Designing dynamic groundwater management strategies through a composite groundwater vulnerability model: Integrating human-related parameters into the DRASTIC model using LightGBM regression and SHAP analysis.

Groundwater nitrate contamination has emerged as a pressing global concern. Given its potential for long-term impacts on aquifers, protective measures should primarily focus on prevention. Drawing on the theory of groundwater vulnerability (GV), the original DRASTIC model and parameters related to human activities are employed as inputs and integrated with the LightGBM regression algorithm to facilitate nitrate index (NI) prediction tasks. The SHAP analysis is conducted to effectively examine the contribution of parameters to the NI prediction and interpret the issue of parameter interactions. In addition, to mitigate the limitations of the intrinsic GV model, a composite nitrate index (CNI) is developed by linearly combining the DRASTIC index with the NI. The framework presented in this study provides adaptive strategies for managing groundwater resources over different time periods. A representative region for arid and semiarid climates, the Yinchuan region, is studied using the framework. As compared to 2012, the intrinsic GV index has changed spatially in 2022. Human activities have increased the influence of the nitrate concentration as shown by the Pearson correlation coefficient of -0.082 between the DRASTIC index and nitrate concentration. A significant increase in pollution levels was predicted by NI, ranging from -0.116 to 0.968. According to SHAP analysis, the significant increase in NI levels in 2022 was mainly due to high-value industrial and agricultural production. In 2022, 12.02% of the areas had an increase of at least 0.549 in the CNI. 42.1% of the areas were classified as moderate or high CNI levels. The farm was identified as a high-contributing source to nitrate pollution. The small-scale agricultural and livestock activities in non-urban areas also contribute to groundwater pollution. Dynamic groundwater management strategies need to be implemented in high-growth and high-level CNI areas.

[Bone mineral density changes in coal workers' pneumoconiosis in Two and Triple stages with increasing ages].

OBJECTIVE: To observe the bone mineral density changes in coal workers' pneumoconiosis in Two and Triple stages with increasing ages. METHODS: Chose 70 cases of coal workers pneumoconiosis in Two and Triple stages in Jincheng Coal Mining Group, all of workers were male, of 55-years old-80 years old, an average of 67 years old. 10 years of ages to grouping, whole body bone mineral densities were measured by body dual-energy X-ray absorptiometry. We analyzed the BMD changes bone loss, osteoporosis occurrence. RESULTS: Chest bone, pelvis, spine bone mineral densities of coal workers pneumoconiosis in Two and Triple stages were significantly decreased. We found that the rate of Pelvic BMD decline of coal workers' pneumoconiosis patients in Two stage was significantly faster after 65 years of age. In Different age groups of coal workers' pneumoconiosis patients in Two and Triple stages, incidence of bone loss and osteoporosis were significantly increased. CONCLUSION: With the age increasing, Coal workers' pneumoconiosis in Two and Triple stages significantly accelerated the speed of the rate of BMD decline. This phenomenon was most obvious in the chest bone, pelvis, and spine.

[Bone mineral density changes in coal workers' pneumoconiosis].

OBJECTIVE: To observe the bone mineral density changes of coal workers' pneumoconiosis. METHODS: We chose 150 cases of One-Triple coal workers pneumoconiosis in Jincheng Coal Mining Group, all of workers were male, of 55-years old-80 years old, an average of 67 years old. 10 years of age to grouping, Whole body bone mineral density and T value were measured by body dual-energy X-ray absorptiometry. We analyzed the BMD changes bone loss, osteoporosis occurrence. RESULTS: The BMD of six parts were not declined obviously in One stage of coal workers' pneumoconiosis; the BMD of Chest bone, pelvis and spine were declined obviously in two stage of coal workers' pneumoconiosis; the BMD of six parts were declined obviously in Triple stage of coal workers' pneumoconiosis; The occurrence rate of bone loss was significantly higher in Two and Triple coal workers pneumoconiosis. The occurrence rate of osteoporosis was significantly higher in Triple coal workers pneumoconiosis. CONCLUSION: With the increase in the severity of coal workers' pneumoconiosis, the BMD of six parts were declined, The occurrence rate of bone loss osteoporosis was significantly higher.