Per- and polyfluoroalkyl substances (PFAS) in the Three-North Shelter Forest in northern China: First survey on the effects of forests on the behavior of PFAS.

Per- and polyfluoroalkyl substances (PFAS) are a family of anthropogenic chemicals, that have attracted increasing attention since the early 2000 s. Although forests have been shown to act as a filter and important sink for nonpolar persistent organic pollutants (POPs), relevant reports on PFAS are lacking. Air, soil, and leaf samples were collected inside and outside the forest from two regions of the Three-North Shelter Forest in northern China between 2017 and 2018. Twenty-seven PFAS were analyzed to study the effect of forest on the transport and fate of PFAS. The average ratios of PFAS in the air outside to inside the forest (Qair) ranged from 2.83 ± 0.78-10.6 ± 3.1. A significant positive correlation was found between Qair and the n-octanol-air partition coefficient of individual PFAS (p = 0.041). Higher Qair values for most ionic PFAS were found in broad-leaved forests than in coniferous forests. Soil samples outside the forests showed higher PFAS levels than those inside. The measured concentrations of 8:2 fluorotelomer alcohol, a volatile neutral PFAS, in leaf samples were two orders of magnitude higher than those estimated using the equilibrium leaf-air partition of nonpolar POPs, indicating that it may not fit the case of PFAS with surface activity.

Occurrence and seasonal distribution of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in different environmental compartments from areas around ski resorts in northern China.

Skiing is an important direct input route of per- and polyfluoroalkyl substances (PFASs) to the environment. However, there has been no study on the occurrence of PFASs in Chinese ski area. In this study, 27 neutral PFASs (n-PFASs) and ionic PFASs (i-PFASs), including 4 emerging PFASs, were analyzed in the multimedia samples collected from areas around six ski resorts in Zhangjiakou and Shenyang to investigate the occurrence and seasonal distribution of PFASs. Both i-PFASs and n-PFASs were found in the air (13.2 ± 9.5 pg/m3 and 167 ± 173 pg/m3, respectively) and pine needles [1.44 ± 0.96 ng/g dry weight (dw) and 0.983 ± 0.590 ng/g dw], whereas only i-PFASs were found in the soil (0.755 ± 0.281 ng/g dw) and snow (3.30 ± 2.66 ng/kg). i-PFASs were significantly higher in samples collected around ski resorts than those from rural sites (n = 105, p < 0.05). Significantly higher perfluorooctanoate concentrations were found in the air around the ski resorts in winter (n = 33, p < 0.05). The i-PFASs were stable in the needle, and the short-chain PFASs in the needle could be ascribed to both air and root uptake. More attention should be paid to PFASs emissions in Zhangjiakou with the approaching 2022 Winter Olympic Games.

Paired­related homeobox 1 overexpression promotes multidrug resistance via PTEN/PI3K/AKT signaling in MCF­7 breast cancer cells.

Multidrug resistance (MDR) is a major cause of disease relapse and mortality in breast cancer. Paired­related homeobox 1 (PRRX1) is associated with the epithelial­mesenchymal transition (EMT), which is involved in tumor development, including cell invasion and MDR. However, the effect of PRRX1 on MDR had not clearly established. The present study investigated the influence of PRRX1 on MDR and the underlying molecular mechanisms in MCF­7 breast cancer cells. MCF­7 cells were divided into PRRX1+ group (cells transfected with a recombinant plasmid carrying the PRRX1 gene), negative control group (cells transfected with a blank vector) and blank group (untreated cells). It was found that the relative protein and mRNA expression levels of PRRX1, N­cadherin, vimentin and P­glycoprotein were significantly higher in PRRX1­overexpressing MCF­7 cells compared with those in control cells. The half­maximal inhibitory concentration of three groups after treatment with docetaxel and cis­platinum complexes were significantly higher in PRRX1­overexpressing MCF­7 cells compared with those in control cells. Furthermore, relative PTEN expression decreased significantly and levels of phosphorylated PI3K and AKT increased substantially in PRRX1­overexpressing MCF­7 cells. These results indicated that PRRX1 overexpression may induce MDR via PTEN/PI3K/AKT signaling in breast cancer. It is highly recommended that PRRX1 gene expression detection should be performed in patients with breast cancer to aid the selection of more appropriate treatments, which will lead to an improved prognosis in clinical practice.

Novel and legacy per- and polyfluoroalkyl substances (PFASs) in a farmland environment: Soil distribution and biomonitoring with plant leaves and locusts.

The occurrence of legacy and novel per- and polyfluoroalkyl substances (PFASs) in multiple matrices from a farmland environment was investigated in the Beijing-Tianjin-Hebei core area of northern China. PFASs were ubiquitously detected in farmland soils, and the detection frequency of 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA) was higher than that of perfluorooctane sulfonic acid (98% vs. 83%). Long-chain PFASs, including 6:2 Cl-PFESA, showed a centered distribution pattern around the metropolis of Tianjin, probably due to the local intensive industrial activity, while trifluoroacetic acid (TFA) showed a decreasing trend from the coast to the inland area. Other than soil, TFA was also found at higher levels than other longer-chain PFASs in dust, maize (Zea mays), poplar (Populus alba) leaf and locust (Locusta migratoria manilens) samples. Both poplar leaves and locusts can be used as promising biomonitoring targets for PFASs in farmland environments, and their accumulation potential corresponds with protein and lipid contents. Apart from being exposed to PFASs via food intake, locusts were likely exposed via uptake from soil and precipitated dust in farmland environments. The biomonitoring of locusts may be more relevant to insectivores, which is important to conducting a comprehensive ecological risk assessment of farmland environments.

Human exposure levels of PAEs in an e-waste recycling area: Get insight into impacts of spatial variation and manipulation mode.

Phthalic acid esters (PAEs) are one important category of additives in plastics, which are ubiquitous products of e-waste recycling areas, where PAEs are released to the environment intensively and higher exposure level is expected for the employees. This study investigated human exposure levels of PAEs in an e-waste recycling area (Ziya Circular Economy Park (ZCEP) in Tianjin, China) with intending to explore the impacts of residence spatial variation and dismantling manipulation mode. We collected 157 urine samples from three sites around ZCEP with different distances from the core dismantling site and urinary phthalate metabolites (mPAEs) concentrations were measured and were compared among these three sites. The exposure levels of PAEs exhibited spatial variation according to the distance from the core dismantling site, and urinary median ∑mPAEs concentrations (389 ng/mL) of the employees in ZCEP were significantly higher than those of residents in Ziya town (285 ng/mL) and the downtown of Jinghai district (207 ng/mL) (p < 0.05). Moreover, PAEs exposure levels were significantly affected by the manipulation modes in the e-waste recycling area and the urinary median ∑mPAEs concentrations in the employees of family workshops (401 ng/mL) were significantly higher than those in plants with centralized management (298 ng/mL). There were obvious differences on the urinary median mPAEs concentrations between subgroups based on age, BMI, and sex; however, no significant statistical associations were found between PAEs exposure levels and these socio-demographic indices (p > 0.05). Besides, there was no correlation between exposure levels of different PAEs and their physicochemical parameters like the logKow (p > 0.05).

[Fabrication and luminescent properties of Dy3+ doped Sr(1-x)Ca(x)MoO4].

Dy3+ doped Sr(1-x)CaxMoO4 phosphors were prepared by solid state method in the present paper. The crystal structure, luminescent properties and the effect of x on the luminescent properties were studied by XRD, SEM, excitation, emission and color parameters. The XRD patterns indicated that the samples were single phase of CaMoO4 and SrMoO4 when x=1 and x=0. It can be seen that the crystal size of samples prepared at 750 degrees C for 3 h were 0.2-1.0 microm, which was matched with solid state luminescent device. The excitation spectra monitored at 576 nm were composed of a broad band at 250-340 nm and a series of narrow band at 340-460 nm. The excitation peaks situation of CT transition and the excitation peaks intensity of narrow bands varied with Sr/Ca. The emission spectra excited by 350 nm were composed of two broad bands at 470 and 576 nm, which were attributed to the transition of 4F(9/2)-->(6)H(15/2) and (4)F(9/2)-->(6)H(13/2). The emission intensity of yellow and blue emission varied with the value of Sr/Ca.