Practical Pollution PDF Microbiology 2024/2025

1 Pollution Microbiology 2024/2025 Environmental pollution Air pollution occurs when harmful substances, including particulates and biological molecules, are introduced into Earth's atmosphere. These substances harm living organisms....

1 Pollution Microbiology 2024/2025 Environmental pollution Air pollution occurs when harmful substances, including particulates and biological molecules, are introduced into Earth's atmosphere. These substances harm living organisms. oise, therma r,n l, li gh te a t w po il, so llu tion Air, Air Pollution Defintion Air pollution occurs when harmful substances, including particulates and biological molecules, are introduced into Earth's atmosphere. These substances harm living organisms Types of air Pollutants Primary Pollutants Secondary Pollutants Directly emitted from Form in the atmosphere a process such as ash from chemical from a volcanic reactions involving eruption primary pollutants ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 2 Major primary pollutants produced by human activity Pollutant Source Impact Volatile organic Methane, Ozone Formation, compounds (VOCs) Non-Methane Cancer Risks Burning of fossil CO2 Global warming fuels Incomplete CO Toxicity Combustion Volcanoes and in SOx various industrial Acid rain processes NOx High Temp. Acid rain Secondary pollutants include: Pollutant Source Impact Peroxyacetyl nitrate NOx, VOCs. CO2 & Warming Earth (C2H3NO5) Greenhouse gas vehicular and Photochemical Particulates (PM) industrial emissions smog (NOx) & Volatile Ozone (O3) Organic Compounds warming Earth (VOCs) ©️Mahmoud Alaa 3 Pollution Microbiology 2024/2025 Effects of Air Pollution on Plants Effects of Air Pollution on Plants Air pollution can damage plants, causing necrotic lesions (dead tissue) or yellowing (chlorosis) of leaves. This reduces growth and can be fatal with repeated exposure. Oxidants Ozone is a major pollutant in oxidant smog, first noticed in Los Angeles in 1944 and widely documented in North America, including Ontario. Ozone levels vary, especially in July and August, influenced by air flows from urban and industrial areas. High ozone levels cause flecking, bronzing, or bleaching on leaf surfaces. Sensitive Plants: White beans, cucumbers, grapes, green beans, lettuce, onions, potatoes, radishes, rutabagas, spinach, sweet corn, tobacco, and tomatoes show more symptoms of ozone damage. Resistant plants include endive, pear, and apricot. Factors Influencing Ozone Injury: Susceptibility to ozone damage depends on environmental factors and plant growth conditions: High relative humidity Optimal soil-nitrogen levels Water availability The age of leaves: younger leaves are initially resistant, becoming susceptible as they grow, then resistant again at full maturity ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 4 Sulfur Dioxide Sources: Major sources include coal-burning operations (electric power, space heating), burning petroleum, and smelting sulfur-containing ores. Entry into Plants: Sulfur dioxide enters leaves through stomata (microscopic openings). Types of Injury: 1. Acute: Caused by high concentrations of sulfur dioxide in a short time. Symptoms: 2-sided (bifacial) lesions between leaf veins or along margins. Necrotic areas can vary in color from light tan to orange-red or brown, depending on time of year, plant species, and weather. Most sensitive: Recently expanded leaves; youngest and oldest leaves are more resistant. 2. Chronic: Long-term absorption of sublethal concentrations. Symptoms: Yellowing (chlorosis) or bronzing on the underside of leaves. Sensitivity varies among species, varieties, and even individuals due to geographical location, climate, growth stage, and maturation. Susceptible Crop Plants: Alfalfa, barley, buckwheat, clover, oats, pumpkin, radish, rhubarb, spinach, squash, Swiss chard, and tobacco. Resistant Crop Plants: Asparagus, cabbage, celery, corn, onion, and ©️Mahmoud Alaa 5 Pollution Microbiology 2024/2025 Fluoride Sources: Combustion of coal Production of brick, tile, enamel frit, ceramics, and glass Manufacture of aluminium and steel Production of hydrofluoric acid, phosphate chemicals, and fertilizers Effects on Plants: Fluorides absorbed by leaves move towards the margins of broad leaves and tips of monocotyledonous leaves. Little injury at the site of absorption, but injurious concentrations build up at leaf margins or tips. Injury starts as gray or light-green water-soaked lesions, turning tan to reddish-brown. Necrotic areas expand inward to the midrib on broad leaves and downward on monocotyledonous leaves. Plant Susceptibility: Sensitive species: Apricot, barley, blueberry, peach, gladiolus, grape, plum, prune, sweet corn, tulip. Resistant species: Alfalfa, asparagus, bean (snap), cabbage, carrot, cauliflower, celery, cucumber, eggplant, pea, pear, pepper, potato, squash, tobacco, wheat. Ammonia Sources: Accidents involving storage, transportation, or application of anhydrous and aqua ammonia fertilizers. ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 6 Effects on Plants: Injury appears as irregular, bleached, bifacial, necrotic lesions. Grasses show reddish, interveinal necrotic streaking or dark upper surface discoloration. Flowers, fruit, and woody tissues usually unaffected. Severe injury to fruit trees can lead to recovery through new leaf production. Plant Susceptibility: Sensitive species: Apple, barley, beans, clover, radish, raspberry, soybean. Resistant species: Alfalfa, beet, carrot, corn, cucumber, eggplant, onion, peach, rhubarb, tomato. Particulate Matter Sources: Cement dust, magnesium-lime dust, carbon soot Effects on Plants: Inhibits normal respiration and photosynthesis within leaves Causes chlorosis and death of leaf tissue through crust formation and alkaline toxicity in wet weather Affects the action of pesticides and agricultural chemicals Increases soil pH, adversely affecting crop growth Ozone Depletion Ozone Layer: Located in the stratosphere, it filters out harmful shortwave ultraviolet (UV) radiation ©️Mahmoud Alaa 7 Pollution Microbiology 2024/2025 Causes: Depletion caused by ozone-depleting substances such as chlorofluorocarbons (CFCs) These substances break down ozone, allowing more UV rays to reach Earth Impacts: Increased UV exposure can affect humans, animals, and plants, causing sunburn, skin cancer, cataracts, plant damage, and reduction in plankton populations Phenomena: Steady decline of ~4% in stratospheric ozone since late 1970s Larger springtime decrease in ozone around polar regions (ozone hole) Mechanisms: Catalytic destruction of ozone by atomic halogens from man-made halocarbon refrigerants, solvents, propellants, and foam-blowing agents These compounds are transported into the stratosphere by winds after emission at the surface Response: Montreal Protocol: Bans production of CFCs, halons, and other ozone-depleting chemicals Concerns: Biological consequences from increased UV exposure due to ozone depletion ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 8 ©️Mahmoud Alaa 9 Pollution Microbiology 2024/2025 Ozone Layer Depletion and UVB Radiation The ozone layer absorbs UVB ultraviolet light from the sun, When the ozone layer is depleted, surface UVB levels increase, potentially causing damage like higher skin cancer rates. This concern led to the Montreal Protocol. Stratospheric ozone decreases are linked to CFCs and higher surface UVB levels. No direct observational evidence connects ozone depletion to increased skin cancer and eye damage, partly because UVA (also linked to skin cancer) is not absorbed by ozone, and lifestyle changes over time complicate statistical analysis Increased UV Radiation and Ozone Depletion Absorption by Ozone: Although ozone is a minor component of the atmosphere, it absorbs most UVB radiation. Decreases in stratospheric ozone levels lead to higher UVB reaching Earth’s surface. Historical Data: UV-driven phenolic formation in tree rings dates ozone depletion in northern latitudes to the late 1700s. A 2008 Ecuadorian Space Agency report found unexpectedly high UV radiation levels in equatorial latitudes, with UV Index reaching 24, compared to WHO’s extreme risk level of 11. The findings were confirmed by the Peruvian Space Agency. ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 10 Biological Effects Main concerns include increased UV radiation's impact on human health. Ozone depletion typically shows a few percent reduction in most locations, with no direct evidence linking it to health damage at most latitudes. Severe depletion, like the Antarctic ozone hole, has led to concerns for Australia, New Zealand, Chile, Argentina, and South Africa, possibly leading to significant health effects. Ozone depletion magnifies UV effects, both positive (e.g., Vitamin D production) and negative (e.g., sunburn, skin cancer, cataracts). Increased surface UV also boosts tropospheric ozone, posing additional health risks Effects on Crops Increased UV radiation affects crops by harming cyanobacteria on plant roots, crucial for nitrogen retention. Despite repair mechanisms, plants struggle to adapt to increased UVB, impacting growth. Global Warming and Climate Change: Global warming refers to the century-scale rise in Earth's average temperature and its effects. Evidence shows unprecedented climate changes since the 1950s. IPCC 2014 Report: Human influence is the dominant cause of warming since mid-20th century, mainly due to greenhouse gases (CO2, methane, N2O). Climate models predict a further rise in global surface temperature by 0.3 to 1.7 °C for the lowest and 2.6 to 4.8 °C for the highest emissions scenarios. ©️Mahmoud Alaa 11 Pollution Microbiology 2024/2025 Future Impacts: Warming temperatures, rising sea levels, changing precipitation patterns, expanding deserts. More extreme weather events: heat waves, droughts, heavy rainfall, floods, snowfall. Ocean acidification, species extinctions, threats to food security, abandonment of populated areas. Long-term Effects: Climate changes will persist for tens of thousands of years due to the longevity of greenhouse gases in the atmosphere. Societal Responses: Mitigation (reducing emissions), adaptation, resilience building, and potential climate engineering. UNFCCC aims to prevent dangerous anthropogenic climate change, with agreements to cut emissions and limit global warming. Public Concern: Increasing global concern, with significant regional differences. Americans and Chinese are among the least concerned, despite their high CO2 emissions. Global Warming & Greenhouse Gases Pollutants contributing to global warming are called greenhouse gases. Major greenhouse gases: Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and chlorofluorocarbons (CFCs). Greenhouse Effect: Greenhouse gases trap heat in the atmosphere. ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 12 Main Greenhouse Gases: Carbon dioxide (CO2): Primary greenhouse gas from human activities, accounting for ~80.9% of emissions in 2014. Naturally present in the Earth's carbon cycle but increased due to human activities, particularly from burning fossil fuels and certain industrial processes. Methane (CH4) Nitrous oxide (N2O) Ozone (O3) Chlorofluorocarbons (CFCs) Human Impact: Human activities add more CO2 to the atmosphere and influence natural sinks like forests. Increased CO2 emissions since the industrial revolution have disrupted the natural carbon cycle. ©️Mahmoud Alaa 13 Pollution Microbiology 2024/2025 Particulate Matter (PM) Definition: Microscopic solid or liquid matter suspended in the atmosphere, known as particulate matter (PM) or particulates. Aerosol refers to the particulate/air mixture. Sources: Manmade or natural, impacting climate and human health. Subtypes: Suspended particulate matter (SPM) Thoracic and respirable particles Inhalable coarse particles (2.5 to 10 µm in diameter, PM10) Fine particles (2.5 µm or less, PM2.5) Ultrafine particles and soot Health Risks: Particulates are Group 1 carcinogens (IARC, WHO). Deadliest air pollution type, penetrating deep into lungs and bloodstream, causing DNA mutations, heart attacks, and premature death. 2013 study: No safe level of particulates; 22% increase in lung cancer risk per 10 µg/m³ of PM10, 36% for PM2.5. Natural Sources: Volcanoes, dust storms, forest and grassland fires, vegetation, sea spray. Human Sources: Burning fossil fuels in vehicles, power plants, industrial processes. Coal combustion in developing countries. Size of Particulate: Natural aerosols (e.g., dust) have larger radii than human-produced aerosols (e.g., pollution). ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 14 Natural sea salt is the primary aerosol in the Southern Hemisphere; land fires and human activities dominate in the Northern Hemisphere. Regional Patterns: Southern Hemisphere: Large aerosols over oceans (sea salt). Northern Hemisphere: Small aerosols over land (fires, human activities). Dust storms prominent in deserts (Sahara, Arabian Peninsula). Fire activities (Amazon, Northern Canada) produce smaller aerosols. Human pollution creates small aerosols over developed areas (eastern U.S., Europe). ©️Mahmoud Alaa 15 Pollution Microbiology 2024/2025 Effects of Air Pollution on Plants Cardiovascular Diseases Respiratory Diseases Habitat Climate Damage Premature Change Death Food Source Damage Health Global Impacts Impact Water Acidification Humans Animals Air Pollution Plants Fluoride SO2 Damage O3 Damage Damage Sensitive Sensitive Species Species ©️Mahmoud Alaa Microbiology 2024/2025 Pollution 16 Effects of Particulate Matter on Vegetation and Humans Vegetation: Impact: Particulate matter clogs stomatal openings, hindering photosynthesis. Result: High concentrations lead to growth stunting or mortality in some plant species. Humans: Health Risks: Inhalation of particulate matter is linked to asthma, lung cancer, cardiovascular disease, respiratory diseases, premature delivery, birth defects, and premature death. Statistics: PM pollution causes 22,000–52,000 deaths per year in the U.S. (2000). Contributed to ~370,000 premature deaths in Europe (2005). Caused 3.22 million deaths globally (2010). Studies: PM2.5 linked to high plaque deposits in arteries, causing vascular inflammation and atherosclerosis. Long-term exposure to PM2.5 linked to coronary events; a 5 µg/m³ increase correlates with a 13% increased risk of heart attacks. Black Carbon exposure impacts bacteria, altering biofilm formation and antibiotic tolerance. WHO Estimates (2005): PM2.5 causes ~3% mortality from cardiopulmonary disease. ~5% mortality from cancer of the trachea, bronchus, and lung. ~1% mortality from acute respiratory infections in children under 5. ©️Mahmoud Alaa