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Marginalized communities experience barriers that can prevent soil monitoring efforts and knowledge transfer. To address this challenge, this study compared two analytical methods: portable X-ray fluorescence spectroscopy (pXRF, less time, cost) and inductively coupled plasma mass spectrometry (ICP-MS, "gold standard"). Surface soil samples were collected from residential sites in Arizona, USA (N = 124) and public areas in Troy, New York, USA (N = 33). Soil preparation differed between groups to account for community practice. Statistical calculations were conducted, paired t test, Bland-Altman plot, and a two-way ANOVA indicated no significant difference for As, Ba, Ca, Cu, Mn, Pb, and Zn concentrations except for Ba in the t test. Iron, Ni, Cr, and K were statistically different for Arizona soils and V, Ni, Fe, and Al concentrations were statistically different for New York soils. Zinc was the only element with high R2 and low p value. Pollution load index (PLI), enrichment factors (EF), and geo-accumulation index (Igeo) were calculated for both methods using U.S. Geological Survey data. The PLI were > 1, indicating soil pollution in the two states. Between pXRF and ICP-MS, the Igeo and EF in Arizona had similar degree of contamination for most elements except Zn in garden and Pb in yard, respectively. For New York, the Igeo of As, Cu, and Zn differed by only one classification index between the two methods. The pXRF was reliable in determining As, Ba, Ca, Cu, Mn, Pb, and Zn in impacted communities. Therefore, the pXRF can be a cost-effective alternative to using ICP-MS techniques to screen soil samples for several environmentally relevant contaminants to protect environmental public health.

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RESUMEN

Environmental Justice (EJ) communities may experience barriers that can prevent soil monitoring efforts and knowledge transfer. To address this gap, this study compared two analytical methods: portable X-ray Fluorescence Spectroscopy (pXRF, less time and costs) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS, "gold standard"). Surface soil samples were collected from yards and gardens in three counties in Arizona, USA (N=124) and public areas in Troy, New York, USA (N=33). Statistical calculations, i.e., two-sample t-tests, Bland-Altman plots, and a two-way ANOVA indicated no significant difference for As, Ba, Ca, Cu, Mn, Pb, and Zn concentrations except for Ba in the two-sample t-test. Iron, Ni, Cr, and K were statistically different for Arizona soils and V, Ni, Fe and Al concentrations were statistically different for New York soils. To assess the degree of contamination, a pollution load index (PLI), enrichment factors (EF), and geo-accumulation index (Igeo) were calculated for both methods using U.S. Geological Survey soils data. The PLI were >1, indicating pollution across the two states. Between pXRF and ICP-MS, the Igeo and EF in Arizona had similar degree of soil contamination for most elements except Zn in garden and Pb in yard, respectively. In New York, the Igeo of As, Cu, and Zn differed by an order of magnitude between the two methods. The results of this study demonstrate that pXRF is a reliable method for the inexpensive and rapid analysis of As, Ba, Ca, Cu, Mn, Pb, and Zn. Thus, EJ communities may use pXRF to screen large numbers of soil samples for several environmentally relevant contaminants to protect environmental public health.

RESUMEN

Kamoyapithecus hamiltoni is a potential early hominoid species described from fragmentary dentognathic specimens from the Oligocene site of Losodok (Turkana Basin, northwestern Kenya). Other catarrhine dental materials have been recovered at Losodok, but were not initially included in the Kamoyapithecus hypodigm. Here we present descriptions of the unpublished canine and incisor specimens from Losodok, and revisit the published specimens in light of recent changes in understanding of hominoid anterior dental evolution. The new fossils include a canine (KNM-LS 18354) that is morphologically compatible with being a female of Kamoyapithecus (KNM-LS 8). Randomization analyses of both Gorilla gorilla and middle Miocene Griphopithecus alpani demonstrate that the size difference between KNM-LS 8 and KNM-LS 18354 is also compatible with their being male and female canines of the same species. Significantly, a canine tip (KNM-LS 18352) attributed to Kamoyapithecus documents the distinctive burin tip morphology now recognized as characterizing Proconsul sensu stricto, which may indicate a close relationship between Kamoyapithecus and Proconsul. We also re-examined the enigmatic KNM-LS 1, a smaller lower canine assumed to derive from Losodok but for which historical provenience data are completely lacking. Elemental data derived from portable X-ray fluorescence spectroscopy show that KNM-LS 1 is almost certainly from Losodok rather than from nearby Miocene sites (i.e., Moruorot, Esha, Kalodirr). KNM-LS 1 displays a nyanzapithecine-like morphology and is shown by randomization analyses to be too small to be associated with the Kamoyapithecus canines. This demonstrates that there is a second hominoid taxon present at Losodok that records one of the earliest occurrences of the Nyanzapithecinae.

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