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 Heavy Metal Contamination in Foods Industrial wastes & effluents Fertilizers Fossil fuels Sewage sludge Contaminated underground water

Heavy Metal Contamination in Bangladesh:Glimpses

Industrial dischargeIndustrial discharge Industrial dischargeIndustrial discharge

Roadside contaminationRoadside contamination Veg. washed with contaminated waterVeg. washed with 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 provide suggestions for actions to reduce contamination

METHODOLOGYMETHODOLOGY

Market Category by income Category by Kcal intake

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)

SAMPLE COLLECTIONSAMPLE COLLECTION

Food samples were collected from 10 different shops of Kawranbazar and Hazaribagh and 3 supermarkets & 7 shops of Gulshan market

Eighty composite food samples were collected from each of the three markets

Standard operating procedures were followed for processing of food samples (NIN, 2009)

Food samples were collected from 10 different shops of Kawranbazar and Hazaribagh and 3 supermarkets & 7 shops of Gulshan market

Eighty composite food samples were collected from each of the three markets

Standard operating procedures were followed for processing of food samples (NIN, 2009)

PROCESSING AND COOKING OF FOODS: RICE

Weight of the parboiled rice (coarse and fine grain) recorded

Washed with tap water

Cooked by both absorption (rice:water=1:3) and draining method (rice:water=1:5)

Excess water discarded in case of draining out method

Weight of raw and cooked rice recorded and calculate YIELD FACTOR

A sub-sample was kept in oven to obtain dry weight

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 SGS laboratory, Bangladesh Ltd

Reliability

The reliability of the procedure was assessed by comparison with the Certified Reference Material GBW(E)080684.

RESULTSRESULTS

Comparative Mineral Content in Rice using Two Cooking Methods

0

200

400

600

Ca Mg

Con

c. (m

g/kg

fw)

Absorption Drained

0

200

400

600

800

Na K

Con

c. (m

g/kg

fw)

0

5

10

15

Fe Cu

Con

c. (m

g/kg

fw)

Absorption Drained

0

0.1

0.2

0.3

0.4

AS Cd

Con

c. (m

g/kg

fw)

Decrease in mineral content through draining method Loss of water causes leaching of nutrients

0

10

20

30

40

50

60

Rice Puffed riceC

on

c. (

mg

/kg

)

Fe

Mn

Al

0

1000

2000

3000

4000

5000

Rice Puffed rice

Co

nc.

(m

g/k

g)

Na

K

Mineral content of Puffed Rice

Loss of moisture increased mineral contentsUse of salt water to prepare puffed riceFe and Al intake from utensil and sand

Cd and As conc. in rice

0

0.1

0.2

0.3

0.4m

g/kg

f.w

t.

Gulshan market

Kawranbazar

Hazaribagh

0

0.1

0.2

0.3

0.4

mg/

kg f.

wt.

Gulshan market

Kawranbazar

Hazaribagh

CdCdAsAs

High As in Gulshan market

High As in Gulshan market

High Cd in Gulshan market

High Cd in Gulshan marketPreliminary results showed higher values

Need further validationSafe limit for Cd: 50 microgram/60 kg bw/day

LEAD CONC.IN RICE AND PULSES

0

0.5

1

mg

/kg

f.w

t.

Ric

e

Che

era

Ata

Moi

da

Lent

il

Lath

yrus

Chi

ckpe

a

Mun

gbea

n

Gulshan market

Kawranbazar

Hazaribagh

Wide variation of Pb in foods from different markets

Any conc. of Pb is harmful

Wide variation of Pb in foods from different markets

Any conc. of Pb is harmful

ZINC CONC. IN VEGETABLES

0

3

6

9

12

mg

/kg

f.w

t.

Pota

to

Brin

jal

Bea

n

Ban

ana

Pata

l

Pum

pkin

Aro

i d

Dhe

rosh

Tom

ato

Spin

ach

Am

aran

th

Cau

li flo

wer

Car

rot

Cab

bage

Gulshan market

Hazaribagh

ARSENIC CONC. IN VEGETABLES

0

0.02

0.04

0.06

mg

/kg

f.w

t.

Pota

to

Brin

jal

Bea

n

Ban

ana

Pata

l

Pum

pkin

Aro

i d

Dhe

rosh

Tom

ato

Spin

ach

Am

aran

th

Cau

li flo

wer

Car

rot

Cab

bage

Gulshan market

Hazaribagh

As level: Very lowAs level: Very low

Any conc of Arsenic is harmful

LEAD CONC. IN VEGETABLES

0

0.1

0.2

0.3

0.4

mg

/kg

f.w

t.

Pota

to

Brin

jal

Bea

n

Ban

ana

Pata

l

Pum

pkin

Aro

id

Dhe

rosh

Tom

ato

Spin

ach

Am

aran

th

Cau

liflo

wer

Car

rot

Cab

bage

Gulshan market

Hazaribagh Hazaribagh: High Pb content

Hazaribagh: High Pb content

Any concentration of lead is harmful

CADMIUM CONC. IN VEGETABLES

0

0.05

0.1

0.15

0.2

mg

/kg

f.w

t.

Pota

to

Br in

jal

Bea

n

Ban

ana

Pata

l

Pum

pkin

Aro

id

Dhe

rosh

Tom

ato

Spin

ach

Am

aran

th

Cau

liflo

wer

Car

rot

Cab

bage

Gulshan market

Hazaribagh

Spinach and Amaranth: High Cd content

Spinach and Amaranth: High Cd content

SELENIUM CONC. IN FISHES

0

0.2

0.4

0.6

mg

/kg

f.w

t.

Hi ls

ha

Praw

n

Roh

u

Kat

la

Mri g

el

Gra

ss c

arp

Pang

as

Gulshan market

Kawranbazar

Hazaribagh market

High variability among marketsRelatively higher in Gulshan market

High variability among marketsRelatively higher in Gulshan market

ELEMENTAL CONCENTRATION IN FOODS

Variation in mineral, trace elements and heavy metals in foods was noted which is attributed to source and location

Cooking rice by draining method decreased the concentration of elements compared to cooking rice by absorption method

Rice grains had higher conc. of As, Pb and Cd

Puffed rice had very high conc. Of Na, K, Fe, Mn, and Al contents than the rice

DIETARY RISK EXPOSUREDIETARY RISK EXPOSURE

CALCULATION OF DIETARY EXPOSURE

Concentration of elements in fresh weight of food items calculated

Individual food item intake by poor and non-poor households in Dhaka city obtained from HIES, 2010

Dietary Exposure = Concentration of elements x amount of food consumed

Compared with the MPL for heavy metals and RDI for minerals and trace elements

CALCIUM INTAKE

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

PoorNon-poor

Source PoorNon-poor

Cereals 27.3 27.3

Pulses 5.2 5.2

Fish 21.8 21.7

Meat 4.8 4.7

Vegetables 14.0 14.9

Milk, dairy 10.6 10.6

Sweetmeat 2.3 2.3

Fruits 1.9 1.7

Sug. molas 1.5 1.5

100% poor below RDI94% non-poor below RDI

100% poor below RDI94% non-poor below RDI

Poor: 297-583 mg d-1;

Non-poor: 196-888 mg d-1

Poor: 297-583 mg d-1;

Non-poor: 196-888 mg d-1

SODIUM INTAKE

100% poor & non-poor below RDI for both Na100% poor & non-poor below RDI for both Na

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

PoorNon-poor

Food group PoorNon-poor

Cereals 34.2 32.9

Pulses 1.9 1.8

Fish 6.4 6.2

Eggs 0.1 0.1

Meat 2.9 2.8

Vegetables 17.9 16.5

Milk & dairy 15.2 14.6

Fruits 0.6 0.6

Poor: 172-471 mg d-1;

Non-poor: 131-542 mg d-1

Poor: 172-471 mg d-1;

Non-poor: 131-542 mg d-1

POTASSIUM INTAKE

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

Poor

Non-poor Food group Poor

Non-poor

Cereals 57.9 37.0

Pulses 8.6 11.76

Fish 3.9 6.8

Meat 1.3 2.73

Vegetables 15.2 29.9

Milk & dairy 7.4 6.43

Fruits 4.4 4.48

Poor: 582-1657 mg d-1;

Non-poor: 899-3299 mg d-1

Poor: 582-1657 mg d-1;

Non-poor: 899-3299 mg d-1

COPPER INTAKE

Poor HHs suffer more Cu deficiency than non-poor HHs

Poor HHs suffer more Cu deficiency than non-poor HHs

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

PoorNon-poor

Poor: 0.6-2.5 mg d-1;

Non-poor: 0.8-4.0 mg d-1

Poor: 0.6-2.5 mg d-1;

Non-poor: 0.8-4.0 mg d-1

Food group PoorNon-poor

Cereals 60.0 59.4

Pulses 9.94 9.83

Fish 6.98 6.91

Eggs 0.07 0.07

Meat 6.51 6.44

Vegetables 8.67 9.66

Milk & dairy 4.09 4.05

Fruits 1.26 1.25

ZINC INTAKE

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

PoorNon-poor

Poor: 3.1-14.3 mg d-1

Non-poor: 4.4-16.7 mg d-1

Poor: 3.1-14.3 mg d-1

Non-poor: 4.4-16.7 mg d-1

Food group Poor Non-poor

Cereals 74.96 68.26

Pulses 8.52 11.02

Fish 1.71 5.24

Eggs 0.01 0.02

Meat 1.00 0.75

Vegetables 9.97 8.32

Sweetmeat 0.77 1.51

Fruits 1.98 2.19

COBALT INTAKE

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI

% P

op

ula

tio

n

Poor Non-poor

32% poor above RDI99% non-poor above RDI

32% poor above RDI99% non-poor above RDI

Food group Poor Non-poor

Cereals 82.62 88.67

Pulses 3.68 1.38

Fish 2.20 2.74

Meat 1.57 0.32

Vegetables 3.00 3.71

Sweetmeat 1.82 2.00

Fruits 0.11 1.06

Poor: 3.3-85.1 mg d-1

Non-poor: 15.0-345.9 mg d-1

Poor: 3.3-85.1 mg d-1

Non-poor: 15.0-345.9 mg d-1

NICKEL & SELENIUM INTAKE

0

400

800

1200

1600

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt

0

400

800

1200

1600

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt

NiNi

0

25

50

75

100

>100 75-99 50-74 25-49 <25

% RDI%

Po

pu

lati

on

Poor

Non-poor SeSePoorPoor

Poor: 100% below RDINon-poor: 27% Above RDI

Poor: 100% below RDINon-poor: 27% Above RDINo RDINo RDI

ALUMINIUM INTAKE

0

25

50

75

100

<100 >100

% MPL

% P

op

ula

tio

n

PoorNon-poor

92% poor and 83% non-poor are at risk of Al contamination

92% poor and 83% non-poor are at risk of Al contamination

Food groups Poor Non-poor

Cereals 76.42 76.3

Pulses 0.04 0.0

Fish 1.41 1.40

Vegetables 16.38 16.40

Sweetmeat 0.34 0.30

Oil & fats 3.72 3.70

Fruits 1.29 1.30

Sugar,molasses 0.26 0.30

Poor: 0.37-12.44 mg d-1

Non-poor: 3.0-34.2 mg d-1

Poor: 0.37-12.44 mg d-1

Non-poor: 3.0-34.2 mg d-1

PTDI of Al: 8.6 mg/60 body wt/day

CADMIUM INTAKE

0

25

50

75

100

<100 >100

% MPL

% P

op

ula

tio

n

PoorNon-poor

94% poor and 78% non-poor are at risk of Cd contamination

94% poor and 78% non-poor are at risk of Cd contamination

Poor: 17.5-204.3 µg d-1;

Non-poor: 5.6-113.4 µg d-1

Poor: 17.5-204.3 µg d-1;

Non-poor: 5.6-113.4 µg d-1

Food group Poor

Non-poor

Cereals87.0

6 86.14

Pulses 0.00 0.00

Fish 5.62 6.62

Eggs 0.00 0.00

Meat 0.16 0.16

Vegetables 7.01 6.93

Fruits 0.08 0.08MPL: 50 micro g/60 kg bw/day

MPL: 50 micro g/60 kg bw/day

ARSENIC AND LEAD INTAKE

0

50

100

150

200

250

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt

0

50

100

150

200

250

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt

ARSENICARSENIC

0

100

200

300

400

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt0

100

200

300

400

0 25 50 75 100

HH No.

mic

ro g

/da

y/a

du

lt

LEADLEAD

ANY CONCENTRATION IS HARMFULANY CONCENTRATION IS HARMFUL

INTAKE OF ANTIMONY, LITHIUM AND MERCURY

Element Poor Non-poor

Antimony(µg d-1)

0-0.02 0.0-0.8

Lithium (µg d-1)

22.1-32.17 1.8-46.5

Mercury(µg d-1)

0.45-3.28 1.0-8.4

ALL ARE SAFEALL ARE SAFE

CONCLUSIONS Poor household males are noted to have

more mineral (Ca, Mg and K) and trace element (Fe, Cu, Zn, Co and Se) deficiency compared to non-poor household males

Intake of Mn and Mo is noted to be higher than the Recommended Daily Intake for both poor and non-poor households.

About 94% males from poor households and 78% males from non-poor households have higher dietary risk exposure to Cd above PTMI, and are exposed to Cd contamination.

Antimony, mercury and lithium intake through foods by males from both poor and non-poor households are below PMTI.

Both poor and non-poor households have high intake of arsenic and lead from different foods. FAO (2010) has withdrawn the PTWA of As and Pb. Therefore, all the males of poor and non-poor households have high dietary risk exposure to As and Pb contamination.

POLICY IMPLICATION

An in-depth study is further needed to identify the hot spots of heavy metals contaminated areas near to and away from Dhaka city

Cultivation of rice with arsenic free water (DTW or surface water) to reduce the arsenic in food chain.

Need to screen and develop rice varieties for lower uptake of arsenic and cadmium by grains in order to decrease the dietary risk exposure to arsenic and cadmium intake by the population

Strong monitoring is needed to ensure the treatment of industrial effluents before its disposal and use of phosphatic fertilizers with very less amount of Cd and use the Pb free fossil fuels.

Decreased consumption of rice and increased consumption of vegetables might keep balance/reduce the dietary risk exposure to arsenic, lead and cadmium

Increased consumption of livestock and fish foods will help decrease the selenium deficiency in the population

Need to build baseline data on the content and extent of contamination of heavy metals following up from this investigation.

POLICY IMPLICATION

High variation in minerals, trace elements and heavy metals in foods among three markets depends on the places of production

Arsenic gets entered into human body through As-contaminated STW irrigation water via plant uptake

Entry of other heavy metals into food chain comes from industrial discharge, combustion of fossil fuels, roadside dust, fertilizers and sewage sludge. The industrial effluents should be treated before draining into the water course.

Exposure to heavy metals by Bangladeshi diet