CONSUMPTION OF UNSAFE FOODS:
EVIDENCE FROM HEAVY METAL, MINERAL AND
TRACE ELEMENT CONTAMINATION
(ToR # 16)
Team Members
Dr. M. Rafiqul Islam
Dr. M. Jahiruddin
Dr. Md. Rafiqul Islam
Dr. Md. A. Alim
Dr. Md. Akteruzzaman
Food security and Food contamination
Food security exists when all people, at all times, have
physical and economic access to enough safe and
nutritious food to meet their dietary needs and food
preferences for an active and healthy lifestyle
(World Food Summit 1996)
Sources of food Contamination







Heavy metals
Pesticide residues
Hormone residues
Chemicals for ripening of fruits & vegetables
Microbiological contamination
Food adulteration
Use of contaminated water
Background
of theofresearch:
Major Routes
Heavy Metal
Contamination:
Example
arsenic
Arsenic
may gain access
to human
body through -
Grain
Drinking water
Livestock
products
Vegetables
Fish
Cow’s milk
Chicken eggs
Broiler meat
Meat
OBJECTIVES
i)
Assess the concentration of major foods and
beverages consumed by poor and non-poor
households for heavy metals (Pb, Cd, Co, Hg, Sb, Li
and As), minerals (Ca, Mg, Na, K) and trace elements
(Fe, Mn, Zn, Cu, Mo Se, Al, Ni and Cr)
ii)
Assess the extent of exposure to heavy metals,
minerals and trace elements through food intake by
poor and non-poor households and the potential
health implications
iii) Draw implications and to provide suggestions for
actions to reduce contamination
METHODOLOGY
FOOD SAMPLING
Location
Food access to
Household
category
1. Gulshan
Upper Income group
2. Kawranbazar
Middle income group
Non-poor (>2122
Kcal/day/person)
3. Hazaribagh
Low income group
Poor (<2122
Kcal/day/person)
Each food sample was collected from 10
different shops of Kawranbazar and Hazaribagh
and 3 supermarkets & 7 shops of Gulshan market
Standard operating procedures were followed for
processing of food samples (NIN, 2009)
Food Samples Collected
Food group
Food Group
6. Vegetables
Sample
#
8
4
8
1
4
18
7.Milk & dairy
2
15. Chewing
2
8.Sweetmeat
3
16. Tap water
1
1. Cereal
2. Pulses
3. Fish
4. Egg
5. Meat
Sample
#
9. Oil
2
10. Fruit
9
11. Drinks
6
12. Sugar & Molasses
2
13. Dinning out
3
14. Spices
7
Total for each location
80
Food samples were cooked with enough water
just to boil, with no salt
Market situations in Bangladesh:
Some Examples Hazaribagh
Market situations in Bangladesh:
Some Examples Gulshan
PROCESSING AND COOKING
OF FOODS: RICE
 Weight of the parboiled rice (coarse and fine
grain) recorded
 Washed with tap water
 Cooked by both absorption and draining
methods
 Excess water discarded in case of draining
out method
 Weight of the cooked rice recorded YIELD
FACTOR
 A sub-sample was kept in oven to obtain dry
weight
Processing of Food Samples
Sweetgourd, Jackfruit, Fish, Meat
Cooking and Processing
Cooking in gas stove
Inert and non-metallic
mortar & pestle
Drying in oven
Foods in powder form
Chemical analysis
Digestion
Food samples were digested with Ultrapure grade HNO3 and
H2O2 using the digestion block at 115 °C.
Determination of elements
Digested samples were analyzed for elements using ICP-MS in
the laboratory of SGS Bangladesh Ltd Dhaka
Reliability
The reliability of the procedure for the estimation of all
elements was assessed by analyzing the Certified Reference
Material GBW(E)080684.
RESULTS
EDIBLE COEFFICIENT AND YIELD FACTOR
OF COOKED VEGETABLES
1
EC
YF
0.8
0.6
0.4
0.2
ba
na
na
is
h
G
re
en
Ra
d
m
pk
in
Pu
ba
ge
Ca
b
Ca
u
lif
l
ow
er
ja
l
Br
in
To
m
at
o
Po
ta
to
0
ELEMENT
CONCENTRATION
COMPARATIVE STATUS OF MINERALS IN FOODS
FROM THREE MARKETS
+ Low, ++ Medium, +++ High
Foods
Elements
Gulshan
K. Bazar
H. Bazar
Fine Rice
Ca
++
++
++
K
++
+++
+
Mg
++
++
++
Ca
+
+++
++
K
++
+++
+
Mg
+
++
++
Ca
+++
++
+
K
+++
+
+
Mg
++
++
+
Ca
+++
++
+
K
+++
+
+
Mg
++
++
++
Coarse
Rice
Lentil
Prawn
COMPARATIVE STATUS OF MINERALS IN
FOODS FROM THREE MARKETS
Food Items
Farm
chicken
Cauliflower
Apple
Onion
Elements
Gulshan
K. Bazar
H. Bazar
Ca
+
++
+++
K
++
+
+++
Mg
++
+
+++
Ca
++
+
+++
K
++
+
++
Mg
++
+
+++
Ca
+++
++
+
K
++
++
+
Mg
++
+
+
Ca
+
+++
++
K
++
+
++
Mg
+
+++
++
COMPARATIVE STATUS OF TRACE ELEMENTS
IN FOODS FROM THREE MARKETS
+ Low, ++ Medium, +++ High
Food Items
Fine Rice
Coarse Rice
Lentil
Prawn
Elements
Gulshan
K. Bazar
H. Bazar
Zn
ND
ND
ND
Mn
++
+++
++
Cu
++
++
+
Zn
ND
ND
ND
Mn
+
+++
++
Cu
++
++
++
Zn
ND
ND
ND
Mn
++
++
+
Cu
+++
++
+
Zn
+++
+
+
Mn
+++
++
+
Cu
+
+++
+
COMPARATIVE STATUS OF TRACE ELEMENTS
IN FOODS FROM THREE MARKETS
Food Items
Farm
Chicken
Cauliflower
Apple
Onion
Elements
Gulshan
K. Bazar
H. Bazar
Zn
ND
ND
ND
Mn
+
++
++
Cu
++
+
+++
Zn
ND
ND
ND
Mn
+
+
++
Cu
+
+
++
Zn
ND
ND
ND
Mn
++
+++
+
Cu
+++
+
+
Zn
ND
ND
ND
Mn
+++
+
++
Cu
++
+
++
COMPARATIVE STATUS OF HEAVY METALS IN
FOODS FROM THREE MARKETS
Food Items
Fine Rice
Coarse Rice
Lentil
Prawn
Elements
Gulshan
K. Bazar
H. Bazar
As
+++
+
++
Cd
+++
+
++
Hg
+
+
+
Pb
+++
+
+
As
++
+++
+
Cd
+
+
+++
Hg
+
ND
ND
Pb
+
+
+++
As
ND
ND
ND
Cd
ND
ND
ND
Hg
ND
ND
ND
Pb
++
+
+++
As
+
++
++
Cd
++
+++
+
Hg
++
+
ND
Pb
+
++
++
COMPARATIVE STATUS OF HEAVY METALS IN
FOODS FROM THREE MARKETS
Food Items
Elements
Gulshan
K. Bazar
H. Bazar
Farm Chicken
As
ND
ND
ND
Cd
ND
ND
ND
Hg
+++
++
+
Pb
+
++
+++
As
ND
+
ND
Cd
+
++
+
Hg
ND
ND
ND
Pb
++
++
+++
As
+
ND
ND
Cd
ND
ND
ND
Hg
ND
ND
ND
Pb
+++
++
+
As
+
ND
ND
Cd
+
++
++
Hg
ND
ND
ND
Cauliflower
Apple
Onion
Wheat
Ata
Moida
60
Cu conc. (ppb)
Mn conc. (ppb)
1200
900
600
300
0
Kawranbazar
30
15
Hazaribagh
Gulshan
Ata
Moida
20
9
Pb conc. (ppb)
Mo conc. (ppb)
45
0
Gulshan
12
Ata
Moida
6
3
0
Kawranbazar
Hazaribagh
Ata
Moida
15
10
5
0
Gulshan
Kawranbazar
Hazaribagh
Gulshan
Kawranbazar Hazaribagh
 Mn & Cu conc. for ata higher in Gulshan,
Chromium, Lithium, Antimony, Mercury: Below detection
limit for both rice and wheat
Sources of Heavy metals
Heavy Metals
Sources of Pollution
Arsenic
Soil minerals
Irrigation water
Wood preservatives
Pesticides
Cadmium
Soil minerals
Sewage sludge
Metal melting and refining
Paints
Lead
Soil minerals
Batteries
Combustion of fossil fuels
metallurgical industries
Fertilizers
Sewage sludge
Semi-conductors
Mercury
Coal fired power station
Fossil fuel burning
Batteries
Pesticides
Chlorine manufacture
CALCULATION OF
DIETARY EXPOSURE
CALCULATION OF DIETARY EXPOSURE
Steps
 Concentration of elements in in fresh weight of
individual food item
 Get the individual food item intake by poor and
non-poor household in Dhaka city
Dietary Exposure = Food chemical concentration x
food consumption amount
 Plot the data of 100 household of each of poor
and non-poor household for a particular element
 Compare with the Acceptable daily intake (ADI)
for heavy metals and Recommended daily intake
(RDI) for minerals and trace elements
Per capita Intake of Major Food Items (g)
Food Items
Rice
Wheat
Potato
Pulses
Vegetables
Edible oil
Onion
Beef
Mutton
Chicken
Eggs
Fish
Milk & Milk products
Fruits
Sugar/Gur
Food taken outside
Miscellaneous
Total
HIES, 2010
Poor
Non-poor
406.19
20.36
63.44
10.15
141.80
14.20
15.69
1.55
0.11
4.11
3.40
31.16
12.18
20.46
3.32
17.70
50.28
816.22
420.52
28.73
73.78
16.22
177.25
23.41
24.74
9.27
0.83
15.09
9.02
57.81
43.63
56.00
10.88
35.41
81.81
1084.53
Dietary Exposure of Cadmium from
Rice
 Cadmium (Cd) level in rice: 0.2 mg/kg
 Rice intake by poor: 406 g/day
 Cd intake from rice: 406x0.2=0.0812 mg/day
=2.436 mg/month
 Provisional Tolerable Monthly Intake:
0.025mg/kg body weight (WHO, 2011)
 An adult having body weight of 70 kg can
tolerate the intake of 1.75mg Cd/month
 Intake of 406 g rice/day having 0.2 mg Cd/kg is
contributing 139% of the PTMI
RDI and UL of minerals and trace
elements for adult male
Elements
RDI
(per day)
UL (per day)
Calcium
1000 mg
2500 mg
Magnesium
400 mg
Sodium
1500 mg
2300 mg
Potassium
3800 mg
ND
Iron
8 mg
45 mg
Zinc
11 mg
40 mg
Manganese
2.3 mg
11 mg
Copper
0.9 mg
10 mg
Selenium
55 µg
400 µg
Molybdenum
45 µg
2000 µg
Cobalt
29 µg
ND
-
Reference Health standards
for toxic heavy metals
Toxic heavy
metals
Reference Health Standard
(mg/kg body wt)
Source
Aluminium
1.0 (PTWI^)
JECFA 74 (2010)
Antimony
2.3 mg/kg body wt
www.strobel.com/
Arsenic
None
JECFA 72 (2010)
Cadmium
0.025 mg/kg body wt
(PTMI*)
WHO (2011)
Chromium
0.06 g/kg body wt
WHO (1996); NAS (1989)
Lead
None
JECFA 73 (2010)
Hg-Inorg.
0.004g/kg body wt
WHO (2011b)
Hg-Organic
0.0016 g/kg body wt
JECFA 72 (2010)
antimony _risks .htm)
^ PTWI = Provisional Tolerable Weekly Intake
* PTMI = Provisional Tolerable Monthly Intake
ˇPMTDI = Provisional Maximum Tolerable Daily Intake
CONCLUSION
• Minerals conc. of foods generally higher in
Gulshan followed by K. bazar and H. bazar.
• Heavy metals conc. Generally higher in
H. bazar followed by K. bazar and
Gulshan.
• Elements Li, Sb and Cr conc. below
detection limit.
• Dietary risk exposure is yet to be
calculated.
Thanks !!!
Thanks !!!
Permissible limit of heavy metals in foods
Heavy Metals
Permissible limit
Reference
Cadmium
0.5 mg/kg
FAO, 1983
Lead
None
Arsenic
None
Mercury
(inorganic)
None
Zinc
30 mg/kg
FAO, 1983
Copper
30 mg/kg
FAO, 1983