1. سرطانهای شغلی occupational cancers
دکتر مرجان غروی
متخصص طب کار
بهداشت و درمان صنعت نفت اصفهان
مرکز تخصصی طب کار دانیال

2. Etiology of cancer The majority of cancers are multifactorial
combination of genetic& nongenetic factors.
Genetic factors alone 5%.
Non-genetic (environmental) factors
lifestyle factors
tobacco use, alcohol consumption, poor diet, obesity…
occupational exposures
Environmental pollution (water, air, food..)

3. Epidemiology
5% of all chemicals have been tested for carcinogenicity ( in animals)
4-10% of all human cancers are occupational

4. carcinigenesis Initiation Promotion
Cancers arrives from a SINGLE ABNOEMAL CELL
The process through which a cell becomes a cancer cell is named CARCINOGENESIS
2 main stages:
Initiation
Endogenous
Exogenous
An irreversible change in the genetic material (DNA) of the cell
necessary, but Not sufficient
Promotion
subsequent to initiation that facilitate tumor development, by stimulating proliferation of the altered cell.

6. INVESTIGATIVE METHODS IN THE ASSESSMENT OF CHEMICAL CARCINOGENICITY
Human epidemiologic studies
Experimental studies in animals
Mechanistic studies.

7. Organizations that publish authoritative lists of carcinogens
International Agency for Research on Cancer (IARC), an agency of the World Health Organization
American Conference of Governmental Industrial Hygienists (ACGIH), an independent US organization
US National Toxicology Program (NTP),

8. IARC Classification Group 1 - Carcinogenic to humans
Sufficient evidence of carcinogenicity in human.
Group 2A - Probably carcinogenic to humans
Limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals
Group 2B - Possibly carcinogenic to human
Limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals
Group 3 - Not classifiable as human carcinogen
Evidence of carcinogenicity is inadequate in humans and inadequate or limited in experimental animals
Group 4 - Probably not carcinogenic to humans
Evidence suggesting lack of carcinogenicity in humans and in experimental animals

9. ACGIH A1 - Confirmed human carcinogen A2 - Suspected human carcinogen
A3 - Confirmed animal carcinogen with unknown relevance to humans
A4 - Not classifiable as a human carcinogen
A5 - Not suspected as a human carcinogen
Carcinogens identified by ACGIH are listed in ACGIH's TLVs & BEIs booklet

12. REGULATORY ACTION
Sufficient evidence of carcinogenicity in humans (group 1 IARC)
prompt immediate protective interventions
sufficient evidence of carcinogenicity in animals (group 2A IARC)
prompt attempts to reduce worker exposure as much as possible
other classes
Control exposure as much as possible

13. Medical Surveillance criteria for screening test Example: Sensitive
Easy to perform
Detect premalignant abnormalities or tumors at an early stage
Effective intervention that reduces morbidity and mortality screening techniques
Effective therapy for early lesions have had a significant impact on the disease.
Example:
pop smear for cervical cancer
Low dose CT scan for heavy smokers
Urin cytology is dose not reduce mortality and morbidity

14. Carcinogens for which medical surveillance is required

15. Medical surveillance for lung cancer
Occupations at Risk
Asbestos-exposed workers, (miners, insulators)
Workers exposed to radon (uranium miners)
Workers exposed to diesel exhaust/diesel particulates
Workers exposed to PAH(aluminum reduction workers, coke oven workers, roofers, rubber production workers)
Workers exposed to chromium compounds
Workers exposed to nickel compounds(nickel mining and refining)
Workers exposed to inorganic arsenic compounds (arsenical pesticide production and use, copper, lead, and zinc smelting

16. Medical surveillance for lung cancer (cont.)
Primary prevention
Avoidance of exposure to lung carcinogens
Adherence to strict workplace standards
Worker education to cease smokeimg
secondary prevention
Medical monitoring
Serial CXR
sputum cytologic examinations
There is no evidence that early detection improves the prognosis for persons with occupationally-induced lung cancer.

17. Medical surveillance for mesothelioma
All types of asbestos are capable of causing mesothelioma, (amphiboles, particularly crocidolite &amosite)
Occupations at Risk
Asbestos miners
Construction workers
Workers exposed to insulation materials in production, installation, and removal
Shipyard workers
Asbestos textile manufacturing
Welders, plumbers, electricians

18. Medical surveillance for mesothelioma (cont.)
Prevention
Control exposure to asbestosis
Medical surveillance
No defined method

19. Medical surveillance for bladder cancer
Occupations at Risk
Dye/pigment manufacturing and us
Workers in rubber manufacturing industries
Painters
Workers in rubber production
Truck drivers
Benzidine-derived azo dyes

20. Medical surveillance for bladder cancer (cont.)
Primary Prevention
Avoidance of cigarette smoking
Prevention of exposure to known carcinogens
Secondary Prevention
Urinary cytological examinations
Cystoscopy when indicates
Urinalysis (microscopic hematuria)

21. Medical surveillance for liver cancer
Occupations at risk
Workers exposed vinyl chloride (PVC manufacture
Workers exposed to arsenic compounds)
Medical tests:
liver function tests (non specific nor sensitive)