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Exposure of Chinese adult females to parabens from personal care products: Estimation of intake via dermal contact and health risks Texto completo
2021
Li, Chun | Zhao, Yang | Liu, Shan | Yang, Dongfeng | Ma, Huimin | Zhu, Zhou | Kang, Li | Lu, Shaoyou
Parabens are added into foodstuffs, pharmaceuticals and personal care products (PCPs) as additives extensively due to their excellent antiseptic and antibacterial effects. In the past decade, parabens have raised great concerns on their potential harm to humans. Existing studies have suggested positive correlations between PCP application and urinary paraben concentrations in females, but little is known about paraben exposure levels and health risks arising from PCP use. In this study, 150 PCP samples covering eleven categories were collected from South China and measured for the concentrations of five parabens, including methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP), butyl paraben (BuP) and benzyl paraben (BeP). Parabens were widely detected in PCPs, with a detection frequency of 100%, 99.3%, 80.0%, 74.0% and 13.3%, for MeP, EtP, PrP, BuP and BeP, respectively. The median concentration of Σ₅parabens was 126 μg/g with a range of 6.38–424 μg/g across all PCP samples. The contents of MeP, EtP and PrP measured in leave-on PCPs were obviously higher than those in the rinse-off ones (p < 0.05). MeP and PrP were the main paraben analogues, together accounting for 93.6% of Σ₅parabens in all PCPs. The daily intakes of parabens through dermal absorption by Chinese adult females estimated by measurements obtained in the present study were 0.15 and 83.2 μg/kg-bw/day on basis of the application of rinse-off and leave-on PCPs, respectively. Among the eleven categories, sunscreen, body lotion and mask constituted the main exposure sources of parabens to females. The hazard quotients of parabens were far less than 1, indicating no considerable health risk for Chinese adult females.
Mostrar más [+] Menos [-]Catalytic upgrading of Quercus Mongolica under methane environment to obtain high yield of bioaromatics Texto completo
2021
Farooq, Abid | Moogi, Surendar | Kwon, Eilhann E. | Lee, Jechan | Kim, Young-Min | Jae, Jungho | Jung, Sang-Chul | Park, Young-Kwon
This work investigated the impact of pyrolysis medium and catalyst on the production of bio-BTX (benzene, toluene, and xylene) from Quercus Mongolica (Q. Mongolica) via catalytic pyrolysis. Two different pyrolysis media (N₂ and CH₄) and five different zeolite catalysts (HY, HBeta, HZSM-5, 1 wt% Ni/HZSM-5, and 1 wt% Ga/HZSM-5) were considered for the Q. Mongolica pyrolysis. The HZSM-5 yielded more BTX than the HY and HBeta due to its strong acidity. The employment of CH₄ as the pyrolysis medium improved the BTX yield (e.g., 2.7 times higher total BTX yield in CH₄ than in N₂) and resulted in low coke yield (e.g., 5.27% for N₂-pyrolysis and 2.57% for CH₄-pyrolysis) because the CH₄-drived hydrogen simulated a hydropyrolysis condition and facilitated dehydroaromatization reaction. CH₄ also led to direct coupling, Diels-Alder, and co-aromatization reactions during the pyrolysis, contributing to enhancing the BTX yield. The addition of Ga to the HZSM-5 could further increase the BTX yield by means of facilitating hydrocracking/demethylation and methyl radical formation from CH₄ assisting the generation of >C2 alkenes that could be further converted into BTX on acid sites of the HZSM-5.
Mostrar más [+] Menos [-]High level of zinc triggers phosphorus starvation by inhibiting root-to-shoot translocation and preferential distribution of phosphorus in rice plants Texto completo
2021
Ding, Jingli | Liu, Lu | Wang, Chuang | Shi, Lei | Xu, Fangsen | Cai, Hongmei
Since the urbanization and industrialization are wildly spread in recent decades, the concentration of Zn in soil has increased in various regions. Although the interactions between P and Zn has long been recognized, the effect of high level of Zn on P uptake, translocation and distribution in rice and its molecular mechanism are not fully understood. In this study, we conducted both hydroponic culture and field trial with different combined applications of P and Zn to analyze the rice growth and yield, the uptake, translocation and distribution of P and Zn, as well as the P- and Zn-related gene expression levels. Our results showed that high level of Zn decreased the rice biomass and yield production, and inhibited the root-to-shoot translocation and distribution of P into new leaves by down-regulating P transporter genes OsPT2 and OsPT8 in shoot, which was controlled by OsPHR2-OsmiR399-OsPHO2 module. High Zn supply triggered P starvation signal in root, thereafter increased the activities of both root-endogenous and -secreted acid phosphatase to release more Pi, and induced the expression OsPT2 and OsPT8 to uptake more P for plant growth. On the other hand, high level of P significantly decreased the Zn concentrations in both root and shoot, and the root uptake ability of Zn through altering the expression levels of OsZIPs, which were further confirmed by the P high-accumulated mutant osnla1-2 and OsPHR2-OE transgenic plant. Taken together, we revealed the physiological and molecular mechanisms of P–Zn interactions, and proposed a working model of the cross-talk between P and Zn in rice plants. Our results also indicated that appropriate application of P fertilizer is an effective strategy to reduce rice uptake of excessive Zn when grown in Zn-contaminated soil.
Mostrar más [+] Menos [-]Interactive effects of microplastic pollution and heat stress on reef-building corals Texto completo
2021
Plastic pollution is an emerging stressor that increases pressure on ecosystems such as coral reefs that are already challenged by climate change. However, the effects of plastic pollution in combination with global warming are largely unknown. Thus, the goal of this study was to determine the cumulative effects of microplastic pollution with that of global warming on reef-building coral species and to compare the severity of both stressors. For this, we conducted a series of three controlled laboratory experiments and exposed a broad range of coral species (Acropora muricata, Montipora digitata, Porites lutea, Pocillopora verrucosa, and Stylophora pistillata) to microplastic particles in a range of concentrations (2.5–2500 particles L⁻¹) and mixtures (from different industrial sectors) at ambient temperatures and in combination with heat stress. We show that microplastic can occasionally have both aggravating or mitigating effects on the corals’ thermal tolerance. In comparison to heat stress, however, microplastic constitutes a minor stressor. While heat stress led to decreased photosynthetic efficiency of algal symbionts, and increased bleaching, tissue necrosis, and mortality, treatment with microplastic particles had only minor effects on the physiology and health of the tested coral species at ambient temperatures. These findings underline that while efforts to reduce plastic pollution should continue, they should not replace more urgent efforts to halt global warming, which are immediately needed to preserve remaining coral reef ecosystems.
Mostrar más [+] Menos [-]Multi-antibiotic resistant bacteria in landfill bioaerosols: Environmental conditions and biological risk assessment Texto completo
2021
Landfills, as well as other waste management facilities are well-known bioaerosols sources. These places may foment antibiotic-resistance in bacterial bioaerosol (A.R.B.) due to inadequate pharmaceutical waste disposal. This issue may foster the necessity of using last-generation antibiotics with extra costs in the health care system, and deaths. The aim of this study was to reveal the multi-antibiotic resistant bacterial bioaerosol emitted by a sanitary landfill and the surrounding area. We evaluated the influence of environmental conditions in the occurrence of A.R.B. and biological risk assessment. Antibiotic resistance found in the bacteria aerosols was compared with the AWaRE consumption classification. We used the BIOGAVAL method to assess the workers' occupational exposure to antibiotic-resistant bacterial bioaerosols in the landfill. This study confirmed the multi-antibiotic resistant in bacterial bioaerosol in a landfill and in the surrounding area. Obtained mean concentrations of bacterial bioaerosols, as well as antibiotic-resistant in bacterial bioaerosol (A.R.B.), were high, especially for fine particles that may be a threat for human health. Results suggest the possible risk of antibiotic-resistance interchange between pathogenic and non-pathogenic species in the landfill facilities, thus promoting antibiotic multi-resistance genes spreading into the environment.
Mostrar más [+] Menos [-]Submicro- and nanoplastics: How much can be expected in water bodies? Texto completo
2021
Annenkov, Vadim V. | Danilovtseva, Elena N. | Zelinskiy, Stanislav N. | Pal’shin, Viktor A.
Plastic particles smaller than 1 μm are considered to be highly dangerous pollutants due to their ability to penetrate living cells. Model experiments on the toxicity of plastics should be correlated with actual concentrations of plastics in natural water. We simulated the natural destruction of polystyrene, polyvinyl chloride, and poly(methyl methacrylate) in experiments on the abrasion of plastics with small stones. The plastics were dyed in mass with a fluorescent dye, which made it possible to distinguish plastic particles from stone fragments. We found that less than 1% of polystyrene and polyvinyl chloride were converted to submicron size particles. In the case of more rigid poly(methyl methacrylate), the fraction of such particles reaches 11%. The concentration of particles with a diameter less than 1 μm in the model experiments was from 0.7 (polystyrene) to 13 mg/L (poly(methyl methacrylate)), and when transferring the obtained data to real reservoirs, these values should be reduced by several orders of magnitude. These data explain the difficulties associated with the search for nanoplastics in natural waters. The toxicity of such particles to hydrobionts in model experiments was detected for concentrations greater than 1 mg/L, which is unrealistic in nature. Detectable and toxic amounts of nano- and submicron plastic particles in living organisms can be expected only in the case of filter-feeding organisms, such as molluscs, krill, sponges, etc.
Mostrar más [+] Menos [-]Highly elevated levels, infant dietary exposure and health risks of medium-chain chlorinated paraffins in breast milk from China: Comparison with short-chain chlorinated paraffins Texto completo
2021
Xu, Chi | Wang, Kunran | Gao, Lirong | Zheng, Minghui | Li, Jingguang | Zhang, Lei | Wu, Yongning | Qiao, Lin | Huang, Di | Wang, Shuang | Li, Da
Short-chain chlorinated paraffins (SCCPs) are persistent organic pollutants which are toxic to human. Median-chain chlorinated paraffins (MCCPs) have similar toxicity to SCCPs. The productions of chlorinated paraffins (CPs) in China were 1 million tons in 2013 and remained high after that, which may lead to high risks for human exposure to CPs. To investigate temporal trends and health risks of SCCPs and MCCPs in breast milk in China, samples (n = 2020) were collected from urban and rural areas of 11 Chinese provinces in 2017 and mixed into 42 pooled samples. SCCPs and MCCPs were analyzed by two-dimensional gas chromatography with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The MCCP concentrations (median (range)) were 472 (94–1714) and 567 (211–1089) ng g⁻¹ lipid in urban and rural areas, respectively, which showed continuously rapidly increasing during 2007–2017. The SCCP concentrations (median (range)) were 393 (131–808) and 525 (139–1543) ng g⁻¹ lipid in urban and rural areas, respectively. The results showed SCCP levels decreased in urban areas between 2007 and 2017. Significant increases in MCCP/SCCP ratios might arise from extensive manufacturing and use of MCCPs. The median estimated dietary intake via breast milk in urban and rural samples were 1230 and 2510 ng kg⁻¹ d⁻¹, respectively, for SCCPs and 2150 and 1890 ng kg⁻¹ d⁻¹, respectively, for MCCPs. Preliminarily risk assessment showed that SCCPs posed a significant health risk to infants via breastfeeding. The high MCCP levels should also be of concern because of continuous growth and negative effect on infants. Correspondence analysis indicated congeners with higher carbon and chlorine numbers in dietary tend to accumulate in breast milk.
Mostrar más [+] Menos [-]Pendimethalin induces apoptosis in testicular cells via hampering ER-mitochondrial function and autophagy Texto completo
2021
Ham, Jiyeon | Lim, Whasun | Song, Gwonhwa
Pendimethalin (PDM) is a dinitroaniline crop pesticide that is extensively utilized worldwide. However, the reproductive toxicity and cellular mechanisms of PDM have not been identified. Therefore, we elucidated the adverse effects of PDM on the reproductive system using mouse testicular Leydig and Sertoli cells (TM3 and TM4 cells, respectively). Our results demonstrated that PDM suppressed the viability and proliferation of TM3 and TM4 cells. Additionally, PDM induced cytosolic calcium upregulation and permeabilization of mitochondrial membrane potential in both TM3 and TM4 cells. We also verified that PDM activates the endoplasmic reticulum (ER) stress pathway and autophagy. Furthermore, we confirmed that activation of ER stress and autophagy were blocked by 2-aminoethoxydiphenyl borate (2-APB) treatment. Finally, we confirmed PDM-induced cell cycle arrest and apoptosis in TM3 and TM4 cells. Thus, we first demonstrated that PDM impedes the survival of testis cells, and further, their function.
Mostrar más [+] Menos [-]The role of Nrf2 in mitigating cadmium-induced oxidative stress of Marsupenaeus japonicus Texto completo
2021
Ren, Xianyun | Xu, Yao | Yu, Zhenxing | Mu, Cuimin | Liu, Ping | Li, Jian
Nuclear factor-erythroid 2-related factor-2 (Nrf2) is an important modulator of cellular responses against Cd in mammalian cells. However, whether such modulation is conserved in Marsupenaeus japonicas remains unknown.In our study, the shrimps were injected with dsRNA targeting Nrf2 at 4 μg g⁻¹ body weight (b.w.) or sulforaphane (SFN) at 5 μg g⁻¹ b.w., and then were exposed to 40 mg L⁻¹ CdCl₂ for 48 h. After Nrf2 knockdown, the Cd content increased, but decreased in the SFN group. This suggested that Nrf2 could promote Cd excretion. A terminal deoxynulceotidyl transferase nick-end-labeling (TUNEL) assay revealed that the Nrf2 knockdown increased the number of apoptotic cells in M. japonicas, while SFN decreased the number of apoptotic cells. After Nrf2 knockdown, the total antioxidant capacity (T-AOC), superoxide dismutase (Sod) activity, and related gene expression decreased significantly, while the malondialdehyde (MDA) content increased remarkably. By contrast, SFN injection alleviated the oxidative stress, as evidenced by increased T-AOC, Sod activity, sod mRNA expression and a reduced MDA content. Similarly, detoxification related enzyme activities (ethoxyresorufin O-deethylase and glutathione-S-transferase (GST)) and their corresponding gene expressions (cyp3a (cytochrome P450 family 3 subfamily A) and gst) were suppressed in the ds-Nrf2 injection group, while they were elevated in the SFN group. In addition, ds-Nrf2 activated mitochondrial apoptotic pathway, as evidenced the mRNA and protein levels of caspase-3, Bcl2 associated X protein (Bax), and p53, while SFN treatment suppressed them. These results displayed that in M. japonicus Cd-induced cellular oxidative damage probably acts via the Nrf2 pathway.
Mostrar más [+] Menos [-]Long-term effects of Cu(OH)2 nanopesticide exposure on soil microbial communities Texto completo
2021
Peixoto, Sara | Henriques, Isabel | Loureiro, Susana
Copper-based (nano)pesticides in agroecosystems may result in unintended consequences on non-target soil microbial communities, due to their antimicrobial broad spectrum. We studied the impact of a commercial Cu(OH)₂-nanopesticide, over 90 days, at single and season agricultural application doses, in the presence and absence of an edaphic organism (the isopod Porcellionides pruinosus), on microbial communities’ function, structure and abundance. Results were compared to the effects of Cu(OH)₂-ionic. The nanopesticide application resulted in significant changes on both bacterial and fungal communities’ structure, particularly at the season application. The exposed bacterial community presented a significantly lower richness, and higher diversity and evenness while the exposed fungal community presented lower diversity and richness. At the functional level, a significant increase on microbial ability of carbon utilization and a significant decrease on the β−glucosidase activity was observed for communities exposed to the nanopesticide. Regarding Cu forms, less pronounced effects were observed in soils spiked with Cu(OH)₂-ionic, which might result from lower Cu concentration in porewater. The presence of P. pruinosus did not induce significant changes in diversity indexes (fungal community) and community-level physiological profiling, suggesting an attenuation of the nanopesticide effect. This study revealed that Cu(OH)₂-nanopesticide, at doses applied in agriculture, impact the soil microbial community, possibly affecting its ecological role. On the other hand, invertebrates may attenuate this effect, highlighting the importance of jointly including different interacting communities in the risk assessment of nanopesticides in soils.
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