intro.

• Microbial and waste contaminants


  Pathogen, poop in water. Make you sick and kill.
• Poster to inform people in South Asia about human activities leading to the pollution of water sources
• Access to safe drinking water

  • Great improvement 2000-2010: 61-71% global population. Urban population: 85%
  • Efficient water disinfection (chlorination) which keeps pathogens away/microorganisms
• Microbial contamination


  Closely monitored everywhere. High risk to human health even at low level
• Safeswim water quality models

  Predict levels of Faecal Indicator Bacteria that exceed national guidelines for swimming, based on guidance published by the Ministry of Health and Ministry for the Environment
• Chemical contamination


  Invisible. Flanders stream so polluted 'water could be used as pesticide'
• Monitoring study detected 70 hazardous pesticides and veterinary medicines in a single stream in Belgium
• The status of rivers in cities

  Have generally improved over the last 50 years
• River Thames in London


  • 1957: pollution levels became so bad it was declared biologically dead. The amount of oxygen in the water fell so low that no life could survive.
  • 2010: successful restoration won an international price. 125 species of fish 400+ species of invertebrate. Microbial and macronutrient status has clearly improved.
• In addition to legacy contaminants, there are many emerging concerns: plastics, pharmaceuticals, drugs of abuse, personal care products etc
• White et al. (2019) analyzed 37 samples for pharmaceuticals along the Thames
• Pharmaceuticals detected


  41 pharmaceuticals (consume) up to 10 µg/L. Diclofenac (painkiller) in 97% of the samples. 2 lifestyle compounds (cocaine and sucralose). Antimicrobials in all samples downstream of the source.
• Bacteria develop resistance, and can't kill it.
• Organic compounds


  From the vitalism doctrine to Wöhler->Starting point of modern organic chemistry. No official definition. Useful (but arbitrary) way to subdivide chemistry.All carbon containing compounds except carbonate salts (CO3 2-), carbon oxides (COx) and cyanide (C=N). C, H, O, S, N> 20 millions known organic compounds 20 times more than all other known chemicals combined.
• Inorganic contaminant


  • Geogenic (e.g. As): affecting 100s millions people drinking water.
  • Anthropogenic activities (e.g. Cd, Pb, N). These atoms do NOT degrade (but chemical speciation can change).
• Rapid development of chemical industry to improve our life hydrocarbons, pesticides, pharmaceuticals, personal care products, chlorinated solvents(dry cleaning), synthetic dyes and contraction material, electronic, textile.
• More than 350,000 chemicals have been registered for production and use (19 countries, Wang et al., 2020)
• In NZ, 50,000 substances are approved, but less than 200 are monitored. We have no national record of chemicals imported, used, discharged in the environment. Data is scarce
• Contaminants


  Concentration > natural conc. as a result of human activity "only" causes deviations from the normal composition of an environment.
• Pollutant


  Concentration > natural conc. as a result of human activity. Net detrimental effect upon its environment or upon something of value in that environment (raw sewage dumped in a river->contamination-> some contaminants have an effects=pollutants).
• Source of contamination


  Environmental fate(soil, air, water are linked)=receptors.
• Summary


  • Biological vs chemical contamination of water resources
  • Important definitions: organic compound, contaminant, pollutant
  • Very large number and wide variety of organic pollutants, we cannot test them all!
  • Need to identify pollutants and avoid compounds that pose an, unacceptable " risk to human and environmental health
  • Source= Behaviour= Monitoring =Action