Dust
• A major component of particulate matter that is
greater than 2.5 um, but less than 10 um in diameter
– PM10
• Major PM10 sources
– Dust
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Livestock operations
Construction
Roads
Agricultural fields
Deserts
– Soot
• EPA limit for PM10
– 24 average – 150 ug/m3
– Annual average – 50 ug/m3
• Effects of PM10
– Human health
• Settles in upper airways
• Aggravates respiratory diseases
– Carries odors
• Extends distance of odor plume
– Reduces visibility
• Clean air act states that it will provide protection for the
visibility of natural parks and wilderness areas
• Extent of the problem
Natural visibility Average visibility
miles
Eastern U.S.
90
12-25
Western U.S.
140
35-90
• Dust contributes 5 – 20% of the reduction of visibility in the
U.S.
• Sources of dust from livestock
– Feeds
• Wastes in buildings
• Damage during delivery
• Processing
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Dry manure
Animal skin
Feathers
Bedding
Bacteria
Molds
• Factors contributing for livestock dust
– Building type
• Solid floor > slats
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Animal activity
Temperature
Humidity
Ventilation
Stocking density
• Lower density > high density
– Feeding method
• Results of these factors causes evening dust peak
around outdoor cattle lots
– Reasons
• Afternoon heat and wind dries manure
• Cattle become active in the evening
– Moving to the feed bunk or waters or interacting socially
• Atmosphere becomes more stable in evening so suspended
dust particles hang in air
• Dust control
– For swine and poultry in confinement buildings
• Feeding system
– Feed pelleted feeds
» May be improved by adding fat during cooling
– Deliver feeds to feeders with drop tubes
– Use liquid feeding systems
» For swine
• Improve skin health
– Improve dietary fat quality
– Supplement with zinc to requirement
• Management
– Frequent cleaning
» Include ventilation fans and motors, louvers and shrouds
» If animals are kept year-round, zone clean part of barn
– Spray vegetable oil
» Do not mist
» Reduces respirable dust by 81%
– Use wet scrubbers
– Use Biofilters
– Use Biomass filters
– Use windbreak walls
– Use vegetative shelter belts
– For cattle in an earthen lot
• Feeding system
– Add up to 5% fat to the diet
– Feed for the last time early in the afternoon
» Minimizes late afternoon activity
– Frequent cleaning
» Also applies to concrete lots
– Set manure scraping equipment to leave 1 to 2 inches of
compacted manure on top of the soil
» Prevent leaching of nutrients into ground water
– Increase stocking rate during hot dry weather
» Increased urine reduces dust
– Sprinkle water over lot
» Most effective in late afternoon when cattle are active
» Need capacity for .25 inches/day
» Sprinklers should have at least 50% overlap, but not
run onto feed apron
» Excessive moisture may increase odor
– Topical application of crop residues on lot surface