Determination of Pb, Ni, Hg, Cr, Cd in Edible Vegetables in the West South of Tehran Province with Atomic Absorption
Eftekhar Shirvani Mahdavi
In this research, edible vegetables from Babasalman
and Eslamshahr regions were sampled in summer 2007 from farms for which
well water was used. The samples were then prepared and concentration
of the trace elements were determined by using atomic absorption spectrometry
in Iranian Atomic Energy Agency. According to the analysis the minimum
and maximum concentration of Pb 0.0050 ± 0.0001 ppm in mint (stem)
of Babasalman and 0.0645 ± 0.0010 ppm in radish (leaf) of Eslamshahr,
Ni 0.0004 ± 0.0001 ppm in radish (root) of Babasalman and 0.0175
± 0.0001 ppm in bulbil (root) of Eslamshahr, Cr 0.0903 ±
0.0006 ppm in radish (root) of Babasalman and 0.8801 ± 0.0036 ppm
in mint (leaf) of Eslamshahr, respectively. Minimum of Cd concentration
was lower than detection limit of spectrometer and maximum was 0.0816
± 0.0002 ppm in radish (leaf) of Babasalman and concentration of
Hg was lower than detection limit of spectrometer in all of the samples
and only was 0.1399 ± 0.0002 ppm in cress of Babasalman.
This study provides data on five trace elements in Iranian edible vegetables.
Some of these metals such as Cd, Hg, Pb, are being potentially toxic. Nickel
is one of the newest trace-elements for which the position as to their essentiality
or toxicity is not fully explored. It should be stressed that the actual physiology
and metabolism and thus also the toxicity of each of the newer trace elements
and others depend on various factors, among others the physico-chemical form
of trace element. This physico-chemical form influences absorption, accumulation,
release, body distribution and physiological effect of the trace element under
consideration (Gharib, 2004a, b).
The another one is chromium with three oxidation number is essential trace element
(Elmadfa and Leitzman, 2004) but with six oxidation number
is toxic. The effects of trace elements in water, plants and animals tissues
are very important. It is mentioned that plants can absorbed them from different
sources such as: factories activity, workshop, fuels, agriculture activities,
sewage, waste and environmental air pollution. Plants absorb them through water,
soil or air. The amount of absorption is the function of soil components. In
light sandy soils, amount of pollution is less than other kind of soils. This
type of soil which has a few amount of clay and humus, can hardly absorb heavy
metals, where as absorption increase in soils which have more clay and humus
compound (Simeonova and Todorova, 2003). In addition,
soil acidification can cause increased risk mobilization of heavy metals. At
low pH value in soil the release rates for cadmium and aluminium increase considerably
(Barthwal, 2002). By increasing in atomic mass of metal,
its absorption by plant is more and the transferring factor will be more. Through
this results for elements like, Cd with lower atomic mass the transfer factor
is 1-10 and the mobility from earth to plants is very high, for Ni with average
mass atomic, transferring factor is 0.1-1 and ion mobility is suitable and for
Pb, Hg elements. Because of their high atomic mass, transferring factor becomes
0.01-0.1 and lack of ions mobility is very high (Uchida et
al., 2007). After entering heavy metals from soil to plants like vegetables
these metals will enter peoples diet. And according to the amount of peoples
daily meal, they appear their effects. In Iran, vegetables have special place
in peoples diet.
|| The sampling points of Babasalman and Eslamshah
The amount of daily receiving is 278 g in Iran (Gharib et
al., 2003). Which is more than many other countries like Bangladesh
with amount of daily receiving 130 g ( Alam et al.,
2003 ). It is important to measure heavy metals in Tehran as there is the
most popular province in Iran; therefore vegetables safeties in this province
have been investigated. Offering conclusions to organizations in addition of
helping health society and prevent appearing some diseases, will be an introduction
for future researches.
MATERIALS AND METHODS
This study have been done of the summer 2007 in Babasalman and Eslamshahr
regions from earths sampling that irrigate with dimple water was done.
Figure 1 shows the sampling points.
The samples were with stem, leaf and they were with root too and numbers of
them were twelve from each plant. All samples have been wet digested in nitric
acid 65% and per choleric acid 75% (Nollet-Leo, 2004).
Dried weight of each digested vegetables were 1 g and all vegetables were in
90 days age. Metal concentration survey by atomic absorption flame photometric
model of Varian A110. In order to statistical calculates in descriptive analysis
and illative research from statistic Z (normal distribution) various t-test,
ANOVA analysis in have been determined by SPSS soft ware.
According to Table 1 and 2, the minimum
and maximum concentration of lead is 0.0050 and 0.0645 ppm, nickel is
0.0004, 0.0175 ppm, mercury is ND (Non Detectable) and 0.1399 ppm, chromium
is 0.0903 and 0.8801 ppm, cadmium is ND (Non detectable) and 0.0816 ppm,
in vegetables is under study, respectively.
Figure 2a-h show the percentage of metals concentration
in vegetables that they were studied. Base on Fig. 2a-d,
the maximum percentage of metals concentration are in radish (leaf) among
the other vegetables of Babasalman region, but Ni is an exception than
other and maximum of concentration of it is in mint (leaf). As Fig.
2b-h show maximum percentage of concentration of metals in Eslamshahr
region are different from variety of vegetables in which Pb in radish
(leaf), Ni in bulbil (root), Cr in mint (leaf) and Cd in radish (leaf)
|| The average of metals concentration (ppm) in vegetables
of Babasalman region
|*ND: Non Detectable, 1: Mentha spicata L., 2:
Raphanus sativus, 3: Ocimum basilicum, 4: Lepidium
sativum, 5: Coriangrum sativum 6: Allium ampeloprasum
|| The average of metals concentration (ppm) in vegetables
of Eslamshahr region
|*ND: Non Detectable, 1: Mentha spicata, 2: Raphanus
sativus, 3: Ocimum basilicum, 4: Allium schoenoprasum
||The maximum percentage of metals concentration (a) Pb%
Babasalman vegetables, (b) Ni% Babasalman vegetable, (c) Cr% in Babasalman
vegetable, (d) Cd% in Babasalman vegetable, (e) Pb% in Eslamshahr
vegetable, (f) Ni% in Eslamshahr vegetable, (g) Cr% Eslamshahr vegetable
and (h) Cd% in Eslamshahr vegetable
Through this research, the concentration of trace elements is lower than NBS1571
standard. In this case, it is important to notice the amount of daily receiving
of trace elements from foods in Iranians diet and their amount of their received
of daily vegetables. Results of research (Gharib et al.,
2003) show that the amount of daily receiving of Cd, Cr, Hg, Ni, Pb in Iranian
women are in this order 0.027, 0.05, 0.057, 0.1999, 0.091 mg and in the Iranian
men are 0.046, 0.050, 0.017, 0.36, 0.109 mg. Also through the same research,
the amount of vegetables that Iranian receives daily is 278 g. This amount has
the fourth place in diet of Iranian, after water, corns and bread (Gharib
et al., 2003).
Selecting the type of vegetables in this examination is not only important
because of the usage of them in the part of the Iranian diet, but also because
these vegetables except radish are leafy vegetables which can be used as proper
new animator of heavy metals. From the results of research (Temmerman
and Hoeing, 2004) it can be understood that there is a lot of attention
to leafy vegetables due to their heavy metal absorption and absorption and association
of metals in the vegetables have relationship with component of metals in the
soil and special characteristics of that plant. In Wang et
al. (2004) research, the concentration of metals in greenery and rootstalk
vegetables like bean, cauliflower, celery, cabbage and eggplant were higher
than those in the melon and fruit and also in the study of Xie
et al. (2006) the heavy metal concentration in vegetables is more
than cabbage because of their higher absorption. In this study the amount of
Pb, Cd in the radish root is lower than other vegetables which that all of them
are leafy vegetables. According to the study of Li et
al. (2004) the amount of Zn, Pb, Cd in the root vegetables are lower
than their concentration in leafy vegetables.
The study of metals concentration in leaf, root and stem of radish in
Eslamshahr and Babasalam regions shows that the concentration of Pb, Ni,
Cr, Cd in the parts of this plant have this order root <stem <leaf.
Statistical study (ANOVA) concluded that the metals concentration in leaf,
root and stem of radish in Eslamshahr and Babasalam regions shows the
significant difference of metals concentration about p<0.05 in the
leaf, root and stem. Study of metals concentration in leaf and root of
bulbil at Eslamshahr region shows that metals concentration in leaf of
bulbil is lower than in its root; also the results of the statistical
study of (paired t-test) there is a significant difference of metals concentration
in leaf and root of bulbil about p<0.05.
Study of metals concentration in leaf and stem of basil shows that the
concentration of Ni, Cr, in the stem is more than leaf and the concentration
of Cd and Pb in leaves are more than stems. Also statistical study of
(paired t-test) shows the significant difference of p<0.05 in metals
concentration in stem and leaf of this plant in Eslamshahr and Babasalam
Determination of metals concentration in leaf and stem of mint in two
Eslamshahr and Babasalam regions shows that the concentration of Ni, Cr
in their leaf is more than in their stem and the concentration of Pb in
stem is higher than in its leaf. Concentration of Cd in both stem and
leaf were reported ND in Eslamshahr and Babasalam and its concentration
in leaf is more than stem. Statistical study also shows significant difference
of p<0.05 about metals concentration in mints stem and leaf.
Study and comparing the concentration of metals in vegetables of Babasalam
and Eslamshahr regions shows that there is a significant difference of
p<0.05 between its concentration vegetables in these two regions and
usually this concentration is higher in Eslamshahr vegetables. As we know
Babasalam is a small region and do not have any industrial center, but
Eslamshahr is a wider region that in addition to its residential houses,
it has some little industry centers.
From Demirezen and Aksoy (2006) study it would be understood
that, there is significant difference between vegetables of cities and villages.
It is important to mentioned that this research becomes complete when we study
and determine the concentration of metals in the soil of regions; because an
important factor that increase the metals concentration in plants is the increasing
of metals concentration in soil or chemical fertilizer of that region (Wu-Zhong
et al., 2002) and this factor needs an essential attention about
all metals that examined; because although the average of all metals is lower
than NBS1571 standard but in many cases their amount is more than the receiving
amount of Iranians men and women that this matter can cause a lot of problems.
Alam, M.G.M., E.T. Snow and A. Tanaka, 2003.
Arsenic and heavy metal contamination of vegetables in Samta village, Bangladesh. Sci. Total Environ., 308: 83-96.CrossRef | Direct Link |
Demirezen, D. and A. Aksoy, 2006.
Heavy metal levels in vegetables in Turkey are within safe limits for Cu, Zn, Ni and exceeded of Cd and Pb. Food Qual., 29: 252-265.CrossRef | Direct Link |
Elmadfa, I. and C. leitzman, 2004.
Emahrung Des Menschen. 1st Edn., Ulmer, Stutgart, Germany
Gharib, A.G., 2004.
Toxicologically important trace elements in Iranian diets. Radioanal. Nuclear Chem., 262: 93-96.CrossRef | Direct Link |
Gharib, A.G., 2004.
Newer trace elements in Iranian diets. Radioanal. Nuclear Chem., 262: 199-204.CrossRef | Direct Link |
Gharib, A.G., S. Fatoorechian and A. Ahmadiniar, 2003.
Determination of essential major and trace elements in daily diets by comparative methodologies and alterations. Trace Elements Med., 1: 43-53.
Li, X., R. Hua, Y. Yue, D. Cao, L. Yuan and W. Shen, 2004.
Evaluation on contamination of Cr, Pb, Cd and Cu in vegetables of hefei region. Anhui Agric. Univ., 31: 143-147.Direct Link |
Nollet-Leo, M.L., 2004.
Hand Book of Food Analysis. 2nd Edn., CRC Press, USA., ISBN: 9780824750374 Direct Link |
Temmerman, L.D. and M. Hoeing, 2004.
Vegetable crops for biomonitoring lead and cadmium deposition. Atmos. Chem., 49: 121-135.CrossRef |
Uchida, S., K. Tagami and I. Hirai, 2007.
Soil-to-plant transfer factors of stable elements and naturally occurring radionuclids upland field groups collected in Japan. Nuclear Sci. Technol., 44: 628-640.Direct Link |
Wang, S., J. Leng, and X. Liu, 2004.
Study on pollution status of nitrate and heavy metals in vegetables in Jinan. Environ. Health, 21: 363-377.
Wu-Zhong, N., L. Xin-Xian and Y. Xiao-E, 2002.
Studies on the criteria of cadmium pollution in grow media of vegetable crops based on the hygienic limit cadmium in food. Plant Nutr., 25: 957-968.Direct Link |
Xie, Z.M., J. Li, J.M. Xu, L.J. Ye and B.L. Wang, 2006.
Evaluation on environmental quality of Pb, Zn and Cu contents in vegetable plantation soils and vegetables in hangzhou suburb. Huan Jing Ke Xue, 27: 742-747.Direct Link |
Simeonova, N. and S. Todorova, 2003.
Analysis of the effect of contamination with heavy metals on the humus status of soils in the region of the non-ferrous works by Plovdiv. Environ. Protect. Ecol., 3: 623-630.
Barthwal, R.R., 2002.
Environmental Impact Assessment. 1st Edn., New Age International, India, ISBN: 8122413579 Direct Link |