Was used in the past as an anesthetic drug now safer

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was used in the past as an anesthetic drug, now safer drugs are used Mercury aka quicksilver, it’s a neurotoxin. Minamata Bay, Japan was the site of a mercury accident. Over 3000 people suffered mercury poisoning, deformities later came to be known as Minamata disease oNeurological syndrome caused by severe mercury poisoning oSymptoms include ataxia, numbness in hands and feet, muscle weakness, damage to hearing, vision and speech. In extreme cases, insanity, paralysis, coma and death follow within weeks of the initial symptoms. The Spring Time Haze The arctic haze is a blob of air pollution that sloshes over the northern cap of the planet in spring time. It’s visible as a murkiness that prevents you from seeing Denali, or as darker banks in the horizon from the windows of planes flying over northern Alaska. On a bad day, it can make Alaska look like Los Angeles or Denver. Desertification Land misuse Poor irrigation practices Livestock overgrazing Over-cultivation of soils Deforestation find more resources at oneclass.comfind more resources at oneclass.com
Lecture 6 & 7 Water Pollution & Eutrophication What is Eutrophication? -Eutrophication is the process by which a body of water becomes enriched in dissolved nutrients that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen. Nutrient input can be increased by human activities (cultural eutrophication) or can occur naturally. -Internationally known examples of Eutrophication: oGulf of Mexico The Mississippi river watershed oBaltic Sea Eutrophication is the biggest problem in the Baltic Sea The Gulf of Finland is the most eutrophic basin in the Baltic Sea oLake Washington phosphorus oLake Nyos volcano oChesapeake Bay and Neuse River Estuary -Oligotrophic bodies of water that have clear water and low biological productivity Symptoms of Eutrophication -Increase in phosphorus concentration -Increase in chlorophyll concentration -Increase in algal productivity -Increase in oxygen depletion -Decrease in water transparency Symptoms of cultural eutrophication (caused by human activities) -Early stage symptoms consist of increase in phytoplankton standing crop (biomass) and biomass at other trophic levels -Algal blooms -Massive growth of cyanobacteria -Complete depletion of oxygen and high concentrations of nutrients (due to redox reactions) in hypolimnion -Invertebrates and fish communities change: species requiring high oxygen levels disappear, species tolerant of low oxygen levels dominate. Species diversity reduced. -Macrophytes and periphyton may increase Point source pollution: It refers to pollution that enters the water body from a specific location. E.g. wastewater treatment facility, sewage waste, industrial water discharge.

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