[Analyses on the characteristics and the trends of pneumoconiosis notified between 1997 and 2009, in China].

Objective To describe the incidence of pneumoconiosis reported in China from 1997 to 2009 and investigate the epidemiological trends and characteristics of pneumoconiosis,and to provide basic data for formulating the guidelines and policies for control of pneumoconiosis,research on pneumoconiosis,and establishing the time series model for monitoring and early warning of pneumoconiosis.Methods The national database of new cases of pneumoconiosis reported from 1997 to 2009 was subjected to systematic arrangement,descriptive analysis,and trend test using SPSS 15.0.The statistical indices included number of new pneumoconiosis cases in each year,types of pneumoconiosis,regional and industrial distributions of pneumoconiosis cases,work types of pneumoconiosis cases,and the annual changes in mean length of service and mean age at the onset of pneumoconiosis.Results From 1997 to 2009,a total of 122 333 new cases of pneumoconiosis were reported; the number of new cases increased since 1998,but fell to 7620 in 2003,and then it increased again to a maximum of 12 492 in 2009.Of all patients,87.5％ were cases of coal-workers'pneumoconiosis and silicosis; 54 068 (44.2％) were coal-workers' pneumoconiosis cases,and 52 930 (43.3％) were silicosis cases.The pneumoconiosis cases were distributed mainly in Hunan Province (12 995 cases,10.6％),Shandong Province (8952 cases,7.3％),and Sichuan Province (8417 cases,6.9％).Most cases were distributed in coal industry (61 270 cases,50.1％),architectural,material industry (9754 cases,8.0％),nonferrous metals industry (9380 cases,7.7％),and metallurgical industry (8773 cases,7.2％).The work types of these cases mainly included tunneling as the main work (15 659 cases,12.8％),mining as the main work (15 009 cases,12.3％),drilling (14010 cases,11.5％),tunneling (12 122 cases,9.9％),and hybrid coal mine work (1 0 612 cases,8.7％).The mean length of service at the onset of pneumoconiosis in new cases of pneumoconiosis was shortened from 1997 to 2009,with a median length of service of 20.00 years; the median lengths of service at the onsets of coalworkers' pneumoconiosis,silicosis,and asbestosis were 21.58,17.00,and 20.00 years,respectively.The median age at the onset of pneumoconiosis was 51.00 years,and the mean age of onset in new cases of pneumoconiosis increased over the 13 years.Conclusion The incidence of pneumoconiosis is still high,with a marked concentrated trend in several industries,work types,and pneumoconiosis types,a marked rising trend in number of new cases,and a marked shortening trend in length of service at the onset of pneumoconiosis.The prevention and control of pneumoconiosis should be enhanced in key industries and for people engaging in key types of work according to the epidemiological characteristics of pneumoconiosis.In addition,the demonstration project of comprehensive prevention and control of occupational dust hazards should be carried out,and the monitoring and early warning system for pneumoconiosis should be established. Key words: China; Pneumoconiosis; Silicosis; Asbestosis; Epidemiological study