Emerging contaminants

• Emerging contaminants


  Studied for ~ 15-20 years, not detected before but perhaps they were there (analytical reasons mainly), detected at much higher level than expected, risks to human and environment may not be known
• Emerging contaminants


  • Pesticides
  • New POPs
  • PPCPs
• Organochlorine pesticides


  DDT, better pesticides for insects and less impact, they have been replaced by less harmful alternatives but that does not mean they are harmless, less toxic
• Pesticides have been used for 4000+ years, mainly sulfur, lead, mercury, arsenic, copper until DDT
• The world pesticide expenditures was US$ 56 billion in 2012, including US$9 billion in the US only
• 20-40% of global crop yields are lost each year to pests and diseases; 25–30% in Europe and the USA, and up to 50% in the tropics
• Pesticide uses


  • Agricultural: to maintain or increase crop yields
  • Professional non agricultural use: railways, streets, golf courses, wood treatment, food storage facilities etc.
  • NZ: control of invasive species (e.g. possums, moths)
  • Amateur: house, garden
• Issues with pesticides


  • Acute human poisoning and diffuse environmental contamination
  • Up to 90% of the product applied may not reach its target
  • Pesticides are bioactive substances and affect pest AND non-target organisms
  • 200,000 deaths/year 99% in developing countries
  • Huge quantity put out and small portion to target, large portion lost e.g. groundwater
• PCBs had to stop producing
• PBDEs


  Brominated flame retardants, used in a wide array of products, fate similar to PCBs: persistent, bioaccumulative, long range transport, effects: endocrine disruptors, reproductive and neurological effects, chronic exposure from household items + food
• 2004: PBDEs partly banned in EU and US, 2009: some PBDEs included under Stockholm convention but remain in items produced before and they were replaced by molecules with similar properties
• Halogenated compounds


  Cl, Br, F atoms give great properties for a wide range of applications like water proofing, non-stick, but bad for environment and come with cost
• New POPs regulated under Stockholm convention

  • PFOS, PFOA
• Reduce plastic as taking too long, down the drain chemicals going out of our homes (toilet and wash hair)
• PPCPs


  Pharmaceuticals (P): prescription, over the counter and veterinary therapeutic drugs used to prevent or treat human and animal diseases, Personal care products (PCPs) are used mainly to improve our quality of daily life, particular concerns with drugs because they are designed to trigger biological effect at low dose, potential bioaccumulation and persistence, chronic exposure, effects of mixtures poorly understood, emerging effects: endocrine disruption and development of resistance
• Main classes of pharmaceuticals


  • Antibiotics
  • Hormones
  • Lipid regulators
  • B-blockers
  • Antiepileptic
  • Selective serotonin reuptake inhibitors
  • Anti-inflammatory
• Entities of pharmaceuticals in the environment
• Risk of chemicals


  Most chemicals are created/produced to improve our quality of life, their use can have unexpected consequences
• Diclofenac: a human pharmaceutical


  Had major ecological consequences when used as veterinary product
• Diclofenac

  Non-steroidal anti-inflammatory drug used as pain killer worldwide for decades, no obvious negative impact on environment, dramatic consequences when introduced for veterinary use in India and Pakistan: accumulation of carcasses, proliferation of dogs->increased risk of rabies and pandemic disease for human population, some for longer lives and left to be eaten, killing birds
• Personal care products (PCPs)


  Ingredients of moisturizers, sunscreens, lipsticks, soaps, shampoos, hair colours, deodorants, toothpastes, functions: antibacterial, UV filters, fragrance
• Microbeads banned in UK, Australia and NZ (microplastic)
• Sewage treatment


  Domestic, commercial, food processing, industrial -> influent -> effluent (sewage sludge)
• Sewage treatment controls the release of PPCPs and all other down-the-drain chemicals in the environment
• PBT


  Persistent Bioaccumulative Toxic