CPH SAS 9

• Water pollution


  Occurs when harmful substances, often chemicals or microorganisms, contaminate a stream, river, lake, ocean, aquifer, or other body of water, degrading water quality and rendering it toxic to humans or the environment
• Categories of water pollution

  • Groundwater
  • Surface water
  • Ocean water
• Groundwater


  • When rain falls and seeps deep into the earth, filling the cracks, crevices, and porous spaces of an aquifer, it becomes groundwater
  • Groundwater gets polluted when contaminants - from pesticides and fertilizers to waste leached from landfills and septic systems - make their way into an aquifer, rendering it unsafe for human use
  • Groundwater can also spread contamination far from the original polluting source as it seeps into streams, lakes, and oceans
• Surface water


  • Covers 70% of the earth
  • Nearly half of our rivers and streams and more than one-third of our lakes are polluted and unfit for swimming, fishing, and drinking
  • Nitrates and phosphates is the leading type of contamination in these freshwater sources
• Ocean water


  • 80% of ocean pollution originates on land - whether along the coast or far inland
  • Contaminants such as chemicals, nutrients, and heavy metals are carried from farms, factories, and cities by streams and rivers into our bays and estuaries; from there they travel out to sea
  • Marine debris - particularly plastic - is blown in by the wind or washed in via storm drains and sewers
  • The ocean absorbs as much as a quarter of man-made carbon emissions
• Point source contamination


  Contamination originates from a single source, such as wastewater discharged legally or illegally by a manufacturer, oil refinery, or wastewater treatment facility, as well as contamination from leaking septic systems, chemical and oil spills, and illegal dumping
• Non-point source contamination


  Contamination derived from diffuse sources, such as agricultural or stormwater runoff or debris blown into water ways from land
• Non-point source contamination is the leading cause of water pollution in the world waters, but it's difficult to regulate, since there's no single, identifiable culprit
• Transboundary pollution


  The result of contaminated water from one country spilling into the waters of another, either from a disaster like an oil spill or the slow, downriver creep of industrial, agricultural, or municipal discharge
• Common types of water contamination

  • Agriculture
  • Nutrient pollution
  • Sewage and wastewater
  • Oil pollution
  • Radioactive substances
• Agriculture


  • The leading cause of water degradation
  • Major contributor of contamination to estuaries and groundwater
  • Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens - such bacteria and viruses - into our waterways
• Nutrient pollution


  Caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife
• Sewage and wastewater


  • Used water from our sinks, showers, and toilets (sewage) and from commercial, industrial, and agricultural activities (metals, solvents, and toxic sludge)
  • Includes stormwater runoff, which occurs when rainfall carries road salts, oil, grease, chemicals, and debris from impermeable surfaces into our waterways
  • More than 80 percent of the world's wastewater flows back into the environment without being treated
• Oil pollution


  • Nearly half of the estimated 1 million tons of oil that makes its way into marine environments each year comes not from tanker spills but from land-based sources such as factories, farms, and cities
  • At sea, tanker spills account for about 10% of the oil in waters around the world, while regular operations of the shipping industry - through both legal and illegal discharges - contribute about one third
  • Oil is also naturally released from under the ocean floor through fractures known as seeps
• Radioactive substances


  • Any pollution that emits radiation beyond what is naturally released by the environment, generated by uranium mining, nuclear power plants, and the production and testing of military weapons, as well as by universities and hospitals that use radioactive materials for research and medicine
  • Can persist in the environment for thousands of years, making disposal a major challenge
• Effects of water pollution on human health

  • Water pollution kills
  • Bacterial contamination
  • Parasite diseases
  • Viral diseases
  • Fungal diseases
• Water pollution kills


  • Caused 1.8 million deaths in 2015
  • Low-income communities are disproportionately at risk because their homes are often closest to the most polluting industries
  • Waterborne pathogens, in the form of disease-causing bacteria and viruses from human and animal waste, are a major cause of illness from contaminated drinking water (cholera, giardia, typhoid)
• Bacterial contamination


  • Toxigenic E. Coli (O157:H7)
  • Ecterotoxigenic E. Coli
  • Campylobacter
  • Salmonella
  • Leptospira
  • Vibrio
• Bacterial contamination


  • Toxigenic E. Coli and Ecterotoxigenic E. Coli can cause bloody diarrhea and may lead to kidney failure and even death
  • Campylobacter is a common cause of food poisoning from meats/unpasteurized dairy products/contaminated water, causing diarrhea and abdominal cramps
  • Salmonella typhi causes typhoid fever, a common cause of food poisoning
  • Leptospirosis is the most common zoonotic disease, spread through the urine of infected animals and rodents, through the soil and water, and during flooding
  • Vibrio is strongly influenced by climate, affecting both fresh and marine waters, with V. Cholera causing an estimated 3-5 million cases and 100,000-120,000 deaths yearly worldwide, most affecting young children in endemic areas
• Parasite diseases


  • Cryptosporidium
  • Giardia lamblia
  • Cyclospora
• Parasite diseases


  • Cryptosporidium causes gastrointestinal illness and is found in 65% to 97% of surface waters tested in the U.S., with common disinfectants like chlorination being ineffective
  • Giardia lamblia cysts are found in 39% of filtered drinking water, with 17% containing Giardia and 27% containing Crypto
  • Cyclospora is associated with fresh produce from contaminated water
• Viral diseases


  • Hepatitis A
  • Norovirus
  • Norwalk virus
• Viral diseases


  • Viruses are heat resistant and likely to survive sewer treatment processes, found in shellfish contaminated with wastewater and fecal sources
• Fungal diseases


  • Cryptococcus
  • Aspergillus