Abstract
General Background: Environmental pollution, particularly by heavy metals, poses a growing threat to aquatic ecosystems and public health. Specific Background: The Euphrates River, a vital water source in southern Iraq, has been increasingly subjected to pollution from urban and industrial activities. Knowledge Gap: Despite its ecological and economic importance, data on spatial distribution and concentration of heavy metals in Suq Al-Shuyukh remain limited. Aims: This study aimed to estimate the concentrations of lead (Pb), copper (Cu), and cadmium (Cd) in the Euphrates River across different locations in Suq Al-Shuyukh city. Results: Using flame atomic absorption spectroscopy, the study found that concentrations of Pb and Cu were notably higher near riverbanks than midstream, indicating waste accumulation in stagnant waters. Pb levels were consistently the highest, suggesting it as the primary pollutant. Novelty: The study provides new comparative data between river center and bank pollution levels, highlighting critical zones of contamination previously underreported. Implications: The findings emphasize the urgent need for environmental monitoring and remediation strategies to mitigate heavy metal pollution in the Euphrates River, thereby protecting human and ecological health.
Highlight :
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The study confirms elevated concentrations of lead and copper in riverbanks compared to midstream, indicating significant localized pollution.
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Cadmium, though less concentrated, exceeds WHO safety limits, posing long-term health risks due to accumulation in living organisms.
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Effective mitigation techniques such as chitosan and biomass treatments are proposed for removing heavy metals from water.
Keywords : Heavy Elements, Euphrates River, Environmental Pollution, Suq Al-Shuyukh, Water Contamination
A.Pollution is defined in different ways, including primary definitions that state that if the water is not composed of H2O% (Meaning it was not completely pure chemically), which means it is contaminated. This definition is not reasonable and is of limited usefulness. When a drop of water comes into contact with air, it contains dissolved gases such as carbon dioxide (CO2) and oxygen (O2). Also, every drop of water that comes into contact with sediments and rocks contains certain elements such as silicon and calcium. These components are completely natural [1] .
The second attempt to define pollution is the presence of any chemical substance in water at a concentration above the natural level (also called the base level). This type of pollution is caused by additions resulting from human activities. Compared to the first definition, this definition is somewhat acceptable.
Pollution can be defined in a third, more useful way: a pollutant is a substance or effect that changes the environment in a negative way by altering the growth rate of living organisms, interfering with the food chain, being toxic, and affecting people’s health, comfort, and prosperity.[2]
According to the definition above, there is a need to develop a standard or recommendations that stipulate that water whose chemical properties exceed the recommended limits can lead to certain environmental changes or interactions.
The following recommendations are made according to the above definitions:
- Physical properties in terms of temperature, color and smell.
- Certain elements, organic compounds, and complex ions.
- Radioactive properties.
- Chemical properties such as pH, total solids, salinity and oil residue.
A brief overview of heavy elements:-
- Heavy metals: There are elements in nature with high densities of more than 5 g/cm3, and these elements have highly toxic effects. The atomic weight of these elements ranges between (63.545 - 200.5) and they are classified as toxic metals. [3]
- Often, human activities are the cause of water pollution with heavy metals. [4]
- There are several applications for heavy metals, including in industry, agriculture, and medicine. A certain fraction of these metals, like copper and zinc, are present in the human body, but not in amounts that are harmful and are adequate to support bodily processes. When the body's tissues absorb significant amounts of heavy metals, toxicity results.[5]
B. The importance of heavy metals to humans, animals, and the environment
- The heavy elements come in the human body through food, drink, and also through the air. [6]
- The metabolism process inside the human body requires heavy elements to complete the metabolism process. These elements must enter the human body in an appropriate amount so that they do not reach toxicity.
- These elements tend to accumulate, and this is where their danger lies (Accumulation is the gradual rise in a chemical's concentration within an organism's body) [7]
Even though these elements are necessary for living things, an increase in concentration makes them hazardous.Table1. showing some heavy metals, These elements include copper, zinc, obalt, nickel, manganese, chromium, and cadmium. Others, such as lead, arsenic, and mercury, are non-essential and are toxic at low concentrations [8] .
Elements | Chemical symbol | atomic weight |
---|---|---|
Aluminum | Al | 27 |
Barium | Ba | 137 |
Arsenic | As | 75 |
Chromium | Cr | 52 |
Copper | Cu | 63.5 |
Cadmium | Cd | 112 |
Lead | Pb | 207 |
Nickel | Ni | 59 |
Manganese | Mn | 55 |
Mercury | Hg | 201 |
Iron | Fe | 56 |
C. Harmful Effects of Heavy Elements:
1. Cadmium: It is considered a highly toxic heavy metal, and interest in it as an environmental pollutant began late in 1960 AD after the appearance of Itai-Itai disease in the data due to feeding on rice irrigated with water contaminated with cadmium (Itai, signifies pain). Consuming food or beverages tainted with a concentration of the metal, such as 16 mg/liter, can result in cadmium poisoning [9]. Symptoms of poisoning appear after several years and after large amounts have accumulated in the body. Symptoms of poisoning include nausea, vomiting, and abdominal pain. Sources of contamination with this element include smoking, cooking utensils, industrial pollution, and waste burning [10] . Cadmium also has toxic effects on the skeletal system due to its impact on phosphorus and calcium metabolism, resulting in decreased calcium absorption and osteomalacia. Cadmium also has a direct impact on high blood pressure due to cadmium's effect on vasoconstriction. Lung and prostate cancer are among the cancers that cadmium can cause. Additionally, it disrupts kidney function and, in more severe cases, can result in renal failure [11]. The effects of cadmium on the environment are due to its chemical toxic properties and essential micronutrients for plants, animals, and humans [12]. The maximum permissible intake of cadmium according to the World Health Organization is 450 micrograms per person.
2. Lead: When lead concentration increases in the aquatic environment and thus affects aquatic organisms such as fish, pollution occurs due to industrial and human activities. Sources of lead pollution are battery factories and mining industries. Solid fuel (coal), liquid fuel (petroleum derivatives), Pipeline pipes for the transportation of potable water and the removal of certain industrial waste [13]. Many systems in the human body are impacted by lead poisoning, including the kidneys, circulatory system (blood), neurological system, and excretory system. Lead is also having an impact on the metabolic functions of living things. [14]. Anemia, appetite loss, blue gum discolouration, and a child's diminished capacity for learning are the most significant signs of poisoning. These symptoms occur when the level of lead in the blood reaches (0.6-0.8 ppm). Lead is one of four metals that pose a danger to human health. Lead enters the human body from the following sources: (65% of food, 20% of water, 15% of air). Lead does not contribute to any vital function in the body, but it harms humans when they ingest it through food, water, and air [15]. One heavy metal that can be found in the air, water, rocks, and soil is copper. While copper's advantages for the human body are significant, there are risks associated with water containing too much copper, many times the benefits it offers. Harmful effects of copper in water:
Harmful effects of copper in water: Increased copper concentration in water that exceeds 15 ppm causes many health problems for the kidneys, stomach, and liver and causes anemia. High copper concentrations are not necessary for human health and should not be present in excess of the specified percent to avoid endangering human well-being.
When copper water pipes are used in residences, there is a risk of water contamination. Gradually, these pipes corrode and rust [16].
3. Nickel: Nickel is a heavy metal. When its concentration in the environment increases, it causes toxicity to plants and animals. Nickel poisoning occurs when low concentrations in food cause liver damage, reduced iron absorption, and decreased activity of many enzymes. When humans are exposed to high concentrations of nickel, such as in alloy workers, it causes toxicity and cancer. Human exposure to nickel occurs through breathing air and drinking water, eating foods contaminated with nickel, or smoking cigarettes. Skin exposure also occurs through contact with soil or water contaminated with this metal.
Foods contain trace amounts of nickel, and consumption rates increase when large quantities of vegetables grown in contaminated soil are consumed. The average daily intake of nickel in a human diet ranges from 200 to 300 micrograms. The human body needs a small amount of it, most of which is found in the pancreas and plays an important role in insulin production. Nickel is also found in the environment in association with oxygen or sulfur and is a product of volcanoes. Nickel causes skin allergies, while nickel and its salts do not cause poisoning, but are known to be carcinogenic and affect the lungs and sinuses. As for the sources of nickel in the environment, it is found in small quantities, despite its presence in many minerals that contain the element nickel.
4. Nickel harms: Consuming small amounts of nickel is essential, but excessive consumption can pose health risks, including lung, nasal, throat, and prostate cancer. It can also cause respiratory failure, birth defects, asthma, and bronchitis. Exposure to nickel gases can cause dizziness and fatigue. Wearing jewelry can also cause allergic reactions, such as skin rashes.
Fish are one of the most important sources of protein in the aquatic environment, ranking first in terms of catch and human consumption. The US Environmental Protection Agency recommends eating two meals of fish per week.
While protein, vitamins, minerals, and unsaturated fats (such omega-3) are all found in good amounts in fish, Additionally, they are a significant supplier of metals that are heavy. The transfer of metals that are heavy through the food chain depends on feeding habits, metabolism, age, size and length of the fish, As in Figure1. shows how heavy metals affect people [17].
Figure 1.shows how heavy metals affect people [18]
D. The purpose of the study and environmental impacts
Knowing everyone : -
- The presence of heavy elements in the Euphrates River in the southern Iraqi governorate of Dhi Qar.
- Environmental pollution with heavy elements and their impact on living organis.
E. Proposals to remove heavy elements or reduce their impact
Many studies have been conducted on pollution and mitigating its effects. Among these studies, researchers from the Hefei Institute of Physics of the Chinese Academy of Sciences have created a nanomaterial from cardboard waste by applying high temperature and pressure. The new material, which can be coated with nano-iron, can effectively remove hexavalent chromium from water.
The biological role of chitosan (chemically prepared from shrimp shells and crab exoskeleton) was also studied. It was used at a concentration of 0.01 w/v and pH range 4-8 for 12 hours in precipitating and retaining heavy metals (Cu, Cd, Fe, Zn, Pb). Metal concentrations were identified with the use of atomic absorption spectroscopy. According to the study's findings, the water's highest concentration of mineral elements was before treatment with chitosan, with a clear decrease in mineral concentrations observed after treatment with chitosan. The study results also demonstrated chitosan's high potential for precipitating mineral ions from polluted water, and that crab chitosan was better than shrimp shell chitosan at precipitating these metals. Furthermore, an acidic medium (pH = 4) was better than an alkaline medium in its ability to precipitate heavy metals.
Another method used to remove heavy metals is biomass, which has the ability to adsorb heavy metals. Biological materials that can adsorb heavy metals, such as bacteria, algae, yeast, fungi, and agricultural waste, are called biomass. These materials are currently widely used to remove heavy metals from aquatic media due to their abundant availability, low cost, and excellent performance [19].
F. Study area:-
The study area in this research was determined within the municipal boundaries of Souq Al-Shuyukh city, the city center.
G. Site description:-
Different locations were selected along the Euphrates River in the center of Suq Al-Shuyukh city, and samples were collected from the middle and river banks of each location.
Materials and Working Methods
A. Instruments used in the research:
Flame atomic absorption spectroscopy.
The study began in the summer of 2024, and samples were collected from within the river in areas identified as potential sources of pollution. Several Samples were gathered from the locations. identified in the study, that includes the city center. Samples were collected from the middle of the river and from the river bankThe purpose of the seasonal study was to determine the levels of heavy metals in site-specific water samples.
B. Estimation of heavy elements in water:
The concentrations of the heavy elements under Lead, zinc, copper, and cadmium were calculated using the methodology outlined in (APHA 1985).
- Take 50 ml of water and put it in a 100 ml glass beaker.
- Add (5 milliliters) of digestive nitric acid.
- Using a hot plate, heat the flask until it reaches the pre-drying stage.
- The sample was then heated until a precipitate formed, then 5 milliliters of strong nitric acid was added. Once cooled, After filtering, 25 milliliters of deionized distilled water were added to finish the volume. When the heavy elements were determined, the sample was prepared. The absorbance of the digested samples was measured using an atomic absorption spectrometer.
- For every heavy element, find the wavelength and current that are employedas in the table2.
Table (2)
Element | Wavelength | Current used (mA) |
---|---|---|
Copper | 224.8 | 5 |
Lead | 217.0 | 6 |
Cadmium | 228.8 | 6 |
Zinc | 213.9 | 10 |
Results and Discussion
Results and discussion: After measuring the element concentrations of the samples, the data were obtained and their average was as follows shown in the table3:
Area | the site | Cd | Pb | Cu |
---|---|---|---|---|
Souq Al-Shuyukh South of Dhi Qar Governorate | center R1 | 0.06 | 2.40 | 0.53 |
The cliff R2 | 0.40 | 28.0 | 14.0 | |
We note from the table above that the concentrations of elements in the river bank R2 are higher than the concentrations of elements in the running water in the middle of the river R1. This is due to the accumulation of waste in the river bank for a period that allows the waste to decompose as pollutants, and stagnant water helps increase the concentration of these elements in the water. We also note that the average concentration of lead is higher than other elements in the middle and bank of the river. While the concentration of cadmium is also higher than the permissible limits, it is considered the least element causing river water pollution with heavy elements according to this study.
Conclusion
We note from the results obtained during the study period that the Euphrates River water in the study area is contaminated with the elements mentioned in Table (4). This pollution causes great harm to human and animal health, as well as agriculture.Therefore, studies are being conducted on this topic and the results are being compared with previous studies, and the lack of following these practices is a result of this pollution.
Sources | Elements | ||
---|---|---|---|
Cd | Pb | Cu | |
Al-Khafaji, (2010) | 0.30 | 11.17 | 30.40 |
Al-Khafaji,1996 | 0.27 | 17.74 | 29.24 |
Current study | 0.40 | 28.0 | 14.0 |
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