Smith T A, Smith P W
Ranks Hovis McDougall Limited, Windsor, Berkshire, UK.
Occup Med (Lond). 1998 Jul;48(5):321-8. doi: 10.1093/occmed/48.5.321.
This purpose of this study was to examine the relationship between exposure to wheat flour, soya flour and fungal amylase and the development of work-related symptoms and sensitization in bread and cake bakery employees who have regular exposure to these substances. The study populations consisted of 394 bread bakery workers and 77 cake bakery workers whose normal jobs involved the sieving, weighing and mixing of ingredients. The groups were interviewed with the aim of identifying the prevalence, nature and pattern of any work-related respiratory symptoms. They were also skin-prick tested against the common bakery sensitizing agents, i.e., wheat flour, soya flour, rice flour and fungal amylase. The results of personal sampling for sieving, weighing and mixing operations at the bakeries from which the study groups were taken were collated in order to determine typical exposures to total inhalable dust from the ingredients, expressed as 8 hour time-weighted average exposures. Data from the health surveillance and collated dust measurements were compared with the aim of establishing an exposure-response relationship for sensitization. The prevalence of work-related symptoms in bread bakery and cake bakery ingredient handlers was 20.4% and 10.4% respectively. However, in a large proportion of those reporting symptoms in connection with work, the symptoms were intermittent and of short duration. It is considered that the aetiology of such symptoms is likely to be due to a non-specific irritant effect of high total dust levels, rather than allergy. None of the cake bakers and only 3.1% of the bread bakers had symptoms which were thought to be due to allergy to baking ingredients. Using skin-prick testing as a marker of sensitization, the prevalence of positive tests to wheat flour was 6% for the bread bakers and 3% for the cake bakers. Comparable prevalences for soya flour were 7% and 1% respectively. However, the prevalence of positive skin-prick tests to fungal amylase was 16% amongst the bread baking group with only a single employee (1%) in the cake baking group having a positive test. Furthermore, this employee had previously worked in a bread bakery. The difference in rates of sensitization to wheat flour between the bread and cake bakers is not statistically significant, whereas the difference for soya flour is at the borderline of statistical significance (p = 0.045). In contrast, the difference in fungal amylase sensitization is significant at the 0.1% level. For both bread and cake bakers, the 8 hour time-weighted average exposures for each of the activities showed a wide variation with mixing having the lowest average exposure and sieving the highest. Out of the allergens studied in this investigation, fungal amylase is the principal sensitizer in large scale bread bakeries, with the main source of exposure being the handling of bread improvers. In contrast, the risk of sensitization to wheat flour is low in both bread and cake bakeries. The absence of positive skin-prick tests in the subgroup of cake bakery employees who regularly handle fungal-amylase-containing flour suggests that their levels of exposure are below the threshold for sensitization to amylase.
本研究的目的是调查面包和蛋糕烘焙店员工长期接触小麦粉、大豆粉和真菌淀粉酶与工作相关症状及致敏反应发生之间的关系。这些员工日常工作涉及筛分、称重和混合配料。研究对象包括394名面包烘焙工人和77名蛋糕烘焙工人。对这些研究对象进行访谈，以确定任何与工作相关的呼吸道症状的患病率、性质和模式。他们还针对常见的烘焙致敏原进行了皮肤点刺试验，这些致敏原即小麦粉、大豆粉、米粉和真菌淀粉酶。对选取研究对象的面包店筛分、称重和混合操作进行个人采样，整理结果以确定配料中可吸入总粉尘的典型暴露量，以8小时时间加权平均暴露量表示。比较健康监测数据和整理后的粉尘测量数据，目的是建立致敏反应的暴露-反应关系。面包烘焙店和蛋糕烘焙店配料处理人员中与工作相关症状的患病率分别为20.4%和10.4%。然而，在很大一部分报告与工作有关症状的人中，症状是间歇性的且持续时间短。认为此类症状的病因可能是高总粉尘水平的非特异性刺激作用，而非过敏。没有蛋糕烘焙师出现被认为是对烘焙配料过敏所致的症状，只有3.1%的面包烘焙师有此类症状。以皮肤点刺试验作为致敏反应的指标，面包烘焙师中小麦粉皮肤点刺试验阳性率为6%，蛋糕烘焙师为3%。大豆粉的相应阳性率分别为7%和1%。然而，面包烘焙组中真菌淀粉酶皮肤点刺试验阳性率为16%，蛋糕烘焙组只有一名员工（1%）试验呈阳性。此外，该员工此前曾在面包烘焙店工作。面包烘焙师和蛋糕烘焙师对小麦粉致敏率的差异无统计学意义，而大豆粉致敏率的差异处于统计学意义的临界值（p = 0.045）。相比之下，真菌淀粉酶致敏率的差异在0.1%水平具有统计学意义。对于面包烘焙师和蛋糕烘焙师，各项活动的8小时时间加权平均暴露量差异很大，混合操作的平均暴露量最低，筛分操作的平均暴露量最高。在本研究调查的过敏原中，真菌淀粉酶是大型面包烘焙店的主要致敏原，主要暴露源是处理面包改良剂。相比之下，面包烘焙店和蛋糕烘焙店中对小麦粉致敏的风险较低。蛋糕烘焙店中定期处理含真菌淀粉酶面粉的员工亚组皮肤点刺试验均为阴性，这表明他们的暴露水平低于淀粉酶致敏阈值。
