Between 1996 and 2009 IARC classified silica as one of the carcinogenic substances to human beings. The relationship of the exposure-response between silica dust and lung cancer is still debated. The article used data from German uranium miner to further study the relationship. The methodology used in the study involved the cohorts who were 58677 workers with detailed information on their occupational exposure to silica dust in mgm-3 per year. In the follow-up data of 1946- 2003 it showed that 2995 miners had died from lung cancer. The internal Poisson regression was used stratified by age and calendar year to determine the excess relative risk per dust year. The result showed a piecewise linear function with knot > 10 mgm-3 per years gave the best model fit for arsenic and radon (Sogl et al., 2012). Thus study confirmed that there is a positive relationship of exposure-response between silica dust and lung cancer, especially for higher exposures.
Yuewei Liu et al., 2013, assessed the relationship between silica dust exposure and lung cancer. The analysis to prove the relationship came because IARC had earlier declared crystalline silica as carcinogenic to human. They investigated 34018 workers who were working in China (1960 – 2003). Cumulative crystalline silica exposure was analyzed by linking the job-exposure matrix to individual’s work history. The categorical analysis by cumulative quartiles of silica exposure gave hazard ratios of >1 compared to the unexposed individuals. The joint effect of smoking and silica was close to multiplicative and more than additive. The findings found in this article confirm that silica is a human carcinogenic (Liu et al., 2013). The results also suggest that the available exposure limits in various nations might not be sufficient to prevent workers working in mines from lung cancer. Since the cancer risks were found to be more in smoking workers, thus smoking cessation can help to reduce the risk of lung cancer to the exposed persons.
Satiavani et al., 2016, studied the relationship of the exposure to the crystalline silica dust and the lung cancer risk. Their desire to study this area was motivated by the fact that conclusions have been controversial. The objective of the article was to summarize and review epidemiological evidence on the probable relationship between silica exposure and the lung cancer risk and provide the update on an occupational health concern. Eligible research studies of up to April 2016 were used. The pooled effect estimates were analyzed according to the study design and reported the outcome. The article found that lung cancer was elevated by both non-silicotis and silicots (Poinen-Rughooputh, Rughooputh, Guo, Rong, & Chen, 2016). The other subgroup analysis indicated that mining cohorts had highest lung cancer risk. Based on this article further research is required to establish how non-silicots are at risk of developing cancer complications.
Irvin Jackson conducted a study of the relationship of the silica dust and lung cancer in the University of Louisville in 2015. The study came after the researchers from Tanzania found that gold miners were exposed to crystalline silica that put them to risk of silicosis, pulmonary TB and lung cancer. The researchers in this article found that there is a causal link between the lung cancer and inhaled silica. The findings were quite important because over two million individuals in the US are exposed to silica dust. The article noted that people cannot cough out all the fine inhaled particles which can cumulatively result in lung cancer (Jackson, 2015). The African research on the silica exposure in the mining found that miners were 337 times higher exposed compared to the recommended limits set by the US department of occupational health and safety. Thus, from the article, it is clear that miners should put control measures that can reduce the crystalline silica exposure.
Ali Faghihi et al., 2015 studied the exposure to silica dust and its relationship with pulmonary disorders among cement workers. The study used a cross-sectional analysis where sixty-two samples were used. The assessment of the respirable dust was concentrations of dust were evaluated using the gravitimetric method. The greatest levels of the respirable dust exposure were found to be with workers in the raw mills. The partial correlation analysis showed a substantial relationship between the exposures of workers to the crystalline silica. The study observed that the individual exposure to the silica dust reduces some pulmonary functions and result in some disorders. These pulmonary could be as a result of the lung cancer that affects the pulmonary parts (Faghihi-Zarandi, Ebrahimnejad, Sekhavati, & Baneshi, 2017). Thus, it is important to control the exposure of the miners to the silica dust more importantly in regions with greatest levels of the silica concentrations.
- Faghihi-Zarandi, A., Ebrahimnejad, P., Sekhavati, E., & Baneshi, M. (2017). OCCUPATIONAL EXPOSURE TO CRYSTALLINE SILICA AND ITS PULMONARY EFFECTS AMONG WORKERS OF A CEMENT FACTORY IN SAVEH, IRAN. Indian Journal of Fundamental and Applied Life Sciences, 5(s1), pp. 2822-2832. Retrieved from http://www.cibtech.org/sp.ed/jls/2015/01/327-JLS-S1-326-BANESHI-OCCUPATIONAL.pdf
- Jackson, I. (2015). Exposure to Silica Dust Linked to Lung Cancer Risk: Study. Journal of Occupational and Environmental Hygiene, 10(s2).
- Liu, Y., Steenland, K., Rong, Y., Hnizdo, E., Huang, X., & Zhang, H. et al. (2013). Exposure-Response Analysis and Risk Assessment for Lung Cancer in Relationship to Silica Exposure: A 44-Year Cohort Study of 34,018 Workers. American Journal of Epidemiology, 178(9), 1424-1433.
- Poinen-Rughooputh, S., Rughooputh, M., Guo, Y., Rong, Y., & Chen, W. (2016). Occupational exposure to silica dust and risk of lung cancer: an updated meta-analysis of epidemiological studies. BMC Public Health, 16(1).
- Sogl, M., Taeger, D., Pallapies, D., Brüning, T., Dufey, F., & Schnelzer, M. et al. (2012). Quantitative relationship between silica exposure and lung cancer mortality in German uranium miners, 1946–2003. British Journal of Cancer, 107(7), 1188-1194.