Abstract：
Exposure to airborne disinfection by-products, especially trichloramine (TCA), could cause various occupational health effects in indoor swimming pools. However, TCA concentration measurements involve specialized analysis conducted in specific laboratories, which can result in significant costs and time constraints. As an alternative, modeling techniques for estimating exposures are promising in addressing these challenges. This study aims to predict airborne TCA concentrations in indoor swimming pools using a mathematical model, the well-mixed box model, found in the IHMOD tool, freely available on the American Industrial Hygiene Association website. The model\'s predictions are compared with TCA concentrations measured during various bather load scenarios. The research involved conducting 2-hr successive workplace measurements over 16- to 18-hr periods in four indoor swimming pools in Quebec, Canada. TCA concentrations were estimated using the well-mixed box model, assuming a homogeneous mixing of air within the swimming pool environment. A novel approach was developed to estimate the TCA generation rate from swimming pool water, incorporating the number of swimmers in the model. Average measured concentrations of TCA were 0.24, 0.26, 0.14, and 0.34 mg/m3 for swimming pools 1, 2, 3, and 4, respectively. The ratio of these measured average concentrations to their corresponding predicted values ranged from 0.51 to 1.30, 0.67 to 1.04, 0.57 to 1.14, and 0.68 to 1.49 for the respective swimming pools. In a worst-case scenario simulating the swimming pool at full capacity (maximum bathers allowed), TCA concentrations were estimated as 0.23, 0.36, 0.14, and 0.37 mg/m3 for swimming pools 1, 2, 3, and 4. Recalculated concentrations by adjusting the number of swimmers so as not to exceed the recommended occupational limit concentration of 0.35 mg/m3 gives a maximum number of swimmers of 63 and 335 instead of currently 80 and 424 for swimming pools 2 and 4, respectively. Similarly, for swimming pools 1 and 3, the maximum number of swimmers could be 173 and 398 (instead of the current 160 and 225, respectively). These results demonstrated that the model could be used to estimate and anticipate airborne TCA levels in indoor swimming pools across various scenarios.
摘要：
暴露于空气中的消毒副产品，尤其是三氯胺（TCA），会对室内游泳池造成各种职业健康影响。然而,TCA浓度测量涉及在特定实验室进行的专门分析，这可能会导致大量的成本和时间限制。作为替代,估算曝光量的建模技术在解决这些挑战方面很有希望。本研究旨在使用数学模型预测室内游泳池中空气中的TCA浓度，混合良好的盒子模型，在IHMOD工具中发现，在美国工业卫生协会网站上免费提供。将模型的预测与在各种沐浴负荷情况下测量的TCA浓度进行比较。该研究涉及在魁北克的四个室内游泳池中进行16至18小时的连续2小时的工作场所测量，加拿大。TCA浓度使用混合箱模型估算，假设游泳池环境内的空气均匀混合。开发了一种新的方法来估计游泳池水的TCA生成率，将游泳者的数量纳入模型。对于游泳池1、2、3和4,TCA的平均测量浓度分别为0.24、0.26、0.14和0.34mg/m3。对于各个游泳池，这些测得的平均浓度与其相应的预测值的比率范围为0.51至1.30，0.67至1.04，0.57至1.14和0.68至1.49。在最坏的情况下，模拟满负荷的游泳池（允许最大游泳者），游泳池1、2、3和4的TCA浓度估计为0.23、0.36、0.14和0.37mg/m3。通过调整游泳者的人数以不超过建议的0.35mg/m3的职业限制浓度，重新计算的浓度可使游泳池2和4的游泳者的最大人数分别为63和335，而不是目前的80和424。同样，对于游泳池1和3，游泳者的最大人数可以是173和398（而不是目前的160和225）。这些结果表明，该模型可用于估计和预测各种情况下室内游泳池中的空中TCA水平。
