METAL CONTAMINATION OF PLANTS GROWN NEAR MEDICAL WASTE DUMPING ZONE DHAKA, BANGLADESH

1
METAL CONTAMINATION OF PLANTS GROWN NEAR MEDICAL
WASTE DUMPING ZONE DHAKA, BANGLADESH
M. A. Patwary, W. T. OHare, G. Street, M. H.
Sarker
1. Introduction
2. Results
2.1. Metal concentrations in soil
In developing countries, such as Bangladesh,
Health Care Establishments (HCEs) may dump
medical waste (MW) (containing, for example,
infectious materials, chemicals and
radio-chemicals) along with regular municipal
waste adjacent to agricultural land (Patwary
et.al., 2009), possibly causing soil and
groundwater pollution. When considering the
different kinds of contaminants, heavy metals are
especially dangerous because of their persistence
and toxicity (Zhuang et.al., 2009) and heavy
metal pollution of soils is a major environmental
problem impacting on plant productivity, food
quality and influencing human health
(Moreno-Jiménez et.al., 2009). The contamination
of soil where MW has been dumped has not been
assessed previously in Bangladesh. 1.1 Aim The
aim of this study was to test the hypothesis that
certain toxic elements may be present in elevated
levels in soils and plants around MW dumping
zones.
Figure a
Figure b

Figure c
Figure d
Figure a, b, c and d shows mean concentrations (
standard error of the mean) in soil sample in
different area of the study area. Cr, Co, Ni and
Zn were found to be significantly high in the
main medical waste dumping zones compared with
the soil obtained from control areas. P-value lt
0.05
1.2 Methods Soil samples and the utilized
portions of a variety of kitchen garden plants
(Indian spinach (green), water spinach, sponge
gourd, bottle gourd, sweet potato, radish, henna,
nim, pomegranate, water-hyacinth) were sampled in
and around a MW dumping zone in Dhaka. An
intermediate sample was taken from agricultural
land adjacent to the MW dumping zone. Control
samples were taken from apparently uncontaminated
agricultural land (with and without fertilizer).
Samples were screened for Mn, Cr, Co, Ni, Cu, Zn,
As, Mo, and Cd using inductively coupled plasma
mass spectrometry (ICP-MS) Two way analysis of
variance (ANOVA) was employed to examine
statistical significance of differences in the
concentration of metals among subjects and
controls.
2.2. Metal concentrations in plant
Figure e
Figure f
Figure g
Figure h
Figure1 Map of the Dhaka city showing different
location of the HCEs and medical waste dumping
zone.
Figure e, f, g and h shows mean concentrations (
standard error of the mean) in the utilized
portion of significant kitchen garden and
agricultural plants. Cr, Co, Ni and Zn were found
to be significantly high in most of test plant
samples compared with similar samples obtained
from agricultural land (with and without
fertilizer). P-value lt 0.05, P-value lt 0.01,
P-value lt 0 .001
Table 1 Soil sample area
3.1 Discussions
Average metal concentrations were found to be
significantly higher close to medical waste dumps
compared with controls. This was true both for
soil and plant material. Many metals such as Fe,
Cu, Co, Mn, Zn, and Cr are essential for humans,
and deficiency states with clinical abnormalities
have been identified. However, high doses of
these essential elements may cause toxic effects
(Caussy et al., 2003). Metal in the environment
causes an adverse effect depends on exposure,
bioavailability and on how much of it enters the
body and reaches the critical target organ(s)
(Caussy et al., 2003).
3.2 Conclusion
Table 2 Plant samples
These initial findings suggest that exposure to
toxic metals can occur due to incidental
ingestion of contaminated soil, or through crops
that have been grown on contaminated soil.
Although further study is required to confirm and
evaluate the risk, there should also be a focus
on remediation of the contaminated soil.
4. References Patwary MA et al. , 2009. Waste
Management (in press).

Ping Zhuang P et al.
,2009. Science of The Total Environment 407
1551-1561. Moreno-Jiménez E et.al., 2009. J
Hazardous Materials 162 854-859. Caussy D
et.al., 2003. Ecotoxicol Environ Saf564551.