At the crossroads between agriculture and environmental preservation, a crucial challenge arises: heavy metal pollution in water and soil. These toxic elements, which include lead, mercury, cadmium and arsenic, represent a latent threat to sustainable agriculture and human health. Let us dive into this complex scenario to understand the hidden dangers and implications it brings.
In an increasingly industrialized world, human activity has released large quantities of heavy metals into the environment. Coming from industries, mines, waste disposal and the indiscriminate use of fertilizers and pesticides, these pollutants find their way into water sources and infiltrate agricultural soils. Over time, they accumulate insidiously, threatening the integrity of our ecosystems and food security.
The heavy metals present in the soil considered to be very toxic and in concentrations that exceed toxicity levels are: Silver (Ag), Arsenic (As), Bismuth (Bi), Cadmium (Cd), Cobalt (Co), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Palladium (Pd), Platinum (Pt), Antimony (Sb), Selenium (Se), Tin (Sn), Tellurium (Te), Thallium (Tl) and Zinc (Zn).
Of all the heavy metals mentioned, only ten They are easily mobilized by human activity in proportions greater than those caused by geological processes, which are: Silver (Ag), Arsenic (As), Cadmium (Cd), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Antimony (Sb), Tin (Sn) and Thallium (Tl)
Among the various existing methods for controlling this type of metals we can find methods such as:
- Precipitation
- Oxidation-reduction
- Ion exchange
- Filtration
- Electrochemical treatment
- Membrane and evaporative recovery technologies
- Adsorption and bioadsorption
Heavy metals deposited in soil tend to remain, mainly in the surface horizons. These metals are subject to retention processes similar to those that occur in natural soils, but are usually found in higher concentrations and in complex forms that vary depending on the contaminant source. Some of these processes include precipitation as a solid phase in the soil, adsorption by inorganic colloids such as clays, oxides and oxyhydroxides of iron and manganese, as well as on organic matter. Chelatization reactions with soil organic matter may also occur.
In the soil, these elements adhere to particles, contaminating the habitat of plants and crops, since, through their roots, plants absorb heavy metals and over time, their effects manifest themselves in the form of physiological alterations, limiting their optimal growth and development. These persistent toxins not only affect the nutritional quality of food, but also represent an obstacle for farmers, who see their ability to produce safe and healthy food diminished.
Metals in water
Water, essential for life and agricultural production, becomes a breeding ground for heavy metal toxicity. Aquifers and waterways used for agricultural irrigation are compromised by the infiltration of these pollutants, reaching the roots of crops directly and spreading throughout the food chain. In addition, rainfall washes heavy metals from the soil, expanding their negative impact on aquatic ecosystems and crops.
These heavy metals affect ecosystems and are mainly caused by human activities, such as mining, smelting and other industrial and urban activities. This leads to a series of problems both for plants, since heavy metals are deposited in the soil transported by rivers, causing decreased growth and yellowing of leaves (chlorosis), and for humans.
“It is estimated that the water pollution rate can reach 200 million cubic meters per day”
But the danger doesn't stop there. Chronic exposure to heavy metals through the consumption of contaminated food can have devastating consequences for human health. From neurological disorders to damage to vital organs such as the kidneys, liver and cardiovascular system, these toxic elements represent a silent threat that increases the risk of serious diseases, including cancer.
The largest source of water pollution from heavy metals comes from wastewater discharges resulting from various human activities, mainly industrial. The degree of contamination of water sources increases every day due to the constant use of these metals in industry, which increases their concentration in water and, therefore, the risk to humans and other living organisms by increasing the probability of exposure to these metals.
Is worrying consider the permissible levels of metals such as mercury, lead and chromium in water intended for human consumption is of 1.0 µg/L, 10 µg/L and 50 µg/L respectively according to legislation RD 140/03 and NTC 183, while the United States Environmental Protection Agency (EPA) establishes maximum values of 2.0 µg/L, 15 µg/L and 100 µg/L respectively.
In this context, it becomes imperative to comprehensively and effectively address heavy metal pollution in water and soil. The implementation of rigorous monitoring, environmental remediation and sustainable management strategies becomes essential to safeguard our natural resources, preserve biodiversity and protect the health of farming communities and consumers.
Join us on this fascinating journey to discover the keys to mitigating the impacts of heavy metal pollution in agriculture. Together, we can cultivate a healthier and more sustainable future, where land and water are true guardians of our well-being.
To read the full article, visit the following link: (25) Environmental Alert! Heavy Metals in Soil and Water: What Dangers Do They Hide? | LinkedIn
References
http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0378-18442003000500007
http://www.scielo.org.co/pdf/ecei/v14n27/1909-8367-ecei-14-27-9.pdf