150 likes | 350 Views
Silica Dust: You Are More At Risk Than You May Think. Gaynor Guthrie Medical Inspector. “It’s only dust you know!”. What is the Problem?. Why is it a Problem?. Particles need to be “respirable” to cause harm Issue is Respirable Crystalline Silica or RCS
E N D
Silica Dust: You Are More At Risk Than You May Think Gaynor Guthrie Medical Inspector
Why is it a Problem? • Particles need to be “respirable” to cause harm • Issue is Respirable Crystalline Silica or RCS • RCS particles can penetrate to deep lung
Why is it a Problem? • A micron is one millionth of a meter. • Human hair varies between 40 to 100 m thick. • Respirable dust = 10 m or less
Silicosis • ?10 to 20% construction workers exposed • Silicosis usually follows at least 10 years of exposure to RCS • It causes stiffening and scarring of the lungs. Nodules visible on X-Ray • Symptoms are coughing and breathlessness • Progressive, even after exposure stops
Silicosis Irreversible • Increased risk of Tuberculosis (TB) • After 15 years of exposure to RCS at the WEL of 0.1mg/m3, the risk of developing silicosis is 1 in 40 • Silicosis is under-reported.
Lung cancer • There is an association between silicosis and lung cancer • Over 500 silica related lung cancer deaths in construction in 2004 – Over 10 a week • Silica is the second most important cause of occupational lung cancer after asbestos
Lung cancer Second commonest cancer in men after prostate Symptoms: cough (phlegm and blood), pain on breathing or coughing, shortness of breath, weight loss Only 7% men survive 5 years after diagnosis
Chronic Obstructive Pulmonary Disease (COPD) • Persistent obstruction of airflow into lungs • Irreversible (unlike asthma) • Progressive • Main cause is smoking • Silica exposure associated with COPD • Construction workers 2 to 3 times risk • Symptoms: breathlessness, cough with phlegm
Health Surveillance • G404 Health surveillance for RCS • Use a health professional • Risk based • Symptom enquiry (COPD, TB) • Lung function test • Chest X-Ray
How Much is a Problem? COSHH sets WEL for dust: General Dust • 10 mg.m-3 (inhalable) • 4 mg.m-3 (respirable) Respirable Silica • 0.1 mg.m-3 (8-hour TWA)