108. Air pollutants and their health effects

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