IJERD – International Journal of Environmental and Rural Development (2013) 4-1

Research article
erd

Dietary Exposure Assessment of Benzylpenicillin Residue inPork Consumed by Age and Gender Groups in thePhilippines
VENN VUTEY*
Faculty of Veterinary Medicine, Royal University of Agriculture, Cambodia
Email: vennvutey@gmail.com

LOINDA R. BALDIAS
College of Veterinary Medicine, University of the Philippines Los Baños, Philippines

BILLY P. DIVINA
College of Veterinary Medicine, University of the Philippines Los Baños, Philippines

RIO JOHN T. DUCUSIN
College of Veterinary Medicine, University of the Philippines Los Baños, Philippines
Received 16 December 2012

Accepted 30 January 2013(*Corresponding Author)

Abstract Exposure assessment is one of the most important key components of the risk
assessment process. Dietary intake of significant amounts of residue can lead to adverse
health effects and development of antimicrobial resistance in the population. The study
was conducted to determine exposure risk to antibiotic drug residues in pork consumed in
the Philippines. The specific aim was to estimate dietary exposure of Benzylpenicillin
residues by age and gender groups. Parameters such as food consumption, substances
residue, body weight, ages, and gender groups were gathered from local and international
institutions. Mathematical equations were used to calculate for Dietary Exposure fromamount of drug residue multiplied by the mean food consumption and adjusted by bodyweight. The present study; dietary exposure of Benzylpenicillin residue for children from 1
to <3 years old had the highest exposed followed by adolescents, adults and infants whilemales were significantly higher than females (p<0.05). This is the first attempt todetermine risk assessment of dietary exposure to antibiotic residue of different populationgroups in the Philippines. Improvement of mathematical models used in this study isproposed to better prioritize exposure assessment models for veterinary drug residues toensure the safety of food produced from farm to table.
Keywords exposure assessment, drug residues, age-gender groups, consumption

INTRODUCTION
The use of risk assessment has gained steadily in importance and recognition as a scientificallybased approach for the development of food safety and quality standards. During recent years there
has  been  increasing  use  of  the  word  “risk”  in   connection with food safety (Sumner et al., 2004).
Consequently, a risk assessment of the food safety implications (Gehring et al., 2005) may be madeon the potential harm or risks of veterinary drug residues to the human consumer. The importanceof risk assessment lies not only in its ability to estimate human risk, but also in its use as aframework for organizing data, as well as for allocating responsibility for analysis. As suchaccording to World Health Organization (1995), it is important to understand that risk assessment
is a process that can include a variety of mathematical models to estimate risks. Risk assessments
also promote international trade by addressing new safety and quality challenges (Graf, 2005).
Exposure assessment is among the components of risk assessment (Codex Alimentarius
Commission, 1999). Dietary exposure to veterinary drugs occurs when residues remain in foodⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2013) 4-1

products derived from animals treated with a veterinary drug (Health Canada, 2003a). Dietary
exposure models have been developed to predict human exposures to chemicals resulting from theconsumption of contaminated food and residue levels and also for substances naturally occurring inthem   (Fryer,   2006).   In   2003b,   Health   Canada   primer   on   “Assessing   exposure   from   pesticides   infood”  indicated  that  risk  exposure  from  food  can  either  result  in  short-term (i.e., acute) or long term(i.e., chronic) effects. In actual risk equations, it is possible that toxicity may be computed utilizing
the estimation of consumer intake of drug residues in foods of animal origin, hence, this study on
exposure assessment.
Thorough literature search revealed no available study on exposure assessment on veterinary
drug residues in the Philippines. With the increase in reports of occurrence of risk of veterinary
drug residues in foods of animal origin in the last two decades (Health Canada, 2003a; Sumner etal., 2004), there is a strong need to study exposure assessment of antibiotic residues. To date, there
is no local study conducted on the exposure risk assessment for residual antibiotics in thePhilippines.   Thus,   this   study   aims   to   make   a   “Dietary   Exposure   Assessment   of   Benzylpenicillin  Residues  in  Pork  Consumed  by  Age  and  Gender  Groups  in  the  Philippines”.
The overall objective of the study is to determine exposure risk to antibiotic drug residues inpork consumed in the Philippines. The specific aim is to estimate the dietary exposure ofBenzylpenicillin residues by ages and gender groups.
METHODOLOGY
The study was conducted using secondary data collected from local and international institutions
for estimating dietary exposure assessment. For instance, local data like the report on veterinary
drug residue (2003-2008) from National Meat Inspection Service, recommendation on Maximum
Residue Limit (MRL) published by Bureau of Aquaculture Fisheries and Product Standard, thereport of Food Consumption Survey in 2003 and Recommended Energy and Nutrient Intake in2002 published by Food and Nutrition Research Institute (FNRI, 2003), the development ofantimicrobial resistance from Research Institute for Tropical Medicine, Philippines. International
data came from Codex Alimentarius Commission (CAC) on amount of antibiotic drug residues, theprocedural guidelines on residues of veterinary drugs in food from JECFA, and from an updated
report of the 32nd session of the Codex Veterinary Drug Residues in Food 2009.
Dietary modelling combines food consumption data with food chemical concentration data toestimate dietary exposure to food chemicals, or intake of nutrients. The Eq. (1) below, the basic
dietary exposure model is of the form:
Dietary Exposure

Food Consumption u Amount of drug residure
Body weight(1)

where food consumption is the amount of food people eating per capita per day expressed in
mg/kg/day and amount of drug residue expressed in µg/kg BW/day.

RESULTSThe benzylpenicillin antibiotic have been test for consecutive years from 2006 to 2008 in thePhilippines. The number of violations was determined using Microbial Inhibition Test and wasmeasured using caliper method (NMIS, 2008). Positive benzylpenicillin residue results in NMIS
were assumed to equivalent to HPLC LOQ 400 µg/kg (Heitzman, 1995) and dietary exposure wascalculated using the following equation (3) which regarded computed using equation (2).
Eq. (2) the Mean Food Consumption Difference Age Groups is as follows;
The mean food consumption difference age groups =average weight difference age groups × the mean food consumption per capita in the Philippines
average weightsⒸ ISERD148(2)

IJERD – International Journal of Environmental and Rural Development (2013) 4-1

Eq. 3 Dietary Exposure of Benzylpenicillin Residue is as follows;
DEPEN =
amount of benzylpenicillin residues of 3% positive results × mean food consumption difference age groups
average weights differences age groups(3)

Based on an update as of the 32nd session of the Codex Alimentarius Commission in 2009 firstdraft prepared by Dr. Macneil, a typical recommended dose by intramuscular injection (IM) inswine, cattle, horses, and sheep of a 300,000 unit/mL formulation is 6,600 units/mL BW. As a feed
additive, a typical dosage for swine or poultry is 55 mg/kg in the diet. Intramammary treatment istypically by administration of 100,000 units per quarter. In the studies reported, 1 mg procaine
benzylpenicillin is equivalent to 1667 IU (international units).
As at 50th report of JECFA in 1999, the Committee considered residues of procaine
benzylpenicillin to be equivalent to residues of benzylpenicillin. Dietary Exposure (DE) wascalculated using equation (1) following the mean one-day per capita food consumption in thePhilippines and by island groups, food groups and adjusted 55-kg person. The DE ofBenzylpenicillin Residue was calculated by the amount of benzylpenicillin of 3% positive results
multiplied the food consumption difference age groups and adjusted by average weight difference
age groups.
Table 1 shows that DE of benzylpenicillin residue for children from 1 to 3 years old had thehighest value at 0.002923 µg/kg bw/day. Such value was calculated as 5 µg/kg of amount residues
× mean one-day per capita pork consumption of 0.0076 kg ÷ 13 kg of average children weights.
Likewise, average DE for children (0.002913 µg/kg bw/day) was higher than adolescents(0.0029096 µg/kg bw/day), followed by adults (0.002909 µg/kg bw/day) and infants (0.002903µg/kg bw/day). Also, DE for males was significantly lower than females (p-value=0.034).
Table 1 Dietary exposure of benzylpenicillin residue of 3% of positive results intake of fresh
pork in the Philippines
Age Groups1.
2.

3.

4.

5.

6.

Infants, month
Birth- <6 (3)
6-<12 (9)Children, year
1-3 (2.5)
4-6 (5.5)
7-9 (8.5)
Adolescents, M, year
10-12 (11.5)
13-15 (14.5)
16-18 (17.5)
Adolescents, F, year
10-12 (11.5)
13-15 (14.5)
16-18 (17.5)
Adults, M, year
19-49
50-64
65 and over
Adults, F, year
19-49
50-64
65 and overAverage
Weight(kg)AmountResidue(µg/kg)

695

Mean One-Day
Per Capita Pork
Consumption (g)DietaryExposure (µg/kg bw/day)

3.5
5.2

0.002917
0.002889131924

5

7.6
11.1
13.9

0.002923
0.002921
0.002896

3450
58

5

19.8
29.1
33.7

0.002911
0.002910
0.002905

3549
50

520.4
28.5
29.1

0.002914
0.002908
0.002910

59
59
59

5

34.3
34.3
34.3

0.002907
0.002907
0.002907

51
51
51

5

29.7
29.7
29.7

0.002911
0.002911
0.002911Ⓒ ISERD

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IJERD – International Journal of Environmental and Rural Development (2013) 4-1

DISCUSSION
To determine the risk of dietary exposure of DEPEN residue using mathematical model gives anestimate of the risk of having toxicity among the populations. In the present study is a first step indetermining the most important fields for generation new data to estimate more accurately theproportion of the population at risk of toxicity and development of antimicrobial resistance due to agiven the amount of antibiotic residue of dietary intake in pork consumption.
Exposure was calculated for the populations in the Philippines based on the consumption percapita (as a major factor), followed by the amount substance residue and body weight. For instance,
Steve (2009) and Kroes et al., (2002) where dietary exposure assessments have been taken, relevant
food consumption data have been utilized. E.g., Ock and Hee (2002) reported estimation of dietary
pesticide risks, following the setting up of food consumption and pesticide residue levels in thecalculation of toxicological risk. E.g., assessment on dietary melamine exposure based on themaximum consumption of melamine and the median levels of melamine detected in the mostcontaminated food (Xu et al., 2009). This dietary modeling combines food consumption data withfood residue concentration data to estimate dietary exposure level to contaminants heavy metal(Haeng et al., 2005).
The present study found that DEPEN residue for children from 1 to 3 years old is the highest
exposed followed by adolescents, adults and infants whilst males are significant for females in thePhilippines. For instance, Kroes et al., (2002) reviewed on children, because of its higher foodconsumption rates per kg bw, is generally expected to have a higher exposure level and is therefore
higher risk of the population. In this respect, children may be of special interest because of theirhigher intake level per kg bw due to growth processes (Kroes et al., 2002). A similar study on
dietary exposure of children and teenagers to benzoates, sulphites, butylhydroxyanisol andbutylhydroxytouen found that between 2 groups of students the younger subjects are more exposed
when the exposure is expressed in kg of bw (p<0.01) (Soubra et al., 2006). Another possible
example was conducted on cumulative risk assessment of the exposure to organophosphorus andcarbamate insecticide in the Dutch diet by Boon et al., (2008). For children the exposure (57 vs. 25µg/kg BW/day) was higher than the total population (18 vs. 23 µg/kg BW/day). The resulting inexposure levels equal to 11% and 25% of the acute reference dose for the total population andyoung children respectively. Another similar study, Caldas et al., (2006) found that children
exposure to acetylcholinesterase (AChE) inhibition pesticides is also of additional concern, as thispopulation might be more sensitive to these compounds than adults. For children, the exposures
were, on average, 2.4 times higher than the exposure found for the general population. Since thedetermination of dietary exposure to antibiotic residues in the present study shows no zero risk, i.e.,there is a risk for possible adverse effects on the population. Another concern for use of antibiotics
in agriculture and aquaculture is the risk for development of antimicrobial resistance. Currently, anantimicrobial resistance surveillance reference laboratory has been prepared with 435 isolates by
the Antimicrobial Resistance Surveillance Program of Research Institute for Tropical Medicine. It
is clear that the percentage of penicillin resistance is 25% Salmonella sp. (RITM, 2009).
CONCLUSION
Based on the finding of the present study, dietary exposure of benzylpenicillin have been detectedin pork which children from 1 to 3 years old is more exposed and more risk, because of their higher
food consumption rates per kg body weight, is generally expected to have a higher exposure level
due to physical activity.
ACKNOWLEDGMENTS
My special thanks go to Veterinary Drug Residue Section (NMIS-DA). I am thankful to
Antimicrobial Resistance Surveillance Program Team (RITM) and National Epidemiology CentreⒸ ISERD150

IJERD – International Journal of Environmental and Rural Development (2013) 4-1and I also wish to thank for Food of Nutrition Research Institute Team in the Department ofAgriculture, Department of Health in the Philippines.
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