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Exploring common factors influencing PM2.5 and O3 concentrations in the Pearl River Delta: Tradeoffs and synergies
2021
Wu, Jiansheng | Wang, Yuan | Liang, Jingtian | Yao, Fei
Particulate matter with an aerodynamic equivalent dimeter less than 2.5 μm (PM₂.₅) and ozone (O₃) are major air pollutants, with coupled and complex relationships. The control of both PM₂.₅ and O₃ pollution requires the identification of their common influencing factors, which has rarely been attempted. In this study, land use regression (LUR) models based on the least absolute shrinkage and selection operator were developed to estimate PM₂.₅ and O₃ concentrations in China's Pearl River Delta region during 2019. The common factors in the tradeoffs between the two air pollutants and their synergistic effects were analyzed. The model inputs included spatial coordinates, remote sensing observations, meteorological conditions, population density, road density, land cover, and landscape metrics. The LUR models performed well, capturing 54–89% and 42–83% of the variations in annual and seasonal PM₂.₅ and O₃ concentrations, respectively, as shown by the 10-fold cross validation. The overlap of variables between the PM₂.₅ and O₃ models indicated that longitude, aerosol optical depth, O₃ column number density, tropospheric NO₂ column number density, relative humidity, sunshine duration, population density, the percentage cover of forest, grass, impervious surfaces, and bare land, and perimeter-area fractal dimension had opposing effects on PM₂.₅ and O₃. The tropospheric formaldehyde column number density, wind speed, road density, and area-weighted mean fractal dimension index had complementary effects on PM₂.₅ and O₃ concentrations. This study has improved our understanding of the tradeoff and synergistic factors involved in PM₂.₅ and O₃ pollution, and the results can be used to develop joint control policies for both pollutants.
Show more [+] Less [-]Assessment and statistical modelling of airborne microorganisms in Madrid
2021
Cordero, José María | Núñez, Andrés | García, Ana M. | Borge, Rafael
The limited evidence available suggests that the interaction between chemical pollutants and biological particles may intensify respiratory diseases caused by air pollution in urban areas. Unlike air pollutants, which are routinely measured, records of biotic component are scarce. While pollen concentrations are daily surveyed in most cities, data related to airborne bacteria or fungi are not usually available. This work presents the first effort to understand atmospheric pollution integrating both biotic and abiotic agents, trying to identify relationships among the Proteobacteria, Actinobacteria and Ascomycota phyla with palynological, meteorological and air quality variables using all biological historical records available in the Madrid Greater Region. The tools employed involve statistical hypothesis contrast tests such as Kruskal-Wallis and machine learning algorithms. A cluster analysis was performed to analyse which abiotic variables were able to separate the biotic variables into groups. Significant relationships were found for temperature and relative humidity. In addition, the relative abundance of the biological phyla studied was affected by PM₁₀ and O₃ ambient concentration. Preliminary Generalized Additive Models (GAMs) to predict the biotic relative abundances based on these atmospheric variables were developed. The results (r = 0.70) were acceptable taking into account the scarcity of the available data. These models can be used as an indication of the biotic composition when no measurements are available. They are also a good starting point to continue working in the development of more accurate models and to investigate causal relationships.
Show more [+] Less [-]Impact of fate properties, groundwater fluctuations and the presence of worm burrows on pesticide leaching assessments through golf areas
2021
Karan, Sachin | Badawi, Nora | Jensen, Anne Mette D. | Rosenbom, Annette E.
The risk of pesticide leaching from recreational areas such as golf course turfs is not distinguished in a regulative framework within the EU where the focus is on agricultural soils. But with increasing popularity of golf, and thus, increasing number of golf courses leading to potentially increasing use of pesticides, understanding the processes determining pesticide leaching are critical to ensure optimal quality of both groundwater and golf turf. This study input the measured variation in fate properties of tebuconazole (TBZ) and MCPA as pure active ingredients and commercial products in simulations with realistic hydrological conceptualizations to investigate their implication in leaching assessments. Scenarios with (i) fluctuating and fixed groundwater levels and (ii) preferential flows including fluctuating and fixed groundwater levels were evaluated. The results showed that mobile MCPA leached in higher concentrations by a factor of 1.3 with fluctuating groundwater levels than with fixed groundwater levels. When preferential flow paths were incorporated in the models, the leaching was substantial for MCPA regardless of its formulation as active ingredient or commercial product, while in multiple simulations without preferential pathways there was no leaching of MCPA. Compared to MCPA leaching without preferential flow paths, the leaching concentrations increased up to a factor of 13.9 when preferential flows were included. With preferential flow paths, the increase in leaching concentration from fixed groundwater levels to fluctuating groundwater levels was up to a factor of 2.3 depending on the formulation of MCPA. This study demonstrated that it is imperative to assess fate parameters in the topsoil of golf courses and consider realistic groundwater BC (boundary condition) and the presence of preferential flow paths to obtain representative pesticide leaching risk assessments.
Show more [+] Less [-]Simulated mobile communication frequencies (3.5 GHz) emitted by a signal generator affects the sleep of Drosophila melanogaster
2021
Wang, Yahong | Zhang, Hongying | Zhang, Ziyan | Sun, Boqun | Tang, Chao | Zhang, Lu | Jiang, Zhihao | Ding, Bo | Liao, Yanyan | Cai, Peng
With the rapid development of science and technology, 5G technology will be widely used, and biosafety concerns about the effects of 5G radiofrequency radiation on health have been raised. Drosophila melanogaster was selected as the model organism for our study, in which a 3.5 GHz radiofrequency radiation (RF-EMR) environment was simulated at intensities of 0.1 W/m², 1 W/m², and 10 W/m². The activity of parent male and offspring (F1) male flies was measured using a Drosophila activity monitoring system under short-term and long-term 3.5 GHz RF-EMR exposure. Core genes associated with heat stress, the circadian clock and neurotransmitters were detected by QRT-PCR technology, and the contents of GABA and glutamate were detected by UPLC-MS. The results show that short-term RF-EMR exposure increased the activity level and reduced the sleep duration while long-term RF-EMR exposure reduced the activity level and increased the sleep duration of F1 male flies. Under long-term RF-EMR, the expression of heat stress response-related hsp22, hsp26 and hsp70 genes was increased, the expression of circadian clock-related per, cyc, clk, cry, and tim genes was altered, the content of GABA and glutamate was reduced, and the expression levels of synthesis, transport and receptor genes were altered. In conclusion, long-term RF-EMR exposure enhances the heat stress response of offspring flies and then affects the expression of circadian clock and neurotransmitter genes, which leads to decreased activity, prolonged sleep duration, and improved sleep quality.
Show more [+] Less [-]Effect of oil pollution on the ecological condition of soils and bottom sediments of the arctic region (Yakutia)
2021
Lifshits, Sara | Glyaznetsova, Yuliya | Erofeevskaya, Larisa | Chalaya, Olga | Zueva, Iraida
Oil and petroleum products are known to be among the most widespread soil pollutants. The risk of emergencies is sure to increase greatly in conditions of abnormally low temperatures. Oil and oil products are not only toxic to the environment, but can also have a negative impact on the state of the permafrost zone, accelerating the processes of permafrost degradation. The goal of the research was to study the soils and bottom sediments for oil pollution in the Arctic region of Yakutia. The research was carried out with using the complex of geochemical and microbiological methods of analysis. It had shown that at present oil pollution was mainly concentrated on the objects bearing a high technogenic load. However, some migration of hydrocarbons was observed with melt, seasonal melt and rainwaters, as a result of which the natural background of the nearby territories became technogenic character. In the Arctic conditions for the first time according to the obtained data on geochemical and microbiological studies oxidative destruction of oil pollutants in soil occurred mainly under the influence of physic and chemical environmental factors, not by microbial oxidation. Sluggish processes of mineralization of organic residues and the transformation of oil pollutants by the type of putrefaction led to the colonization of oil-polluted soils of the Arctic with putrefying and pathogenic microorganisms. The purpose of further research will be studying the possibility of intensification of soil remediation processes of technologically disturbed soils at abnormally low temperatures.
Show more [+] Less [-]Long-term exposure to particulate matter and roadway proximity with age at natural menopause in the Nurses’ Health Study II Cohort
2021
Li, Huichu | Hart, Jaime E. | Mahalingaiah, Shruthi | Nethery, Rachel C. | Bertone-Johnson, Elizabeth | Laden, Francine
Evidence has shown associations between air pollution and traffic-related exposure with accelerated aging, but no study to date has linked the exposure with age at natural menopause, an important indicator of reproductive aging. In this study, we sought to examine the associations of residential exposure to ambient particulate matter (PM) and distance to major roadways with age at natural menopause in the Nurses’ Health Study II (NHS II), a large, prospective female cohort in US. A total of 105,996 premenopausal participants in NHS II were included at age 40 and followed through 2015. Time-varying residential exposures to PM₁₀, PM₂.₅₋₁₀, and PM₂.₅ and distance to roads was estimated. We calculated hazard ratios (HR) and 95% confidence intervals (CIs) for natural menopause using Cox proportional hazard models adjusting for potential confounders and predictors of age at menopause. We also examined effect modification by region, smoking, body mass, physical activity, menstrual cycle length, and population density. There were 64,340 reports of natural menopause throughout 1,059,229 person-years of follow-up. In fully adjusted models, a 10 μg/m³ increase in the cumulative average exposure to PM₁₀ (HR: 1.02, 95% CI: 1.00, 1.04), PM₂.₅₋₁₀ (HR: 1.03, 95% CI: 1.00, 1.05), and PM₂.₅ (HR: 1.03, 95% CI: 1.00, 1.06) and living within 50 m to a major road at age 40 (HR: 1.03, 95%CI: 1.00, 1.06) were associated with slightly earlier menopause. No statistically significant effect modification was found, although the associations of PM were slightly stronger for women who lived in the West and for never smokers. To conclude, we found exposure to ambient PM and traffic in midlife was associated with slightly earlier onset of natural menopause. Our results support previous evidence that exposure to air pollution and traffic may accelerate reproductive aging.
Show more [+] Less [-]PCDD/Fs emissions from secondary copper production synergistically controlled by fabric filters and desulfurization
2021
Li, Haifeng | Liu, Wenbin | Lu, Anxiang | Li, Cheng | Die, Qingqi | Lei, Rongrong | Wu, Xiaolin
The effects of fabric filters and desulfurization systems during secondary copper smelting on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations, emission coefficients, and profiles were studied in an oxygen-rich smelting furnace and an anode furnace. In the anode furnace, the toxic equivalent (TEQ) concentration ranges were 0.106–1.04 ng World Health Organization (WHO)-TEQ/m³ at the fabric filters inlet and 0.027–0.17 ng WHO-TEQ/m³ at the outlet. For the oxygen-rich smelting furnace, the TEQ concentration ranges were 1.21–1.93 and 0.010–0.019 ng WHO-TEQ/m³ at the desulfurization system inlet and outlet, respectively. The TEQs in the outlet stack gases of the desulfurization system from the anode furnace were 0.0041–0.016 ng WHO-TEQ/m³. It is likely that PCDD/Fs that were taken away from the stack gases were adsorbed by the fly ash and gypsum. Solid residues were the dominant release routes for PCDD/Fs. PCDD/Fs congener and homologue profiles of stack gases from different smelting stages were similar. The contributions of more chlorinated homologues from the anode furnace decreased observably after the stack gases passed through the fabric filters. However, the desulfurization process did not greatly change the PCDD/Fs homologue profiles. Overall, both the fabric filters and desulfurization systems showed excellent removal efficiencies for PCDD/Fs in the stack gases, which reduced the TEQ emissions to well below the 0.5 ng WHO-TEQ/m³ to achieve standard discharge.
Show more [+] Less [-]Di (2-ethylhexyl) phthalate impairs primordial follicle assembly by increasing PDE3A expression in oocytes
2021
Liu, Jing-Cai | Yan, Zi-Hui | Li, Bo | Yan, Hong-Chen | De Felici, M. (Massimo) | Shen, Wei
It is known that Di (2-ethylhexyl) phthalate (DEHP) may impact mammalian reproduction and that in females one target of the drug’s action is follicle assembly. Here we revisited the phthalate’s action on the ovary and from bioinformatics analyses of the transcriptome performed on newborn mouse ovaries exposed in vitro to DEHP, up-regulation of PDE3A, as one of the most important alterations caused by DEHP on early folliculogenesis, was identified. We obtained some evidence suggesting that the decrease of cAMP level in oocytes and the parallel decrease of PKA expression, consequent on the PDE3A increase, were a major cause of the reduction of follicle assembly in the DEHP-exposed ovaries. In fact, Pde3a RNAi on cultured ovaries reducing cAMP and PKA decrease counteracted the primordial follicle assembly impairment caused by the compound. Moreover, RNAi normalized the level of Kit, Nobox, Figla mRNA and GDF9, BMP15, CX37, γH2AX proteins in oocytes, and KitL transcripts in granulosa cells as well as their proliferation rate altered by DEHP exposure. Taken together, these results identify PDE3A as a new critical target of the deleterious effects of DEHP on early oogenesis in mammals and highlight cAMP-dependent pathways as major regulators of oocyte and granulosa cell activities crucial for follicle assembly. Moreover, we suggest that the level of intracellular cAMP in the oocytes may be an important determinant for their capability to repair DNA lesions caused by DNA damaging compounds including DEHP.
Show more [+] Less [-]Fate of antibiotic resistance genes in industrial-scale rapid composting of pharmaceutical fermentation residue: The role implications of microbial community structure and mobile genetic elements
2021
Tang, Zhurui | Huang, Caihong | Tian, Yu | Xi, Beidou | Guo, Wei | Tan, Wenbing
Composting is an effective technology to recycle organic solid waste as a green resource. However, pharmaceutical fermentation residue (PFR) contains a variety of pollutants, such as residual drug and antibiotic resistance genes (ARGs), which limits the green cycle of using PFR as a resource. To promote the green recycling of PFR, this study evaluated the characteristics of abundance and the response relationship of ARGs during the process of rapid composting. Different rapid composting samples were collected, and DNA was extracted from each sample. The absolute abundance of ARGs was quantified using quantitative PCR, and the microbial community structure was identified using high-throughput sequencing. The results showed that ermB, ermF, tetM and tetQ were reduced by 89.55%, 15.10%, 89.55%, and 82.30% respectively, and only sul2 increased by approximately 5-fold. Mobile genetic elements (MGEs) directly affected the changes in abundance of ARGs. As typical MGEs, intl1 and intl2 decreased by 3.40% and 54.32%, respectively. Potential host microorganisms important factors that affected ARGs and MGEs. A network analysis indicated that the potential host microorganisms were primarily distributed in Firmicutes and Proteobacteria at the phylum level. The pH and content of water-extractable sulfur were physicochemical parameters that substantially affected the abundance of potential host microorganisms through redundancy analysis. Industrial-scale rapid composting could reduce the number of ARGs and shorten the composting cycle, which merits its popularization and application.
Show more [+] Less [-]Palm oil industrial wastes as a promising feedstock for biohydrogen production: A comprehensive review
2021
Ong, Ee Shen | Rabbani, Alija Haydar | Habashy, Mahmoud M. | Abdeldayem, Omar M. | Al-Sakkari, Eslam G. | Rene, Eldon R.
By the year 2050, it is estimated that the demand for palm oil is expected to reach an enormous amount of 240 Mt. With a huge demand in the future for palm oil, it is expected that oil palm by-products will rise with the increasing demand. This represents a golden opportunity for sustainable biohydrogen production using oil palm biomass and palm oil mill effluent (POME) as the renewable feedstock. Among the different biological methods for biohydrogen production, dark fermentation and photo-fermentation have been widely studied for their potential to produce biohydrogen by using various waste materials as feedstock, including POME and oil palm biomass. However, the complex structure of oil palm biomass and POME, such as the lignocellulosic composition, limits fermentable substrate available for conversion to biohydrogen. Therefore, proper pre-treatment and suitable process conditions are crucial for effective biohydrogen generation from these feedstocks. In this review, the characteristics of palm oil industrial waste, the process used for biohydrogen production using palm oil industrial waste, their pros and cons, and the influence of various factors have been discussed, as well as a comparison between studies in terms of types of reactors, pre-treatment strategies, the microbial culture used, and optimum operating condition have been presented. Through biological production, hydrogen production rates up to 52 L-H₂/L-medium/h and 6 L-H₂/L-medium/h for solid and liquid palm oil industrial waste, respectively, can be achieved. In short, the continuous supply of palm oil production by-product and relatively, the low cost of the biological method for hydrogen production indicates the potential source of renewable energy.
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