GEOL 105 Lecture Notes - Lecture 5: Atrazine, Spinach, Waterborne Diseases
Document Summary
Toxic waste (chemicals, heavy metals, radioactive waste) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) * pollutant- and out of place resource * Dead organic matter decomposed by bacteria, an oxygen-demanding process. Bod ( biologic oxygen demand) : high associated with a high level of decaying organic matter in water, reducing do (dissolved o) for other healthy organisms. Sources of oxygen-demanding waste: natural processes, agricultural applications, urban sewage , and runoff. Harmful risks (diseases and death) of e. coli. People exposed to waterborne diseases, especially in poor countries. Outbreaks do occur in developed countries, e. g. , Ga"s water park in 1998; walkerton public water supply, ontario in 2000; ca spinach contamination in 2006. Epidemic risks of waterborne diseases during natural disasters, such as earthquake, tsunami, flooding (cid:1) (cid:1) (cid:1) Major problems: cultural eutrophication-algae bloom, triggering bod problem. Major sources of nutrients: fertilizer, feedlots, and discharge from wastewater treatment plants. Areas of certain land use: agriculture and urban (cid:1) (cid:1)
