Heavy metal levels in the soil near typical coal-fired power plants: partition source apportionment and associated health risks based on PMF and HHRA.

In this study, five priority metals recommended by the Ministry of Ecology and Environment of China (MEEC) were investigated. In the Bijie region of Guizhou Province, three typical coal-fired power plants were chosen as the research locations. A combination of 24 soil samples was obtained at various distances and depths from the point source of contamination. The authors found that the average contents of As, Cd, Cr, Ni, and Pb were 14.15, 1.52, 16.80, 40.71, and 53.00 mg kg-1, respectively, with Cd and Pb pollution prominent. In another, soil heavy metal (SHM) content tends to increase or decrease dependently with the increase of sampling distance and depth, with total concentrations ranging from 77.14 to 157.33 mg kg-1. Combining PCA and PMF models, the number of source factors was determined more clearly and accurately using PCA, and the Q-value of PMF was used for validation. The PCA-PMF indicated that the primary anthropogenic sources were transportation-related activities and emissions from coal combustion. The health risks of SHMs under three different exposure routes were then assessed using the HHRA. The findings showed the five HMs in order of non-carcinogenic risk were As > Pb > Cr > Ni > Cd. The comprehensive non-carcinogenic risk for children under the oral intake route around plant B and C was greater than 1, pointing to a potential health risk to children from the soils. The carcinogenic risk of HM was less than 1.00E-04 for both single-factor and multifactor under all three exposure routes, which is below the tolerable limit.

[Laparoscopic Y-shaped polypropylene mesh for uterine and vaginal vault prolapse].

OBJECTIVE: To investigate the effectiveness oflaparoscopic Y-shaped polypropylene mesh in the treatment of uterine and vaginal vault prolapse. METHODS: Between June 2010 and December 2012, 24 patients with uterine and vaginal vault prolapse were treated by laparoscopic pelvic reconstruction (vagina and uterus-sacral fixation) with Y-shaped polypropylene mesh. The age of patients was 35-60 years (mean, 48.6 years). The disease duration was 2-8 years (mean, 5 years). According to the pelvic organ prolapse quatitative (POP-Q) classification by International Continence Society (ICS), 16 cases were classified as uterine prolapsed degree II and 8 cases as degree III; 15 cases were classified as vaginal prolapse degree I, 7 cases as degree II, and 2 cases as degree III. All patients received postoperative follow-up regularly. Subjective evaluation was done based on prolapse quality of life questionnaire (P-QOL), and objective evaluation based on POP-Q classification. RESULTS: All the patients were operated successfully. The operation time was 22-68 minutes (mean, 33 minutes); the blood loss was 30-80 mL (mean, 51 mL); the indwelling urethral catheter remain was 3-7 days (mean, 4 days); and the hospitalization days were 4-9 days (mean, 6.8 days). Twenty-four patients were followed up 3-12 months (mean, 9 months), of whom, 2 were followed up less than 6 months. All patients had normal urination after withdrawal of urethral catheter, and the residual urine volume was in normal range. No patients had mesh erosion and discomfort during sex, vaginal and anal bearing down. The P-QOL scores at 3, 6, and 12 months after operation were significantly improved when compared with the preoperative value (P < 0.05); but there was no significant difference among 3, 6, and 12 months after operation (P > 0.05). The postoperative POP-Q classification was degree 0 in 19 cases and degree I in 3 cases, and the objective cure rate was 91.7%. No recurrence was found during followup. CONCLUSION: Laparoscopic Y-shaped polypropylene mesh for treatment of uterine and vaginal vault prolapse is a safe and effective method, especially applicable to preserve the uterus, and higher requirements of sexual life of patients.