The spatial distribution and epidemic trend of silicosis in Guangdong province

Abstract

Objective: To investigate the characteristics, temporal trend of silicosis, and provide basis for risk assessment and precise prevention and control of occupational diseases. Methods: Using descriptive statistics to analyze the reported cases of silicosis by SPSS 20.0 software. Reported silicosis cases, the constituent ratio, the incidence age and the working age at onset were analyzed by a linear trend test. Analyzing the variation trends of regional, industry, economic type and enterprise scale distributions by the chi-square trend test. Moreover, using Moran's I method for spatial autocorrelation analysis and trend-surface analysis. Results: (1) During 2006 to 2015, Guangdong province had reported 1, 428 cases of silicosis, mainly gathered in Foshan, Zhongshan, Guangzhou, Shenzhen, which included 1391 male cases accounting for 97.41%. And the average incidence age was 45 (39, 51) . The average working age of onset was 9 (5.5, 15) . In economic type distribution, the private economy took the main part, accounting for 59.1%. In enterprise scale distribution, it was dominated by small and medium enterprises (SMEs) , accounting for 32.4% and 37.3% respectively. In industry distribution, most cases were gathered in materials and mining industry, accounting for 32.1% and 22.9% respectively. (2) The number of silicosis cases, the incidence age and the working age of onset showed a rising trend (P<0.01) . Meanwhile, the constituent ratios of medium-sized enterprises and building materials industry were increasing (P<0.05) . The annual variation trends of regional, economic type and age distributions were not statistically significant (P> 0.05) . (3) The spatial distribution trend showed an inverted U type, which was firstly raised and then declined from south to north and from east to west. The distribution characteristic demonstrated some high-high cluster areas, including Chancheng, Nanhai, Shunde, Panyu, Dongguan, Pengjiang, and Zhongshan. While Wuhua showed a high-low outlier form (P<0.01) . Conclusion: Silicosis cases, age and working age of onset were on the rise, as well as the industry and enterprise scale distributions of occupational diseases presented a certain trend in Guangdong province from 2006 to 2015. There were high-high cluster and high-low outlier phenomena in spatial distribution with spatial correlation. Therefore, our work of silicosis epidemic trend and distribution may provide some bases for the occupational disease risk assessment and control.