Industrial hygiene II exam 4

• **optical spectrum includes

  UV 10-400 nm

  Visible 400-760 nm

  IR 760nm - 1mm
• **ultraviolet subdivisions

  Vacuum 10-200 nm

  UV-C 100-280 nm

  UV-B 280-315nm

  UV-A 315-400nm
• visible

  "7" colors

  400-760 nm
• **IR subdivisions

  IR-A 760-1400 nm

  IR-B 1.4-3.0 um

  IR-C 3.0um-1mm
• **types of non-ionizing radiation

  optical spectrum [UV, V, IR]

  radiofrequency [microwave]

  ELF EMF
• microwave wavelength

  1mm-1meter
• radio wavelength

  1 meter - 100,000 km
• common occurrences of non-ionizing radiation

  industrial

  residential
• **common devices that give off non-ionizing radiation

  microwave ovens/dryers

  cell phones/communication systems

  fluorescent/intense lighting

  LASER devices

  AC power grid
• what health effects does UV cause

  melanoma

  or other skin cancers
• what health effects foes IR cause

  cataracts
• non-well documented/non-scientific adverse health effects include

  cell phones causing brain cancer

  electromagnetic hypersensitivity
• **optical spectrum

  wavelength 0.01 um- 1 mm[1000um]

  between X-ray - radiofrequency waves
• **UV natural sources

  sun

  broad spec UV-solar radiation

  ozone layer
• **UV man-made sources used through industry

  welding equipment

  plasma torches

  high intensity lamps
• **types of high intensity lamps from man-made sources of UV

  mercury vapor

  metal halide

  hydrogen

  xenon

  deuterium

  "black"
• **other man-made sources of UV not in industry

  treatment systems for water and waste water

  food processing

  lab/medical equipment sterilization

  UV ink curing system

  medical applications
• UV fluorescences

  can come from scorpions under UV light
• **employees at risk to UV exposure

  sunlight workers

  arc lamps

  germicidal lamps

  Hg-HID lamps

  welders
• UV exposure primarily targets what 2 organs

  skin and eyes

  < 280 nm absorbed completely by stratum corneum [UVC]

  280-315nm absorbed by epidermis [UVB]

  315-400nm penetrates dermis [UVA]
• **non-cancerous adverse health effects include

  erythema

  accelerated skin aging

  photokeratitis

  photosensitivity

  immune system
• erythema from UV exposure

  comes from acute exposure

  max peak = 260nm [UVC]

  sec. peak = 290nm [UVB]
• which peak effect do humans get sunburns from

  secondary peak effect
• accelerated skin aging from UV exposure

  comes from chronic exposure to UV
• photokeratitis from UV

  corneal burns

  UVB and UVA

  commonly found in welders

  corneal epithelium absorbed 99% of energy less than 350nm
• photosensitivity from UV

  commonly associated with employees exposed to coal tar pitch volatiles
• immune system effects from UV exposure

  excessive UVB interferes with normal immune system functions

  systemic immunosuppressive effects of both acute and low dose UV exposure
• carcinogenicity from UV exposure

  broad-band UV is classified as a known human carcinogen by several agencies including

  NTP, AIHA, WHO[IARC]
• **types of cancer associated with UV exposure

  basal cell carcinomas

  squamous cell carcinomas

  melanoma skin cancers

  eye cancers
• **how to control UV exposure

  isolate the employee

  enclose the source

  wear protective clothing, creams, and lotions
• visible region of optical spec.

  400-760nm

  includes violet, indigo, blue, green, yellow, orange, red

  high wl -- ROYGBIV -- low wl

  decrease in wl as go through color spec.
• **sources of visible non-ionizing radiation exposure

  natural comes from sun

  man-made sources is all other types of lighting
• **employees at risk for visible region exposure

  sunlight workers

  arc lamps

  Hg-HID lamps

  Carbon Arcs
• **consequences that come from too much visible region exposure

  -night/color vision impairment

  -high-energy visible light that damages retinal cells, has blue-violet light, and can cause increase risk of developing age-related macular degeneration
• **how to control visible region exposure

  -using equalizing lighting or transition lenses to protect from vision impairment

  -using blue-blocker lenses or blue filter screens to protect from high-energy visible light
• IR


  760-1,000,000 nm

  IR-C mid/far from IF

  IR-B

  IR-A near fromIR
• **natural sources of IR

  sun

  radiated from other objects
• **man-made sources of IR

  heaters/driers

  engines

  lighting

  anything above absolute zero
• **employees at risk to IR exposure

  sunlight workers

  arc lamps

  Hg-HID lamps

  ovens/driers

  metal working

  glass blowing

  food industry
• **consequences of IR exposure

  photochemical reactions can occur from low energy

  IRC & IRB is absorbed by cornea

  IRA is absorbed by eye lenses and can lead to cataract formation