Assessment of socio – economic, environmental and human health impacts of informal recycling of e-waste

By:

Samuel Obiri, Saada Mohammed and Ansa – Asare Osmund (PhD)

Introduction Objectives of the study Concepts of human health risk assessment Methodology Theory/Calculation of the human health risk and

socio – economic survey Results & Discussion Conclusion & Recommendation Publication List

Outline of presentation

E – waste contains numerous toxic or hazardous chemicals that poses significant health hazard to human beings.

In Ghana, informal disposal and recycling of e - waste take place, often in small workshops with open burning of plastics and wires, and acid leaching of printed circuit boards.

introduction

Environmental fate and transport analysis of toxic emissions from recycling of e – waste

(1) Determine the concentrations of Pb, Cd, Cr, Cu, As, Sn, Zn and Co in bottom ash and soil samples from areas where e – wastes are openly burnt or dismantled,

(2) Assess the cancer and non – cancer human health risks from oral and dermal exposure to the aforementioned toxic chemical in the bottom ash or soil samples by workers involved informal recycling of e - waste.

(3) Assess socio – economic perception of e-waste workers using logistic regression.

Objectives of the study

30 ash samples were randomly collected from 3 places (AGH1, AGH2 and AGH3) where open burning of the e – waste at Agbogbloshie scrap yard.

30 soil samples were also collected from the Agbogbloshie scrap yard.

All these samples were transferred into well – labelled plastic containers from September 2012 to March 2013.

The samples were collected on bi – weekly basis.

44 questionnaires were admitted to the e – waste workers.

Methodology

Risk assessment is a process of estimating the probability of the occurrence of an event and the probable magnitude of adverse health effects on human exposures to environmental hazards (Obiri et al., 2013; USEPA, 1989; Kollunu et al., 1996).

Human health risk assessment process involves four steps, namely;

Hazard identification. Exposure assessment Dose assessment Risk characterization

Concepts of human health risk assessment

In this study, the average daily dose (ADD) of Pb, Cd, Cr, Cu, As, Sn, Zn and Co ingested from bottom ash and soil samples in the study area were calculated using:

  ADD = EPC x IR x FS, B x ED x EF x 10-6 (1) BW x AT x 365

ADD = Average Daily Dose of the toxicants

EPC = Exposure point concentration of the toxicants, e.g. As, Cd, etc in mg/kg

IR = Soil/Ash Ingestion Rate in mg/day

FS = Fraction of Soil/Ash ingested

B = Bioavailability

ED Exposure Duration (years)

EF = Exposure Frequency (day or years)

BW = Body Weight (kg)

AT = Averaging Time (Years) 

Quantification of the human health risk

For dermal exposure to As, Cd, Co, Cu, Sn, Cr, Pb and Zn in soil, the ADD is calculated as follows (USEPA, 1999b):

  ADD = [(EPC x DA x SA x AF x EF x ED)] / (BW x AT)] …. 2

Where:EPC = EPC of As, Cd, Co, Cu, Sn, Pb and Zn in soil/Ash (mg/kg),DA = Dermal Absorption Fraction (unitless),AF = Soil/Ash – skin Adherence Factor (mg/cm2),SA = Skin surface area exposed (cm2/day),EF = Exposure frequency (days/years),ED = Exposure Duration (years)BW = Body weight (kg), and AT = Averaging Time (days)

In this study, the following key indicators were used to assess the socio – economic impacts of informal recycling of e-waste:

- Safe and healthy working conditions of the workers

- Economic viability of e – waste recycling - Impacts on the environment- Working hours

Analysis of the socio – economic data

Sample Location

Concentration in mg/kg

Pb Cd Cr(VI)

Cu As Sn Zn Co

ASH1 5,388 2.39 42 7,940 20 225 276 123

ASH2 3,257 4.58 35 1,190 15 195 274 68

ASH3 4,654 5.37 45 2,457 25 323 124 96

Intervention Level by Lacatusu et al., 2009

100 5.0 300 200 - - 600 -

Mean concentrations of lead, Cadmium, Chromium, Copper, Arsenic, tin, Zinc and Cobalt in the bottom ash samples

Sample Location

Concentration in mg/kg

Pb Cd Cr(VI)

Cu As Sn Zn Co

ASG1 1,685 26.9 36.86 1,427 1,622 234 783 135

ASG2 12,492 67.2 351.82 15,761 1,348 171.6 387 87.0

ASG3 699.2 112.7 1,378 1,839 4,142 563 618 563.9Intervention level by Lacatusu et al., 2009

100 5 100 200 - - 600 -

Mean concentrations of lead, Cadmium, Chromium, Copper, Arsenic, tin, Zinc and Cobalt in Soil samples

Table 1.0 Cancer health risk faced e – waste workers from accidental oral ingestion and dermal contact of As and Cd in bottom ash

Results and discussion

Sampling Location

Exposure route

Cancer health riskAdults e – waste workers (Arsenic)

Adult e – waste workers (Cadmium)

CTE RME CTE RME

ASH1 Oral

Dermal

0.0043

0.0080

0.065

0.060

0.063

0.0034

0.092

0.0017

ASH2 Oral

Dermal

0.0012

0.0052

0.0099

0.0040

0.076

0.014

0.0019

0.0021

ASH3 Oral

Dermal

0.12

0.0026

0.010

0.0076

0.080

0.0086

0.0020

0.0025

Sampling Location

Exposure route

Cancer health risk

Adults e – waste workers (Arsenic)

Adult e – waste workers (Cadmium)

CTE RME CTE RME

ASG1Oral

Dermal

0.037

0.076

0.059

0.087

0.023

0.054

0.072

0.067

ASG2 Oral

Dermal

0.082

0.066

0.099

0.098

0.076

0.014

0.091

0.051

ASG3Oral

Dermal

0.039

0.026

0.060

0.076

0.080

0.0086

0.093

0.095

Table 2.0 Cancer health risk faced e – waste workers from accidental oral ingestion and dermal contact of As and Cd in soil samples

Samplin

g

Location

Exposure

route

Non – cancer health risk

Pb Cd Cr Cu

CTE RM

E

CTE RM

E

CTE RM

E

CTE RM

E

ASH1 Oral

Dermal

24

56

36

65

2.2

4.5

2.9

6.2

4.3

4.6

5.7

4.5

78

112

89

245

ASH2 Oral

Dermal

33

82

91

97

1.3

7.3

5.6

9.1

2.0

2.2

4.5

3.7

45

52

73

78

ASH3 Oral

Dermal

15

24

21

98

2.4

3.1

7.5

2.6

0.19

0.56

0.37

0.67

22

12

44

23

Table 3.0 Non – cancer health risk from exposure to Pb, Cd, Cr and Cu in bottom ash by the e – waste workers

Samplin

g

Location

Exposure

route

Non – cancer health risk

As Sn Zn Co

CTE RM

E

CTE RM

E

CTE RM

E

CTE RM

E

AGH1 Oral

Dermal

0.37

0.67

0.11

0.50

1.7

1.2

4.4

6.4

6.3

1.2

5.7

2.6

1.5

27

1.3

6.2

AGH2 Oral

Dermal

1.3

2.3

3.8

1.7

5.9

4.0

1.5

2.2

2.2

4.0

2.0

3.0

1.9

3.5

1.9

3.5

AGH3 Oral

Dermal

2.2

4.0

6.5

3.0

1.0

6.9

2.0

3.8

3.7

6.8

3.4

9.0

2.5

4.6

2.3

10

Table 4.0 Non – cancer health risk from exposure to As, Sn, Zn and Co in bottom ash by e – waste workers

Injuries 31%

Respiratory disease21%

Gastrointestinal disease

17%

Bodily pains21%

Body cuts4%

Cough6%

Perceptions of e-waste workers about com-

mon diseases they suf-fer

≤ 12 Hours48%≥ 12 Hours

52%

Hours of work

Copper23%

Lead20%

Aluminium18%

Iron36%

Gold2%

Silver0%

Palladium0%

chromium0%

Tin0%

Nickel0%

Antimony0%

Percentage of materials recovered

Category Total No.

Employed e – waste worker (recyclers + collectors)

9,500 – 11,400

Dependents of e – waste workers 98,000 – 142,000

Number of people employed and dependent on e – waste recycling at Agbogbloshie

Category E – waste worker’s earnings

Amount in US $ Amount in GH₵

Remuneration per month 354 – 542 11,143.42 – 1,750.66

Remuneration per year 4,248 – 6,504 13,721.04 – 21,007.92

No. of people employed in informal recycling of e – waste

9,500 – 11,400

Contribution to national economy per year

403,560.00 - 741,456.00

130,349,880 - 239,490,288

Informal e-waste recycling contribution to Ghana’s economy

Note: 1USD = 3.23 GH₵

From the results of the study, the following conclusions can be drawn:

o High concentration of Pb, Cd, Cr, Cu, As, Sn, Zn and Co were found in bottom ashes of where the e – waste are burnt. The levels of the aforementioned chemicals in the toxic fumes emitted though have not been estimated could pose significant health hazard.

o The cancer and non – cancer health risk results in most cases exceeded the acceptable USEPA cancer health risk range of 1 case of cancer out of every 1,000,000 people or to 10,000 people; and hazard quotient value of 1.0.

Conclusion

Further work should concentrate on epidemiological studies to ascertain disease profile of the e – workers at the study area.

Levels of the aforementioned toxic chemicals in the toxic fumes from open burning of the e – waste should be measured and the health risk quantified.

Government agencies such as the Ghana Health Service and other civil society organisations should team up to educate the workers on the health risk they faced.

recommendation

Ansa – Asare, O. D., Obiri, S. and Mohammed, S. 2014): Heavy metal contamination in vegetables sold near informal e – waste recycling sites in Ghana. (In Press). Journal of Hazardous materials.

Ansa – Asare, O. D., Obiri, S.and Mohammed, S. (2014): Assessment of socio – economic, environmental and human health impacts of informal recycling of e-waste

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