Unit 3: Soil Pollution

SOIL POLLUTION SOIL? Soil is the top layer of the earth's crust, made of solid, liquid, and gas substances, including minerals, organic matter, microbes, water, and air. It forms slowly, taking hundreds to thousands of years. Soil supports plants and various life forms and has important ecological functions. Composition of soil: - Organic mineral matter: 45% - Organic matter: 5% - Soil water: 25% - Soil air: 25% SOIL POLLUTION Soil Pollution - Contamination of soil with pollutants and toxic chemicals - Reduces soil quality and makes it uninhabitable for organisms - Addition of chemicals in toxic quantities - Mainly caused by human activities - Activities include mining, modern agriculture, deforestation, and improper waste disposal Soil contamination or soil pollution due to both natural as well as human activities. TYPES OF SOIL POLLUTION Causes of Soil Pollution are mainly classified into two categories:Naturally Caused Soil Pollution Anthropogenic Soil Pollution Natural Pollution Of Soil Pollution caused by soil is a very rare phenomenon, this happens when toxic materials are added to the soil through a volcanic eruption and pollutants are also added to the soil by water. Anthropogenic Soil Pollution Anthropogenic Soil Pollution is soil pollution which is caused by human activity. So, almost all cases of soil pollution are anthropogenic in nature. ●​ AGRICULTURAL POLLUTION The use of synthetic insecticides and fertilizers in agriculture causes chemical soil contamination, harming fertility and increasing erosion. Plants also absorb these chemicals, worsening soil pollution. ●​ URBAN WASTE POLLUTION Source: Improper disposal of solid waste, plastics, sewage, and construction debris.​ Effect: Causes clogging of soil pores, reduces water infiltration, and leads to long-term contamination. ●​ MINING AND QUARRYING POLLUTION Source: Dumping of mining debris, exposure of soil to chemicals and heavy metals. Effect: Depletes soil nutrients, alters pH, and destroys surrounding vegetation. ●​ BIOLOGICAL POLLUTION Source: Waste from humans or animals, such as untreated sewage, animal manure, and decaying organic matter. Effect: Increases microbial load and can spread diseases through the soil. ●​ ACID RAIN POLLUTION Source: Sulfur and nitrogen compounds released into the atmosphere from factories and vehicles, falling as acid rain. Effect: Acidifies soil, leaches nutrients, and harms plant life. ●​ INDUSTRIAL POLLUTION Source: Discharge of industrial waste, heavy metals (like lead, mercury, cadmium), chemicals, and oil spills.​ Effect: Makes soil toxic and unsuitable for agriculture; affects groundwater quality. ●​ HEAVY METAL POLLUTION Often a result of industrial processes or mining, leading to toxic concentrations of metals like cadmium, chromium, and lead.​ CAUSES OF SOIL POLLUTION ●​ INDUSTRIAL WASTE Industries produce a lot of waste, including harmful chemicals and heavy metals. Improper disposal can contaminate soil, making it toxic for agriculture and habitation. ●​ DEFORESTATION The removal of vegetation exposes soil to the elements, increasing erosion. Once the topsoil is removed, pollutants can more easily enter and accumulate in the soil, reducing its natural cleansing ability. ●​ SEWAGE AND WASTEWATER Untreated or poorly treated sewage and industrial wastewater often discharge into open lands. These contain waste, pathogens, and chemicals that harm soil and human health. ●​ IMPROPER DISPOSAL OF HAZARDOUS WASTE Hazardous materials such as paints, batteries, e-waste, and medical waste often go to landfills or are dumped illegally, containing harmful substances. ●​ URBAN AND DOMESTIC WASTE In many places, garbage is dumped in open areas or poorly managed landfills. Non-biodegradable waste like plastics, glass, and batteries pollutes the soil. Leachate from landfills can contaminate soil and groundwater. ●​ OIL SPILLS AND LEAKAGES Petroleum products used in machinery, transportation, and industries can leak or spill onto the soil. These hydrocarbons are toxic and difficult to clean, severely affecting soil quality and nearby vegetation. EFFECTS OF SOIL POLLUTION ON PLANTS,ANIMALS,HUMAN HEALTH AND GROUNDWATER Soil pollution is the contamination of soil by harmful chemicals, waste materials, or biological agents. It has serious consequences for ecosystems, agriculture, and public health. Here's a breakdown of its effects on plants, animals, human health, and groundwater: ●​ EFFECT ON PLANTS Soil Pollution and Its Effects on Plant Life - Pollutants include heavy metals, pesticides, industrial waste, and fertilizers,these pollutants degrade soil structure and reduce fertility. - Contaminants hinder nutrient and water absorption by plants. - Poor growth, yellowing leaves, and low crop yields result. - Toxic substances can accumulate in edible plant parts. Soil pollution harms beneficial microorganisms vital for nutrient cycling and plant health. ●​ EFFECT ON ANIMALS Bioaccumulation: Animals ingest pollutants through plants or soil, leading to toxin build-up in tissues. Health disorders: Exposure can cause neurological damage, reproductive issues, or death in wildlife. Habitat degradation: Soil pollution alters ecosystems and reduces food sources.​ Behavioral changes: Toxic exposure may lead to changes in animal behavior and reduced survival rates. ●​ EFFECT ON HUMAN HEALTH Soil is essential for our survival, and its contamination has serious effects on our health. Polluted crops absorb toxins and can lead to various illnesses. Long-term exposure can change our genetic makeup, resulting in congenital and chronic health issues like cancer,organ failure and birth defects. It also harms livestock and can cause food poisoning. Soil pollution may eventually result in widespread famines if plants cannot grow. ●​ EFFECT ON GROUNDWATER Groundwater supplies drinking water for millions but is vulnerable to soil pollution. -Rain can cause harmful chemicals in polluted soil to leach and contaminate underground aquifers ,contaminants include nitrates, pesticides, and heavy metals. - Polluted groundwater is unsafe for consumption and difficult and costly to clean. - Contamination can flow into rivers, lakes, or oceans, affecting aquatic ecosystems. CONTROL OF SOIL POLLUTION A. Prevention of soil erosion: ●​Contour farming Contour farming involves planting crops in rows along the land's contours to slow water runoff. ●​Conversational till farming and no till farming Conservational till farming or no-till farming involves minimal soil disturbance. Seeds, fertilizers, and water are injected into slits made in unploughed soil. ●​Terracing Terracing converts steep slopes into wide terraces along the contour, helping retain water and reduce soil erosion. ●​ Wind Breaks And Shelter Belts Trees are planted in long rows along land boundaries to block wind, reduce erosion, retain moisture, supply wood, and provide bird habitat. B.Ways to minimize the soil acidification process: The use of less acidifying farming practices includes retaining crop residue, avoiding nitrate residue, and reducing tillage. Applications of agricultural lime raise soil pH to a target range of 6. 0 to 7. 0. C. Remedies to correct salt affected soil ●​Deep tilling can enhance drainage in salty soils by breaking up hard layers, but effects are often temporary ●​Flushing Soil and Preventing Evaporation: Involves irrigating with low-salt water to wash salt below roots Evaporation leaves salt on dry soil; mulching helps retain moisture ●​Chemical remediation with substances like sulphur can replace sodium, but local conditions must be considered. ●​A combination of methods may be more effective, with steps like deep tilling followed by flushing ●​Land reclamation aims to restore soil health by adding organic matter and managing land better. A World Bank project in Maharashtra aims to reclaim saline lands, impacting 1,000 villages, particularly in vulnerable areas. D. Production and use of natural fertilizers: To prevent harmful effects of chemical fertilizers, biological routes of soil fertility are being adopted. Organic farming should be practiced. E. Sustainable Practices: Number of sustainable practices can be applied in order to prevent spreading of desertification. Such as following : a)Checking Overgrazing b)Plant more trees Explain them F. Education: Education is an important tool that needs to be utilized in order to help people to understand the best way to use the land. By educating them on sustainable practices, more land will be saved from being polluted.