Predicting Redox Conditions in Groundwater at a National Scale Using Random Forest Classification.

Redox conditions in groundwater may markedly affect the fate and transport of nutrients, volatile organic compounds, and trace metals, with significant implications for human health. While many local assessments of redox conditions have been made, the spatial variability of redox reaction rates makes the determination of redox conditions at regional or national scales problematic. In this study, redox conditions in groundwater were predicted for the contiguous United States using random forest classification by relating measured water quality data from over 30,000 wells to natural and anthropogenic factors. The model correctly predicted the oxic/suboxic classification for 78 and 79% of the samples in the out-of-bag and hold-out data sets, respectively. Variables describing geology, hydrology, soil properties, and hydrologic position were among the most important factors affecting the likelihood of oxic conditions in groundwater. Important model variables tended to relate to aquifer recharge, groundwater travel time, or prevalence of electron donors, which are key drivers of redox conditions in groundwater. Partial dependence plots suggested that the likelihood of oxic conditions in groundwater decreased sharply as streams were approached and gradually as the depth below the water table increased. The probability of oxic groundwater increased as base flow index values increased, likely due to the prevalence of well-drained soils and geologic materials in high base flow index areas. The likelihood of oxic conditions increased as topographic wetness index (TWI) values decreased. High topographic wetness index values occur in areas with a propensity for standing water and overland flow, conditions that limit the delivery of dissolved oxygen to groundwater by recharge; higher TWI values also tend to occur in discharge areas, which may contain groundwater with long travel times. A second model was developed to predict the probability of elevated manganese (Mn) concentrations in groundwater (i.e., ≥50 µg/L). The Mn model relied on many of the same variables as the oxic/suboxic model and may be used to identify areas where Mn-reducing conditions occur and where there is an increased risk to domestic water supplies due to high Mn concentrations. Model predictions of redox conditions in groundwater produced in this study may help identify regions of the country with elevated groundwater vulnerability and stream vulnerability to groundwater-derived contaminants.

Beyond the mammography quality standards act: measuring the quality of breast cancer screening programs.

OBJECTIVE: A high-quality screening mammography program should find breast cancer when it exists and when the lesion is small and ensure that suspicious findings receive prompt follow-up. The Mammography Quality Standards Act (MQSA) guidelines related to tracking outcomes are insufficient for assessing quality of care. We used data from a quality improvement project to determine whether screening mammography facilities could show that they met certain quality benchmarks beyond those required by MQSA. MATERIALS AND METHODS: Participating facilities provided aggregate data on screening mammography examinations performed in calendar year 2009 and corresponding diagnostic follow-up, including patients lost to follow-up, timing of diagnostic imaging and biopsy, cancer detection rates, and the proportion of cases of cancer detected as minimal and early-stage tumors. RESULTS: Among the 52 participating institutions, the percentage of institutions meeting each benchmark varied from 27% to 83%. Facilities with American College of Surgeons or National Consortium of Breast Centers designation were more likely to meet benchmarks pertaining to cancer detection and early detection, and disproportionate share facilities were less likely to meet benchmarks pertaining to timeliness of care. CONCLUSION: The results suggest a combination of quality of care issues and incomplete tracking of patients. To accurately measure the quality of the breast cancer screening process, it is critical that there be complete tracking of patients with abnormal screening mammography findings so that results can be interpreted solely in terms of quality of care. The MQSA guidelines for tracking outcomes and measuring quality indicators should be strengthened for better assessment of quality of care.

Predictions of groundwater PFAS occurrence at drinking water supply depths in the United States.

Per- and polyfluoroalkyl substances (PFAS), known colloquially as "forever chemicals", have been associated with adverse human health effects and have contaminated drinking water supplies across the United States owing to their long-term and widespread use. People in the United States may unknowingly be drinking water that contains PFAS because of a lack of systematic analysis, particularly in domestic water supplies. We present an extreme gradient boosting model for predicting the occurrence of PFAS in groundwater at the depths of drinking water supply for the conterminous United States. Our model results indicate that 71 to 95 million people in the conterminous United States potentially rely on groundwater with detectable concentrations of PFAS for their drinking-water supplies prior to any treatment.

Regular screening mammography before the diagnosis of breast cancer reduces black:white breast cancer differences and modifies negative biological prognostic factors.

Black women present with later stage breast cancers compared to white women, and their cancers are more likely to be larger, receptor negative, and undifferentiated. This study evaluated black:white differences in the stage and biology of breast cancer among women who had a screening mammogram at one of two Chicago academic medical centers within two years of the breast cancer diagnosis (regularly screened) and compared them to the black:white differences in the stage and biology of breast cancer in women who had not received mammographic screening within two years of a breast cancer diagnosis (irregularly screened.) There were no significant black:white differences in the proportion of early breast cancers (black = 74 %; white = 69 %, p = NS) in the regularly screened population or in the irregularly screened group (black = 60 %; white = 68 %, p = NS.) The regularly screened population received significantly more mammograms (58 % ≥4 mammograms) compared to the irregularly screened population (41 % ≥4 mammograms.) Black women in the regularly screened population were less likely than irregularly screened black women to have estrogen negative breast cancers (26 vs. 36 %, p < .05), progesterone negative breast cancers (35 vs. 46 %, p < .05), and poorly differentiated breast cancers (39 vs. 53 %, p < .05.) White women in the irregularly screened population also had worse prognostic factors than white women in the regularly screened population, though these were not statistically significant. Regular mammographic screening can contribute to the narrowing of black:white differences in presentation of breast cancer.

Older Californians and the Mental Health Services Act: Is an Older Adult System of Care Supported?

This policy brief summarizes findings from the first study to evaluate how California's public mental health delivery system has served older adults (60 years of age and over) since the passage of the Mental Health Services Act (MHSA) in 2004. Study findings indicate that there are unmet needs among older adults with mental illness in the public mental health delivery system. There are deficits in the involvement of older adults in the required MHSA planning processes and in outreach and service delivery, workforce development, and outcomes measurement and reporting. There is also evidence of promising programs and strategies that counties have advanced to address these deficits. Recommendations for improving mental health services for older adults include designating a distinct administrative and leadership structure for older adult services in each county; enhancing older adult outreach and documentation of unmet need; promoting standardized geriatric training of providers; instituting standardized data-reporting requirements; and increasing service integration efforts, especially between medical, behavioral health, aging, and substance use disorder services.

Mental Health Services for Older Adults: Creating a System That Tells the Story.

In 2004, voters in California approved Proposition 63 for passage of the Mental Health Services Act (MHSA). From that time until 2014, over $13 billion in the state's tax revenue was allocated for public mental health services. There is very little information available to answer critical questions such as these: How much of this amount was spent in the interests of older adult mental health? What benefits were gained from services delivered to older adults? This policy brief promotes recommendations for specific age-relevant indicator utilization and for an expanded system of uniform and transparent data for all types of MHSA-funded programs. These two policy directions are necessary in order to document the older adult mental health care services provided and to track outcomes at the state level for MHSA programs. A third recommendation centers on assuring that the mental health workforce is prepared to utilize and report age-relevant data indicators.