The health of the South African mining workforce: trends, progress and challenges Jill Murray and Zodwa Ndlovu

Transcription

1 The health of the South African mining workforce: trends, progress and challenges Jill Murray and Zodwa Ndlovu International Public Health Symposium, University of the Witwatersrand, School of Public Health, Jan 2013

2 Diseases caused by silica dust Silicosis Tuberculosis Silica dust Emphysema Lung cancer Cowie, The epidemiology of tuberculosis in with silicosis. Am J Respir Crit Care Med 1994 Rees & Murray, Silica, silicosis and tuberculosis. Int J Tuberc Lung Dis 2007 Corbett et al., HIV infection and silicosis: the impact of two potent risk factors on AIDS

3 Authors Study design Study period Irwig and Rocks 1978 Cross sectional 1968 to 1971 Cowie and van Schalkwyk 1987 Silicosis rates in South African Study Population Employed white miners Cross sectional 1984 Employed black miners Churchyard et al Cross sectional 2000 to 2001 Employed black miners Mean employment (years) Diagnostic tool Proportion with silicosis (%) Not stated Chest X rays 6.8 Not stated Chest X rays Chest X rays Steen et al Cross sectional 1994 Living black exminers Trapido et al Cross sectional 1996 Living black exminers 15.5 Chest X rays Chest X rays Meel 2002 Cross sectional 1997 to 1999 Living black exminers Not stated Chest X rays 34.0 Girdler-Brown et al Cross sectional 1999 Living black exminers 25.6 Chest X rays 24.6 Park et al Cohort (1 year follow up) 1999 to 2000 Living black exminers 26.1 Chest X rays 27.0 Hnizdo and Sluis-Cremer 1993 Cohort 1940 to 1991 Deceased white 23.5 Chest X rays 14.0 Murray and Hnizdo 2005 Cohort 1940 to 2003 Deceased white 23.5 Autopsy 51.6 Murray et al Cross sectional trend analysis 1975 to 1991 Deceased black Autopsy Nelson et al Cross sectional trend analysis 1975 to 2007 Deceased black Deceased white Autopsy

4 Silicosis at autopsy in deceased current black, % 3% Data source: PATHAUT database, Pathology Division, National Institute for Occupational Health Nelson et al. Three decades of silicosis: disease trends at autopsy in SA Environ Health Perspect

5 Authors Silicosis rates in South African Study design Study period Irwig and Rocks 1978 Cross sectional 1968 to 1971 Study Population Employed white miners Mean employment (years) Diagnostic tool Proportion with silicosis (%) Not stated Chest X rays 6.8 Cowie and van Schalkwyk 1987 Cross sectional 1984 Employed black miners Not stated Chest X rays 1.4 Churchyard et al Cross sectional 2000 to 2001 Employed black miners 21.8 Chest X rays Steen et al Cross sectional 1994 Living black exminers Trapido et al Cross sectional 1996 Living black exminers 15.5 Chest X rays Chest X rays Meel 2002 Cross sectional 1997 to 1999 Living black exminers Not stated Chest X rays 34.0 Girdler-Brown et al Cross sectional 1999 Living black exminers 25.6 Chest X rays 24.6 Park et al Cohort (1 year follow up) 1999 to 2000 Living black exminers 26.1 Chest X rays 27.0 Hnizdo and Sluis-Cremer 1993 Cohort 1940 to 1991 Deceased white 23.5 Chest X rays 14.0 Murray and Hnizdo 2005 Cohort 1940 to 2003 Deceased white 23.5 Autopsy 51.6 Murray et al Cross sectional trend analysis 1975 to 1991 Deceased black Autopsy Nelson et al Cross sectional trend analysis 1975 to 2007 Deceased black Deceased white Autopsy

6 >3000 SA Gold miners 795 SA population WHO epidemic level USA PREVALENCE OF TB PER

7 Active pulmonary tuberculosis in Black miners at autopsy, all commodities, Rate/ Year Data source: PATHAUT database, 21 January 2013 Pathology Division, National Institute for Occupational Health, Johannesburg 7

8 Risk factors for TB in High background rate Socio-economic factors Latent TB Previous TB Ageing workforce Housing HIV Silica dust Migrancy 8

9 TB control and molecular epidemiology Godfrey-Faussett, Lancet 2000 HIV does not affect active case finding of TB Lewis, Am J Resp Crit Care Med 2009 HIV and the outcome of TB treatment Murray, Am J Resp Crit Care Med 1999 HIV and the prevalence of undiagnosed TB Corbett, Am J Resp Crit Care Med 2004 Emergence of extensively drug-resistant TB Calver, Emerg Infect Diseases 2010 HIV-1 and recurrence, relapse, and re-infection of TB Sonnenberg, Lancet 2001 Thibela TB: isoniazid preventive therapy amongst Fielding, Contemp Clin Trials 2011 A dusty business. Burki, Lancet: Infectious Diseases

10 Policy, legislative and service initiatives affecting miners in SA Regulatory Initiative Leon Commission of Inquiry into Safety & Health in the Mining Industry1994 Primary responsibility Presidential Inquiry Comment Incorporation of recommendations into law Mine Health and Safety Act 1995 DMR Focus on safety, poor enforcement, inadequate data collection Dust control Silicosis Control Programme 1990s DMR Milestones not met (ongoing) TB TB Guidance Note 2003 DMR Not updated Tuberculosis Strategic Plan for SA DoH 2007/2012 TB Programme Review Tool 2010 Chamber of Mines Ongoing implementation SADC Declaration on TB in the Mining Sector 2012 Housing Social Contract for Rapid Housing Delivery 2005 Housing and Living Conditions Standard for the Mining Industry 2009 HIV HIV/AIDS programmes 1993 (ongoing) SADC Health Ministers Dept of Housing DMR DMR, DoH, industry, unions Progress but hostels still in existence Promulgated, not yet implemented Consensus, widespread implementation Compensation ODMWA amended 1993 DoH Former miners unable to access system Integration of ODMWA with COIDA 1999 DoL Separate systems persist; contested domains of authority, unfunded liabilities

11 11

12 Factors influencing translation of research and policy initiatives into effective interventions Migrant labour system Unequal power relationships Limited civil society activism Competing demands for resources Fragmented OH legislation Weak enforcement, monitoring and evaluation Focus on safety Lurie & Stuckler The role of mining in spread of TB in Africa: policy implications. Expert Rev Anti Infect Ther 2010 Murray et al. Occupational lung disease in the SA mining industry: research and policy implementation. J Public Health Policy

13 Improving miners health: It s a marathon not a sprint 13

14 14