Absorption photometry of patterned deposits on IMPROVE PTFE filters.

The IMPROVE program (Interagency Monitoring of PROtected Visual Environments) tracks long-term trends in the composition and optics of regional haze aerosols in the United States. The absorptance of red (633-nm) light is monitored by filter photometry of 24 h-integrated samples of fine particulate matter (PM 2.5).

Quantifying residual elemental carbon by thermal-optical analysis using an extended IMPROVE_A protocol with higher maximum temperature.

Thermal-optical analysis (TOA) has long been used to quantify organic carbon (OC) and elemental carbon (EC) on quartz-fiber filter samples collected in national ambient air monitoring networks. In the routine analysis of samples from the Chemical Speciation Network (CSN), we observed a considerable fraction of filter punches that remain gray or black in color after TOA was completed, suggesting the presence of EC that was not fully evolved at the highest temperature specified by the IMPROVE_A protocol (840°C). In this work, we explored the operational conditions necessary to evolve and quantify such residual EC.

Granuloma annulare on the palms.

We present the case of a 72-year-old man with a one-week history of a red rash on the palms of both hands. A 4mm punch biopsy revealed interstitial granulomatous inflammation within the dermis and a colloidal iron stain showed increased dermal acid mucin. Immunohistochemical staining for CD68 confirmed the presence of abundant histiocytes within the dermis.

Decreasing Vanadium Footprint of Bunker Fuel Emissions.

The Interagency Monitoring of Protected Visual Environments (IMPROVE) network measures the chemical composition of atmospheric particulate matter at over 160 locations throughout the United States. As part of the routine quality control process, we noted decreases in the network-wide vanadium (V) and nickel (Ni) concentrations in 2015 relative to the previous years. Enriched V and Ni with respect to soil are indicative of heavy fuel oil burning and are often used as tracers for emissions from marine vessels.

Assessing the Suitability of Historical PM(2.5) Element Measurements for Trend Analysis.

The IMPROVE (Interagency Monitoring of Protected Visual Environments) network has characterized fine particulate matter composition at locations throughout the United States since 1988. A main objective of the network is to evaluate long-term trends in aerosol concentrations. Measurements inevitably advance over time, but changes in measurement technique have the potential to confound the interpretation of long-term trends.

Reanalysis of archived IMPROVE PM2.5 samples previously analyzed over a 15-year period.

The IMPROVE (Interagency Monitoring of Protected Visual Environments) network has collected airborne particulate matter (PM) samples at locations throughout the United States since 1988. These samples have been analyzed for elemental content using analytical methods that evolved over the years. Changes in analytical methods sometimes introduced shifts in reported concentrations that are evident in the historical record.

Identifying sources of uncertainty from the inter-species covariance of measurement errors.

A standard metric of measurement precision in environmental monitoring is the variance of differences between duplicate (collocated) samples. With duplicate measurements of multiple species, we can extend this variance analysis to include the interspecies covariance of differences between duplicate samples; these covariances can provide clues about the sources of error. We illustrate the potential of such an analysis with atmospheric aerosol measurements from two national air quality monitoring networks: Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciation Trends Network (STN).

Considerations in the use of ozone and PM(2.5) data for exposure assessment.

The US national ambient-air monitoring network, created to verify compliance with health-based standards, now doubles as an important source of exposure data for the epidemiological analyses on which these standards increasingly rest, particularly in the case of ozone and PM(2.5). This paper was written for a workshop called to facilitate and inform the use of routine ozone and PM(2.

Toward establishing the stability of multi-year monitoring of elements in airborne particles.

Crocker Nuclear Laboratory uses a custom built energy-dispersive X-ray fluorescence system with a molybdenum anode to provide routine analysis of elements from nickel to zirconium and lead in Interagency Monitoring of Protected Visual Environments (IMPROVE) samples. Standard methods are used to ensure accuracy and statistical control of the data, including repeated analysis of single-element standards, standard reference materials, and selected actual samples from the IMPROVE network. This paper compares the short-term (week) precision and long-term (2-yr) reproducibility revealed by the actual sample reanalyses.

Estimating precision using duplicate measurements.

Precision is a concept for which there is no universally accepted metric. Reports of precision vary depending on the formula and inclusion criteria used to calculate them. To properly interpret and utilize reported precisions, the user must understand exactly what the precision represents.

A prospective study of weight gain after premenopausal hysterectomy.

Purpose: Many women who have had hysterectomies have the perception that they gained weight after surgery that cannot be attributed to changes in diet or physical activity. The purpose of this analysis was to assess weight gain in premenopausal women in the first year after hysterectomy compared with a control group of women with intact uteri and ovaries.

Methods: As part of a prospective cohort study designed to assess the risk for ovarian failure after premenopausal hysterectomy, weight was measured at baseline and 1-year follow-up in 236 women undergoing hysterectomy and 392 control women.

An empirical approach to estimating detection limits using collocated data.

Measurements of trace species generally become less certain as concentrations decrease. Data analysts need guidance on the ranges in which particular measurements are meaningful. This guidance is normally stated in the form of detection limits.

Retrospective data quality audits of the Harvard Six Cities and American Cancer Society studies.

The Harvard Six Cities (6-Cities) and American Cancer Society (ACS) studies are longitudinal cohort mortality studies of large populations that provided important information about the human health effects associated with long-term exposure to fine particulate air pollution. Possible changes to federal regulation of particulates prompted a review of data collection methods, analysis, and reported results from these two studies. This article describes the methodology used to conduct quality assurance audits of both studies and summarizes the audit findings.

Overview of the reanalysis of the Harvard Six Cities Study and American Cancer Society Study of Particulate Air Pollution and Mortality.

This article provides an overview of the Reanalysis Study of the Harvard Six Cities and the American Cancer Society (ACS) studies of particulate air pollution and mortality. The previous findings of the studies have been subject to debate. In response, a reanalysis team, comprised of Canadian and American researchers, was invited to participate in an independent reanalysis project to address the concerns.

Day-of-Week behavior of atmospheric ozone in three U.S. cities.

The weekly cycles of atmospheric ozone (O3) are of interest because they provide information about the response of O3 to changes in anthropogenic emissions from weekdays to weekends. The weekly behavior of O3 in Chicago, IL; Philadelphia, PA; and Atlanta, GA, is contrasted. In Chicago and Philadelphia, maximum 1-hr average O3 increases on weekends.

Metastatic endocervical adenocarcinoma presenting as a virilizing ovarian mass during pregnancy.

Background: We report a case of metastatic endocervical adenocarcinoma that presented as a virilizing ovarian mass in a young pregnant woman and simulated a primary ovarian endometrioid tumor.

Case: A 34-year-old woman underwent cesarean delivery and right salpingo-oophorectomy at 34 weeks' gestation for a 32-cm androgen-producing ovarian mass. The ovarian tumor, initially interpreted as a primary ovarian endometrioid carcinoma, was demonstrated to represent metastatic endocervical endometrioid adenocarcinoma based on detection of human papillomavirus 16 (HPV-16) deoxyribonucleic acid in the tumor by in situ hybridization.

Attribution of Particulate Sulfur in the Grand Canyon to Specific Point Sources Using Tracer-Aerosol Gradient Interpretive Technique (TAGIT).

Since aerosol particulate sulfur is generally a secondary airborne pollutant, most source attribution techniques require many assumptions about the transport and chemistry of sulfur dioxide (SO) emissions. Uncertainties in our understanding of these processes impair our ability to generate reliable attribution information that is necessary for designing cost-effective pollution control policies. A new attribution technique using artificial tracer is presented in hopes of reducing the uncertainty of secondary aerosol source attribution.

Phantom Spatial Factors: An Example.

A simple example shows that source contributions cannot generally be deduced from factor analysis of ambient concentration fields.