Size matters

DUST: Never just a ‘nuisance’ depends on substance/size of particulate matter (PM)

Inhalable Dust = 100 microns (μm) & less

Over 10 microns (PM10) filtered out by nose/throat

Thoracic dust = 10microns & below, gets to lungs μm

Respirable dust = 5 microns (PM5) and below, gets deep into lungs

WHO say: PM2.5 microns & less absorbed into blood crosses blood brain barrier – NO SAFE LEVEL

0.3 microns are absorbed through skin

WELs- Work Environment Limits about 500 in mg/cubic metre, not safe levels

I micron, μm = 1 thousandth of millimetre

1 millionth of metre

PM10 = particle matter with diameter of 10 microns. Nanometre = 1 billionth of a metre smaller than a virus, size of DNA strand

Nanoparticles of carbon/any material far more hazardous than normal carbon dust

Trade Union Principles on exposure:Use the Precautionary Principle

• Remember Legal/official limits WELs are NOT safe health based limits

• The only safe level of a hazardous substance is zero… or as near to zero as you can get

• No Hazard = No risk

Diesel

Silica