Hurley J F, Alexander W P, Hazledine D J, Jacobsen M, Maclaren W M
Institute of Occupational Medicine, Edinburgh, UK.
Br J Ind Med. 1987 Oct;44(10):661-72. doi: 10.1136/oem.44.10.661.
Data gathered since 1953 concerning more than 30,000 coalminers while employed at 24 collieries in England, Scotland, and Wales have been used to study the incidence of progressive massive fibrosis (PMF) in working coalminers. Results refer to 52,264 approximately five year intervals when the miners were at risk of an attack of PMF. One objective of the present study was to describe how the five year attack rate of PMF was related to miners' age, colliery, and simple pneumoconiosis category at the start of the periods at risk. The main objective was to estimate the relation between exposure to dust and incidence of PMF and to examine how this relation changes in the presence of coalworkers' simple pneumoconiosis (CWSP). Film readings, in some cases based on clinical assessments only, showed 462 attacks of PMF over the five year risk periods. The men concerned had experienced higher cumulative exposures to dust than their colleagues of similar age at the same collieries, a result found at 65 of the 68 age colliery groups where an attack had occurred. The association was highly significant statistically. Simple pneumoconiosis clearly predisposed to PMF, with five year attack rates of 13.9%, 12.5%, 4.4%, and 0.2% among men with categories 3, 2, 1, and 0 respectively at the start of the risk periods. Once simple pneumoconiosis category 1 or more had been attained, those with higher cumulative exposure to dust were not at greater risk of an attack of PMF than other men with the same CWSP category. Among most miners, those with category 0, however, the risks of an attack of PMF increased clearly with exposure. Risks of an attack were higher among older men irrespective of CWSP category. In addition, there were large colliery specific variations in incidence related to variations in the carbon content of the coal though not fully explained by them. It is concluded that cumulative exposure to respirable dust is the decisive central factor in the development of PMF. Its effect is primarily in causing simple pneumoconiosis category 1 or higher which predisposes to PMF, though the dust related incidence among men with category 0 is not negligible in view of the large numbers at risk. Continuation of the policy to minimise dust concentrations underground therefore seems the only secure strategy to limit, and eventually eliminate, PMF.
自1953年以来，在英格兰、苏格兰和威尔士的24个煤矿收集的有关30000多名煤矿工人在职期间的数据，已用于研究在职煤矿工人中进行性块状纤维化（PMF）的发病率。结果涉及52264个大约五年的时间段，在此期间矿工有患PMF的风险。本研究的一个目的是描述在有风险的时间段开始时，PMF的五年发病率与矿工年龄、煤矿以及单纯尘肺类别之间的关系。主要目的是估计接触粉尘与PMF发病率之间的关系，并研究在存在煤工单纯尘肺（CWSP）的情况下这种关系如何变化。在某些情况下仅基于临床评估的胸片读数显示，在五年的风险期内有462例PMF发作。这些患病的男性在相同煤矿中比年龄相仿的同事接触粉尘的累积量更高，在发生发作的68个年龄 - 煤矿组中的65个组都发现了这一结果。这种关联在统计学上具有高度显著性。单纯尘肺显然易引发PMF，在风险期开始时，3级、2级、1级和0级的男性五年发病率分别为13.9%、12.5%、4.4%和0.2%。一旦达到1级或更高等级的单纯尘肺，累积接触粉尘量较高的人患PMF发作的风险并不比具有相同CWSP等级的其他人更高。然而，在大多数0级的矿工中，PMF发作的风险随接触量明显增加。无论CWSP类别如何，年龄较大的男性发作风险更高。此外，发病率存在很大的煤矿特异性差异，这与煤中碳含量的变化有关，尽管不能完全由此解释。得出的结论是，累积接触可吸入粉尘是PMF发生的决定性核心因素。其作用主要是导致1级或更高等级的单纯尘肺，这易引发PMF，不过鉴于有风险的人数众多，0级男性中与粉尘相关的发病率也不可忽视。因此，继续实施将地下粉尘浓度降至最低水平的政策似乎是限制并最终消除PMF的唯一可靠策略。
