Date post: | 19-Dec-2015 |
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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
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
Mercury
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
Impact Importance
Stressor Open Water
Developed
Forest
Herbaceous
Agriculture
Wetlands
Pesticides 1 0.5 0.5 0.5 1 1
Dioxins & the like 2 1 1 1 1 2
Pthalates 1 0 0 0 0 1
Herbicides 2 1 1 2 2 1
Hydrocarbons 1 2 0 0 1 1
Heavy metals 2 1 1 1 1 2
Impact Link
Stressor Open Water
Developed
Forest
Herbaceous
Agriculture
Wetlands
Pesticides 1 0.5 0.5 0.5 1 1
Dioxins & the like 1 1 1 1 1 1
Pthalates 1 0 0 0 0 1
Herbicides 1 0.5 0.5 1 1 1
Hydrocarbons 1 1 0 0 0.5 0.5
Heavy metals 1 1 1 1 1 1
Impact Filter
Stressor Open Water
Developed
Forest
Herbaceous
Agriculture
Wetlands
Pesticides 1 0.25 0.25 0.25 1 1
Dioxins & the like 2 1 1 1 1 2
Pthalates 1 0 0 0 0 1
Herbicides 2 0.5 0.5 2 2 1
Hydrocarbons 1 2 0 0 0.5 0.5
Heavy metals 2 1 1 1 1 2