Environmental Characterization of Underwater Munitions Constituents at a Former Military Training Range

As a result of military activities, unexploded ordnance and discarded military munitions are present in underwater environments, which has resulted in the release of munitions constituents including the high explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), along with their primary degradation products, to the water column and adjacent sediments. The present study focused on the characterization of underwater exposure and concentrations of energetics such as TNT and RDX at the former Vieques Naval Training Range at Bahia Salina del Sur (Vieques, Puerto Rico, USA), a bay with documented high incidence of munitions. In situ passive sampling using polar organic chemical integrative samplers (POCIS) was used for the detection and quantification of constituents in water at target locations approximately 15 to 30 cm from 15 individual potentially leaking munitions, and also at 15 unbiased locations approximately evenly spaced across the Bay. For comparison with POCIS-derived concentrations, grab samples were taken at the POCIS target locations. The POCIS-derived and averaged grab samples agreed within a factor of 3. When detected, munitions constituent concentrations (primarily TNT and RDX) were observed at ultratrace concentrations (as low as 4 ng/L for RDX), except 30 cm from one General Purpose bomb where the TNT concentration was 5.3 µg/L, indicating that low-level contamination exists at Bahia Salina del Sur on a very localized scale despite the relatively high density of munitions, similar to previously reported results for other munitions sites around the world. Sediment and porewater sampled at 4 stations where munitions constituents were detected in the water column had concentrations below detection (approximately 5 µg/kg and 5 ng/L, respectively), suggesting that the sediment was not a sink for these constituents at those locations. Environ Toxicol Chem 2022;41:275-286. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

The Synergistic Value of Time-Averaged Serum Albumin and Globulin in Predicting the First Peritonitis in Incident Peritoneal Dialysis Patients

BACKGROUND

The prognostic value of serum time-averaged albumin (TA-Alb) and time-averaged globulin (TA-Glo) combination on the peritonitis in peritoneal dialysis (PD) patients is unknown.

METHODS

The patients who started PD treatment between July 2013 and 2018 were included. Serum Alb and globulin (Glo) were tested at baseline and monthly during follow-up. TA-Alb and TA-Glo were calculated until first peritonitis occurred or the end of the study. PD patients were divided into 4 groups based on the medians of TA-Alb and TA-Glo separately. Cox regression was conducted to identify the hazard ratios (HRs) of peritonitis among categorical groups.

RESULTS

Three hundred and sixty-three patients were included and among them 109 patients experienced first peritonitis. Peritonitis patients had lower baseline Alb, TA-Alb, and TA-Glo levels and ultrafiltration volume. Multivariate cox regression analysis revealed that TA-Alb, TA-Glo, and baseline Alb were significantly associated with first peritonitis. The highest HR existed in Group 1 with lower Alb and lower Glo (HR 4.57, 95% CI 2.36-8.87, p < 0.001) compared with Group 4 with higher Alb and higher Glo.

CONCLUSION

Lower TA-Glo is an independent risk factor for the first peritonitis in PD patients. Combined with lower TA-Alb will increase the predictive effect than separate factor alone.

Field validation of POCIS for monitoring at underwater munitions sites

The present study evaluated polar organic chemical integrative samplers (POCIS) for quantification of conventional munitions constituents, including trinitrotoluene (TNT), aminodinitrotoluenes, diaminonitrotoluenes, dinitrotoluene, and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in a field setting. The POCIS were deployed at varying distances from the commonly used explosive formulation composition B (39.5% TNT, 59.5% RDX, 1% wax) in an embayment of Santa Rosa Sound (Pensacola, FL, USA). Time-weighted averaged water concentrations from a 13-d deployment ranged from 9 to 103 ng/L for TNT and RDX, respectively, approximately 0.3 to 2 m from the source. Concentrations decreased with increasing distance from the source to below quantitation limits (5-7 ng/L) at stations greater than 2 m away. Moderate biofouling of POCIS membranes after 13 d led to a subsequent effort to quantify potential effects of biofouling on the sampling rate for munitions constituents. After biofouling was allowed to occur for periods of 0, 7, 14, or 28 d at the field site, POCIS were transferred to aquaria spiked with munitions constituents. No significant differences in uptake of TNT or RDX were observed across a gradient of biofouling presence, although the mass of fouling organisms on the membranes was statistically greater for the 28-d field exposure. The present study verified the high sensitivity and integrative nature of POCIS for relevant munitions constituents potentially present in aquatic environments, indicating that application at underwater military munitions sites may be useful for ecological risk assessment. Environ Toxicol Chem 2018;37:2257-2267. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.