Department of Environmental Health Engineering, Genetic and Environmental Adventures Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Student Research Committee, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Environ Sci Pollut Res Int. 2021 Dec;28(46):65945-65951. doi: 10.1007/s11356-021-14791-9. Epub 2021 Jul 29.
Regular monitoring and measurement of Legionella in tower water and preventive measures against contamination are particularly important in hospitals. This study aimed at risk assessment and disease burden because of legionella presence in cooling towers of Iran's central hospitals. Then its correlation with temperature, pH, turbidity, residual chlorine, and EC was investigated by the Pearson test. The health risk and burden of diseases caused by Legionella exposure were determined using QMRA and DALY models. Statistical analysis and modeling were performed in MATLAB. Of the total samples, 30-43% was infected with Legionella. The mean concentrations in hospital A and B were 5-102.5 ± 10 and 5-89.7 ± 0.7 CFU/L, respectively. Among environmental factors, turbidity and pH were the most effective factors in increasing and decreasing Legionella concentration, respectively. According to the QMRA model, the risks of Legionella infections and annual mortality in both hospitals were 0.2-0.3, 0-0.19, 2-2.9 × 10, and 0-0.7 × 10, respectively, which was higher than the acceptable risk range for Legionella (10-4-10-7). However, the trend of its change was negatively correlated with time (R = - 0.77). According to the results, the concentration of Legionella and the exposure risk in both hospitals were higher than the permissible range, which is necessary to decrease to 0.1 current concentrations.
定期监测和测量塔式水中的军团菌，并采取预防措施防止污染，这在医院中尤为重要。本研究旨在评估风险和疾病负担，因为军团菌存在于伊朗中心医院的冷却塔中。然后通过 Pearson 检验研究其与温度、pH 值、浊度、余氯和 EC 的相关性。使用 QMRA 和 DALY 模型确定由军团菌暴露引起的健康风险和疾病负担。统计分析和建模在 MATLAB 中进行。在总样本中，30-43%的样本感染了军团菌。医院 A 和 B 的平均浓度分别为 5-102.5 ± 10 和 5-89.7 ± 0.7 CFU/L。在环境因素中，浊度和 pH 值是分别增加和降低军团菌浓度的最有效因素。根据 QMRA 模型，两家医院的军团菌感染风险和年死亡率分别为 0.2-0.3、0-0.19、2-2.9×10 和 0-0.7×10，均高于军团菌的可接受风险范围（10-4-10-7）。然而，其变化趋势与时间呈负相关（R = -0.77）。根据结果，两家医院的军团菌浓度和暴露风险均高于允许范围，有必要将当前浓度降低至 0.1。
