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结果 1-10 的 31
Urinary excretion of arsenic following rice consumption 全文
2014
Meharg, A.A. | Williams, P.N. | Deacon, C.M. | Norton, G.J. | Hossain, M. | Louhing, D. | Marwa, E. | Lawgalwi, Y. | Taggart, M. | Cascio, C. | Haris, P.
Patterns of arsenic excretion were followed in a cohort (n = 6) eating a defined rice diet, 300 g per day d.wt. where arsenic speciation was characterized in cooked rice, following a period of abstinence from rice, and other high arsenic containing foods. A control group who did not consume rice were also monitored. The rice consumed in the study contained inorganic arsenic and dimethylarsinic acid (DMA) at a ratio of 1:1, yet the urine speciation was dominated by DMA (90%). At steady state (rice consumption/urinary excretion) ∼40% of rice derived arsenic was excreted via urine. By monitoring of each urine pass throughout the day it was observed that there was considerable variation (up to 13-fold) for an individual's total arsenic urine content, and that there was a time dependent variation in urinary total arsenic content. This calls into question the robustness of routinely used first pass/spot check urine sampling for arsenic analysis.
显示更多 [+] 显示较少 [-]Arsenic speciation in total contents and bioaccessible fractions in atmospheric particles related to human intakes 全文
2014
Huang, Minjuan | Chen, Xunwen | Zhao, Yinge | Yu Chan, Chuen | Wang, Wei | Wang, Xuemei | Wong, Ming Hung
Speciation of inorganic trivalent arsenicals (iAsIII), inorganic pentavalent arsenicals (iAsV), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in total arsenic (As) content and its bioaccessible fractions contained in road dust, household air-conditioning (AC) filter dust and PM2.5 was investigated. Inorganic As, especially iAsV, was observed as the dominant species. Physiologically based extraction test (PBET), an in-vitro gastrointestinal method, was used to estimate the oral As bioaccessibility in coarse particles and the species present in the oral bioaccessible fraction. A composite lung simulating serum was used to mimic the pulmonary condition to extract the respiratory bioaccessible As and its species in PM2.5. Reduction of iAsV to iAsIII occurred in both in-vitro gastrointestinal and lung simulating extraction models. The inorganic As species was the exclusive species for absorption through ingestion and inhalation of atmospheric particles, which was an important exposure route to inorganic As, in addition to drinking water and food consumption.
显示更多 [+] 显示较少 [-]Concentrations of polybrominated diphenyl ethers (PBDEs) in central air-conditioner filter dust and relevance of non-dietary exposure in occupational indoor environments in Greece 全文
2014
Besis, Athanasios | Katsoyiannis, Athanasios | Botsaropoulou, Elisavet | Samara, Constantini
Polybrominated Diphenyl Ethers (PBDEs) are ubiquitous in the indoor environment owing to their use in consumer products and various studies around the world have found higher concentrations indoors than outdoors. Central air conditioner (A/C) systems have been widely used in many workplaces, therefore, studying of PBDEs in central A/C filter dust is useful to better understand the occurrences and health implications of PBDEs in indoor environments. The present study examined the occurrence of PBDEs in central A/C filter dust collected from various workplaces (n = 20) in Thessaloniki, Greece. The sum concentrations of 21 target congeners (∑21PBDE) in A/C dust ranged between 84 and 4062 ng g−1 with a median value of 1092 ng g−1, while BDE-209 was found to be the most abundant BDE congener. The daily intake via dust ingestion of PBDEs estimated for the employees of the occupational settings ranged from 3 to 45 ng day−1 (median 12 ng day−1).
显示更多 [+] 显示较少 [-]Levels and profile of several classes of organic contaminants in matched indoor dust and serum samples from occupational settings of Pakistan 全文
2014
Ali, Nadeem | Mehdi, Toufeer | Malik, Riffat N. | Eqani, Syed A.M.A.S. | Kamal, Atif | Dirtu, Alin C. | Neels, Hugo | Covaci, Adrian
Dust ingestion is an important route of human exposure to organic contaminants, especially for flame retardants (FRs) in occupational settings. Several classes of organic contaminants were analyzed in matched dust and serum samples from academics and workers in electronics and clothing stores of Faisalabad, Pakistan. The concentrations of contaminants varied in dust as follow: organophosphate FRs (∑PFRs) > novel brominated FRs (∑NBFRs) > polybrominated diphenyl ethers (∑PBDEs) > organochlorine pesticides (∑OCPs) > polychlorinated biphenyls (∑PCBs), while, in serum, concentration varied: ∑OCPs > bromophenols (∑BPs) > ∑PCBs > ∑HO-PCBs ≈ ∑PBDEs. Two NBFRs, namely 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE) and bis(2-ethylhexyl) tetrabromophthalate (TBPH), were detected in <10% of the serum samples. p,p′-DDE was the major contaminant in serum contributing to ∼75% of the total contaminant burden. Levels of Penta-BDE congeners in serum and dust were significantly correlated (r = 0.64, p < 0.01) for the academics, suggesting dust ingestion as an important determinant for their serum levels.
显示更多 [+] 显示较少 [-]Plastic ingestion by Flesh-footed Shearwaters (Puffinus carneipes): Implications for fledgling body condition and the accumulation of plastic-derived chemicals 全文
2014
Lavers, Jennifer L. | Bond, Alexander L. | Hutton, Ian
To provide much needed quantitative data on the lethal and sublethal effects of plastic pollution on marine wildlife, we sampled breast feathers and stomach contents from Flesh-footed Shearwater (Puffinus carneipes) fledglings in eastern Australia. Birds with high levels of ingested plastic exhibited reduced body condition and increased contaminant load (p < 0.05). More than 60% of fledglings exceed international targets for plastic ingestion by seabirds, with 16% of fledglings failing these targets after a single feeding (range: 0.13–3.21 g of plastic/feeding). As top predators, seabirds are considered sentinels of the marine environment. The amount of plastic ingested and corresponding damage to Flesh-footed Shearwater fledglings is the highest reported for any marine vertebrate, suggesting the condition of the Australian marine environment is poor. These findings help explain the ongoing decline of this species and are worrying in light of increasing levels of plastic pollution in our oceans.
显示更多 [+] 显示较少 [-]Lead and other elements in house dust of Japanese residences – Source of lead and health risks due to metal exposure 全文
2014
Yoshinaga, Jun | Yamasaki, Kumiko | Yonemura, Ayumi | Ishibashi, Yuri | Kaido, Takaya | Mizuno, Kodai | Takagi, Mai | Tanaka, Atsushi
The levels of 25 elements in house dust collected from 100 general Japanese residences were measured. Factor analysis was applied on the multi-element data to explore source of Pb (median concentration 49.1 mg/kg) in house dust. Six factors were extracted and Pb was found to have great loading on the fifth factor with Sb and Sn, suggesting solder (Sn), and plastic and metals (Sb) may be the sources of Pb in the house dust of Japanese residences. No significant loading was found on soil-related factors indicating non-significant contribution of Pb in track-in soil. Seven heavy metals (Cd, Cu, Mo, Pb, Sb, Sn, and Zn) were found in house dust at >10 times more condensed than crustal abundance. Health risk of these elements to children via the ingestion of house dust was estimated based on the comparison with tolerable daily intake and found to be non-significant for most of the elements.
显示更多 [+] 显示较少 [-]The present and future of microplastic pollution in the marine environment 全文
2014
Ivar do Sul, Juliana A. | Costa, Monica F.
Recently, research examining the occurrence of microplastics in the marine environment has substantially increased. Field and laboratory work regularly provide new evidence on the fate of microplastic debris. This debris has been observed within every marine habitat. In this study, at least 101 peer-reviewed papers investigating microplastic pollution were critically analysed (Supplementary material). Microplastics are commonly studied in relation to (1) plankton samples, (2) sandy and muddy sediments, (3) vertebrate and invertebrate ingestion, and (4) chemical pollutant interactions. All of the marine organism groups are at an eminent risk of interacting with microplastics according to the available literature. Dozens of works on other relevant issues (i.e., polymer decay at sea, new sampling and laboratory methods, emerging sources, externalities) were also analysed and discussed. This paper provides the first in-depth exploration of the effects of microplastics on the marine environment and biota. The number of scientific publications will increase in response to present and projected plastic uses and discard patterns. Therefore, new themes and important approaches for future work are proposed.
显示更多 [+] 显示较少 [-]Titanium dioxide nanoparticles as carrier facilitate bioaccumulation of phenanthrene in marine bivalve, ark shell (Scapharca subcrenata) 全文
2014
Tian, Shengyan | Zhang, Yaodan | Song, Chunzheng | Zhu, Xiaoshan | Xing, Baoshan
To evaluate the impact of titanium dioxide nanoparticles (nTiO2) on the uptake of hydrophobic organic chemicals by marine bivalves, we conducted a comparative bioaccumulation study by exposing clam, Scapharca subcrenata, to phenanthrene (Phe) in the presence and absence of nTiO2. The large surface area of nTiO2 resulted in adsorption of co-existing Phe in aqueous solution to form nTiO2-Phe complexes. Accumulation of nTiO2 was not observed in clams at exposed concentration (500 μg/L) in this study. However, enhanced uptake of Phe by clams was observed in the presence of nTiO2, with ku and BAFs values being 2 and 1.7 times higher than that of Phe alone, respectively. The enhanced uptake can be explained by ingestion of nTiO2-Phe complexes into the gut and subsequent desorption of Phe there. Therefore, nTiO2 as a carrier facilitated the uptake of Phe by marine bivalves.
显示更多 [+] 显示较少 [-]Microplastics in bivalves cultured for human consumption 全文
2014
Van Cauwenberghe, Lisbeth | Janssen, Colin R.
Microplastics are present throughout the marine environment and ingestion of these plastic particles (<1 mm) has been demonstrated in a laboratory setting for a wide array of marine organisms. Here, we investigate the presence of microplastics in two species of commercially grown bivalves: Mytilus edulis and Crassostrea gigas. Microplastics were recovered from the soft tissues of both species. At time of human consumption, M. edulis contains on average 0.36 ± 0.07 particles g−1 (wet weight), while a plastic load of 0.47 ± 0.16 particles g−1 ww was detected in C. gigas. As a result, the annual dietary exposure for European shellfish consumers can amount to 11,000 microplastics per year. The presence of marine microplastics in seafood could pose a threat to food safety, however, due to the complexity of estimating microplastic toxicity, estimations of the potential risks for human health posed by microplastics in food stuffs is not (yet) possible.
显示更多 [+] 显示较少 [-]Leaching of plastic additives to marine organisms 全文
2014
Koelmans, Albert A. | Besseling, Ellen | Foekema, Edwin M.
It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Arenicola marina (lugworm) and Gadus morhua (North Sea cod). We use a biodynamic model that allows calculations of the relative contribution of plastic ingestion to total exposure of aquatic species to chemicals residing in the ingested plastic. Uncertainty in the most crucial parameters is accounted for by probabilistic modeling. Our conservative analysis shows that plastic ingestion by the lugworm yields NP and BPA concentrations that stay below the lower ends of global NP and BPA concentration ranges, and therefore are not likely to constitute a relevant exposure pathway. For cod, plastic ingestion appears to be a negligible pathway for exposure to NP and BPA.
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