Transfer and accumulation of cadmium in soil, forages and animals: Risk assessment

Over past several years pollution in industrialized areas is the most attention seeking issue. Higher level of heavy metals especially cadmium is accumulated in atmosphere evolved from smoke of automobiles. Living system present around the contaminated areas accumulate heavy metals in their bodies. Heavy metals have been accumulated in soil, water, forages and animals so study was conducted in industrialized area Faisalabad to evaluate the possible risk. Three sites was selected to check the accumulation of cadmium in soil, water, forages and animals. These sampling sites was areas along the roadsides of Chak Jhumra, Jaranwala and Samundri. Sample of soil, forages,water and blood,hair feces of animals was collected from these sites. The digestion of samples was carried out with the help of nitric acid and hydrogen peroxide. Atomic absorption spectrophotometer was used to evaluate heavy metal analysis. Analysis of variance was done by using SPSS Software (version no. 20) and two ways ANOVA. Result indicated that concentration of Cd was higher in soil irrigated with municipal wastewater and concentration of Cd was highest in forages C. album present at site III. Higher concentration of Cd was observed in blood of sheep higher than critical value. Concentration of cadmium was higher than critical in blood of animals indicating transfer of metal via intake of contaminated forages. The sample collected from site III showed high daily intake of metals (DIM), health risk index (HRI), pollution load index (PLI), enrichment factor (EF) and Bioconcentration factor (BCF). This study will bring consideration concerning the development of approaches in order to overcome the toxic effects of cadmium. of and other ordinary procedure. Cadmium concentration in Sargodha, Mianwali and Bhakkar higher concentration found in Sargodha 4.57 to 4.94, 2.98 to 3.95 in mianwali, and least concentration found in bhakar which is from 1.65 to 2.98mg/kg. forages of Sargodha contain cadmium level from 2.745–3.432 in Mianwali forages have 2.245–3.196 cadmium values and forages of bhakkar contain cadmium 1.9-2.036 mg/kg. blood of goat and sheep grazing on a contaminated forages which is grown in contaminated soil is examined and it shows that the values of cadmium in goat and sheep of Sargodha is between 2.152–2.436, 2.152 to 2.436 mg/L correspondingly. Goat and sheep of Mianwali contain cadmium level 1.727–2.39, 1.794 to 2.286 mg/L respectively and in district bhakkar cadmium level in blood of goat and sheep is 2.3–2.62, 1.97 to 2.066 mg/L correspondingly. These values are within the acceptable values as set by the WHO (Khan et al.2019). Aim of present study was to investigate the concentration of cadmium in soil and transfer of cadmium in soil-plant-animal systems Square kilometers comprehending of subsequent eight tehsils. The specimens of available soil, forages, fodder crops and blood of animals are collected from three different sites of GW I Chak Jhumra, CW II Jaranwala, MWW III Jaranwala of District Faisalabad. Three replicates of sample are collected from each site. Sampling was done in Aug-2019 to May 2020.


Introduction
Any metallic element that have higher density than water are termed as heavy metal(1a) many natural as well as anthropogenic activities (scorching of fossil fuel, mining operations, metallurgy industry, means of traveling) have distributed toxic metals in environment. these metals linger for extended duration ultimately effecting all the components of environment (Kaplan et al.2010). Over the past several years these toxic metals contamination associated with the ecologic as well as public health issues. Use of toxic metals in various daily based activities including (technical, manufacturing activities, household, farming) have increased human exposure to toxic metals (Bradl, H.,2005). separate researches have been conducted to investigate the effect of various metals in soil, water air and plants (Kabata Pendias.,2001;Kabata Pendias.,2007). plant considered as good bio-indicators for presence of metal at particular soil as plant could absorb metals naturally. They are intermediate medium by which metals move from soil, forages to animals and humans (Kabata Pendias.,2007) in case of lead small quantity of Pb absorbed by the roots of plants and its subsequent transfer to aerial parts limited (Kabata Pendias.,2001). Toxic metals are gathered in vegetation, and faunas nourished on these vegetation resulting in accumulation of lethal metals. Wastewater contain most persistent contaminants known as heavy metals and trace metals. Many environmental danger are produced by the liberation of toxic metals into water especially in enormous amount. Heavy metals are exposed to humans by different ways some of these are by eating and drinking contaminated food and water, evaporation, breathing in air full of dust and smoke. Toxicity due to pollutants may be long or short term basis and water ecological unit is also effected by the heavy metals by expiring biota, eutrophication, reduction of locale as a result of sediment formation and waterlogging. Metabolism and functional processes that result in nutrient uptake and growth of fodder crops can be prevented by the heavy metals in soils present in large number and lessen the superiority and magnitude of food obtain. Animals are also threatened by the heavy metals as some effects caused by metals can lead to death these effects includes ,tumor formation, malfunctioning of nerves and different body parts. Numerous chemical or natural strategies are suggested by the researchers in order to overcome the destructive effects of toxic material on all the organisms living or non-living. For the avoidance of availability of heavy metals in soil and water treatment method of wastewater supplied to the irrigated fodder crops are vital by using natural avoidance method by the plants or different microbiota (bacteria, fungi, algae, protozoa) living in soil near the crops grown these help to restore the surrounding (Akpor et al.2014). Various districts of Punjab was studied to examine heavyweight elements metals pollution and their occurrence in soil, water, forages, animals and humans and appraisal of health problems due to different activities which may be related to industries, farming, extraction of minerals and other ordinary procedure. Cadmium concentration in Sargodha, Mianwali and Bhakkar higher concentration found in Sargodha 4.57 to 4.94, 2.98 to 3.95 in mianwali, and least concentration found in bhakar which is from 1.65 to 2.98mg/kg. forages of Sargodha contain cadmium level from 2.745-3.432 in Mianwali forages have 2. 245-3.196 cadmium values and forages of bhakkar contain cadmium 1.9-2.036 mg/kg. blood of goat and sheep grazing on a contaminated forages which is grown in contaminated soil is examined and it shows that the values of cadmium in goat and sheep of Sargodha is between 2.152-2.436, 2.152 to 2.436 mg/L correspondingly. Goat and sheep of Mianwali contain cadmium level 1.727-2.39, 1.794 to 2.286 mg/L respectively and in district bhakkar cadmium level in blood of goat and sheep is 2.3-2.62, 1.97 to 2.066 mg/L correspondingly. These values are within the acceptable values as set by the WHO (Khan et al.2019). Aim of present study was to investigate the concentration of cadmium in soil and transfer of cadmium in soil-plant-animal systems Materials And Methods

Location
The study area Faisalabad district is an area of Punjab, Pakistan. This is a industrial area where most of the crops are grown in wastewater. Different fodder crops and forages are being cultivated in a wastewater directly or indirectly. This city of Pakistan is well-known for its industrial activities are contributing to the economy of country as well as to the growing pollution in the region. High tra c are being observed in this city which is largely due to the population explosion which is ultimately increasing demand for food. Conferring to the 1998 survey of Pakistan. Faisalabad is the 3 rd biggest city of Pakistan after Karachi and Lahore. Faisalabad ranges above an area of 5856 Square kilometers comprehending of subsequent eight tehsils. The specimens of available soil, forages, fodder crops and blood of animals are collected from three different sites of GW I Chak Jhumra, CW II Jaranwala, MWW III Jaranwala of District Faisalabad. Three replicates of sample are collected from each site. Sampling was done in Aug-2019 to May 2020.

Climate
Regular yearly precipitation is around 615 millimeters (24.2 in).Summer season is hot and dry but during the month of July and August monsoon season brings rainfall. Monsoon season ends in September passes precipitation beginning loud over owing. July is the rainiest duration yearly result in ood. winter season brings considerable rainfall accompanying with hail.

Vegetation
District Faisalabad is primarily urban area with industrial and agricultural activities. Along with the large production of vegetables food crops are also cultivated to ful ll the feeding requirements of livestock as well as human beings. These crops includes kharif crops and Rabi crops Kharif Fodder Crops Guar maize, sorghum S.S. Hybrid, millet etc Rabi Fodder Crops berseem Lucerne mustard Rape & Mustard. Major fruit production includes citrus, guava and mangoes

Collection of sample
Forage samples samples of four forages have been collected. This specimens selection ware executed in ve duplicates of every specimen for each place. Samples of Berseem, Brassica, sugar beet, sugar cane have been collected from the roadsides of each site. Samples of forages have been exposed to dry in the air and in oven at 75°C for week. When sample was completely dried this was subjected to grind into powder form and 2g sample was taken for further digestion process. Soil Samples 1kg soil sample were collected along with forages about 30 soil sample were collected. Soil sample were weighed in order to check the moisture content then soil sample were air dried for 24 hours then these sample were further dehydrated in microwave to remove moisture content was removed from the soil. Then these samples have been beaten using pestle mortar and about 2g of every sample used to be saved for the in addition technique after sieving of all samples.

Water samples
Water which is supplied to the relevant fodder collected were also taken in 1Litre bottles from each site. 5ml were stored for additional digestion

Dry digestion
Dry digestion was carried out in order to decompose all the natural rely in the samples of forage and soil. Principally made to obtain: Thorough disintegration of biological environment

Avoiding impurity
A whole solution of matrix (Jones, 1984) Weighing each crucible Before performing dry digestion each crucible were weighted and noted by using weigh balance.

Forage
Forage (5g) were added in each crucible and again weight of crucible+ forage noted. It was heated until the formation of ash and then after drying this ash is kept for 24 hours. Ash weighted again and dissolve in 50ml water and kept it for metal analysis.

Soil
Soil (5g) added in digestion chamber along with 2ml sulfuric acid.Entire concentration of toxic minerals in soil has been investigated afterward the digestion. About 2.5ml of nitric acid, 0.5ml 30% hydrogen peroxide and 7.5ml of hydrochloric acid have been used (Kilburn, 2000).

Water
Few drops of sulfuric acid were added in beaker containing 5ml of water and boil it until the appearance of smoke then 2ml of hydrogen peroxide was added process was repeated until and unless water becomes clear by using lter paper water was ltered and lled in a bottle.

Dilution and ltration
All the digested samples have been diluted via freshly prepared distilled water making their extent up to 50ml. The dilution of the samples used to be followed through their ltration and labeling. All the samples have been then saved in plastic bottles

Metal analysis
All the processed samples are then analyzed through Atomic Absorption Spectrophotometer to nd heavy metal concentration in samples.

Statistical analysis
Data obtained from soil, forage, and blood samples were investigated and mean contents of heavy metals were present in each replicate. Variance and correlation were determined using SPSS Software and two way ANOVA.
Indices for pollution exposure assessment  and smallest values was found in feces cow at municipal wastewater irrigated site (Table 4) Water Heavy metal analysis showed result of concentration of Cd in ground water varied from 0.42-0.71 mg/L, while in canal water values varied from 1.06 to 1.29 mg/L. Municipal waste water showed values from 0.94 to 1.12 mg/L (

Pollution load index (PLI), Bio-concentration factor (BCF), Enrichment factor (EF) of cadmium
Higher BCF value was found in C .album at municipal waste water irrigated site while lower BCF value was observed in S. o cinarum. Pollution Load index varied from 0.286 to 0.689 mg/kg. Highest concentration was present in T .alexandrinum and lowest concentration was observed in S. o cinarum. EF values ranged from 1.77 to 10.32 mg/kg. Maximum concentration was found in C .album at municipal wastewater irrigated site while minimum concentration was found in S. o cinarum at municipal wastewater irrigated site ( Table 6) Daily intake of metal (DIM) and Health risk index (HRI) Highest DIM of Cd was observed in sheep grazing at C. album while lowest DIM of metal was present in cow feeding on T.alexandrinum. Maximum HRI was observed in sheep eating C. album while minimum value was present in cow feeding S. o cinarum. (Table 7) Discussion Nawab et al. (2015) noted that Cd concentration ranged from 0.5 to 8 mg kg − 1 which is higher than our present concentration. Khan et al. (2013) studied the effect of wastewater irrigation in soil and reported Cd concentration 0.098-0.52mg/kg lower than those observed by present study. Faiz et al. (2009) observed Cd concentration in the soil ranged between 5.8-6.1 mg kg collected from Islamabad city higher than present study. Cd can be toxic for human if exposed for a longtime it can damage kidney. Similar result was found by Liang et al. (2012) that Cd concentrations surveyed in ve sites was ranging from 0.90 to 1.76 mg/kg. Concentration of Cd revealed by current observation found higher than Iqbal et al. (2016). Karimi et al. (2020) reported higher concentration than current concentration. Similar result has been found by Yu et al. (2016) studied metal concentration in soil with sewage irrigation Different factor are responsible in transferring metal from soil to growing plants. Various researcher reported that availability of metal in soil effected by different factors for example PH, carbon content age of growing fodder crops etc. it is obvious that availability depends upon metal content in soil its PH and type of soil. (Yu et al., 2016: Mapanda et al., 2005. Current values lower than values observed by Khan et al., (2015). Similar nding was observed by Ruchuwararak et al.(2019). Our value was greater than critical limit (1.1 mg/L) noted by FAO/WHO (1996). Current result of Cd illustrated higher than reported by Yu et al. (2016)Absorption of cd by forages is largely greater as compared to other metals higher concentration of Cd surpasses the permissible limit and considered harmful for humans (Li et al., 1994).Cd is easily absorbed by forages and its buildup in human beings results in damage to vital organs including liver, brain and heart.(Tataruch and Kierdorf 2003). Khan et al. (2015) observed 2.15 to 9.50mg/kg in different forages irrigated with wastewater these values are higher than our values. Okareh and Oladipo (2015) reported concentration of Cd in blood ranged from0.01 6.11 mg/L which was higher than current concentration. Present concentration were found above the critical limit which is 0.1 mg /L (WHO 1983) Present study reported larger content than those informed by Gowda et al.(2003). Ubwa et al. (2017) reported lower concentration of cd in blood than present observed concentration. Reason of different concentration of Cd in blood of animals was due to Grazing of animals on contaminated area and drink contaminated water originated from different sources for example river, streams and ponds similar result was reported by Nwude et al.(2010). Present content of Cd was higher than critical limit of Cd in blood of animals 0.5 mg/L as observed by WHO (2000). (Krupa et al., 2006: Cygan-Szczegielniak et al., 2014: Gabryszuk et al.,2008:Su et al., 2017 reported lower concentration of Cd in hair of animals than current observed concentration. Yang et al.(2017) studied cd content in feces of animals ranged from 0.01-8.7mg/kg. Sharma et al. (2006) suggested values of Cd in water varied from 0.02-0.04mg/L while Ahmed et al.
(2010) noted values ranged from 0.02 to 0.08mg/L both of the ndings were Found lower than current observed concentration of Cd in irrigation water while safe limit of Cd in water was reported 0.01mg/L (Pescod ,1992) our concentration of Cd surpass this concentration. Alrawiq et al.(2014) reported BCF values varied from 0.221-0.490 mg/kg lower than present study. Liu et al.(2005) reported that BCF > 1 indicates that metal is present. Rabee et al.(2011) studied greater PLI concentration than present observed concentration. Pollution load index is measurement tool to assess the heavy metal pollution. PLI greater than 1 indicate contamination by metal but PLI less than 1 showed metal is not causing pollution. ( Chakravarty and Patgiri 2009

Conclusion
Heavy metal pollution becomes serious concern now a days.in this research heavy metals analysis of soil, forages and animals indicated higher concentration of cadmium in forages than allowable limit. Cadmium concentration in blood of animals was higher than critical limit.so consumption of such forages may not safe for animals grazing on it however further investigation on contamination of other forages is necessary.

Declarations Ethics declarations
Con ict of interest: The authors declare that they have no con ict of interest.
Ethical approval: The authors declare that the manuscript has not been published previously.
Consent to participate: All authors voluntarily to participate in this research study.
Consent to publish: All authors consent to the publication of the manuscript.
Availability of data and materials: All data generated or ana-lyzed during this study are included in this published article.
Contributions: RS and AA were responsible for writing the manuscript. KA and ZIK supervised the study. Ayesha