Use of Pulsed-UV Processes to Destroy NDMA

About five years ago, N-nitrosodimethylamine (NDMA) began to be detected in drinking water sources. Typically an oxidative degradation product of unsymmetrical dimethylhydrazine, NDMA is a component of rocket fuel and is also formed during numerous industrial manufacturing processes as a byproduct of reactions involving chemicals called alkylamines. The US Environmental Protection Agency has identified NDMA as a probable human carcinogen. However, because NDMA had not historically been considered a common drinking water contaminant, no federal or state drinking water standards were established for it until 1998 in California. In addition to its presence in drinking water, it has recently been suggested that NDMA may be present in sewage and reclaimed water after chlorination, as well as surface water processed by conventional drinking water treatment methods. The mechanisms of NDMA formation appear to be associated with the chlorination process. Therefore, an urgent need has developed for technologies that can remediate drinking water sources contaminated by this compound. This need sparked a growing interest in the potential of pulsed-ultraviolet (UV) and pulsed-UV/hydrogen peroxide treatment processes for removing NDMA from drinking water. The authors of this article evaluated the effectiveness of these treatments for NDMA removal. The results showed that NDMA can be reduced with UV light treatment. This finding will help drinking water utilities to better comply with state and federal standards and to more effectively protect public health

High Precision J/ψJ/\psi and Υ\Upsilon-production data and the Nuclear Glue

We use the high statistics E-772 data on the nuclear dependence of the production of quarkonia $(J/\psi$ and $\Upsilon)$ and dimuons at large transverse momentum $(p_T)$ in $p$-$A$ collisions to get information about the gluonic EMC effect. We find a satisfactory quantitative agreement of the theoretical predictions with the data although none of the models of the EMC effect we consider could account for the entire data. Since all the qualitative features are understood none the less in terms of perturbative QCD with nuclear dependent parton densities, our results suggest that these data can now be used for a better determination of the nuclear parton densities. Our conslusions are shown to be insensitive to the hadronisation mechanism for the quarkonia.Comment: 28 pages, 8 Figures (included as uuencoded figs.uu file at the end), RevTeX, TIFR/TH/93-57, BU-TH-93/

The Role of Medical Interpretation on Breast and Cervical Cancer Screening Among Asian American and Pacific Islander Women

We examined whether the impact of medical interpretation services was associated with the receipt of a mammogram, clinical breast exam, and Pap smear. We conducted a large cross-sectional study involving four Asian American and Pacific Islander (AAPI) communities with high proportions of individuals with limited English proficiency (LEP). Participants were recruited from community clinics, churches and temples, supermarkets, and other community gathering sites in Northern and Southern California. Among those that responded, 98% completed the survey rendering a total of 1,708 AAPI women. In a series of multivariate logistic regression models, it was found that women who typically used a medical interpreter had a greater odds of having received a mammogram (odds ratio [OR] = 1.85; 95% confidence interval [CI] = 1.21, 2.83), clinical breast exam (OR = 3.03; 95% CI = 1.82, 5.03), and a Pap smear (OR = 2.34; 95% CI = 1.38, 3.97) than those who did not usually use an interpreter. The study provides support for increasing language access in healthcare settings. In particular, medical interpreters may help increase the utilization of breast and cervical cancer screening among LEP AAPI women

Application of the U.S. EPA Mode of Action Framework for Purposes of Guiding Future Research: A Case Study Involving the Oral Carcinogenicity of Hexavalent Chromium

Mode of action (MOA) analysis provides a systematic description of key events leading to adverse health effects in animal bioassays for the purpose of informing human health risk assessment. Uncertainties and data gaps identified in the MOA analysis may also be used to guide future research to improve understanding of the MOAs underlying a specific toxic response and foster development of toxicokinetic and toxicodynamic models. An MOA analysis, consistent with approaches outlined in the MOA Framework as described in the Guidelines for Carcinogen Risk Assessment, was conducted to evaluate small intestinal tumors observed in mice chronically exposed to relatively high concentrations of hexavalent chromium (Cr(VI)) in drinking water. Based on review of the literature, key events in the MOA are hypothesized to include saturation of the reductive capacity of the upper gastrointestinal tract, absorption of Cr(VI) into the intestinal epithelium, oxidative stress and inflammation, cell proliferation, direct and/or indirect DNA modification, and mutagenesis. Although available data generally support the plausibility of these key events, several unresolved questions and data gaps were identified, highlighting the need for obtaining critical toxicokinetic and toxicodynamic data in the target tissue and in the low-dose range. Experimental assays that can address these data gaps are discussed along with strategies for comparisons between responsive and nonresponsive tissues and species. This analysis provides a practical application of MOA Framework guidance and is instructive for the design of studies to improve upon the information available for quantitative risk assessment