John Baker, CIH

1
Environmental and Workplace Perspectives
Particulates

• Presented by
• John Baker, CIH
• April 8, 2009

2
Outline

• Environmental and Industrial Hygiene define and
  assess particulates differently
• Basis for compliance and corrective action
  decisions
• Emerging issues including ultrafine particulates
  and nanoparticles

3
Global Particulate Pollution
http//veimages.gsfc.nasa.gov/1651/toms_indonesia_
smog_lrg.jpg
4
Workplace Particulate Exposure
http//www.hfinster.de/StahlArt2/archive-Integrate
dSteelworks-C-260-6-11.01.1993-en.html
5
Environmental - Industrial Hygiene

• Considers the very young, and elderly
• Health compromised
• 24/7 exposure
• Effects on property
• Haze and visibility
• Epidemiology
• Different scientific references than IH

• To protect most nearly every worker
• Medical surveillance
• Historically industrial
• More recently, office and residential
• Toxicology
• OSHA not cover all workplaces (MSHA, States)

6
Particulate Matter Pathology
Pope, C.A. and Dockery, D.W., JAWMA 56709-742
(2006)
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Definitions

• Particulate
• Aerosol
• Dust
• Fiber

• Mists
• Fogs
• Fume
• Smoke

8
Combustible Dust

• Safety issue in addition to health
• Surface area
• Chemical nature
• Concentration
• Enclosed space
• Available oxygen

9
Sizing Considerations

• Retention on Surfaces
• Inertial Motion and Deposition
• Sedimentation
• Diffusion
• Aerodynamic Diameter

10
Environmental Sizing

• Total Particulate Matter up to 100 um
• Particulate Matter
• PM10 particles lt 10 um
• Fine PM
• PM2.5 particle lt 2.5 um
• Coarse PM
• PM10 PM 2.5

11
2006 NAAQS for PM species
12
2005 WHO Guidelines for PM
13
Environmental PM Samplers
14
Respiratory Deposition
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ACGIH Criteria

• Inhalable
• Hazardous anywhere in respiratory tract
• 50 cut point at 100 um
• Thoracic
• Within lung airways and gas-exchange region
• 50 cut point at 10 um
• Respirable
• 50 cut point at 4 um

16
Nuisance Dust

• Particles (insoluble or poorly soluble) Not
  Otherwise Specified PNOS
• ACGIH warns against misuse of PNOS
• Guideline, not a TLV
• Inflammation or lung overload effects
• 3 mg/m3 respirable
• 10 mg/m3 inhalable

17
Total Dust Monitor

• NIOSH 0500
• Gravimetric
• 37mm PVC 5 um
• Preweighed Filter
• 0.03 mg/sample LOD
• 1 2 Lpm (7 133 L)
• Matched Weight
• MCE 0.8 um

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Total Dust Monitor
19
Inhalable Dust Sampler

• SKC IOM Inhalable sampler
• 100 um
• 2 lpm
• Could be a high degree of error

20
Respirable Dust Samplers

• Left
• Dorr-Oliver 10 mm Nylon Cyclone
• Right
• SKC Aluminum Cyclone

21
Particle Counters

• Optical
• 6 bin sizes
• 0.2 - 0.3 um minimum
• Light scattering
• Condensation
• 0.02 1 um
• Not separated by size
• Alcohol or water droplets 5 -15 um

22
Timely Particle Issues

• OSHA National Emphasis Program for Crystalline
  Silica
• Ultrafine particles
• Engineered Nanoparticles

23
Remember

• The vague term particulate matter with no
  designation of its chemical or physical nature
  violates every principle of toxicology.
• W.C.L. Hemeon, A critical review of regulations
  for the control of particulate emissions, JAPCA
  23 376-387 (1973)

24
Silica Update

• OSHA National Emphasis Program (NEP)
• January 24, 2008
• Builds upon the 1996 Special Emphasis Program
  (SEP)
• Construction and Maritime guidance on using OSHA
  adopted conversion of
• 0.1 mg/m3 per 1 mppcf

25
Respirable Silica Monitoring

• ACGIH/ISO/CEN curve (4 um cut off)
• 2.5 lpm for SKC Aluminum cyclone
• BMRC curve (5 um cut off)
• 1.9 lpm for SKC Aluminum cyclone
• OSHA must use former ACGIH curve (3.5 um cut off)
  and nylon cyclone
• 1.7 lpm
• PW 37 mm 5 um PVC filter XRF analysis

26
Standards and Guidelines

• OSHA 29 CFR 1910.1000 General Ind.
• PEL (10 mg/m3) / (2 resp. quartz)
• Cristobalite or Tridymite ½ Quartz PEL
• OSHA 29 CFR 1926.55(a) Construction
• PEL (250 mppcf) / (5 resp. quartz)
• Divide by 10 to convert to mg/m3
• ACGIH TLV
• a Quartz Cristobalite, 0.025 mg/m3 Resp.
• Tridymite withdrawn 2005, insufficient data

27
Piggy Back Toxic Chemicals

• Some environmental scientists have estimated that
  50 to 75 of the toxic species are in the PM
  2.5 fraction
• 70 of PM 2.5 may reach alveoli and be taken into
  the bloodstream with their toxic adsorbents
• JAWMA, 45 680-681 (1995)

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For Example

• Some PM 10 is considered to have a microsponge
  structure
• Some PM 1 is considered to have a snowflake or
  fractal structure
• These surface characteristics may act as
  molecular sieves with huge and indeterminate
  surface areas

29
Diesel Particulate Update

• MSHA
• 160 ug/m3 total carbon 8 TWA (May 20, 2008)
• Specialized cassette/filter/cyclone
• NYSDEC other State Env. Agencies
• Investigating ultra-fine diesel emissions
• Less than 100 nm particle size

30
Nanotechnology Definition

• ASTM E 2456 Terminology Standard
• 1 to 100 nm length scale
• Novel chemical and/physical properties emerge at
  this length scale
• Ability to control or manipulate on the atomic
  scale

31
Engineered Nanoparticles

• Fullerenes
• Carbon Nanotubes
• Nanoshells
• Quantum Dots

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Aggregates of Nanotubes

• Individual nanotubes have extremely short
  lifetime in air
• Agglomerate by Van der Waals or capillary forces
• Aggregate by fusing, sintered, metallically
  bonded forces
• May be hundreds of nm in smallest length scale

33
Guidance on Nanoparticles

• ASTM E 2535 07 Std Guide for Handling Unbound
  Engd NPs in Occ. Settings
• Approaches to Safe Nanotechnology An Information
  Exchange with NIOSH
• www.cdc.gov/niosh/topics/nanotech/safenano
• EPA Fact Sheet for Nanotech under TSCA
• http//www.epa.gov/oppt/nano/nano-facts.htm
• ICON at Rice University
• http//icon.rice.edu

34
Respiratory Protection
35
Protective Clothing
36
Summary

• Environmental and Industrial Hygiene may
  classify particles differently.
• Size matters, but so do chemical and other
  considerations.
• What information do you need for the decision you
  must make?
• Sample accordingly.