Occupational Cancer

1
Occupational Cancer

• Tim Morse, Ph.D.
• University of Connecticut Health Center,
  Farmington, CT, US
• Spring 2000

2
Objectives

• Theoretic concerns in identifying carcinogens
• Estimates of occupational cancer
• Known exposures and occupations related to
  occupational cancer
• Asbestos and cancer case study
• History
• Risks
• Control
• U.S. Regulations

3
Issues

• Multiple causation interaction
• Multiple stages
• Latency period
• Threshold level

4
Testing for Cancer

• Analysis of structure-activity relations
• Cell tests
• Animal studies
• Epidemiologic studies

5
Problems in testing

• Prolonged high exposure is uncommon
• Usually mix of exposures
• Epi expensive, long, past exposures, poor
  exposure data
• Animal high dose, ? Validity in humans
• In vitro mutagens, not carcinogens

6
How much cancer is occupational?

• Doll Peto (1981) 2-8
• Viewed as conservative
• For US, 25,000-100,000 new cases/year
• Higher proportions for exposed workers

7
NJ Cancer Registry by Industry Excess

• Nasopharyngeal carpenters and other blue collar
  special trade construction
• Colorectal machinery manufacturing, printing
• Liver general construction and rubber and
  plastics
• Gallbladder electrical equipment
• Lung primary metals, shipbuilding, construction,
  and stone, clay, and glass
• Mesothelioma shipbuilding and asbestos
  manufacturing

8
NJ Cancer Registry by Industry Excess

• Breast (Black females) chemical and
  pharmaceutical
• Bladder (white males) apparel and textile
  industries.
• Non-Hodgkin's lymphoma
• (white females) printing
• (white male) bakers and motor vehicle
  manufacturing
• Lymphocytic leukemia chemical and construction

9
Lung cancer (Steenland, 1996)

• silica
• asbestos
• diesel engine exhaust
• radon progeny
• arsenic

• chromium,
• beryllium,
• nickel, and
• cadmium
• acrylonitrile

10
Lung Cancer Annual Incidence (Steenland, 1996)

• 9,000-10,000 men
• 900-1,900 women
• half asbestos

11
Non-Hodgkins Lymphoma (Figgs, 1995)

• 24 state death certificate study 47 occupations,
  and 28 industries.
• firefighters,
• farm managers,
• aircraft mechanics,
• electronic repairers,
• mining machine operators, and
• crane and tower operators
• also white collar

12
Women

• 25 increase in lung cancer among production
  workers (9 decrease overall cancer) (Delzell,
  1994)
• Breast cancer tissue had 50-60 higher levels of
  DDT and PCBs (Wolff, 1993)
• 38 Breast cancer increase in electrical workers
  (217 for telephone installers) (Loomis, 1994)

13
Review of breast cancer (Goldberg, 1996)

• Limited evidence pharmaceutical industry and
  among cosmetologists and beauticians
• Possible associations chemists and occupations
  with potential exposure to extremely low
  frequency electromagnetic fields.
• Little support textiles workers, dry cleaning
  workers, and nuclear industry workers

14
Roofers asphalt workers (meta analysis
Partanan, 1994)

• Stomach cancer
• bladder cancer
• skin cancer
• leukemia

15
Firefighters review (Golden, 1995)

• leukemia,
• nonHodgkin's lymphoma,
• multiple myeloma,
• cancers of the brain, urinary bladder, and
• possibly from cancer of the prostate, large
  intestine, and skin.

16
Construction workers review (Sullivan, 1995)

• Lung (70 increase from NHIS, 1988),
• larynx,
• oropharyngeal and nasal cancers,
• mesothelioma,

17
Dry cleaning using perchloroethane (Ruder, 1994)

• 23 increase among 20-year workers
• esophogeal, intestinal, bladder

18
Cutting fluid exposure (Eisen, 1992)

• 85 increase of laryngeal cancer (also stomach)

19
Occupational Cancer

• IARC ID carcinogens by worker studies
• 21/22 lung carcinogens
• 34/62 carcinogens overall

20
Asbestos and Health
21
Overview

• Background on asbestos
• Uses of asbestos
• Health Effects
• Risk factors
• Medical tests
• Proper handling
• Standards/ guidelines

22
What is Asbestos?

• Mineral
• Fibrous
• White/grey
• Indestructible
• Fireproof

23
How Long Has it Been a Problem?

• Early Greek miners wore face masks from animal
  bladders
• Insurers stopped selling insurance in 1915
• Cancer cases in 1930s
• Asbestos industry withheld information
• Selikoff studies in 1960s
• Banning of some uses in 1980s

24
Uses of Asbestos

• Fireproofing of buildings
• Heat insulation
• Strengthen building materials

25
Products that can contain asbestos

• Spray insulation
• Pipecovering
• Asbestos cloth
• Cements, mastic, sealants
• Roofing materials
• Floor ceiling tiles
• Plaster taping compound

26
Hazards of Asbestos

• Harmful only when breathed in (maybe when
  swallowed)
• Fiber shape long, thin
• Travels in air, gets deep in lungs
• Sharp shape gets stuck in lungs
• Doesnt break down

27
Asbestos Diseases

• Asbestosis
• Pleural Plaques
• Cancer
• Lung
• Mesothelioma
• G-I Tract

28
Asbestos Diseases

• No completely safe levels
• Higher the exposure, higher the risk
• Low exposures have low risk
• Everyone exposed to asbestos
• Lag time (latency) of 10-40 years
• No acute effects

29
Asbestosis

• Not cancer
• Scarring of lungs
• From high exposures
• Causes shortness of breath

30
Pleural Plaques

• Scars on lungs
• Shows up on x-rays
• Marker of asbestos exposure
• Half of heavily exposed will have
• Not a disease no symptoms
• Does not change into cancer
• Legally considered a disease

31
Lung cancer

• Most common problem with asbestos
• Heavily exposed workers have 5-7 times increased
  risk over lifetime
• About same level of risk as a pack a day
  cigarette smoking
• Interacts with cigarettes 50-90 times increased
  risk for both combined
• Quitting smoking reduces risk

32
Other Cancers

• Mesothelioma
• Cancer of lining of the lungs
• Only caused by asbestos
• Smoking not a risk factor
• G-I tract cancer
• 2-3 times increased risk for heavily exposed

33
Medical tests

• Physical
• History
• X-rays
• Lung function tests

34
What is Risk?

• Studies are from heavily exposed asbestos workers
• Construction trades working with asbestos have
  1/4 or less risk than asbestos workers
• Chemical plant maintenance has about 1/8
• Other maintenance workers are much lower
• Asbestos has been phased out removed in many
  areas

35
Safe handling of asbestos

• Find out where the asbestos is
• Management plan
• Remove if needed by licensed contractors
• Only dangerous if is in the air
• Removal may be more dangerous than leaving
• If is bound in material (tiles, etc) is not a
  hazard
• Should be labeled if left in place

36
Safe handling of asbestos

• No absolutely safe exposure
• Wet methods
• HEPA vacuums and respirators
• Never dry sweep or compressed air
• Stays in air for days
• Small fibers cant be seen
• Friable asbestos means it can be crumbled

37
Maintenance asbestos

• Do not drill, sand, or saw asbestos materials
• Wet mop rather than dry sweep or dust
• Do not use a regular vacuum only HEPA
• Do not disturb asbestos materials
• If use a face mask, only HEPA
• If are air filters, use wet methods, do not shake

38
Training/ removal

• Removal by certified contractors
• Enclosures, ventilation, wet methods, HEPA
• Glove bags, wetting agents, signs
• Encapsulation
• Training needed based on level of exposure
• Level 4 for clean up of asbestos containing
  materials
• Proper disposal while still wet labeled bags

39
Regulations

• EPA regulations on removal
• OSHA Standard for general industry or
  construction
• State licensing for asbestos removal
• Workers compensation
• Reporting of suspected occupational diseases

40
EPAControl of Asbestos in Buildings

• Survey to see if asbestos is present
• Operations and Management Program
• Assess the asbestos
• Abatement if needed

41
Survey

• Appoint manager team
• Check building records
• Locate document all asbestos in records
• Inspect for friable
• Collect test samples
• Document

42
Operations and Maintenance

• Contact building managers maintainers
• Educate employees and occupants
• Train custodians/ maintainers
• Clean using HEPA wet methods regular basis
• Special precautions for construction work
• Inspect twice a year
• Continue program until all asbestos removed

43
Assess Asbestos

• Assess current conditions and chances of
  disturbance
• Determine
• Need for further action
• When it needs to be done
• What abatement methods to use

44
Conduct Abatement if Needed

• Hire contractor
• To select
• Precise contract
• Check references
• Interview
• Insurance
• Best, not low bid

45
Managing Abatement

• Inspect 4 times a day
• Containment barrier
• Coveralls respirators
• Changing decontamination facilities
• Stop work if problem
• Release only when
• Cleaned at least twice
• Visual test
• Airborne asbestos test

46
OSHA Standard

• Applies if over maximum exposure
• Maximum of 0.2 fibers per cc of air (8 hour)
• Maximum of 1 fiber per cc (30 minute)
• Exposure monitoring if above action level (0.1
  fiber per cc)
• Engineering controls where feasible
• Proper respirators

47
OSHA Standard (2)

• Regulated areas
• Labels
• Recordkeeping for 30 years
• Protective clothing
• Change rooms showers
• Medical Exams