The effect of the Environmental Protection Agency maximum contaminant level on arsenic exposure in the USA from 2003 to 2014: an analysis of the National Health and Nutrition Examination Survey (NHANES)

Summary: Background: In 2006, the current US Environmental Protection Agency (EPA) maximum contaminant level for arsenic in public water systems (10 μg/L) took effect. We aimed to assess national trends in water arsenic exposure in the USA, hypothesising that urinary arsenic concentrations would decrease over time in individuals using public water systems but not in those using well water (which is not federally regulated). We further estimated the expected number of avoided skin or lung and bladder cancer cases. Methods: In this analysis of the 2003â14 cycles of the National Health and Nutrition Examination Survey (NHANES), we used data for dimethylarsinate (DMA), the main metabolite of inorganic arsenic in human beings, and total urine arsenic to reflect water arsenic exposure in survey participants. To isolate exposure to water arsenic, we expanded a residual-based method to remove tobacco and dietary sources of urinary DMA and total arsenic. We also applied EPA risk-assessment approaches to estimate the expected annual number of avoided skin or lung and bladder cancer cases comparing arsenic exposure in 2013â14 with 2003â04. Findings: We obtained data from 14â127 individuals who participated in the NHANES between 2003 and 2014. Among public water users, fully adjusted geometric means of DMA decreased from 3·01 μg/L in 2003â04 to 2·49 μg/L in 2013â14 (17% reduction; 95% CI 10â24; p-trend<0·001); no change was observed in well water users (p-trend=0·35). Assuming these estimated exposure reductions will remain similar across a lifetime, we estimated a reduction of 200â900 lung and bladder cancer cases or 50 cases of skin cancer per year depending on the approach used. Interpretation: The decrease in urinary arsenic observed in public water but not private well users in NHANES 2003â14 suggests that the implementation of the current maximum contaminant level regulation is associated with reduced arsenic exposure in the US population. Our study suggests that well water users are inadequately protected against drinking water arsenic, and supports the crucial role of federal drinking water regulations in reducing toxic exposures and protecting human health. Funding: The National Institute of Environmental Health Sciences

Immediate Lymphatic Reconstruction with Vascularized Omentum Lymph Node Transplant: Reducing the Risk of Both Painful Contracture and Lymphedema

Summary:. Patients undergoing extensive lymph node dissection and radiation are at high risk for not only lymphedema but also painful contracture. In a standard lymphadenectomy, immediate lymphatic reconstruction using a lymphovenous bypass is effective in reconstructing the lymphatic defect. However, a more aggressive nodal clearance leaves the patient with a large cavity and skeletonized neurovascular structures, often resulting in severe contracture, pain, cosmetic deformity, and venous stricture. Adjuvant radiotherapy to the nodal bed can lead to severe and permanent disability despite physical therapy. Typically, these patients are referred to us after the fact, where surgery will rarely restore the patient to normal function. In an effort to avoid lymphedema and contracture, we have been reconstructing both the lymphatic and soft tissue defect during lymphadenectomy, using vascularized omentum lymphatic transplant (VOLT). A total of 13 patients underwent immediate reconstruction with VOLT at the time of axillary (n = 8; 61.5%) or groin (n = 5; 38.5%) dissection. No postoperative complications were observed. The mean follow-up time was 15.1 ± 12.5 months. Only one lower extremity patient developed mild lymphedema (11% volume differential), with excellent scores in validated patient-reported outcomes. All patients maintained full range of motion with no pain. None of the 13 patients required a compression garment. Immediate lymphatic reconstruction with VOLT is a promising procedure for minimizing the risk of lymphedema and contracture in the highest risk patients undergoing particularly extensive lymph node dissection and radiotherapy