Assessing human metal accumulations in an urban superfund site

A comparison of field portable X-ray fluorescence (FP XRF) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) methods for analysis of metals on surface dust

The traditional method for sampling for lead on surfaces uses inductively coupled plasma atomic emission spectroscopy (ICP-AES) to analyze the concentration of lead and other metals on surfaces. This type of analysis is time consuming and costly. Field portable X-ray fluorescence (FP XRF) is another analysis method that is not as accurate as traditional laboratory methods but is more cost efficient and has a turnaround time of less than an hour. The primary goal of this study is to find the best method to increase the level of agreement between the ICP-AES concentrations and the FP XRF concentrations when analyzing lead concentrations on surface wipes. Inverse regression and ratio of the means correction factors were analyzed to try to improve the prediction of ICP-AES concentrations using FP XRF results. Fifty-seven dust wipe samples were analyzed using a split-half design. Half of the samples were used to create the correction factor and the other half were used to test the level of agreement. Linear regression and Bland -Altman plots were used to determine the correction factor that provided the highest level of agreement. A ratio of the means correction factor was determined to be the most appropriate.

A comparison of field portable X-ray fluorescence (FP XRF) and inductively coupled plasma mass spectrometry (ICP-MS) for analysis of metals in the soil and ambient air

When analyzing metal concentrations in the soil and ambient air, accurate and reliable results are essential. Inductively coupled plasma mass spectrometry (ICP-MS) is considered the benchmark analytical method for environmental soil and air filter samples containing metals. Field portable X-ray fluorescence (FP XRF) can provide more timely results with lower ongoing costs, but the results are not as accurate as ICP-MS. The primary goal of this study was to find an optimal method to maximize the level of agreement between FP XRF results and ICP-MS results when analyzing metal concentrations in soil and ambient air samples in a U.S. Superfund community. Two different correction factor methods were tested to improve the prediction of ICP-MS concentrations using FP XRF for arsenic and lead in soil and ambient air. Ninety-one residential soil samples and 42 ambient air filter samples were analyzed in a split-half design, where half the samples were used to create the correction factors and the other half to evaluate the level of agreement between the analytical methods following FP XRF correction. Paired t-tests, linear regression plots, and Bland-Altman plots were utilized to examine which correction factor provided the highest level of agreement between the two methods. Based on the results from this study, it was determined that a ratio correction factor method provided the best fit for this FP XRF analytical device.

Effects of Residential Environmental Screening and Perception Surveys on Superfund Environmental Health Risk Perceptions

Residents at one of the nation’s largest and longest-operating Superfund sites (Butte, Montana) have expressed environmental health risk perceptions that often diverge from those of EPA and other official stakeholders responsible for the investigation and remediation of site contamination aimed at protecting human health and the environment. A random sample of Butte residents participated in a study of how home-based environmental screening influences environmental health perceptions. Participants completed surveys measuring environmental health perceptions before and after a home site screening of soil and drinking water for lead and arsenic conducted by the research team. Local air monitoring for the same contaminants was also completed during the study period. The home-based screening intervention improved the alignment of subjective participant environmental health perceptions with objective environmental screening measures. Key features of the process that helped achieve this effect included (1) co-locating the collection of participant perceptions and individualized screening measurements; (2) sharing environmental screening results in a clear and unbiased manner; and (3) conducting this work independent of agencies and organizations with direct responsibility for Superfund-related cleanup activities. Empowering residents of a Superfund community with knowledge of the specific kinds and levels of environmental contamination in their home environment may help overcome the gap between agency conclusions regarding environmental health risk and the perceptions of community members.

Environmental health perceptions in a superfund community

A disconnect between community perceptions and officially documented Superfund remedial actions and health outcomes may hinder the essential community engagement at Superfund sites. This study evaluates the extent of one such potential disconnect in Butte, Montana, which is part of the largest U.S. Superfund site in the U.S. Since the 1860s, when mining began in Butte, mine waste disposal practices in Butte and surrounding areas have left behind massive deposits that have contaminated the area's soil, sediment, groundwater and surface water with arsenic and heavy metals. Over the last four decades, a substantial amount of remediation work has been completed along with requisite community engagement and health studies at this Superfund site. The potential disconnect was evaluated using a new survey instrument that covered: (a) general environmental health perceptions, (b) mine-waste specific environmental health perceptions, (c) effectiveness of community engagement, (d) knowledge of health outcomes, and (e) demographics. The survey results demonstrated a disconnect in many instances where objective remedial improvements may not have resulted in improved environmental health perceptions in the community. The disconnect was most pronounced in the case of drinking water protection from mine waste and knowledge of health outcomes (cancer incidence rates and children's blood levels). The use of similar environmental health perception measurements may aid responsible agencies in monitoring for and addressing environmental health perception disconnects through better community engagement for the benefit of the impacted communities.

Meconium identifies high levels of metals in newborns from a mining community in the U.S

BACKGROUND

This pilot study was conducted to determine if we could identify intrauterine exposure to metals in meconium, as a measure of exposure for mother-child pairs living in proximity to a mining operation.

OBJECTIVES

We used meconium as a means to measure metal exposure in utero. We set out to quantify the exposure to selected metals that are currently being mined and also are found in the Superfund site in Butte, Montana, and to compare it to that of Columbia, South Carolina, US, where mining is not occurring.

METHODS

This cross-sectional study was conducted between May and November 2018. We received Institutional Review Board approval and we consented women following the birth of their newborns, and collected meconium within 24 h of birth, without any identifiers. Each laboratory used the same protocol for collection, transport, and storage; and the same laboratory protocol was used for the analysis of all samples. Samples were digested using standard acid/peroxide digestion methods and measured by inductively coupled plasma mass spectroscopy.

RESULTS

We collected meconium specimens from 17 infants in Columbia, South Carolina and 15 infants in Butte, Montana. The concentrations found in Columbia were in the low μg kg^-1 range (or less) and were similar to the low levels that have been identified in other studies of meconium. The magnitude of the differences in concentrations found in Butte compared to Columbia was 1792 times higher for Cu, 1650 times higher for Mn, and 1883 times higher for Zn.

CONCLUSION

Using meconium to measure exposure of newborns has implications for risk assessment in a mining-exposed population. This approach was inexpensive and thorough. The magnitude of the differences in the metal levels identified from the two study sites suggests there is an urgent need for further research to learn if there are health consequences to these highly exposed infants.

High incidence of brain and other nervous system cancer identified in two mining counties, 2001-2015

Two counties in Montana, Deer Lodge and Silver Bow (DL/SB), have two Superfund sites, as well as an active copper and molybdenum mine in SB. The population living in proximity to these sites are exposed to additional metals and some have been shown to be neurotoxic, especially for children; thus, this study focused on the incidence of brain and other nervous system cancers. The Montana Central Tumor Registry data was used to identify the cases in DL/SB and the remaining 54 counties of Montana (comparison group). After controlling for sex, cancer stage, and year of diagnosis, we found an incidence rate ratio for DL/SB versus comparison group of 6.28 (95% CI: 2.32-17.02) for children ages birth to 4 years, and 3.95 (95% CI: 1.66-9.38) for adults age 30-34 years. The high incidence rate of the brain cancer in the two age groups requires public health action.

A Review of Biomarkers Used for Assessing Human Exposure to Metals from E-Waste

Electronic waste recycling presents workers and communities with a potential for exposures to dangerous chemicals, including metals. This review examines studies that report on blood, hair, and urine biomarkers of communities and workers exposed to metals from e-waste. Our results from the evaluation of 19 publications found that there are consistently elevated levels of lead found in occupationally and non-occupationally exposed populations, in both the formal and the informal e-waste recycling sectors. Various other metals were found to be elevated in different exposure groups assessed using various types of biomarkers, but with less consistency than found in lead. Antimony and cadmium generally showed higher concentrations in exposed groups compared to reference group(s). Mercury and arsenic did not show a trend among exposure groups due to the dietary and environmental considerations. Observed variations in trends amongst exposure groups within studies using multiple biomarkers highlights the need to carefully select appropriate biomarkers. Our study concludes that there is a need for more rigorous research that moves past cross-sectional study designs, involves more thoughtful and methodical selection of biomarkers, and a systematic reporting standard for exposure studies to ensure that results can be compared across studies.

Population-based mortality data suggests remediation is modestly effective in two Montana Superfund counties

The health effects of living in proximity to Superfund sites with ongoing remediation were evaluated for residents of two contiguous Montana counties, Deer Lodge and Silver Bow. Deer Lodge and Silver Bow are home to the Anaconda Smelter and Silver Bow Creek/Butte Area Superfund sites, respectively. Established by the Environmental Protection Agency in 1983, both sites have had ongoing remediation for decades. Employing county level death certificate data obtained from the Centers for Disease Control and Prevention WONDER site, sex and age-adjusted standardized mortality ratios (SMRs) for composite targeted causes of death were calculated using observed versus expected mortality for both counties, and compared to the expected mortality from the remaining Montana counties. Cancers, cerebro- and cardiovascular diseases (CCVD), and organ failure were elevated for the two counties during the study period, 2000-2016, with SMRs of 1.19 (95% CI 1.10, 1.29); 1.36 (95% CI 1.29, 1.43); and 1.24 (95% CI 1.10, 1.38), respectively. Neurological conditions were not elevated for the two counties (SMR = 1.01; 95% CI 0.89, 1.14). Time trend analyses performed using Cox regression models indicate that deaths from cancers (HR = 0.97; p = 0.0004), CCVDs (HR = 0.95; p ≤ 0.0001), and neurological conditions (HR = 0.97; p = 0.01) decreased over the study period. While the ecological approach applied limits the interpretation of our results, our study suggests that while mortality is elevated, it is also decreasing over time for these two Superfund sites.