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Daniel Farcas Martin Harper Jed W. Januch Teri A. Jacobs Khachatur Sarkisian Larry D. Stetler Diane Schwegler-Berry 《Environmental Earth Sciences》2017,76(3):126
Three sets of soil samples were collected by the National Institute for Occupational Safety and Health and one set by South Dakota School of Mines & Technology from in and around the Slim Buttes Land Unit of the Sioux Ranger District of the Custer–Gallatin National Forest in the northwest of South Dakota. The rocks forming the Slim Buttes are sedimentary clays, sands and gravels including re-worked volcanic ash-falls in which the zeolite mineral erionite has crystallized during diagenesis in a fibrous form or morphology similar to that of asbestos. The samples were prepared using the fluidized bed asbestos segregator (FBAS) and analyzed by phase contrast microscopy (PCM) or transmission electron microscopy to detect the presence of mineral fibers. FBAS–PCM results compared to semi-quantitative polarized light microscopy (PLM) and X-ray diffraction analysis indicated a recovery of approximately 1% and a linear relationship that likely can be extrapolated to concentrations well below the 1% detection limit of PLM. There were small variations between a PCM count of 10 fibers to a count of 100 fibers (or a maximum of 200 microscopic fields of view), which indicates the possibility of rapid turnaround of results. Although the four sets of samples examined in this work were collected by slightly different techniques, some tentative conclusions can be drawn about the distribution of erionite in soils. Erionite was detected in almost every soil sample, even those taken several miles from the outcrop, but without any distribution indicating recent transportation from the current volcaniclastic sediment outcrops. Removal of more extensive volcaniclastic sediments through erosion may have resulted in remnant material in soils, including erionite crystals, but this possibility requires further study. Although we have demonstrated that erionite in soils can be detected through FBAS–PCM, we have not attempted to correlate those results with human inhalation exposure through activity-based sampling, and thus, any risk inherent in working these soils is unknown. 相似文献
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Ylitalo GM Stein JE Hom T Johnson LL Tilbury KL Hall AJ Rowles T Greig D Lowenstine LJ Gulland FM 《Marine pollution bulletin》2005,50(1):30-39
Wild California sea lions (Zalophus californianus) have an unusually high prevalence of neoplasms (18% of stranded dead adults) and high levels of contaminants. The contribution of organochlorine (OC) tissue burdens to the probability of sea lions dying from carcinoma was explored using a logistic regression model. Levels of PCBs and DDTs were determined in blubber of sea lions diagnosed with metastatic carcinoma and animals that had died from non-carcinoma-related incidents (e.g., gunshot, domoic acid poisoning). Animals with carcinoma had higher mean concentrations (based on wet weight) of PCBs and DDTs (more than 85% and 30% higher, respectively) in blubber than did sea lions without carcinoma; the highest concentrations of OCs in the sea lions affected with carcinoma were measured in the males. Blubber thickness was significantly different between the two groups of sea lions, but after controlling for this difference, there was still a significant effect of PCBs, but not DDTs, on the probability of sea lions dying with carcinoma. Age, sex, mass and length did not affect the probability of dying from carcinoma. 相似文献
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