Assessing arsenic in human toenail clippings using portable X-ray fluorescence

Authors:  David Fleming, Samantha Crook, Colby Evans, Michael Nader, Manuel Atia, Jason Hicks, Ellen Sweeney, Christopher McFarlane, Jong Sung Kim, Erin Keltie, Anil Adisesh Journal: Applied Radiation and Isotopes Abstract: Arsenic is a toxic metalloid which has been associated with a wide range of health effects in humans including skin abnormalities and an elevated risk of skin, bladder, kidney, and lung cancer, diabetes, and cardiovascular disease. The measurement of arsenic concentration in nail clippings is often used in population studies as an indicator of arsenic exposure. Portable X-ray fluorescence (XRF) is an emerging technique for measuring arsenic in nail clippings. In the current study, single toenail clippings from 60 Atlantic Canadian participants were assessed for arsenic using a new portable XRF approach. A mono-energetic portable XRF system using doubly curved crystal optics was used to measure each clipping for a total of 900 s. Energy spectra from each clipping were analyzed for arsenic characteristic X-rays to provide a normalized arsenic signal. The same clippings were then analyzed for arsenic concentration using a “gold standard” method of inductively coupled plasma mass spectrometry (ICP-MS). Nail clipping arsenic concentrations measured by ICP-MS ranged from 0.030 μg/g to 2.57 μg/g, with a median result of 0.14 μg/g. Portable XRF results for arsenic were compared against ICP-MS arsenic concentrations, with a linear equation of best fit determined between the two variables. A correlation coefficient of r = 0.77 was found from the 59 nail clippings returning an ICP-MS arsenic concentration above the limit of quantitation. When the comparison was limited to the 20 clippings having an XRF normalized signal at least twice as large as the associated uncertainty of measurement, the correlation coefficient was r = 0.89. With the selection of an arsenic concentration of 0.1 μg/g as a cut-off value between “exposed” and “non-exposed” individuals, the XRF method provided a test sensitivity of 76% and a specificity of 81%. The corresponding positive predictive value was 88% and the negative predictive value was 65%. The portable XRF technique used in this study shows promise as a means of assessing arsenic concentration in toenail clippings.   Doi: https://doi.org/10.1016/j.apradiso.2020.109491

Portable X-ray fluorescence of zinc applied to human toenail clippings

We are pleased to announce a publication in Applied Radiation and Isotopes examining Portable X-Ray Fluorescence of Arsenic using Atlantic PATH’s toenail samples!! This work was led by Dr. David Fleming at Mount Allison University. The full text is available via open access: bit.ly/2G17SjM. This work builds on the first publication in the Journal of Trace Elements in Medicine and Biology which examines Portable X-Ray Fluorescence of Zinc. The full text is available via open access: https://bit.ly/35zlKdU

Diet Quality and Neighborhood Environment in the Atlantic Partnership for Tomorrow’s Health Project

Authors: Kaitlyn Gilham, Qianqian Gu, Trevor JB Dummer, John J Spinelli, Rachel A Murphy  Abstract An understanding of relationships between different constructs of the neighbourhood environment and diet quality is needed to inform public health interventions. This study investigated associations between material deprivation, social deprivation and population density with diet quality in a cohort of 19,973 Canadian adults aged 35 to 69 years within the Atlantic PATH cohort study. Diet quality, a metric of how well diet conforms to recommendations was determined from a 24-item food frequency questionnaire. Neighbourhood environment data were derived from dissemination area level Census data. Two deprivation indices were evaluated: material and social deprivation, which reflect access to goods and amenities and social relationships. Multi-level models were used to estimate relationships (mean differences and 95% CI) between neighbourhood environment and diet quality, adjusting for covariates. Mean diet quality was lower in the most socially deprived neighbourhoods compared to the least socially deprived: −0.56, 95% CI (−0.88, −0.25). Relationships between diet quality and population density differed between urban and rural areas (p-interaction < 0.0001). In rural areas, diet quality was higher in intermediate-density neighbourhoods: 0.54, 95% CI (0.05, 1.03). In urban areas, diet quality was lower in intermediate-density and the most-dense neighbourhoods: −0.84, 95% CI (−1.28, −0.40) and −0.72, 95% CI (−1.20, −0.25). Our findings suggest socially deprived and high-density neighbourhoods are associated with lower diet quality and possible urban-rural differences in neighbourhood environment-diet quality relationships. Additional studies are needed to determine the temporal nature of relationships and whether differences in diet quality are meaningful. Doi: https://doi.org/10.3390/nu12103217  

UNB Saint John data scientist pioneering in occupational health informatics

UNB Saint John alum Hongchang (Gary) Bao’s work with Dr. Chris Baker and Dr. Anil Adisesh produced an automated coding algorithm for occupational data (job title and industry codes for the Canadian National Occupation Classification (NOC) system). Funded by CanPath and the New Brunswick Health Research Foundation, the algorithm is now being applied data from Atlantic PATH and the Alberta’s Tomorrow Project. https://bit.ly/31Cd5pR

Assessing the Variation within the Oral Microbiome of Healthy Adults

Authors: Jacob Nearing, Vanessa DeClercq, Johan Van Limbergen, Morgan Langille   ABSTRACT More than 1,000 different species of microbes have been found to live within the human oral cavity, where they play important roles in maintaining both oral and systemic health. Several studies have identified the core members of this microbial community; however, the factors that determine oral microbiome composition are not well understood. In this study, we exam the salivary oral microbiome of 1,049 Atlantic Canadians using 16S rRNA gene sequencing to determine which dietary, lifestyle, and anthropometric features play a role in shaping microbial community composition. Features that were identified as being significantly associated with overall composition then were additionally examined for genera, amplicon sequence variants, and predicted pathway abundances that were associated with these features. Several associations were replicated in an additional secondary validation data set. Overall, we found that several anthropometric measurements, including waist-hip ratio (WHR), height, and fat-free mass, as well as age and sex, were associated with overall oral microbiome structure in both our exploratory and validation data sets. We were unable to validate any dietary impacts on overall taxonomic oral microbiome composition but did find evidence to suggest potential contributions from factors such as the number of vegetable and refined grain servings an individual consumes. Interestingly, each one of these factors on its own was associated with only minor shifts in the overall taxonomic composition of the oral microbiome, suggesting that future biomarker identification for several diseases associated with the oral microbiome can be undertaken without the worry of confounding factors obscuring biological signals.   Doi: 10.1128/mSphere.00451-20