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 contaminationFood security exists when all people, at all times, havephysical and economic access to enough safe andnutritious food to meet their dietary needs and foodpreferences 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

Drinking water

Grain

Background of the research:Background of the research:Arsenic may gain access to human body through Arsenic may gain access to human body through --

Chicken eggsCow’s milk MeatBroiler meat

Liv

esto

ck

Liv

esto

ck

prod

ucts

prod

ucts

Vegetables

Major Routes of Heavy Metal Contamination: Example arsenic

Fish

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

METHODOLOGYMETHODOLOGY

Location Food access to Household category

1. Gulshan Upper Income group

Non-poor (>2122

Kcal/day/person)

2. Kawranbazar

Middle income group

3. Hazaribagh Low income group Poor (<2122 Kcal/day/person)

FOOD SAMPLING

FOOD SAMPLING

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)

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 group Sample #

Food Group Sample #

1. Cereal 8 9. Oil 2

2. Pulses 4 10. Fruit 9

3. Fish 8 11. Drinks 6

4. Egg 1 12. Sugar & Molasses

2

5. Meat 4 13. Dinning out 3

6. Vegetables 18 14. Spices 7

7.Milk & dairy 2 15. Chewing 2

8.Sweetmeat 3 16. Tap water 1

Total for each location 80

Food Samples CollectedFood Samples Collected

Food samples were cooked with enough water just to boil, with no salt

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 SamplesSweetgourd, Jackfruit, Fish, Meat

Cooking and Processing

Inert and non-metallic mortar & pestle

Inert and non-metallic mortar & pestle

Cooking in gas stove

Cooking in gas stove

Drying in oven Drying in oven

Foods in powder form

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.

RESULTSRESULTS

EDIBLE COEFFICIENT AND YIELD FACTOR OF COOKED VEGETABLES

0

0.2

0.4

0.6

0.8

1

Potato

Tomato

Brinja

l

Cauliflo

wer

Cabbage

Pumpki

n

Radish

Green b

anana

EC

YF

ELEMENT CONCENTRATION

ELEMENT CONCENTRATION

Foods Elements Gulshan K. Bazar H. Bazar

Fine Rice

Ca ++ ++ ++

K ++ +++ +

Mg ++ ++ ++

Coarse Rice

Ca + +++ ++

K ++ +++ +

Mg + ++ ++

Lentil Ca +++ ++ +

K +++ + +

Mg ++ ++ +

Prawn Ca +++ ++ +

K +++ + +

Mg ++ ++ ++

COMPARATIVE STATUS OF MINERALS IN FOODS FROM THREE MARKETS

+ Low, ++ Medium, +++ High

Food Items

Elements Gulshan K. Bazar H. Bazar

Farm chicken

Ca + ++ +++

K ++ + +++

Mg ++ + +++

Cauliflower

Ca ++ + +++

K ++ + ++

Mg ++ + +++

Apple Ca +++ ++ +

K ++ ++ +

Mg ++ + +

Onion Ca + +++ ++

K ++ + ++

Mg + +++ ++

COMPARATIVE STATUS OF MINERALS IN FOODS FROM THREE MARKETS

Food Items

Elements

Gulshan K. Bazar H. Bazar

Fine Rice Zn ND ND ND

Mn ++ +++ ++

Cu ++ ++ +

Coarse Rice

Zn ND ND ND

Mn + +++ ++

Cu ++ ++ ++

Lentil Zn ND ND ND

Mn ++ ++ +

Cu +++ ++ +

Prawn Zn +++ + +

Mn +++ ++ +

Cu + +++ +

COMPARATIVE STATUS OF TRACE ELEMENTS IN FOODS FROM THREE

MARKETS+ Low, ++ Medium, +++ High

Food Items

Elements Gulshan K. Bazar H. Bazar

Farm Chicken

Zn ND ND ND

Mn + ++ ++

Cu ++ + +++

Cauliflower

Zn ND ND ND

Mn + + ++

Cu + + ++

Apple

Zn ND ND ND

Mn ++ +++ +

Cu +++ + +

Onion

Zn ND ND ND

Mn +++ + ++

Cu ++ + ++

COMPARATIVE STATUS OF TRACE ELEMENTS IN FOODS FROM THREE MARKETS

COMPARATIVE STATUS OF HEAVY METALS IN FOODS FROM THREE

MARKETSFood Items Elements Gulshan K. Bazar H. Bazar

Fine Rice

As +++ + ++

Cd +++ + ++

Hg + + +

Pb +++ + +

Coarse Rice

As ++ +++ +

Cd + + +++

Hg + ND ND

Pb + + +++

Lentil

As ND ND ND

Cd ND ND ND

Hg ND ND ND

Pb ++ + +++

Prawn

As + ++ ++

Cd ++ +++ +

Hg ++ + ND

Pb + ++ ++

Food Items

Elements

Gulshan K. Bazar H. Bazar

Farm Chicken

As ND ND ND

Cd ND ND ND

Hg +++ ++ +

Pb + ++ +++

Cauliflower As ND + ND

Cd + ++ +

Hg ND ND ND

Pb ++ ++ +++

Apple As + ND ND

Cd ND ND ND

Hg ND ND ND

Pb +++ ++ +

Onion As + ND ND

Cd + ++ ++

Hg ND ND ND

Pb + ++ ++

COMPARATIVE STATUS OF HEAVY METALS IN FOODS FROM THREE

MARKETS

Wheat

0

300

600

900

1200

Gulshan Kawranbazar Hazaribagh

Mn c

onc.

(ppb)

Ata

Moida

0

15

30

45

60

Gulshan Kawranbazar Hazaribagh

Cu c

onc.

(ppb)

Ata

Moida

0

3

6

9

12

Gulshan Kawranbazar Hazaribagh

Mo c

onc.

(ppb)

Ata

Moida

Mn & Cu conc. for ata higher in Gulshan,

Mn & Cu conc. for ata higher in Gulshan,

0

5

10

15

20

Gulshan Kawranbazar HazaribaghPb c

onc.

(ppb)

Ata

Moida

Chromium, Lithium, Antimony, Mercury: Below detection limit for both rice and wheat

Chromium, Lithium, Antimony, Mercury: Below detection limit for both rice and wheat

Sources of Heavy metals

Heavy Metals Sources of PollutionArsenic Soil minerals

Irrigation water Wood preservatives Pesticides

Cadmium Soil minerals Sewage sludge Metal melting and refiningPaints

Lead Soil minerals Batteries Combustion of fossil fuels metallurgical industries Fertilizers Sewage sludge Semi-conductors

Mercury Coal fired power stationFossil fuel burningBatteries Pesticides Chlorine manufacture

CALCULATION OF DIETARY EXPOSURE

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 Poor Non-poorRice 406.19 420.52Wheat 20.36 28.73Potato 63.44 73.78Pulses 10.15 16.22Vegetables 141.80 177.25Edible oil 14.20 23.41Onion 15.69 24.74Beef 1.55 9.27Mutton 0.11 0.83Chicken 4.11 15.09Eggs 3.40 9.02Fish 31.16 57.81Milk & Milk products 12.18 43.63Fruits 20.46 56.00Sugar/Gur 3.32 10.88Food taken outside 17.70 35.41Miscellaneous 50.28 81.81Total 816.22 1084.53

HIES, 2010

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/ antimony _risks .htm)

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. 0.004g/kg body wt WHO (2011b)

Hg-Organic 0.0016 g/kg body wt JECFA 72 (2010)^ PTWI = Provisional Tolerable Weekly Intake* PTMI = Provisional Tolerable Monthly IntakeˇPMTDI = Provisional Maximum Tolerable Daily Intake

^ PTWI = Provisional Tolerable Weekly Intake* PTMI = Provisional Tolerable Monthly IntakeˇPMTDI = 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.

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