108. Air pollutants and their health effects

From greek.doctor
  • PCB = polychlorinated biphenyl
    • Used as a fluid in electronics
    • Production has been banned for many years, but because it lasts for long, it can still be found in old electronics and the environment
    • Symptoms of toxicity, collectively known as Yusho disease
      • Chloracne – a severe form of acne
      • Hepatotoxicity
      • Foetal abnormalities
      • Cancer
  • PCP = pentachlorophenol
    • Use as pesticide, disinfectant
    • Symptoms of toxicity
      • Hyperthermia (by uncoupling oxidative phosphorylation)
      • Damage to liver, kidneys, lung, CNS, etc.
  • TCA = 1,1,1-trichloroethane
    • Is used as a solvent
    • It’s an ozone-depleting substance and is therefore being phased out
    • Symptoms of toxicity
      • Similar to those of ethanol
      • Foetal abnormalities
  • Greenhouse gases
    • The greenhouse effect traps heat from the sun on the surface of the earth
    • Major greenhouse gases
      • CO2 – 55%
      • CFC11, CFC12 (fluoromethanes)
      • Methane
      • NOx
    • The greenhouse effect drives climate change
  • Smog
    • Smog is a combination of smoke and fog
    • Industrial smog = London smog = reducing smog
      • A sulphurous smog (contains sulphurs)
      • From burning coal or oil at power plants
      • Is chemically reducing
    • Photochemical smog = Los Angeles smog = oxidizing smog
      • From car emissions
      • Requires sunlight
      • Contains ozone, VOC, NOx
      • Is chemically oxidizing
      • Can form acid rain
  • Ozone (O3)
    • Is formed in the upper atmosphere when sunlight acts on oxygen (O2)
    • Concentrations higher than 0,1 ppm is toxic
  • Particles
    • Mostly from cars, wood-burning and industries
    • Types
      • Dust
      • Fibres
        • Asbestos
      • Nanoparticles
    • Deposition in lungs
      • Particles > 5 µm are trapped in upper airways
      • Particles 1 – 5 µm are trapped in the bronchi
      • Particles < 1 µm are trapped in the alveoli
    • Health issues
      • Irritation of eyes
      • Coughing
      • Allergies
      • Chronic obstructive pulmonary disease
      • Pneumoconiosis (interstitial lung fibrosis)
      • Asbestos -> mesothelioma
  • Pollutants which are present both indoor and outdoor
    • NOx, CO, CO2
      • From fuel burning, metabolic activity, tobacco smoke
    • Particles, aerosols
      • From combustion, tobacco smoke, condensation
    • VOC (volatile organic compounds)
      • From fuel burning, painting, metabolic activity, pesticides, solvents, cosmetics, etc.
      • Formaldehyde, benzene, styrene, etc.
    • Spores
      • From fungi, moulds
  • Prevention of air pollution
    • Primordial prevention
    • Countries must cooperate to reduce air pollution
    • Separating industrial from residential areas
    • Facilitate public transport, biking or walking instead of driving