this point, the only recommendation to
238 F. M. S. El-Din El-Dars & W. M. H. Hassan
be set forth is for individuals to improve upon their personal hygiene by always washing hands
to limit infection. Also, before recommending any regulatory measures, further work is
required to provide a complete picture about the extent of contamination of other
denominations in circulation as well as coins used.
The authors would like to acknowledge the valuable assistance received from Prof. Andrew J.
Main, Chairman of the Biology Department, the American University in Cairo as well as that
of Mrs. Hanan El-Kassas, for facilitating the undertaking of the experimental part of this work
at the student research laboratory.The authors would also like to acknowledge the valuable
assistance received from Dr Laila M. Asker, MD, during the process of write-up as well as her
enlightening discussions and explanations on bacteria and other microorganisms.
Bonifazi WL. 2002. ‘Money’s dirty, but health risks overstated’. Natural Foods Merchandiser XXIII(3):36. Available:
Brown A. 2003. ‘How dirty is your money?’ CNN International. Available:
Chase R. 2000. ‘Dirty money: Amount of bacteria on different denominations of money’. Available: http://
Craig S. 2002. ‘How dirty is your money?’ Dave Summer International. Available: http://www.summers1.freeseve.-
Gadsby P. 1998. ‘Filthy lucre – money is contaminated with bacteria – including related article on money taken from
magazine editors’. Available:
Leutwyler K. 2001. ‘Estimating the dollar’s bacterial exchange rate’. Scientific American Inc. Available: http://
Podhajny RM. 2004. ‘How dirty is your money?’ Paper Film & Foil Converters (PFFC). Available: http://pffc-
Pope TW, Ender PT, Woelk WK, Koroscil MA, Koroscil TM. 2002. Bacterial Contamination Paper Currency.
Southern Medical Journal 95(12): 1408 1410.
Siddique S. 2003. ‘Dirty money: You’re carrying more than cash in your wallet’. Philippine Headline News Online.
Wilson GS, Miles AA. 1957. Topley and Wilson’s principles of bacteriology and immunity, vol. 1. London: Edward
Arnold Ltd. pp 699 – 777.
Bacterial study of Egyptian paper money 239
... This may be as a result of the rough surface of the paper notes which probably promotes a good attachment area for the parasites whereas polymer notes has a smooth and slippery surface which will not support adherence of the parasites. El-Dars and Hassan [22] had opined that paper notes which are made of 75% cotton and 25% linen offer large surface area for pathogen attachment. Also, Dehghani et al. [23] reported that the degree of contamination is dependent on the texture of the currency. ...
... For instance, food vendors often times handle money while they serve food at the same time to their customers. Previous works by FSA [24] and El-Dars and Hassan[22] suggests that simultaneous handling of food and money contributes and may as well cause sporadic food borne-diseases. ...
... They have evolved different physiological resting stages, which gives them the advantage for surviving or hibernating due to low water activity. Some gram-negative bacteria can remain as long as eleven days on surfaces [14]. ...
Full-text available
Automated Teller Machines (ATM) are visited everyday by millions of people. This machine is accessible to the general public irrespective of class, age or race. The contact point of all ATM machines is the hand which on their own are ‘vaults’ of microorganisms. An elaborate survey was taken for complete assessment of possible microbial contamination in the Federal Polytechnic Ede campus. Selected ATM machines on campus were used as case study to characterize, identify and determine the degree of bacterial contamination of microorganisms and their potential as reservoir of microbes. Swabs were collected from each ATM screen, buttons, floor, user’s hand, and exposure of plates. After collection of the samples, they were plated in nutrient agar. The results showed the presence of increased bacterial count subsequently, most pathogens on characterization revealed the genus of the particular organisms E . coli , Pseudomonas , Staphylococcus aureus , Klebsiella , Micrococcus , Salmonella and Serratia . The study showed the potential hazard inherent in ATM machine usage and draws attention to our level of hand hygiene compliance.
... Other potential sources of cross-contamination include the use of paper bills and coins. The older the paper bill or coin is, the more the microbial contamination [53]. A study conducted in Bangladesh reported that the majority of paper bills were contaminated with Staphylococcus spp. ...
Full-text available
Staphylococcus aureus is a well-known foodborne pathogen. This aim of the study was to determine the percentage of S. aureus isolated from serving utensils in food processing environments in Mymensingh city, Bangladesh and to determine their antibiogram. A total of 120 environmental samples were collected from different food settings. Isolation and identification were made based on standard biochemical characteristics. Molecular identification of isolates and detection of methicillin and vancomycin resistance were done using polymerase chain reaction (PCR) with specific primers targeting Tuf, nuc, mecA, and mecC genes. Antibiotic sensitivity tests were performed, and resistant genes were also detected by amplifying blaTEM, vanA, vanB, and vanC genes. Among the 120 samples, 81 (67.5%) were positive for Staphylococcus spp. and 41 (50.62%) were positive for the nuc-gene. Among the 41 isolates, 5 (12.20%) were positive for mecA, but none were positive for mecC. 12.2% of the isolates were vanC-positive, of which 4 isolates (9.76%) were also positive for the mecA gene. The antibiotic sensitivity test revealed that all hotel Staphylococcus aureus isolates (100%) were sensitive to Ciprofloxacin and Chloramphenicol, 90.32% were sensitive to Doxycycline, and 80.65% were sensitive to Streptomycin. Conversely, all isolates (100%) were resistant to Ampicillin, and 29.03% were resistant to vancomycin. All non-hotel Staphylococcus aureus isolates were susceptible to Chloramphenicol, Ceftriaxone, Ciprofloxacin, Doxycycline, Meropenem, and vancomycin; however, 40% of isolates were resistant to Novobiocin. Among the hotel isolates, 29 (93.55%) of ampicillin-resistant isolates expressed the blaTEM gene while 5 (55.55%) of the vancomycin-resistant isolates were expressed the vanC gene. Four of the five vanC positive isolates were positive for the mecA gene. The presence of methicillin-resistant S. aureus (MRSA) which is also vancomycin-resistant in food processing environments is a threat to human public health. This is the first report on the molecular detection of methicillin and vancomycin-resistant S. aureus from food processing environments in Bangladesh.
... The capacity of currency notes to absorb moisture also facilitates the growth and viability of microorganisms. 6,7 Micro floral load of Bacilli, Coccus, Fungal species 5 from Axum-Ethiopia, Streptococcus species, Micrococcus species, Staphylococcus, Enterobacteriaceae, 4 from Jimma-Ethiopia were reported from Ethiopian Birr. Microbial contaminated currency rate handled by food sellers (62.1 %) and butchers (78.0 %) was also reported from Nepal. ...
Full-text available
The present study was conducted to isolate pathogenic bacteria and their antimicrobial resistance pattern from Ethiopian paper currency notes in Wolaita Sodo town. A total of 240 Ethiopian paper currency notes samples in different denominations were collected from four different sources such as market, taxi drivers, fruit sellers and hotels. All the samples were processed to isolate bacterial pathogens using standard techniques and identified by different biochemical tests. Further all identified isolates were used to know the sensitivity/resistant patterns by Bauer-Kirby method based on the zone formation. Out of 240 paper currency notes samples, 120 were showed positive with four different genus such as Staphylococcus aureus, Escherichia coli, Shigella sp. and Salmonella sp. Among these four different genera, S. aureus were highly prevalent (20.8%) followed by E. coli (14.58%), Shigella sp. (10.81%), and Salmonella sp. (3.74%). From the selected four different sources of currency notes such as market, taxi drivers, fruit sellers and hotel, currency notes collected from market area showed the highest rate of contamination followed by taxi drivers, fruit sellers and hotel. S.s aureus, E. coli, Salmonella spp. and Shigella sp. showed resistivity varied from 70-100% against all the antibiotics. Tobramycin showed 20% effective against S. aureus, 11.5% effective against Shigella spp. and 33% effective against Salmonella spp. while E. coli showed 14% sensitivity against Metronidazole antibiotics. Therefore, the present study concludes that the Ethiopian Paper currency notes contaminated with bacterial pathogens and play significant role in the transmission of human pathogenic microorganisms. Keywords: Prevalence, Pathogenic bacteria, Paper Currency and Antimicrobial susceptibility
... Antibacterial banknote paper (50 piasters) has a good resistance against bacteria but it does not last for a long time and loses its properties, so it needs more modifications to be a more highly durable antibacterial banknotes' substrate. Other previous researches [29,30] showed that lower denominations were found to have the highest level of bacterial contaminants as their turnover was more. This accounts for the fact that these small denominations of currency were frequently used and exchanged more times among all types of people. ...
... The present study results revealed interesting facts that the lower denominations have relatively highest loads of microorganisms as compared to higher denominations. The reasons could be the highest circulations and exchange of lower denomination [22]. It was found that an increase in denomination decreases the percentage of contaminations. ...
Full-text available
ackground: Currency is a public support tool for exchange of commodity and services. It's prevalent practice for acquiring bread to broast and bath to bed has connected all human being together irrespective of race and occupation. Currency notes along with their denomination values also carry pathogens if contaminated and will act as an agent for infection transference. Therefore the objective of this cross-sectional study was to assess the load microbial pathogens of paper currency collected in selected public places of Al-Kharj, Saudi Arabia. Methods: Currency notes under study were assessed through microbiological culture, microscopic and biochemical visualization techniques. Results: The results from this cross-sectional study suggested that lower the currency denominations higher was the microbial contaminations, frequency percentage was lower with higher isolations. Small eateries were the biggest source of contaminated currency from the ten selected centres. Percentage microorganism occurrence for Bacillus sp., Staphylococcus sp., Klebsiella sp. and E. coli was 56.84%, 25.03%, 13.40% and 04.71% respectively in all currency notes under study. Conclusions: The outcomes of this study revealed that currency notes can be a source for microbe transmission causing infectious diseases represent public health hazards to the community and individuals. B Abstract
Full-text available
The present study was carried out to determine the type and nature of bacterial contamination of Iraqi paper currency notes (Dinar) in circulation. 100 paper currency notes of different denominations were randomly collected from different places and different occupational groups in Baghdad city. Identification and characterization results showed bacterial contamination of all 100 samples with 100% contamination. A total of 114 bacterial isolates were obtained from the one hundred samples made up of 12 different bacterial species. Bacteria isolated from Iraq paper currency notes include Bacillus spp. (28.1%)، Coagulase negative Staphylococci (21.1%), Staphylococcus aureus (7.9%)، Proteus spp. (7.9%), Escherichia coli (6.1%), Citrobacter spp. (6.1%)، Klebsiella spp. (5.3%)، Pseudomonas aeruginosa (4.4%), Enterobacter spp. (4.4%), Salmonella spp. (3.5%), β- hemolytic Streptococcus (3.5%), α- hemolytic Streptococcus (1.8%). All the denominations were contaminated with Bacillus spp. And Coagulase-negative Staphylococci, also the small denominations were more contaminated than high denominations. The antibiotic susceptibility patterns of pathogenic bacteria isolated from Iraqi paper currency notes showed resistance to some used antibiotics with different percentages.
Full-text available
Paper currency notes are continuously contaminated by poor handling and poor storage practices. Microorganisms may live on paper currency for longer periods of time. Paper currency notes may represent a good medium for the transmission of microbes in the environment and humans. These microbes may cause infectious disease. This study was to determine the bacterial contamination of Indian currency notes at Chennai. This study was started from September 2020 to February 2021 in the Central Research Laboratory (CRL) of MAHER, Chennai. A total of sixty-five Indian currency notes of four denominations (10, 20, 50, 100) were collected from twenty-six different sources such as Automated teller machine (ATM) The samples were collected in sterile polyethylene bags using gloves were taken and carried to the lab within 24 hours for further processing. All samples of currency notes had microbial contamination. A total of 93 bacterial strains and 79 fungal strains were isolated from collecting samples of Indian currency notes. From these isolated samples, 11 different genera of bacteria and 6 different genera of fungi were identified on the basis of cultural characteristics and biochemical characteristics. This study showed that the microbial contamination of different sources of Indian currency notes. And this study was to evaluate the most prevalent bacteria and fungi.
Banknotes have been an integral part of buying and selling for many years. There are about 7 billion Banknote leaves in Iran that have been in circulation in a 5-year period. This amount of Banknotes and the frequency with which they are touched can promote transmission of many pathogenic factors, especially bacteria. Based on scientific research results, Banknotes are seriously contaminated and must be considered a potential danger to society. In this study, for antibacterial Banknote paper production, 100 ppm of Nanosilver was used as an antibacterial agent accompanied by cationic polyacrylamide at the 0, 0.3, 0.5, 0.7, 1 percent (based on O.D. pulp) as a retention aid of Nanosilver particles on cotton fibers. Then standard handsheets (90 g/m 2) were made from the above-mentioned pulps and tested for physical and mechanical properties. Also, for antibacterial tests of handsheets, Escherichia coli and Staphylococcus aureus were used as Gram-negative and Gram-positive bacteria, respectively. The results showed that handsheets strengths decreased with increasing of Nanosilver absorption. But antibacterial properties of handsheets increased by increasing of Nanosilver absorption so that the most antibacterial properties for handsheets were achieved at the 1% level of retention aid addition.
One-dollar bills were collected from the general community in western Ohio to survey for bacterial contamination. Pathogenic or potentially pathogenic organisms were isolated from 94% of the bills. These results suggest a high rate of bacterial contamination of one-dollar bills.
Money's dirty, but health risks overstated'. Natural Foods Merchandiser XXIII(3):36. Available
  • Wl Bonifazi
Bonifazi WL. 2002. 'Money's dirty, but health risks overstated'. Natural Foods Merchandiser XXIII(3):36. Available:
How dirty is your money? CNN International
  • A Brown
Brown A. 2003. 'How dirty is your money?' CNN International. Available: asiapcf/
Dirty money: Amount of bacteria on different
  • R Chase
Chase R. 2000. 'Dirty money: Amount of bacteria on different denominations of money'. Available: http://
How dirty is your money? Dave Summer International
  • S Craig
Craig S. 2002. 'How dirty is your money?' Dave Summer International. Available:
Filthy lucre - money is contaminated with bacteria - including related article on money taken from magazine editors
  • P Gadsby
Gadsby P. 1998. 'Filthy lucre -money is contaminated with bacteria -including related article on money taken from magazine editors'. Available:
Estimating the dollar's bacterial exchange rate
  • K Leutwyler
Leutwyler K. 2001. 'Estimating the dollar's bacterial exchange rate'. Scientific American Inc. Available: http://
How dirty is your money?' Paper Film & Foil Converters (PFFC) Available
  • Rm Podhajny
Podhajny RM. 2004. 'How dirty is your money?' Paper Film & Foil Converters (PFFC). Available:
Dirty money: You're carrying more than cash in your wallet Philippine Headline News Online
  • S Siddique
Siddique S. 2003. 'Dirty money: You're carrying more than cash in your wallet'. Philippine Headline News Online. Available: