Chapter 4:
Environmental Hazards
Lead
Can you name some materials in
a house that might contain lead?
What is Lead?
•Chemical element
•Pb: Latin “Plumbum”
•Plumber, Plumb bob
•Heavy,soft (malleable)
metal
49
In
Indium
114.82
50
Sn
Tin
118.69
51
Sb
Antimony
121.75
81
Tl
Thallium
204.37
82
Pb
Lead
207.19
83
Bi
Bismuth
208.980
What’s the Matter with Lead?
• Highly toxic poison
• Accumulates in body
tissues
• Harms many body
systems
– blood
– nerves, brain
– reproductive
How Can I Be Exposed to Lead?
• Deteriorated lead
paint
• Burning or cutting
metals containing or
painted with lead
– Plumbing lines
– Solder joints
– Corrosion resistant
metal coatings
What Steps Do I Take First?
• Before you begin work, have a
“Competent Person” determine if workers
will be potentially exposed to lead
• If workers are potentially exposed,
determine if the concentration of these
exposures exceeds OSHA limits
• If workers conduct “Trigger Tasks”, certain
controls are required
TRIGGER TASK 1 (< 10 x the PEL)
• Manual demolition of structures
• Hand scraping or sanding
• Heat guns
• Using power tools with dust collection
systems
• Spray painting
TRIGGER TASK 2 (10-50 X PEL)
• Using power tools without dust collection
systems attached
• Movement/removal of enclosures
• Cleanup where dry expendable abrasives
are used
• Lead containing mortar, rivet busting
TRIGGER TASK 3 (>50 x the PEL)
• Abrasive blasting
• Welding or torch cutting metals containing
lead or lead based paint
Respiratory Protection
(Minimum requirements)
• Trigger task 1
– ½ mask air purifying respirator with high
efficiency filters (HEPA)
• Trigger task 2
– Full face piece respirator with high
efficiency filters (HEPA)
• Trigger task 3
– Supplied air pressure/demand respirator
Other Requirements
• Personal protective clothing, such as
disposable jump suits
• Change areas for work clothing and shoes
• Hand washing facilities
• Biological monitoring (Blood Lead)
• Training
METHODS OF COMPLIANCE
Lead in Construction
• Exposures > PEL (From Day One)
– Engineering Controls
– Respiratory protection
– Compliance program
– Mechanical ventilation
– Administrative controls
– Good work practices
Silica
Silica
• What is Silica?
• Where is it found on
construction sites?
• When does silica
become hazardous?
What are the Health
Effects of Silica?
• Silicosis
• Affects alveolar
surface of lungs
– Decreases elasticity
– Prevents oxygen/CO2
exchange
• Lung X-ray is required
to diagnose silicosis
• Silica also contributes to
tuberculosis, heart
disease, and lung cancer
What Jobs Cause Exposure?
• Cutting concrete slabs
• Finishing and grinding on
concrete
• Block and brick cutting
• Jack hammering on
concrete
• Abrasive blasting
Control Silica Using Wet Methods
• Water suppression
of dust is effective
• Minimal water use
is required
• Planning for water
supply is required
Using Ventilation to Control Dust
• Use when wet
methods are not
feasible
• Collect dust at the
source
• Supplement with
respirators
• Avoid contaminating
co-workers
Asbestos
Asbestos
1. Surfacing Material
2. Thermal System Insulation
(TSI)
3. Miscellaneous
Photo: oldhouseweb.com
Health Effects of Exposure to
Asbestos
• Asbestos exposure can cause:
– Asbestosis
– Mesothelioma
– Lung Cancer
– Other Illnesses/Cancers
FEDERAL ASBESTOS
REGULATIONS
(Occupational Exposures)
1. OSHA
Asbestos in Construction
Asbestos in General Industry
2. EPA
Worker Protection Rule
Major Elements of OSHA’s
Asbestos Standard
29 CFR 1926.1101 (Construction)
– Exposure monitoring
• Permissible Exposure Limit (PEL) of 0.1
f/cc, 8 hour TWA
• Excursion Limit of 1.0 f/cc, 30 minutes
– Employee training and education
– Regulated areas
Major Elements of OSHA’s
Asbestos Standard (cont.)
– Defines 4 Classes of work activity
• Training for each class of work activity
– Engineering and work practice controls
– Protective equipment
– Medical surveillance
– Recordkeeping
MOLD
Mold
• Molds are
microscopic
organisms found
everywhere.
• Some molds can
cause adverse
health effects.
How to Recognize Mold
• Sight—Usually
appears as colored
woolly mats
• Smell—Often
produces a foul,
musty, earthy smell
Hidden Mold in Buildings
How to Protect Yourself
• Avoid mold spores
• Use respiratory protection.
• Protect your skin
How to Protect Yourself (continued)
• Wear goggles
• Avoid getting
mold or mold
spores in your
eyes.
Cleanup of Mold
• Disinfect hard, water
resistant, non-porous
surfaces
• Consider discarding
water-damaged porous
materials.
• After working with moldcontaminated materials,
wash thoroughly,
including the hair, scalp,
and nails.
Regulation of Mold Cleanup
•
•
•
•
•
No exposure limits
No federal rules
State and local rules may apply
State/local certification may apply
Specific contractual obligations
may apply