210 likes | 321 Views
Toxic Substances in Lake Champlain. Justin Minott Ethan Morehouse Maya Thomas. Goals. Determine which chemicals present (or potentially present) in the Lake Champlain basin would cause detrimental effects Determine the pathways in which these chemicals come about. Objectives.
E N D
Toxic Substances in Lake Champlain Justin Minott Ethan Morehouse Maya Thomas
Goals • Determine which chemicals present (or potentially present) in the Lake Champlain basin would cause detrimental effects • Determine the pathways in which these chemicals come about
Objectives • Identify potentially hazardous substances • Establish links between potentially hazardous substances and the habitats they may impact within the Lake Champlain basin • Determine the degree of impact each substance has upon each habitat type
Subcategories • Hydrocarbons • Polycyclic aromatic hydrocarbons (PAHs) • Volatile organic compounds (VOCs) • Herbicides • Atrazine • Alachlor • Heavy Metals • Mercury • Cadmium • Lead
Subcategories (cont.) • Pesticides • Dioxins & like compounds • Polychlorinated biphenyls (PCBs) • Polychlorinated dibenzodioxins (PCDDs) • Polychlorinated dibenzofurans (PCDFs) • Pthalates
Polycyclic Aromatic Compounds • Form during the incomplete combustion of organic material • Released in the atmosphere from the burning of fossil fuels, and are transported to aquatic and terrestrial ecosystems by way of atmospheric deposition • Travel via water and sediments, accumulate in soils • Can bioaccumulate in organisms, leading to higher concentrations within the organisms than in the surrounding environment • Have carcinogenic effects, as well as negative effects on reproduction, development, behavior, and longevity
Volatile Organic Compounds • Typically human-derived/isolated solvents with high vapor pressure • Indoor air pollutants which can cause skin irritation and disorientation when inhaled • Enter the environment through volatilization or by dissolving into water, which can have a negative effect on aquatic ecosystems • Have been identified as carcinogens with chronic exposure
Atrazine • A non-selective herbicide that inhibits photosynthesis in plants • Used in commercial agriculture • Risk to aquatic systems based on toxicity and high mobility • Degrades slowly, which allows it to accumulate in animal tissue • Impacts gill function, hematology, metabolism, and behavior in fish species, and sexual determination in frogs
Alachlor • Selective herbicide which controls unwanted grasses and broad-leafed weed species in commercial agriculture • Can travel through both groundwater and surface water, moderately through soils • Chronic exposure increases the likelihood of cancer in fish and mammals • Has toxic effects on the liver, spleen, kidneys, and eyes of rats
Mercury • Generated from industrial activities, mainly coal-burning • Transported through the environment in the form of methyl mercury • Affects mostly marine and wetland habitats, but moves to terrestrial habitats through bioaccumulation
Cadmium • Sources: burning of coal and oil, incineration of municipal waste, smelting of zinc/lead/copper ores, phosphate fertilizers, sewage sludge • Increases the ability of certain plants to resist infection and disease • Wide range of health effects
Lead • Found in most plant and animal tissues, more so than mercury and cadmium • Human sources: paints, dishware glazes, moonshine, gasoline, pipes containing water for a long time • Causes anemia, neurological damage, chronic renal disease • Completely decays Daphnia in 15 days and is toxic to algae in 30 days • Lead air pollution in ecosystems causes loss in biodiversity, change in community composition, and decrease in growth and reproductive rates in animals
Pesticides • Organochlorines have been the most harmful and persistent type of pesticide • Endosulfan is one of the last organochlorines still being used today, and transports quickly throughout the environment due to its volatility, persistence, and ability to bioaccumulate • Known to have additive and synergistic effects with other pesticides, and therefore risk should not be determined solely upon chemical concentrations • Amphibians are affected the most by pesticides, esp. leopard frogs
Dioxins and Like Compounds • Released through the incineration of municipal waste, notably medical waste • Fat soluble, allowing them to move through habitats in animal tissue • Effects of PCBs, PCDDs, and PCDFs can be grouped as endocrine disruptors, neurotoxins, and carcinogens • Dioxins function like hormones, having negative effects on the reproductive and immune systems, and can cause tumors
Pthalates • Absorbed by humans and organisms through skin exposure, inhalation, and ingestion • Enter the environment through leaching from plastics and secretion from urine • Affect human (male and female) and aquatic organism reproductive systems
Thank You Questions?