Transcript Document
Health Healthand andSafety Safety Executive Executive 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 • 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 • It causes stiffening and scarring of the lungs. Nodules visible on X-Ray • Symptoms are coughing and breathlessness • Progressive, even after exposure stops Silicosis usually follows at least 10 years of exposure to RCS Silicosis Irreversible • • Increased risk of Tuberculosis (TB) • Silicosis is under-reported. After 15 years of exposure to RCS at the WEL of 0.1mg/m3, the risk of developing silicosis is 1 in 40 Normal chest X-Ray Tuberculosis 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 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)