Silicosis epidemiology and demographics: Difference between revisions
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==Epidemiology and Demographics== | ==Epidemiology and Demographics== | ||
Workers in a broad range of industries are exposed to crystalline silica | Workers in a broad range of industries are exposed to crystalline silica. Up to 200,000 miners and 1.7 million non-mining workers in the United States have experienced significant occupational exposure to inhaled silica, and new cases of silicosis are recognized worldwide every year [9,10]. | ||
Among hard rock miners, radiographic evidence of silicosis is present in approximately one-third. The rate of positive chest radiographs correlates at least in part with the degree of dust exposure, although other factors such as race may play a role. African Americans have a two to seven times higher rate of developing silicosis compared with white workers with the same dust exposure [11]. | Among hard rock miners, radiographic evidence of silicosis is present in approximately one-third. The rate of positive chest radiographs correlates at least in part with the degree of dust exposure, although other factors such as race may play a role. African Americans have a two to seven times higher rate of developing silicosis compared with white workers with the same dust exposure [11]. | ||
It is estimated that there were between 3600 and 7300 cases per year of silicosis in the United States between 1987 and 1996 [12]. During that decade, nearly 3000 deaths were attributed to silicosis in the United States [13]. The overall mortality attributable to silicosis has decreased substantially in the United States over the past 30 years, largely because of improved workplace protection [14,15]. From 1968 to 2002, silicosis was recorded as an underlying or contributing cause of death on 16,305 death certificates; of these, 15,944 (98 percent) deaths occurred in men [14]. From 1968 to 2002, the number of silicosis deaths decreased from 1157 (8.91 per million persons aged ≥15 years) to 148 (0.66 per million), corresponding to a 93 percent decline in the overall mortality rate. However, the number of annual silicosis deaths identified each year has remained fairly constant since the late 1990s [16]. In the Work-Related Lung Disease (WoRLD) Surveillance Report, NIOSH reported that the number of silicosis deaths in 2003, 2004, and 2005 were 179, 166, and 161, respectively, slightly higher than that reported in 2002 [17]. | It is estimated that there were between 3600 and 7300 cases per year of silicosis in the United States between 1987 and 1996 [12]. During that decade, nearly 3000 deaths were attributed to silicosis in the United States [13]. The overall mortality attributable to silicosis has decreased substantially in the United States over the past 30 years, largely because of improved workplace protection [14,15]. | ||
From 1968 to 2002, silicosis was recorded as an underlying or contributing cause of death on 16,305 death certificates; of these, 15,944 (98 percent) deaths occurred in men [14]. | |||
From 1968 to 2002, the number of silicosis deaths decreased from 1157 (8.91 per million persons aged ≥15 years) to 148 (0.66 per million), corresponding to a 93 percent decline in the overall mortality rate. However, the number of annual silicosis deaths identified each year has remained fairly constant since the late 1990s [16]. In the Work-Related Lung Disease (WoRLD) Surveillance Report, NIOSH reported that the number of silicosis deaths in 2003, 2004, and 2005 were 179, 166, and 161, respectively, slightly higher than that reported in 2002 [17]. | |||
During 1999–2013, a total of 2,065 decedents had silicosis listed as the underlying or as a contributing cause of death (1,122 [54.3%] decedents had silicosis listed as the underlying cause of death) (Table). The annual number of silicosis deaths declined 40% from 185 in 1999 to 111 in 2013 (p-value for trend <0.001), but the decline appears to have leveled off during 2010–2013. The lowest number of silicosis deaths (88) occurred in 2011. Higher numbers of deaths occurred in 2012 (103) and 2013 (111), but remained within the 95% confidence interval predicted by the first-order autoregressive linear regression model used to evaluate trends for 1999–2013. Among all silicosis deaths, 47 (2.3%) decedents were aged 15–44 years; of these, 34 (72.3%) had silicosis coded as the underlying cause of death (Table). The annual number of silicosis deaths in persons aged 15–44 years varied and was 4, 0, and 8 in 2011, 2012, and 2013, respectively. | During 1999–2013, a total of 2,065 decedents had silicosis listed as the underlying or as a contributing cause of death (1,122 [54.3%] decedents had silicosis listed as the underlying cause of death) (Table). The annual number of silicosis deaths declined 40% from 185 in 1999 to 111 in 2013 (p-value for trend <0.001), but the decline appears to have leveled off during 2010–2013. The lowest number of silicosis deaths (88) occurred in 2011. Higher numbers of deaths occurred in 2012 (103) and 2013 (111), but remained within the 95% confidence interval predicted by the first-order autoregressive linear regression model used to evaluate trends for 1999–2013. Among all silicosis deaths, 47 (2.3%) decedents were aged 15–44 years; of these, 34 (72.3%) had silicosis coded as the underlying cause of death (Table). The annual number of silicosis deaths in persons aged 15–44 years varied and was 4, 0, and 8 in 2011, 2012, and 2013, respectively. | ||
According to CDC data<ref>http://www2.cdc.gov/niosh-chartbook/ch2/ch2-10-3-5.asp</ref>, silicosis in the United States is relatively rare. The incidence of deaths due to silicosis declined by 84% between 1968 and 1999, and only 187 1999 deaths had silicosis as the underlying or contributing cause.<ref>http://www2.cdc.gov/niosh-chartbook/imagedetail.asp?imgid=234</ref> Additionally, cases of silicosis in Michigan, New Jersey, and Ohio are highly correlated to industry<ref>http://www2.cdc.gov/niosh-chartbook/imagedetail.asp?imgid=232</ref> and occupation<ref>http://www2.cdc.gov/niosh-chartbook/imagedetail.asp?imgid=232</ref>. | |||
Although silicosis has been known for centuries, the industrialization of mining has led to an increase in silicosis cases. Pneumatic drilling in mines and less commonly, mining using explosives, would raise rock dust. In the United States, a 1930 Hawk's Nest incident (epidemic of silicosis) due to the construction of the Hawk's Nest Tunnel near Gauley Bridge, West Virginia caused the death of more than 400 workers. The prevalence of silicosis led some men to grow what is called a miner's mustache, in an attempt to intercept as much dust as possible. | |||
There is some concern that a batch of cannabis contaminated with silica found in the UK may cause silicosis in some users. <ref>[http://www.ukcia.org/library/contam/default.php Cannabis contamination in the UK]</ref> | |||
China has the most patients with silicosis, with more than 500 000 cases recorded between 1991 and 1995, and 6000 new cases and more than 24 000 deaths reported annually. | China has the most patients with silicosis, with more than 500 000 cases recorded between 1991 and 1995, and 6000 new cases and more than 24 000 deaths reported annually. | ||
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In Quebec, Canada, in the years 1988-1994, 40 newly diagnosed workers were compensated (12 were less than 40 years old). | In Quebec, Canada, in the years 1988-1994, 40 newly diagnosed workers were compensated (12 were less than 40 years old). | ||
The Colombian Government estimates that 1.8 million workers in the country are at risk of developing the disease. | The Colombian Government estimates that 1.8 million workers in the country are at risk of developing the disease. | ||
*Also, the mining establishment of Delamar Ghost Town, Nevada was ruined by a dry-mining process that produced a silicosis-causing dust. After hundreds of deaths from silicosis, the town was nicknamed ''The Widowmaker''. The problem in those days was somewhat resolved with an addition to the drill which sprayed a mist of water, turning dust raised by drilling into mud, but this inhibited mining work. | |||
Recently, silicosis in Turkish denim sandblasters was detected as a new cause of silicosis due to recurring, poor working conditions. | |||
Silicosis is seen in horses associated with inspiration of dust from certain cristobalite-containing soils in California. | |||
Also, the mining establishment of Delamar Ghost Town, Nevada was ruined by a dry-mining process that produced a silicosis-causing dust. After hundreds of deaths from silicosis, the town was nicknamed ''The Widowmaker''. The problem in those days was somewhat resolved with an addition to the drill which sprayed a mist of water, turning dust raised by drilling into mud, but this inhibited mining work. | |||
Silicosis is an occupational hazard to mining, sandblasting, quarry, ceramics and foundry workers, as well as grinders, stonecutters and those continually exposed to silica dust. | Silicosis is an occupational hazard to mining, sandblasting, quarry, ceramics and foundry workers, as well as grinders, stonecutters and those continually exposed to silica dust. | ||
Protective measures such as respirators have brought a steady decline in death rates due to silicosis in Western countries. Unfortunately, this is not true of less developed countries where work conditions are poor and respiratory equipment is seldom used. For instance, life expectancy for silver miners in Potosí, Bolivia is around 40 years due to silicosis. | Protective measures such as respirators have brought a steady decline in death rates due to silicosis in Western countries. Unfortunately, this is not true of less developed countries where work conditions are poor and respiratory equipment is seldom used. For instance, life expectancy for silver miners in Potosí, Bolivia is around 40 years due to silicosis. | ||
==References== | ==References== | ||
Revision as of 14:08, 22 June 2015
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Epidemiology and Demographics
Workers in a broad range of industries are exposed to crystalline silica. Up to 200,000 miners and 1.7 million non-mining workers in the United States have experienced significant occupational exposure to inhaled silica, and new cases of silicosis are recognized worldwide every year [9,10].
Among hard rock miners, radiographic evidence of silicosis is present in approximately one-third. The rate of positive chest radiographs correlates at least in part with the degree of dust exposure, although other factors such as race may play a role. African Americans have a two to seven times higher rate of developing silicosis compared with white workers with the same dust exposure [11].
It is estimated that there were between 3600 and 7300 cases per year of silicosis in the United States between 1987 and 1996 [12]. During that decade, nearly 3000 deaths were attributed to silicosis in the United States [13]. The overall mortality attributable to silicosis has decreased substantially in the United States over the past 30 years, largely because of improved workplace protection [14,15]. From 1968 to 2002, silicosis was recorded as an underlying or contributing cause of death on 16,305 death certificates; of these, 15,944 (98 percent) deaths occurred in men [14]. From 1968 to 2002, the number of silicosis deaths decreased from 1157 (8.91 per million persons aged ≥15 years) to 148 (0.66 per million), corresponding to a 93 percent decline in the overall mortality rate. However, the number of annual silicosis deaths identified each year has remained fairly constant since the late 1990s [16]. In the Work-Related Lung Disease (WoRLD) Surveillance Report, NIOSH reported that the number of silicosis deaths in 2003, 2004, and 2005 were 179, 166, and 161, respectively, slightly higher than that reported in 2002 [17].
During 1999–2013, a total of 2,065 decedents had silicosis listed as the underlying or as a contributing cause of death (1,122 [54.3%] decedents had silicosis listed as the underlying cause of death) (Table). The annual number of silicosis deaths declined 40% from 185 in 1999 to 111 in 2013 (p-value for trend <0.001), but the decline appears to have leveled off during 2010–2013. The lowest number of silicosis deaths (88) occurred in 2011. Higher numbers of deaths occurred in 2012 (103) and 2013 (111), but remained within the 95% confidence interval predicted by the first-order autoregressive linear regression model used to evaluate trends for 1999–2013. Among all silicosis deaths, 47 (2.3%) decedents were aged 15–44 years; of these, 34 (72.3%) had silicosis coded as the underlying cause of death (Table). The annual number of silicosis deaths in persons aged 15–44 years varied and was 4, 0, and 8 in 2011, 2012, and 2013, respectively. According to CDC data[1], silicosis in the United States is relatively rare. The incidence of deaths due to silicosis declined by 84% between 1968 and 1999, and only 187 1999 deaths had silicosis as the underlying or contributing cause.[2] Additionally, cases of silicosis in Michigan, New Jersey, and Ohio are highly correlated to industry[3] and occupation[4].
Although silicosis has been known for centuries, the industrialization of mining has led to an increase in silicosis cases. Pneumatic drilling in mines and less commonly, mining using explosives, would raise rock dust. In the United States, a 1930 Hawk's Nest incident (epidemic of silicosis) due to the construction of the Hawk's Nest Tunnel near Gauley Bridge, West Virginia caused the death of more than 400 workers. The prevalence of silicosis led some men to grow what is called a miner's mustache, in an attempt to intercept as much dust as possible.
There is some concern that a batch of cannabis contaminated with silica found in the UK may cause silicosis in some users. [5] China has the most patients with silicosis, with more than 500 000 cases recorded between 1991 and 1995, and 6000 new cases and more than 24 000 deaths reported annually.
In Viet Nam the cumulative number of diagnosed cases has now reached 9 000. They constitute 90% of all cases of occupationally compensated diseases. Some 18% of workers engaged in surface coal mining, quarrying, foundry and metallurgy have been found to have silicosis. In India, a prevalence of 55% was found in one group of workers, many of them very young, engaged in the quarrying of shale sedimentary rock and subsequent work in small, poorly ventilated sheds. Studies on silicotic pencil workers in Central India demonstrated high mortality rates; the mean age at death was 35 years and the mean duration of the exposure was 12 years. In Brazil, in the state of Minas Gerais alone more than 4 500 workers have been diagnosed with silicosis. In drought-affected regions in the north-east of the country the hand-digging of wells through layers of rock with very high quartz content (97%), an activity that generates great quantities of dust in confined spaces, resulted in a prevalence of 26% of silicosis, with many cases of accelerated forms. The state of Rio de Janeiro banned sandblasting after a quarter of shipyard workers were found to have silicosis. In the USA, it is estimated that more than one million workers are occupationally exposed to free crystalline silica dusts (more than 100 000 of these workers are sandblasters), of whom some 59 000 will eventually develop silicosis. It is reported that each year in the USA about 300 people die from it, but the true number is not known. Abrasive blasting with silica sand, often used to prepare surfaces for painting, has been associated with exposures 200 times greater than the level recommended by the US National Institute for Occupational Safety and Health. This agency recommended that silica sand be prohibited as an abrasive blasting agent. In Quebec, Canada, in the years 1988-1994, 40 newly diagnosed workers were compensated (12 were less than 40 years old). The Colombian Government estimates that 1.8 million workers in the country are at risk of developing the disease.
- Also, the mining establishment of Delamar Ghost Town, Nevada was ruined by a dry-mining process that produced a silicosis-causing dust. After hundreds of deaths from silicosis, the town was nicknamed The Widowmaker. The problem in those days was somewhat resolved with an addition to the drill which sprayed a mist of water, turning dust raised by drilling into mud, but this inhibited mining work.
Recently, silicosis in Turkish denim sandblasters was detected as a new cause of silicosis due to recurring, poor working conditions. Silicosis is seen in horses associated with inspiration of dust from certain cristobalite-containing soils in California.
Silicosis is an occupational hazard to mining, sandblasting, quarry, ceramics and foundry workers, as well as grinders, stonecutters and those continually exposed to silica dust.
Protective measures such as respirators have brought a steady decline in death rates due to silicosis in Western countries. Unfortunately, this is not true of less developed countries where work conditions are poor and respiratory equipment is seldom used. For instance, life expectancy for silver miners in Potosí, Bolivia is around 40 years due to silicosis.