113. Occupational cancers

General about occupational cancers
- International Agency for Research on Cancer – IARC
  - Involved in occupational cancer research
  - Evaluates and classifies chemicals, occupations, physical effects, industrial processes, according to their carcinogenetic potential
    - Group 1 – definitely carcinogenic
      - 113 substances
      - Alcohol
      - Smoking
      - UV radiation
      - Processed meat
    - Group 2A – probably carcinogenic
      - Red meat
      - Fried food
    - Group 2B – possibly carcinogenic
      - Coffee
      - Welding fumes
    - Group 3 – not classifiable as carcinogenic
      - Due to lack of enough evidence
      - Magnetic fields
      - Tea
    - Group 4 – probably not carcinogenic
      - Only 1 substance
- Annually registered cases of occupation cancer in Hungary – 10 to 30 cases
  - Massive underreporting
- CAREX database – holds data on the occupational carcinogen exposure in Europe
- Occupational cancer is the main cause of occupational death in Europe
- Occupational cancer accounts for 8% of cancers
- 23% of the workforce is exposed to occupational carcinogens on a daily basis
- Most frequent occupational carcinogenic exposures
  - Solar (UV) radiation
  - Tobacco smoke
  - Silica crystals
  - Diesel exhaust
- Cancer initiators
  - One-time exposure is sufficient
  - Bind to DNA and cause mutations
  - Irreversible effect
  - Examples
    - PAH
    - Tobacco
    - Nitrosamines
- Cancer promoters
  - Repeated exposure is necessary
  - No carcinogenic effect without an initiator
  - Does not bind to DNA
  - Reversible effect
  - Examples
    - DDT
    - PCB
    - Tobacco smoke
- Carcinogens are stochastic, i.e. there is no “safe” level of exposure to the carcinogens, and the probability of cancer increases with dose
- Many environmental carcinogens are also encountered in occupations, so the distinction between environmental and occupational carcinogens is not always straight forward
  - Aflatoxin, cyclophosphamide, UV radiation, PAH, etc.
- Most frequent occupational cancers
  - Lung and pleura
  - Bladder
  - Skin
Lung cancer
- Occupations
  - Miners
  - Construction workers
  - Shipyard workers
- Occupational carcinogens
  - Asbestos
  - Radon
  - PAHs
  - Arsenic
- Prevention of asbestos exposure
  - Find out where asbestos is
  - Only qualified workers should remove it
  - It’s more dangerous to remove it than to leave it (as that releases it into the air)
  - Use HEPA filters
Bladder cancer
- Slow acetylators (slow NAT2) have higher risk
- Occupations
  - Dye industry
  - Leather industry
  - Rubber industry
- Occupational carcinogens
  - Benzidine
  - Naphthylamine
  - Anillin dye
Skin cancer
- Occupations
  - Outside workers (agriculture, etc.)
- Occupational carcinogens
  - Arsenic
  - UV
- Prevention
  - Protective clothing
  - Sunscreen
Leukaemia
- Occupational carcinogen
  - Benzene