Archives of

1. Introduction
Medicinal plants have found widespread applications in the treatment, prevention, and management of diseases. Due to the numerous benefits of herbal medicines, the majority of the world’s population depends on them in any way for various health benefits [1]. According to the World Health Organization (WHO), it is estimated that 65–80% of the world’s population relies on traditional medicine [2], and the use of herbs to treat diseases, including cancer, is accepted in many countries around the world [3].
Medicinal plants also play an important role in the healthcare industry, cosmetics, traditional medicines, and food [4]. The issue of food security and safety of medicinal plants is of great interest considering that their harvesting takes place from pastures, plains, and mountains [1,2].
Heavy metal contamination of plant materials is a potential health hazard, especially for populations that are already vulnerable [3]. Heavy metals of non-human origin are always present in parent rocks and soils decomposed by weathering and erosion [5], but concentrations of heavy metals in certain ecosystems have also increased dramatically due to human activities [6]. Heavy metals are often formed as cations that interact strongly with the soil network and can be mobilized as a result of changing environmental conditions [7]. Due to their ability to tolerate potential toxic ions in the environment, plants can accumulate trace elements, especially heavy metals, in and on their tissues [8]. The uptake of heavy metals by plants can increase the potential for certain toxic elements to enter the food chain, so understanding how these elements progress through food webs and the effects of such elements on organisms is significant [9].
Several studies have been conducted on the heavy metal contamination of medicinal plants in different countries [10,11]. Despite this, considering the severe consequences that it may have on health and the environment, risk factor assessment, and environmental risk assessment have been conducted by researchers [12,13]. It has been shown that the contamination of heavy metals in herbal
Health Risk Assessment of Heavy Metals in the Medicinal Plants Ziziphora clinopodioides and Echinophora platyloba in West Islamabad and Sanandaj Regions
remedies is an area that requires immediate attention and
whose potential risk to human health has already been
confirmed [14]. It was reported that lead (Pb) was present
in all 10 studied medical plant species, except for Ocimum
gratissimum. Cadmium (Cd) was also detected in some
medicinal plant species, while mercury (Hg) and arsenic
(As) in all plant species were below detection. Therefore,
plant species that grow in different environments absorb
and accumulate different levels of heavy metals [1]. In
another study in South Africa, levels of As, chromium
(Cr), Cd, and Pb were reported to be higher than
permissible levels in medicinal plants, and the risk index
was higher than 1, indicating that the combined effects
of heavy metal contaminants found in a particular plant
product were associated with health [3]. In Indonesia,
heavy metals such as Hg, Pb, As, and Cd in Chromolaena
odorata were studied, and Cd concentrations were
higher than the permissible limit [15]. In a study on 20
medicinal plant samples in Ghana, it was reported that
some concentrations of Cr, Cd, As, manganese (Mn),
and Pb analyzed in every 20 medicinal plant samples
exceeded the WHO limit, while concentrations of Hg
and nickel (Ni) for all samples were lower than the WHO
limit [16]. The concentration of heavy metals in 33 species
of medicinal plants studied in Turkey in industrial and
mineral areas was slightly higher than the limits set
by the WHO. As a result, to avoid the accumulation of
these heavy metals, collecting aromatic herbs must be
done from rural areas, near clean rivers, or mountainous
areas far from highways, mines, and industrial areas [17].
Ziziphora clinopodioides is one of the plants belonging to
the Lamiaceae family, which is found in many parts of
Iran. For this plant, several therapeutic properties have
been reported, including strengthening and relieving
stomach pain, antifever, anti-inflammatory, and relaxing
properties. In different powdered and dried areas, this
plant is used as a dairy seasoning for frying foods and
other items [18].
Khosharizeh, with its scientific name, Echinophora
platyloba, is a pasture and edible plant that is an
automobile in Iran. Khosharizeh is a matte green plant
with a yellowish, sturdy, prickly, and single stem, and it
is very branched, with interlaced branches. This plant is
traditionally used as a food condiment and for yogurt
and cheese aromatization. In addition to the treatment
of gastrointestinal diseases and the control of abdominal
cramps, this plant has antimicrobial, antispasmodic, and
antifungal effects [19]. Heavy metals are important for
human health, and the western regions of the country
are the hubs of medicinal plants in Iran and have high
consumption of these plants. Therefore, it seems that
the concentrations of heavy metals in the case study on
two Ziziphora and Khriz from the Islamabad-e-Gharb
area located in the hills and foothills of Tajar Karam
Panahabad village (the nearest removable area of these
plants to the Industrial Zone in Islamabad West) and
the Sanandaj Mountains are essential. Considering the
high consumption of these two high-profile plants and
their multiplicity in recent years due to the coronavirus
disease and its harvesting from unknown places (i.e.,
mountains and foothills), the issue of food security and
the consequences of heavy metals for the overuse of these
drugs and its implications for society is highly necessary
and researchable. For this reason, the closest place to the
industrial estate in Islamabad Gharbhas chosen a high
harvest rate of its mountains. There has been research
in this field, but, to the best of our knowledge, there is
no research on heavy metals in these two plants and on
a case-by-case basis. Accordingly, this study sought to
evaluate the levels of pollution and health risks caused
by heavy metals to humans, specifically in the medicinal
plants of Kakuti and Khosharizeh.
2. Materials and Methods
This descriptive cross-sectional study was conducted
in the summer of 2021 in Islamabad and Sanandaj.
Five sampling stations were identified in each region.
In Islamabad and Sanandaj, 5 samples of Kakuti and
5 samples of Khosharizeh plants were collected from 3
different points of non-agricultural lands (Figure 1).
A total of 100 samples of Kakuti and Khosharizeh were
prepared, and complete plant samples were placed in
a paper bag for transportation and transferred to the
laboratory. The mountains are located around the village
of Tajar Karam Panahabad from the functions of West
Islamabad at a latitude of 46 degrees and 31 minutes, a
width of 34 degrees and 6 minutes, a height of 135 meters
above sea level, 65 km south of Kermanshah, and on the
way to Kermanshah Khosravi. The climate of this city is
moderate Mediterranean, and the annual rainfall averages
478 mm. Sanandaj is one of the cities of Iranian Kurdistan
and the 21st largest city in Iran. Sanandaj is the capital
of Kurdistan province in western Iran, which is located
at an altitude of 1450–1538 meters above sea level, and
in the mountainous region of Zagros and has a cold and
semi-arid climate. The city is limited to Abidar Mountain
to the west, the famous Sheikh Mountain to the north and
Sirajuddin Mountain in the south, and is spread over an
area of 3688.6 hectares.
In this study, inductivity-coupled plasma-optical
emission spectrometry (ICP-OES) was used to measure
the concentration of heavy metals.
Digested samples were injected into the ICP-OES model
Varian 710-ES device manufactured by Varian Company
in the United States, and the detection limit of μg/kg (ppb)
was calibrated to determine the concentration of Hg, As,
Cd, Pb, copper (Cu), zinc (Zn), Ni, iron (Fe), aluminum
(Al), and Mn in each sample as mg/kg. For the chemical
digestion of the leaves of Kakuti and Khosharizeh, 0.5 g
of each leaf sample was digested in 9 mL of concentrated
Arch Hyg Sci. Volume 13, Number 1, 2024 3
Health risk of heavy metals in medicinal plants
nitric acid (to increase the solubility of heavy metals)
for 15 minutes using an appropriate microwave system.
Samples and acids were placed in suitable inert polymer
microwave containers. The containers were sealed
and heated in the microwave system. Temperature
specifications are specified to allow specific reactions and
include reaching 180 ± 5 °C in less than 5 minutes and
remaining at 180 ± 5 °C for 9 minutes to complete specific
reactions. After cooling, the contents of the sedimentation
vessel and filter of 100 mL were passed and centrifuged,
and the dilute volume of the liquid sample was prepared
for injection into the machine [20]. The risk of consuming
plant products contaminated with heavy metals for human
health was assessed based on daily intake of metal, hazard
quotient, and hazard index. Daily intake (estimated daily
intake, EDI) was calculated to estimate the average daily
intake of body metals, according to the body weight
of a consumer. The amount of daily consumption was
determined by Relation 1 as follows [21]:
Relationship 1: EDI = Cmetal × IR / BW
The risk index (HQ) is used to assess the noncarcinogenic
risk to humans from prolonged exposure to
heavy metals from vegetables, herbs, and fruits. If HQ is less
than 1, it implies that no potential health effect is expected
from exposure, while if HQ is higher than 1, it indicates
that there are potential health risks due to exposure. HQ
is calculated as a fraction of the dose determined to the
reference dose as shown in Relation 2 [21]:
In this regard, the concentration of heavy metals in
plant samples was measured as mg/kg, the IR mean intake
of medicinal plants was determined 20 g/d for adults
and 10 g/d for children, and the body weight (BW) was
considered 70 kg for adults and 15 kg for children in this
study [22]:
Relationship 2: HQ = EDI / RFD
Where EDI is the average daily use of herbal medicines
(mg/kg/d), and RfD denotes the reference dose of metal
(mg/kg/d). RfD is an approximation of the tolerable daily
exposure that a person is expected to have throughout life
without any significant risk of harmful effects. RfD for Pb,
Cu, Cd, Cr, As, Hg, Cu, Zn, Fe, Mn, and Ni was 0.004,
0.04, 0.001, 0.003, 0.0003, 0.0005, 0.04, 0.3, 0.7, 0.014, and
0.02 mg/kg/d, respectively [23].
The risk index (HI) helps assess the overall risk of
carcinogenicity for human health through more than one
heavy metal. Exposure to more than one pollutant leads to
additive effects, as explained in Relation 3 [21]:
Relationship 3: HI = Σ HQmetals
The data were analyzed using SPSS software, version
22. The means of treatments were compared using oneway
analysis of variance and Duncan’s test to determine
the presence or absence of significant differences at the
level of 5% (P = 0.05). An independent t-test was used to
compare the concentration of heavy metals in the studied
plants, Islamabad and Sanandaj. Excel software was
utilized to draw charts and tables.
Figure 1. Geographical Location for Sampling Ziziphora and Other Medicinal Plants
Pour Abbasi et al
4 Arch Hyg Sci. Volume 13, Number 1, 2024
3. Results
The accumulation pattern of heavy metals in
Kakuti in the Islamabad region was obtained as
Mn < Al < Fe < Zn < Cu < Pb < Ni < Hg < Cd < As. In
addition, in the samples obtained from the Islamabad
region, the average of Mn metal was 4725.13 mg/kg,
significantly higher than other heavy metals (P < 0.05).
Further, the mean As content of 0.001 mg/kg significantly
had the lowest values among the studied heavy metals
(P < 0.05). The accumulation pattern of heavy metals
in Kakuti in the Sanandaj region was obtained as
Mn < Al < Fe < Zn < Cu < Ni < Cd < Hg = Cd < As.
Furthermore, as in the Islamabad region, in the Kakuti
samples obtained from the Sanandaj region, the average
Mn metal was 4437.31 mg/kg, significantly higher than
other heavy metals (P < 0.05).
Moreover, the mean As content of 0.01 mg/kg
significantly had the lowest values among the studied
heavy metals (P < 0.05). Cd, Ni, Hg, and Zn (P < 0.001), as
well as Mn and Pb (P < 0.002), were significantly different
in the two regions, and according to the reported averages,
their values in the Sanandaj region were significantly
lower (Table 1).
The accumulation pattern of heavy metals in plant
Khosharizeh in both Sanandaj and Islamabad regions
was obtained as Mn < Al < Fe < Zn < Cu < Ni < Pb < Hg
< Cd < As. Additionally, in the samples obtained from the
Islamabad region, the average Mn metal was 4932.85 mg/
kg, significantly higher than other heavy metals (P < 0.05).
Likewise, the mean As metal content of 0.005 mg/kg
had the lowest value among the studied heavy metals
(P < 0.05).
The average Mn metal in Khosharizah samples of the
Sanandaj region was 4778.29 mg/kg, significantly higher
than other heavy metals (P < 0.05).
Similarly, the mean As metal content of 0.007 mg/kg
was significantly the lowest among heavy metals (P < 0.05).
Cd, Ni, Hg, Cu, and Zn (P < 0.001) as well as Mn and Pb
(P < 0.002) were significantly different in the two regions,
and according to the reported averages, their values in
Sanandaj were significantly lower (Table 1).
The results of the comparison of heavy metal
concentrations in Khosharizeh and Kakuti plants were
obtained as Mn < Al < Fe < Zn < Cu < Ni < Hg < Pb < Cd
< As. In the studied samples, in Khosharizeh, the average
Mn metal was 5112.95 mg/kg higher than other heavy
metals (P < 0.05). In addition, the mean As metal content
of 0.002 mg/kg had the lowest value among the studied
heavy metals (P < 0.05). Further, in the samples of Kakuti,
the average Mn metal was 4258.67 mg/kg higher than
other heavy metals (P < 0.05). The mean As metal content
(0.001 mg/kg) had the lowest value among the studied
heavy metals (P < 0.05).
The results revealed that the amount of metals Ni, Mn, Fe,
Table 1. Statistical Parameters of Heavy Metals in Ziziphora clinopodioides and Echinophora platyloba From Islam Abad and Sanandaj
Location Metals
Ziziphora clinopodioides Echinophora platyloba
Mean ± SD (mg kg-1) P Mean ± SD (mg kg-1) P
Islam Abad
Al
3334.35 ± 577.20
0.152
3551.23 ± 509.40
0.241
Sanandaj 3227.06 ± 679.40 3193.58 ± 508.67
Islam Abad
As
0.001 ± 0
0.046
0.007 ± 0.003
0.003
Sanandaj 0.01 ± 0 0.005 ± 0.002
Islam Abad
Cd
0.04 ± 0.02
0.001
0.011 ± 0.015
0.001
Sanandaj 0.02 ± 0.02 0.049 ± 0.028
Islam Abad
Cu
23.61 ± 6.98
0.112
15.31 ± 6.51
0.002
Sanandaj 21.01 ± 4.20 25.38 ± 9.57
Islam Abad
Fe
74.29 ± 14.94
0.014
72.50 ± 9.27
0.064
Sanandaj 58.94 ± 13.96 74.33 ± 11.05
Islam Abad
Hg
0.06 ± 0.02
0.001
0.028 ± 0.019
0.001
Sanandaj 0.02 ± 0.01 0.058 ± 0.018
Islam Abad
Mn
4725.13 ± 464.22
0.002
4778.29 ± 525.75
0.004
Sanandaj 4437.31 ± 222.60 4932.85 ± 494.31
Islam Abad
Ni
0.29 ± 0.14
0.001
0.229 ± 0.17
0.001
Sanandaj 0.18 ± 0.14 0.289 ± 0.06
Islam Abad
Pb
0.30 ± 0.13
0.002
0.073 ± 0.08
0.001
Sanandaj 0.09 ± 0.11 0.202 ± 0.09
Islam Abad
Zn
35.39 ± 13.53
0.001
39.96 ± 20.87
0.001
Sanandaj 35.29 ± 7.38 41.23 ± 13.78
Note. SD: Standard deviation.
Arch Hyg Sci. Volume 13, Number 1, 2024 5
Health risk of heavy metals in medicinal plants
Cu, and Zn (P < 0.001) in the two regions was significantly
different, and according to the reported averages, their
values in the Sanandaj area were significantly lower. One
sample t-test was used to compare the concentrations of
heavy metals such as Hg, Cu, As, Fe, Pb, Cd, Mn, Zn, Ni,
and Al in two medicinal plants, Khosharizeh and Kakuti,
according to the Iranian national standard and the WHO.
The results demonstrated that the concentrations of heavy
metals, except for Cd, in both plants were significantly
different compared to the national standard limit of
Iran and Ni in both plants compared to the global health
standard (P < 0.001). In the two studied areas, these values
were higher than national and global standards (Table 2).
The results of the health risk assessment of heavy metal
concentration in Kakuti showed that the highest risk
index of heavy metals in the age group of children was
related to Mn (12.15). On the other hand, the lowest value
of the heavy metals risk index for consumption of Kakuti
in children and adults was 0.48 (Table 3).
The highest carcinogenic risk index in two age groups
of children and adults in the Islamabad region was 0.099
and 0.098, respectively (Table 4).
Based on the results of the health risk assessment of
heavy metal concentration in the Khosharizeh plant, the
Table 2. Comparison of the Concentrations of Heavy Metals in Ziziphora clinopodioides and Echinophora platyloba With the National Standard of Iran and the
World Health Organization
Metals Plant Mean ± SD (mg kg-1) P NSI (mg kg-1) P WHO (mg kg-1) P
Hg
Zc 0.049 ± 0.006
0.402 0.1
< 0.001
-
-
Ep 0.051 ± 0.009 < 0.001 -
Cu
Zc 22.53 ± 3.59
0.005 1.5
< 0.001
1.5
< 0.001
Ep 29.59 ± 9.39 < 0.001 < 0.001
As
Zc 0.001 ± 0.0009
0.272 1
< 0.001
1
< 0.001
Ep 0.002 ± 0.0005 < 0.001 < 0.001
Fe
Zc 70.28 ± 4.82
0.008 1
< 0.001
1
< 0.001
Ep 69.73 ± 2.07 < 0.001 < 0.001
Pb
Zc 0.197 ± 0.13
0.873 0.1
< 0.001
0.1
< 0.001
Ep 0.089 ± 0.16 < 0.001 < 0.001
Cd
Zc 0.002 ± 0.0001
0.496 0.1
0.017
0.003
< 0.001
Ep 0.021 ± 0.002 0.004 < 0.001
Mn
Zc 4258.67 ± 423.60
0.001 0.5
< 0.001
0.5
< 0.001
Ep 5112.95 ± 204.52 < 0.001 < 0.001
Zn
Zc 47.31 ± 15.74
0.002 15
< 0.001
15
< 0.001
Ep 42.42 ± 11.21 < 0.001 < 0.001
Ni
Zc 0.140 ± 0.001
0.001 0.07
< 0.001
1.5
0.142
Ep 0.34 ± 0.086 < 0.001 0.005
Al
Zc 3885.58 ± 148.17
0.104 -
-
1.5
-
Ep 3008.77 ± 352.48 - -
Note. Zc: Ziziphora clinopodioides; Ep: Echinophora platyloba; NSI: National Standard of Iran; WHO: World Health Organization; SD: Standard deviation.
Table 3. Health Risk Assessment of Heavy Metals in Ziziphora clinopodioides From Islam Abad and Sanandaj for Adult Consumption
Metals
Islam Abad Sanandaj
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
As 0.102 1.23 0.114 - 0.082 1.08 0.114 -
Cd 0.007 6.82 0.052 0.099 0.006 6.14 0.052 0.087
Cu 0.024 0.52 0.872 - 0.016 0.45 0.601 -
Fe 0.452 0.48 0.809 - 0.304 0.46 0.721 -
Hg 0.236 0.41 0.264 - 0.212 0.08 0.218 -
Mn 0.174 10.11 0.029 - 0.123 7.39 0.027 -
Ni 0.065 1.11 0.176 0.074 0.047 0.97 0.11 0.037
Pb 0.049 6.18 0.051 0.036 0.037 6.09 0.045 0.033
Zn 0.092 0.98 0.965 - 0.074 0.43 0.749 -
Note. EDI: Estimated daily intake; HQ: Hazard quotient; CLI: Consumption limit; HI: Hazard index.
Pour Abbasi et al
6 Arch Hyg Sci. Volume 13, Number 1, 2024
highest risk index of heavy metals in the age group of
children was 12.74 in the Islamabad region. The lowest
value of the heavy metals risk index in Khosharizeh for
adults with Fe in the Sanandaj area was 0.32 (Table 5).
The highest carcinogenic risk index in the two age
groups of children and adults in Islamabad was obtained
for Cd (0.109 and 0.111, respectively, Table 6).
4. Discussion
Heavy metals are biodegradable. Considering that the
accumulation of heavy metals in human tissues and their
adverse effects cause disease and carcinogenesis, the
maximum control of heavy metals in medicinal plants is
one of the issues that should be considered to maintain
the health of consumers and achieve food safety [3,6].
Table 4. Health Risk Assessment of Heavy Metals in Ziziphora clinopodioides From Islam Abad and Sanandaj for Children Consumption
Metals
Islam Abad Sanandaj
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
As 0.072 1.42 0.114 - 0.042 1.19 0.114 -
Cd 0.016 7.32 0.052 0.098 0.003 6.38 0.052 0.095
Cu 0.020 0.49 0.970 - 0.018 0.43 0.733 -
Fe 0.412 0.48 0.852 - 0.384 0.46 0.718 -
Hg 0.098 0.54 0.624 - 0.098 0.68 0.251 -
Mn 0.174 1.15 0.030 - 0.124 9.09 0.046 -
Ni 0.024 1.61 0.094 0.038 0.018 1.03 0.281 0.027
Pb 0.041 8.70 0.049 0.036 0.037 7.09 0.042 0.029
Zn 0.095 0.49 1.645 - 0.071 0.23 0.980 -
Note. EDI: Estimated daily intake; HQ: Hazard quotient; CLI: Consumption limit; HI: Hazard index.
Table 5. Health Risk Assessment of Heavy Metals in Echinophora platyloba From Islam Abad and Sanandaj for Adult Consumption
Metals
Islam Abad Sanandaj
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
As 0.102 0.86 0.138 - 0.069 0.99 0.109 -
Cd 0.008 7.22 0.058 0.109 0.007 6.64 0.055 0.047
Cu 0.038 0.72 1.41 - 0.028 0.55 0.973 -
Fe 0.349 0.34 0.714 - 0.278 0.32 0.682 -
Hg 0.416 1.96 0.299 - 0.401 1.21 0.121 -
Mn 0.304 12.15 0.038 - 0.213 9.47 0.029 -
Ni 0.076 2.83 0.197 0.084 0.062 1.47 0.16 0.059
Pb 0.042 6.45 0.053 0.041 0.034 6.12 0.049 0.038
Zn 0.061 0.67 0.817 - 0.059 0.54 0.007 -
Note. EDI: Estimated daily intake; HQ: Hazard quotient; CLI: Consumption limit; HI: Hazard index.
Table 6. Health Risk Assessment of Heavy Metals in Echinophora platyloba From Islam Abad and Sanandaj for Children Consumption
Metals
Islam Abad Sanandaj
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
EDI
(mg/kg/d)
HQ
CLI
(mg/kg/d)
HI
As 0.062 0.73 0.084 - 0.042 1.01 0.103 -
Cd 0.008 7.84 0.060 0.111 0.007 7.04 0.049 0.050
Cu 0.042 0.76 1.525 - 0.034 0.59 0.980 -
Fe 0.381 0.39 0.791 - 0.201 0.48 0.734 -
Hg 0.386 1.84 0.318 - 0.474 1.37 0.177 -
Mn 0.362 12.74 0.046 - 0.178 9.11 0.036 -
Ni 0.070 2.96 0.141 0.089 0.085 1.62 0.180 0.064
Pb 0.039 6 0.059 0.053 0.034 5.86 0.057 0.047
Zn 0.066 0.601 0.901 - 0.062 0.59 0.832 -
Note. EDI: Estimated daily intake; HQ: Hazard quotient; CLI: Consumption limit; HI: Hazard index.
Arch Hyg Sci. Volume 13, Number 1, 2024 7
Health risk of heavy metals in medicinal plants
In this study, the concentration of Mn in the medicinal
plants Kakuti and Khosharizeh vulgaris in the two regions
of Islamabad West and Sanandaj was significantly higher
than other heavy metals (P < 0.05).
Further, the mean As metal content of two medicinal
plants had the lowest values among heavy metals
(P < 0.05). Mn is an essential and important element for
plant growth and development, maintains a metabolic
role in different parts of plant cells [24], and can perform
two different functions as an enzymatic cofactor as well as
a metal with catalytic activity in biological activities [25].
In addition, Mn plays a role in diverse plant processes such
as chloroplast development, purine and urea catabolism,
phospholipid biosynthesis, DNA repair, and histidine
biosynthesis [26, 27]. Therefore, the high concentration of
Mn in both medicinal plants Kakuti and Khosharizeh sativa
is probably due to the mentioned cases and the application
of Mn in plant physiology. Different amounts of heavy
metals, including Mn, have been reported in a study of
eight medicinal plant species in Sanandaj [28], which is
consistent with the results of this study. Furthermore,
Ziziphora clinopodioides, Centaurea virgata, and Cirsium
congestum have determined the amounts of heavy metals
and Mn [29, 30], which confirms the results of this study
on Kakuti and Khosharizeh. The researchers reported a
concentration of 0.0001–0.002 mg/kg in medicinal plants
[31], which is in line with the results of this study. As is a
toxic element that has no physiological or biological role
in living organisms [32], and probably the reason for its
low content is related to the medicinal plants of Kakuti
and Khosharizeh. It can probably be mentioned that the
alkaline nature of the soil, the amount of organic matter,
and the soil texture are responsible for the transfer of heavy
metals from soil to plants [33]. Cd, Ni, Hg, Cu, and Zn
(P < 0.001) as well as Mn and Pb (P < 0.002) in Kakuti were
significantly different in the two regions, and according
to reported averages, their values were significantly lower
in the Sanandaj region. Moreover, in the medicinal plant
of Khosharizeh, the amount of metals Ni, Mn, Fe, Cu,
and Zn (P < 0.001) in the two regions was significantly
different, and according to the reported averages, their
values were significantly lower in the Sanandaj region.
All elements are naturally present in the environment
with different concentrations, among which are toxic
and dangerous elements. In fact, natural environments
are contaminated with toxic elements on a global scale,
with varying amounts and concentrations [19]. Element
contamination can be of natural and abnormal origin,
and industrial and agricultural activities can also cause
heavy metals to enter the environment, where polluting
metals pollute soil and climate and ultimately harm
the environment [15]. Therefore, due to the sampling
of medicinal plants Kakuti and Khosharizeh in the
vicinity of Islamabad industrial town, it is likely that the
concentration of heavy metals in samples in this region is
higher than in Sanandaj. Habibollahi et al, in a study on
the medicinal plants of Mentha spicata, Mentha spicata,
Glycyrrhiza glabra, Cichorium intybus, Foeniculum
vulgare, and Echium amoenum in Sistan and Baluchestan
province, reported that the most important reason for
the low level of heavy metals in the studied medicinal
plants was the natural growth of these plants in remote
areas of urban and industrial areas that are not affected
by environmental pollutants [22]. This confirms the
results of heavy metal concentration in medicinal plants
of Kakuti and Khosharizeh communis in the Sanandaj
area compared to Islamabad Gharb. Many factors, such
as the abundance of heavy metals in the soil, excessive
application of fertilizers and chemical toxins, as well as
the presence of industrial and mineral wastes in nature
and soil, may lead to the accumulation of heavy metals
in plants [5,7]. The analysis of health risk assessment of
heavy metals in Kakuti and Khosharizeh samples in two
regions of Islamabad and Sanandaj showed that Hg, Pb,
Ni, and Mn metals were higher than 1 in the age groups
of children and adults, but the risk index for Zn, Fe, Cd,
Cu, As, and Al was lower than 1. The carcinogenic risk
indexes of toxic metals Cd, Pb, Ni, and As in Kakuti and
Khosharizeh samples in Islamabad and Sanandaj regions
were higher than 104. In one study, the amount of target
hazard quotient of metals such as As, Hg, Pb, Cd, and Cu,
as well as the hazard index values of the studied metals
in the medicinal plants of mint (Mentha spicata), licorice
(Glycyrrhiza glabra), chicory (Cichorium intybus), fennel
(Foeniculum vulgare), and borage (Echium amoenum), in
the Sistan and Baluchestan region, have been reported to
be lower than 1 [22]. In another Brazilian study, for six
medicinal plant samples, all recorded hazard index values
(Cd, Pb, cobalt, Cu, Fe, Cr, barium, and As) were reported
for adults (30 years old) and children (6 years old) with
an abundance of exposure of 90 days per year less than
1, demonstrating a non-carcinogenic adverse effect
caused by this pathway. However, the long-term health
risk is high, and the non-carcinogenic adverse effect is
not negligible. In fact, the presence of elements such as
Pb, Cd, Cr, and cobalt can harm human health [34]. The
presence of potassium, magnesium, sodium, phosphorus,
Al, Fe, Zn, Mn, Cu, Ni, and selenium in dry samples and
herbal tea has been reported in three species of medicinal
plants, namely, Bauhinia forficata, Eleusine Indica, and
Orthosiphon stamineus.
The studied medicinal plants had high concentrations
of potassium and phosphorus and contained more
magnesium, sodium, Al, Fe, Mn, Ni, Zn, and Cu than the
limits set by the WHO. All hazard index values in medicinal
plants are in the safe range for human consumption [35].
Likewise, in Ghana, EDI and hazard quotient of Hg, As,
Pb, Cd, Cr, Ni, and Mn in 20 medicinal plant samples were
less than the recommended tolerable intake and less than
1 for the reported , and the amount of carcinogenic risk
Pour Abbasi et al
8 Arch Hyg Sci. Volume 13, Number 1, 2024
was within the acceptable range for human consumption,
indicating the absence of potential long-term health
risks for consumers [16]. In another study, 33 Eastern
Mediterranean medicinal plants in Turkey were measured
the recommended dietary allowance for trace elements
and the estimated target hazard quotient and hazard
index for heavy metals. The concentration of heavy metals
in some of the studied plants distributed in industrial and
mineral areas was slightly higher than the limit set by
the WHO [17]. Very low concentrations of some metals
can be toxic and can cause serious health problems if
medicinal plants containing metals accumulated in their
leaves [35].
5. Conclusion
In this study, the concentration of Mn in the medicinal
plants of Kakuti and Khosharizeh in two regions of
Islamabad West and Sanandaj was higher than other
heavy metals. Mn is an essential and important element
for plant growth and development. Therefore, the high
concentration of Mn in both medicinal plants, Kakuti
and Khosharizeh, is probably due to the application of Mn
in plant physiology. The accumulation patterns of heavy
metals in Kakuti plants in the Islamabad and Sanandaj
areas were Mn < Al < Fe < Zn < Cu < Pb < Ni < Hg < Cd < As
and Mn < Al < Fe < Zn < Cu < Ni < Pb < Hg = Cd < As,
respectively. The comparison of heavy metal
concentrations in both Ziziphus and Capsicum L. was
Mn < Al < Fe < Zn < Cu < Ni < Hg < Pb < Cd < As. Analysis of
the health risks of heavy metals in Kakuti and Khosharizeh
samples in Islamabad and Sanandaj regions showed that
the consumption of these two herbs is dangerous for the
health of different age groups. It is recommended that a
comprehensive map of soil contamination is prepared for
medicinal plant-growing areas. Moreover, comprehensive
and complete studies should be carried out on medicinal
plant species that are resistant to heavy metals and on
accumulating plant species from soils and these plant
species should be introduced to the EPA. Considering
that the accumulation of heavy metals in these two species
of medicinal plants have not been studied in Iran, it is
necessary to investigate this topic further and compare
the heavy metals of these two plants in different vegetative
regions throughout Iran.
Acknowledgments
The authors of the article would like to thank the dear colleagues
who helped in the process of conducting this research.
Authors’ Contribution
Conceptualization: Khoshnaz Payandeh, Hosna Pour Abbasi,
Mehrnoosh Tadayoni.
Data curtain: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Formal analysis: Khoshnaz Payandeh, Hosna Pour Abbasi,
Mehrnoosh Tadayoni.
Investigation: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Methodology: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Project administration: Khoshnaz Payandeh, Hosna Pour Abbasi,
and Mehrnoosh Tadayoni.
Resources: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Software: Khoshnaz Payandeh, Hosna Pour Abbasi, and Mehrnoosh
Tadayoni.
Validation: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Visualization: Khoshnaz Payandeh, Hosna Pour Abbasi, Mehrnoosh
Tadayoni.
Writing–original draft: Khoshnaz Payandeh, Hosna Pour Abbasi,
Mehrnoosh Tadayoni.
Writing–review & editing: Khoshnaz Payandeh, Hosna Pour
Abbasi, Mehrnoosh Tadayoni.
Competing Interests
There is no conflict of interests between the authors.
Ethical Approval
This article is a part of the Master’s thesis (ID Number:
1062917537017081400162448179) of the Department of
Food Industries, Islamic Azad University, Ahvaz Branch, and is
entitled “Investigating and comparing the number of heavy metals
and health risk assessment of the medicinal plants Ziziphora
clinopodioides and Echinophora platyloba in the cities of West
Islamabad and Sanandaj”.
Funding
This article has not been sponsored.
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