Dissolved arsenic and lead concentrations in rooftop harvested rainwater: Community generated dataset.

Here, we detail arsenic (As) and lead (Pb) concentrations in community science generated rooftop harvested rainwater data from Project Harvest (PH), a co-created community science study, and National Atmospheric Deposition Program (NADP) National Trends Network wet-deposition AZ samples as analyzed by Palawat et al. [1]. 577 field samples were collected in PH and 78 field samples were collected by NADP. All samples were analyzed via inductively coupled plasma mass spectrometry (ICP-MS) for dissolved metal(loid)s including As and Pb by the Arizona Laboratory for Emerging Contaminants after 0.45 um filtration and acidification. Method limits of detection (MLOD) were assessed and sample concentrations above MLODs were considered detects. Summary statistics and box and whisker plots were generated to assess variables of interest such as community and sampling window. Finally, As and Pb data is provided for potential reuse; the data can be used to assess contamination of harvested rainwater in AZ and to inform community use of natural resources.

Patterns of contamination and burden of lead and arsenic in rooftop harvested rainwater collected in Arizona environmental justice communities.

As climate change exacerbates water scarcity, rainwater harvesting for household irrigation and gardening becomes an increasingly common practice. However, the use and quality of harvested rainwater are not well studied, and the potential pollutant exposures associated with its use are generally unknown. There are currently no federal standards in the United States to assess metal(loid)s in harvested rainwater. Project Harvest, a community science research project, was created to address this knowledge gap and study the quality of harvested rainwater, primarily used for irrigation, in four environmental justice communities in Arizona, USA. Community scientists collected 577 unique rooftop harvested rainwater samples from 2017 to 2020, which were analyzed for metal(loid)s, where arsenic (As) concentrations ranged from 0.108 to 120 µg L-1 and lead (Pb) concentrations ranged from 0.013 to 350 µg L-1 and compared to relevant federal/state standards/recommendations. Community As and Pb concentrations decreased as: Hayden/Winkelman > Tucson > Globe/Miami > Dewey-Humboldt. Linear mixed models were used to analyze rooftop harvested rainwater data and results indicated that concentrations of As and Pb in the summer monsoon were significantly greater than winter; and contamination was significantly greater closer to extractive industrial sites in three of the four study communities (ASARCO Hayden Plant Superfund Alternative site in Hayden/Winkelman, Davis-Monthan United States Air Force Base in Tucson - Pb only, and Freeport McMoRan Copper and Gold Mine in Globe/Miami). Based on models, infrastructure such as proximity to roadway, roof material, presence of a cistern screen, and first-flush systems were not significant with respect to As and Pb when controlling for relevant spatiotemporal variables; whereas, cistern age was associated with Pb concentrations. These results however, indicate that concentrations vary seasonally and by proximity to industrial activity, not by decisions made regarding collection system infrastructures at the individual home level. This study shows that generally, individuals are not responsible for environmental contamination of rooftop harvested rainwater, rather activities and decisions of government and corporate industries control contaminant release.

Organic micropollutants measured in roof-harvested rainwater from rural and urban environmental justice communities in Arizona.

Due to global water scarcity and population growth, multiple solutions are needed to conserve and collect water, especially in arid and semi-arid regions of the planet. As the practice of harvesting rainwater grows, it is important to assess the quality of roof-harvested rainwater (RHRW). This study measured twelve organic micropollutants (OMPs) in RHRW samples collected between 2017 and 2020 by community scientists, with approximately two hundred RHRW samples and corresponding field blank analyzed annually. The OMPs analyzed were atrazine, pentachlorophenol (PCP), chlorpyrifos, 2,4-dichlorophenoxyacetic acid (2,4-D), prometon, simazine, carbaryl, nonylphenol (NP), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), and perfluorononanoic acid (PFNA). OMP concentrations measured in RHRW were below the following existing standards: US EPA Primary Drinking Water Standard, Arizona Department of Environmental Quality (ADEQ) Partial Body Contact for Surface Waters, and ADEQ Full Body Contact for Surface Waters for analytes in this study. At the time the study was conducted, 28 % of RHRW samples exceeded the non-enforceable US EPA Lifetime Health Advisory (HA) of 70 ng L-1 for the combined sum of PFOS and PFOA with a mean exceedance concentration of 189 ng L-1. When comparing PFOA and PFOS to the June 15, 2022 interim updated HAs of 0.004 ng L-1 and 0.02 ng L-1, respectively, all samples exceeded these values. No RHRW samples exceeded the final proposed HA of 2000 ng L-1 for PFBS. The limited number of state and federal standards established for the contaminants highlighted in this study indicate potential regulatory gaps and that users need to be aware that OMPs may be present in RHRW. Based on these concentrations, domestic activities and intended uses should be carefully considered.

A review of interval breast cancers diagnosed among participants of the Nova Scotia Breast Screening Program.

PURPOSE: To conduct a radiologic review of interval breast cancer cases to determine rates of true interval and missed cancers in Nova Scotia, Canada. MATERIALS AND METHODS: This quality assurance project was exempt from institutional review board approval. Interval cancer cases were identified among women aged 40-69 years who were participants in the Nova Scotia Breast Screening Program from 1991 to 2004. For each case, the index negative screening mammogram was reviewed blindly by three radiologists from a pool of experienced radiologists. Cases were identified as those with normal or abnormal findings, the latter being a case that required further investigation. True interval cases were identified as cases in which a minimum of two radiologists reviewed the findings as normal. True interval and missed cancer rates were calculated separately for women according to age group and screening interval (for ages 40-49 years, a 1-year interval; for ages 50-69 years, a 1-year and a 2-year interval). RESULTS: The rate of missed cancers per 1000 women screened was one-half of the true interval rate among women screened annually (for ages 40-49 years, 0.45 vs 0.93; for ages 50-69 years, 1.08 vs 2.22). Among women aged 50-69 years who were screened biennially, the rate of missed cancers per 1000 women screened was one-third of the true interval rate (0.90 vs 3.15). Similarly, the rate of missed cancers per 10,000 screening examinations was one-half of the true interval rate among those 40-49 years old (1.95 vs 3.99) and one-third of the true interval rate among those 50-69 years old (3.34 vs 10.44). CONCLUSION: In screening programs, true interval cancer rates should be differentiated from missed cancer rates as part of ongoing quality assurance.

Comparison of clinical-pathologic characteristics and outcomes of true interval and screen-detected invasive breast cancer among participants of a Canadian breast screening program: a nested case-control study.

BACKGROUND: Previous analyses of interval breast cancers have been limited because of a lack of control for screening interval length and patient age, failure to restrict the interval group to 'true' intervals, and incomplete descriptions of pathology, adjuvant therapies and clinical outcomes. PATIENTS AND METHODS: A nested case-control study within the population-based Nova Scotia Breast Screening Program was performed. All true interval cases between 1991 and 2004 were identified, matched 1:2 to screen-detected cases (age, screening interval, time period), and compared in terms of pathologic characteristics and adjuvant therapies via logistic regression. Disease-free and overall survival was estimated, controlling for pathology and adjuvant chemotherapy receipt. RESULTS: A total of 241 true interval invasive cases were matched to 481 screen-detected cases. Interval cases were more likely to be > 1 cm (odds ratio [OR] = 1.76; 95% CI, 1.10-2.83), grade 3 (OR = 2.71; 95% CI, 1.49-4.92), and have lymphovascular invasion (OR = 3.06; 95% CI, 1.85-5.07). Interval cases received more adjuvant chemotherapy (OR = 4.37; 95% CI, 3.03-6.30) and radiation (OR = 1.43; 95% CI, 1.02-2.00). The 5-year Kaplan-Meier estimates of disease-free and overall survival rates for true intervals and screens were 0.830 (95% CI, 0.770-0.875) versus 0.926 (95% CI, 0.898-0.947) and 0.860 (95% CI, 0.804-0.901) versus 0.937 (95% CI, 0.910-0.956), respectively. CONCLUSION: True interval breast cancers have more adverse prognostic factors compared with screen-detected cases and, despite receiving more adjuvant chemotherapy, are associated with significantly poorer survival outcomes.

Mixed redox catalytic destruction of chlorinated solvents in soils and groundwater.

A new thermocatalytic method to destroy chlorinated solvents has been developed in the laboratory and tested in a pilot field study. The method employs a conventional Pt/Rh catalyst on a ceramic honeycomb. Reactions proceed at moderate temperatures in the simultaneous presence of oxygen and a reductant (mixed redox conditions) to minimize catalyst deactivation. In the laboratory, stable operation with high conversions (above 90% at residence times shorter than 1 s) for perchloroethylene (PCE) is achieved using hydrogen as the reductant. A molar ratio of H(2)/O(2)= 2 yields maximum conversions; the temperature required to produce maximum conversions is sensitive to influent PCE concentration. When a homologous series of aliphatic alkanes is used to replace hydrogen as the reductant, the resultant mixed redox conditions also produce high PCE conversions. It appears that the dissociation energy of the C-H bond in the respective alkane molecule is a strong determinant of the activation energy, and therefore the reaction rate, for PCE conversion. This new method was employed in a pilot field study in Tucson, Arizona. The mixed redox system was operated semicontinuously for 240 days with no degradation of catalyst performance and complete destruction of PCE and trichloroethylene in a soil vapor extraction gas stream. Use of propane as the reductant significantly reduced operating costs. Mixed redox destruction of chlorinated solvents provides a potentially viable alternative to current soil and groundwater remediation technologies.

The effect of reformulated gasoline on ambient carbon monoxide concentrations in southeastern Wisconsin.

Reformulated gasoline (RFG) contains oxygen additives such as methyl tertiary butyl ether or ethanol. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of carbon monoxide (CO) and volatile organic compounds (VOCs). Because VOCs react with sunlight to form ozone (O3), the Clean Air Act requires severe O3 nonattainment areas such as southeastern Wisconsin to use RFG. On July 17, 2001, the U.S. Environmental Protection Agency (EPA) granted Milwaukee, WI, and Chicago, IL, a waiver from the VOC reduction requirement of Phase II RFG. The VOC reduction requirement was lowered from 27.4% of the 1990 baseline fuel to 25.4%. The assumption was that ethanol-blended RFG would lower summertime CO concentrations sufficiently to offset the increased VOC emissions. The waiver is estimated to increase VOC emissions by approximately 0.8%, or 0.4 t of VOC on a hot summer weekday. This study evaluates whether RFG has been effective in lowering southeastern Wisconsin ambient CO concentrations. Three years of ambient CO data before RFG was introduced were compared with the first three years of ambient CO data after RFG was introduced. This paper also evaluates how the meteorology, vehicle inspection/maintenance program, vehicle miles traveled, and stationary source emissions influence CO concentrations. The winter decrease in ambient CO concentrations was found to be statistically significant, while the summer data showed no statistically significant change, indicating that RFG is most effective lowering ambient CO concentrations in cold weather.