Whilst silica is a naturally occurring substance found in most rocks, clay and sand, when it is processed in any way whether through mining, cutting, crushing or grinding, silica dust is generated which if inhaled can cause significant chest conditions including lung cancer, silicosis, COPD (including bronchitis and emphysema) and chest infections of varying severity.
Whilst silica is a naturally occurring substance found in most rocks, clay and sand, when it is processed in any way whether through mining, cutting, crushing or grinding, silica dust is generated. If inhaled, it can cause significant chest conditions including lung cancer, silicosis, COPD (including bronchitis and emphysema) and chest infections of varying severity. Indeed, the NHS describes silicosis as, 'a long term incurable lung disease caused by inhaling large amounts of silica dust' and notes that silicosis in itself can cause heart failure, arthritis, kidney disease and TB.
The dangers of exposure to respirable crystalline silica and the attributable injuries are well known. Silicosis is a Prescribed Disease (D1), the COSHH Regulations specify a limit for daily exposure and there are recognised latency periods depending upon the nature and extent of the exposure. Whilst the latency period for chronic silicosis can be 10 -20 years, very heavy exposure could result in acute silicosis, significantly reducing the latency period, causing a much earlier onset of symptoms (possibly within a few months) and a more serious condition. The World Health Organisation recommends lifelong surveillance for workers exposed to crystalline silica.
For masons and polishers, wet working has for the most part protected against the risk of working granite and other quartz containing rock. Within the mining industry alternative solutions were needed. Positive ventilation and pausing for clearance of the air after shot firing (to allow dust and fume to be removed) provide a workable solution. Dust suppression within pottery and refractory making was more difficult to achieve so better solutions were provided by automation of process and/or by altering ingredients to the process to those which are not fibrogenic. For moulders and fettlers , even the replacement of silica sand as a main casting medium by less fibrogenic material such as 'green sand' did not completely solve the problems. This therefore led to the work being completely enclosed within a specially ventilated cabinet. In addition, high precision casting for motor industry components use binders within the moulding medium together with separating agents to remove dust.
The distinction between acute and chronic disease is a matter of the level and duration of exposure. The presence of other dusts, cigarette smoking and environmental pollution outside the workplace can also modify the effect of quartz.
Each area of work and process demands subtly altered solutions and then monitoring and review to ensure that the problem is removed but without introducing other risks. As a result, silicosis is often seen as an historic problem in the UK, referred to as 'potter's rot' or 'miner's lung.' It is commonly believed that the number of silicosis cases in the UK is rare. Indeed, an HSE prosecution in 2014 made the news when Stonyhurst College was fined £100,000 for exposing a stonemason undertaking refurbishment works to silica dust whilst working with power tools on sandstone, which resulted in him sustaining injury. Moreover, the HSE identified 11 silicosis deaths in 2012 and only 45 new cases of silicosis were assessed for Industrial Injuries Disablement Benefit in 2013.
Having said this, the HSE itself believes that these figures are underestimated particularly when one considers the other diseases arising from exposure to silica dust, estimating that the number of lung cancer deaths attributable to exposure to silica dust is in the region of 800 per annum. The recent HSE report entitled "Health and Safety Statistics 2014/15" found that there are 13,000 yearly deaths from work-related lung disease and cancer estimated to be attributed to past exposure, primarily from chemicals and dust at work.
Within this global figure, current estimates suggest that there are at least 8,000 work-related cancer deaths each year in the UK. Aside from a major asbestos connection, one of the next 4 largest categories of cause is silica (with diesel engine exhaust, mineral oils and breast cancer due to shift work the other causes within that group). The report also predicts that claims volumes for work related lung disease and cancer will continue at their present rate for the next decade before starting to reduce.
Currently, exposure to silica and the resultant issues are nowhere more prevalent than in South Africa where thousands of gold miners have presented allegations that exposure to silica during the course of their employment has resulted in them developing silicosis and other related conditions. Presently, the lawsuit involving approximately 27,000 gold miners, ex-miners and their families is coming to a head. The outcome of the Certification hearing which took place in October 2015 to determine whether the case can proceed by way of a certified class action is anticipated in the Spring of this year.
The judgment could open the floodgates in circumstances where the number of silicosis sufferers in South Africa is estimated to exceed the current numbers of claimants by hundreds of thousands.
Similarly, over recent years the USA has seen an increase in silicosis claims. The question to be asked is whether this increase results from the prevalence of hydraulic fracturing, more commonly known as fracking? In addition to the breaking of the ground to establish the well, silica sand is often a proppant in the fracking process, used in significant quantities to hold open the fractures to allow the gas/oil to be released. According to Forbes, ninety five billion pounds of sand was used in fracking operations in the USA in 2014.
The delivery, movement, transportation and use of the sand can, of course, generate dust which can be respirable. Indeed, the American National Institute for Occupational Safety and Health (NIOSH) has expressed concerns with regard to the levels of respirable crystalline silica to which workers involved in fracking operations are exposed. NIOSH collected 116 samples from fracking sites with 79% of the samples showing silica exposures greater than the NIOSH recommended exposure level and 31% of all samples showing exposure ten times greater than the NIOSH REL.
Fracking is big business in the USA and the alleged associated risks of silica exposure appear well advertised with US law firms seeking silica dust exposure claims not only from workers involved in fracking activities but also from individuals living in the vicinity of fracking sites.
With fracking raising its profile in the UK, and the Institute of Directors "backing plans to fast track fracking applications" is this claims trend likely to transfer across the Atlantic?
Not according to the Government which refers to the 2012 review of the Royal Academy of Engineering and Royal Society, who concluded that “the health, safety and environmental risks associated with hydraulic fracturing (often termed ‘fracking’) as a means to extract shale gas can be managed effectively in the UK as long as operational best practices are implemented and enforced through regulation." Previous trends within industry indicate that whilst it is now uncommon to find chronic (active) silicosis in developed countries mainly due to safer alternative materials and/or modern methods of dust control and the enforcement of international standards, this tends to minimise risk rather than remove the spectre of it. As with all risks in all industries and processes failure to take precautions leads to accelerated levels of disease. Focus upon such issues will therefore need to remain unremitting.