Research Article - (2021) Volume 8, Issue 3
Received: 10-Jan-2021
Published:
26-Mar-2021
, DOI: 10.37421/2380-2391.2021.8.292
Citation: Swati Singh Chandel, Amar Singh Rana and Muhammad Ibrahim. “Physiological Analysis and Contamination of Heavy Metal Contents in Vegetables and Fruits Irrigated with Wastewater.” J Environ Anal Chem 8(2021). 292.
Copyright: © 2021 Swati Singh C, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The following research work has been undertaken to examine the presence of heavy metals i.e., lead (Pb), Cadmium (Cd), Copper (Cu), Iron (Fe), Cobalt (Co) in some selected vegetables and fruits supplied in the local market. The process used to determine heavy metals is Atomic Absorption Spectrometer. Iron concentration in spinach, tomato, cauliflower and lady finger showed higher ranges which were exceeding the permissible limits. Cauliflower and spinach were within the limits specified. The pH value, ascorbic concentration and moisture content significantly decreased after oven drying of vegetables and fruits. However, the Total Soluble Solids (TSS) and ash content significantly increased after oven drying as compared with fresh vegetables and fruits. The present research data revealed that the fresh and oven dried vegetables such as Spinach, Cauliflower, Lady finger and Tomato contains 0.13-1.50%, 0.25-2.32%, 0.26-2.52% and 0.19-3.13% Titratable acidity respectively. Similarly, fresh and oven dried Guava Titratable acidity was highest 0.27 and 1.92 as compared with Water melon and Mango. The reduction in acidity may be due to catabolic activities in fruit cells and increased in pH. The pH value of vegetables and fruits dropped after oven drying. Similarly, ascorbic concentration and moisture content significantly decreased after oven drying as compared to fresh vegetables and fruits. However, the Total Soluble solids (TSS) and ash content significantly increased after oven drying as compared with fresh vegetables and fruits. Overall, from the following study we can conclude that vegetables and fruits were found to be contaminated by heavy toxic metals. Regular monitoring is required because these toxic metals will damage human body as well disturb our food chain. The main objective to conduct this study is to monitor the heavy metal toxicity and provide some recommendation, which in future will assure food safety and human health.
Vegetables • Heavy metals • Fruits • Human health • Soil • Dietary intake
Vegetables and fruits are of great value and widely used for dietary purposes globally. Fruits are an important constituent because of vitamins, mineral salts, water, nutrients such as calcium (Ca), iron (Fe), Sulphur (S) and potassium (K) [1]. They protect our body from foreign infections. Presence of heavy metals in food supplies will not only cause harm to our body but will also damage our food chain. Due to easy availability of wastewater and scarcity of freshwater, it is mostly used for irrigation of vegetables and fruits. Waste irrigation is thought to make a considerable contribution to presence of heavy metals in wastewater [2]. The metals content of the soil are dangerous because they do not get degrade easily and they can easily get assemble in our body. In-addition these metals are dangerous because they can easily dissolve in our water bodies [3]. A small amount of these metals is harmful because there is no proper method to remove these metals from our body. Heavy metals find their use in many industrial applications and so there are widely spread [4]. Due to this reason the available wastewater have large unit of these heavy metals in them as which when indirectly used for irrigation severely effects human body. Excess amount of accumulation in agricultural land irrigated by wastewater affects the food quality. The metal requirement in our body is obtained from the food and water that we consume and this in turn directly exposes us from the entry of toxic heavy metals [5]. Vegetables play an important role in our daily diet because it has vitamins, minerals dietary fiber and antioxidants. Leaves from different plant species such as perennial and annuals are consumed especially in rural areas and there has been an increased trend of the consumption among the persons living in metro cities. Vegetables which have leaves as edible part are an economic source to ensure the micronutrient intake. Examples include Spinach, Cauliflower, Ladyfinger, Tomato, Watermelon, Mango and Guava.
Rapid industrialization and the use of natural resources have increased the accumulation of toxic substances like heavy metals in the soil. The required protein and vitamin which are supplied by vegetables are best to act against rough digestion and prevents constipation are supplied by vegetables [6]. The spreading of urban waste and sewage sludge in agricultural fields has been a common practice since decades. Sewage sludge, livestock manure, waste water irrigation are feasible alternatives for reutilization of residual resource of high nutrient and organic matter contents representing a good fertilizer or soil conditioner for plants and soil [7]. Besides agricultural fields, recreational parks, golf courses, home gardens are also irrigated using waste waters from sewage plants [8]. The solids from the sewage plants are processed and sold as soil amendments and low grade fertilizers Reclaimed lands are known to contain significant amount of metals and are being used for growing food crops and vegetables. The current research work was conducted with a view to calculate the amount of heavy metals that enter in our body through the agricultural practices that involves the use of wastewater irrigation [9]. The various disadvantage of using wastewater was noticed and daily intakes of heavy metals were calculated with regard to different section of society.
Study area
The following study was conducted in Prayagraj (Figure 1) formerly known as (Allahabad) market which is located at 25.45°N 81.84°E in the southern part of the Uttar Pradesh, at an elevation of 98 meters, shown in Figure 1. It stands at the confluence of two rivers Ganges and Yamuna. It is one of the famous holy cities of India, well known for Magh Mela.
Figure 1. Site selected for sample collection.
Samples collection site
The selected fruits and vegetables for the following study (Table 1) were collected from transporter who were bringing these products from the farmers and were shifting them to local markets. We have taken the edible portions of the vegetables selected for the study.
| Common name | Botanical names |
|---|---|
| Selected vegetables | |
| Spinach | Spinacia oleracea. L. |
| Tomato | Solanum lycopersicum. L. |
| Cauliflower | Brassica oleracea. L. |
| Selected fruits | |
| Mango | Mangifera indica. L. |
| Watermelon | Citrullus Lanatus thumb |
| Guava | Psidium guajava. L |
Determination of pH
pH of each fig sample was measured with the help of digital pH meter (AD 1020) by standard method described by AOAC (2006).
Total Soluble Solids (TSS): Total soluble solids were measured according to procedure of AOAC (2006) using digital refractometer at room temperature.
Moisture Content: Moisture content was measured by using the method prescribed by AOAC (2006).
Determination of titratable acidity: Total titratable acidity was measured by standard literature method given by AOAC (2006) by using 100 ml volumetric flasks separately.
Determination of ascorbic acid
Ascorbic acid was determined with the help of standard method described in AOAC (2006).
Total ash content
Ash content was determined by using AOAC method (2000). Ash content
was determined by applying following formula: 
Preparation of sample
To remove harmful chemicals from the different vegetable samples double distilled water was used. Water content from the edible parts of the plant was removed by weighing the plant sample and then air-drying it. Vegetable samples were dried in oven at 70 - 80°C for 24 hrs to remove moisture from it. Dry vegetable samples were crushed with mortar and pestle and filtered through cotton fabric. All the samples were run in triplicates.
Digestion of the samples
From different irrigation method three powder samples weighing 0.5 g was prepared for each leafy vegetable and three replicates were made. Crushing of ash was done with the help of perchloric acid and HNO3 which was in the ratio 1:4. The sample was left to cool down and it was then filtered using Whatman filtrater paper No 42. A final volume of solution was made with 25 ml of distilled water and was sent for Atomic absorption spectrophotometry.
Standards and statistical analysis of data
Standard solution used (1000 mg/l) (Merck, Germany). Different concentration solution for various metals were also prepared. Data was compiled in Excel sheet and analyzed statistically by using Statistics 8.1 (Statistics software). The analysis of the data was achieved by using one-way analysis of variance (ANOVA) and LSD value of P < 0.05.
When any form of wastewater is added to the soil it changes the physical and chemical properties of the soil. We all know that heavy metals intake by the vegetables and fruits are not only affecting the soil profile but also causing serious health issues. In the following study heavy metal accumulation in edible parts of the vegetable was studied showing the presence of heavy metals i.e., iron, copper, cadmium, cobalt, lead and zinc. Heavy metals showed their presence could be due to following reasons i.e., agricultural practices, geographic position and ability of the plant to absorb heavy metals. The pH value of vegetables and fruits dropped after oven drying. Similarly, ascorbic concentration and moisture content significantly decreased after oven drying as compared to fresh vegetables and fruits. However, the total soluble solids (TSS) and ash content significantly increased after oven drying as compared with fresh vegetables and fruits.
Suggested measure may include regular examination of heavy metals in all the food commodities grown in and out. Daily consumption of food results in long term low level body accumulation of heavy metals, with negative impacts only after certain time interval of metal exposure. As a consequence, regular inspection of these heavy metals from different water sources, vegetables and other daily intake is necessary to their entry in our food chain.
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
The results of the triplicate measurements data used to support the findings are available from the corresponding author upon request.
Swati Singh Chandel and Amar Singh Rana performed the manuscript writing, collected the data and done the partial analysis work of the study. Muhammad Ibrahim carried out the analysis presented in the study and also edited and corrected the manuscript.
The authors are grateful to Dr. Ram Bharose Assistant Professor, Shuats, Allahabad for facilitating the necessary support to carry out the current study.
The authors declare no potential conflict of interest regarding the publication of this work. In addition, the ethical issues including plagiarism, informed consent, misconduct, data fabrication and, or falsification, double publication and, or submission and redundancy have been completely witnessed by the authors.
Journal of Environmental Analytical Chemistry received 1781 citations as per Google Scholar report
