M. Díez

Mobility of arsenic and heavy metals in a sandy-loam textured and carbonated soil.

Abstract The continued effect of the pyrite-tailing oxidation on the mobility of arsenic, lead, zinc, cadmium, and copper was studied in a carbonated soil under natural conditions, with the experimental plot preserved with a layer of tailing covering the soil during three years. The experimental area is located in Southern Spain and was affected by a pyrite-mine spill. The climate in the area is typically Mediterranean, which determines the rate of soil alteration and element mobility. The intense alteration processes that occurred in the soil during three years caused important changes in its morphology and a strong degradation of the main soil properties. In this period, lead concentrated in the first 5 mm of the soil, with concentrations higher than 1 500 mg kg−1, mainly associated to the neoformation of plumbojarosite. Arsenic was partially leached from the first 5 mm and mainly concentrated between 5–10 mm in the soil, with maximum values of 1 239 mg kg−1; the retention of arsenates was related to the neoformation of iron hydroxysulfates (jarosite, schwertmannite) and oxyhydroxides (goethite, ferrihydrite), both with a variable degree of crystallinity. The mobility of Zn, Cd, and Cu was highly affected by pH, producing a stronger leaching in depth; their retention was related to the forms of precipitated aluminium and, in the case of Cu, also to the neoformation of hydroxysulfate.

Results of treatment with azacitidine in patients aged ≥ 75 years included in the Spanish Registry of Myelodysplastic Syndromes

Abstract The tolerability of azacitidine (AZA) allows its administration in elderly patients. The objective of this study was to analyze the clinical and biological characteristics, transfusion independence (TI), overall survival (OS) and toxicity in a series of 107 patients ≥ 75 years of age from the Spanish Registry of Myelodysplastic Syndromes (MDS) treated with AZA. The median age (range) was 78 (75–90) years. According to the World Health Organization (WHO) classification, 86/102 (84%) had MDS, 10/102 (10%) had mixed myeloproferative/myelodysplastic disorder and 6/102 (6%) had acute myeloblastic leukemia. Regarding MDS by the International Prognostic Scoring System on initiation of AZA, 38/84 (45%) were low–intermediate-1 risk and 46/84 (55%) were intermediate-2–high risk. Ninety-five patients (89%) were red blood cell or platelet transfusion dependent. The AZA schedule was 5-0-0 in 39/106 (37%) patients, 5-2-2 in 36/106 (34%) patients and 7 consecutive days in 31/106 (29%) patients. The median number of cycles administered was 8 (range, 1–30). Thirty-eight out of 94 (40%) patients achieved TI. Median OS (95% confidence interval [CI]) was significantly better in patients achieving TI (n = 38) compared to patients who did not (n = 56) (22 [20.1–23.9] months vs. 11.1 [4.8–17.5] months, p = 0.001). No significant differences were observed in TI rate and OS among the three different schedules. With a median follow-up of 14 (min–max, 1–50) months, the median OS (95% CI) of the 107 patients was 18 (12–23) months and the probability of OS (95% CI) at 2 years was 34% (22–46%). Cycles were delayed in 31/106 (29%) patients and 47/101 patients (47%) were hospitalized for infection. These results show that treatment with AZA was feasible and effective in this elderly population, with 40% achieving TI, having a better OS than patients not achieving it. The schedule of AZA administration did not affect efficacy and toxicity.

Remediation measures and displacement of pollutants in soils affected by the spill of a pyrite mine.

The soils affected by the spill of a pyrite mine were analysed in 100 sampling points at three depths (0-10, 10-30, and 30-50 cm) in 1998 (after the tailings were removed), 1999 (after the cleaning of the highly contaminated areas), and 2004 (after the tilling of the upper 20-25 cm). The comparative study reveals that the removal of the tailings left a heterogeneous distribution pattern of the contaminants, with highly polluted spots alternating with less contaminated areas. The cleanup did not substantially lower the concentration in the highly polluted soils, and the spread of the pollutants increased the concentration in As and Pb in the uppermost 10 cm of 60% of the soils, while the Zn and Cd concentrations increased in only 30% of the soils. Given the high concentration of pollutants in the topsoil (especially As), the tilling of the upper 20-25 cm, despite reducing the average concentration of pollutants in the uppermost 10 cm, did not substantially lower the percentage of soils that exceeded the concentration of 40 mg As kg(-1) dry soil and almost doubled the percentage of soils that surpassed this concentration between 10 and 30 cm. Meanwhile, the displacement of Zn and Cd within the soil supported the reduction in the percentage of soils that in the upper 10 cm exceeded the reference concentrations of these elements (900 mg Zn kg(-1) dry soil and 2 mg Cd kg(-1) dry soil), and the percentage of soils exceeding these concentrations between 10 and 50 cm in depth did not increase. Six years after the spill and at the end of all remediation measures, the intervention levels defined by the Environmental Agency of the Regional Government of Andalusia for natural parks were exceeded in the uppermost 10 cm in 35% of the soils.