Hydrocephalus and Growth Retardation: A Fetal RNU4ATAC-opathy Missed by Whole-Exome Sequencing.

Introduction: Whole-exome sequencing (WES) is becoming widely available in prenatal diagnosis. However, as with most scientific methods, WES also has its limitations. The aim of the study was to report a fetal case of RNU4ATAC-opathy which was missed by prenatal WES. Case Presentation: A 28-year-old healthy primigravida was revealed by ultrasound at 20 + 3 weeks of gestation to have a fetus with ventriculomegaly (left 15.1 mm/right 11.9 mm), hypoplastic vermis, and mild growth retardation. Chromosomal microarray analysis and trio WES failed to detect a pathogenic copy number variation and sequence variant. A repeat ultrasound at 23 + 3 weeks showed worsened growth delay and hydrocephalus (left 20.3 mm/right 11.0 mm) with vermis hypoplasia and agenesis of corpus callosum. Further study with whole-genome sequencing (WGS) detected 2 missense mutations of the noncoding RNU4ATAC (NR_023343.1) gene, n.51G>A (rs188343279) and n.16G>A (rs750325275), in the fetus, which were inherited from the father and mother, respectively. Discussion: Our study highlights the limitation of WES. WGS might be a clinical option for patients who have a structurally abnormal fetus tested negative by WES.

[Analysis of the Composition of Atmospheric Fine Particles (PM2.5) Produced by Burning Fireworks].

Burning fireworks is one of the sources of atmospheric fine particles (PM2.5). The Chinese Spring Festival in Quanzhou City was taken as an example to study the effects of burning fireworks on the occurrence of PM2.5, and provide information on protection against air pollution caused by special pollution sources. The results showed that the concentrations of SO2, PM10, and PM2.5 increased appreciably, and the concentration of PM2.5 increased most significantly during the fireworks burning period. The peak daily average concentration in the urban area was about 4 times the annual average concentration in the urban area. The peak value of the hourly average concentration of PM2.5 in the Tushan Street station was about 21 times the annual average concentration in the urban area. At the peak of the discharge, the ratios of the characteristic elements of fireworks, such as Al, Mg, Ba, Cu, and Sr, increased rapidly, and the hourly number concentrations of Al+, Mg+, Ba+, and Cu+ were highly correlated. During the monitoring period, the main pollution sources of fine particles in Quanzhou City were fireworks and biomass burning, which accounted for more than half of the total particulate matter. The proportion of pollutants originating from coal-based and industrial process sources were relatively low, and both of them accounted for less than 10.0% of the particulate matter. The concentration of PM2.5 was up to 0.578 mg·m-3 during the fireworks burning period, the rate of contribution by fireworks increased to 58.2%. Analysis of the pollution process showed that the changes in the concentration of PM2.5 have a similar trend with the number concentration and the ratio of fireworks burning. The results indicated that the main reason of the deterioration of the atmospheric environment during the Chinese Spring Festival in Quanzhou is the centralized discharging of fireworks.

Land scale biogeography of arsenic biotransformation genes in estuarine wetland.

As an analogue of phosphorus, arsenic (As) has a biogeochemical cycle coupled closely with other key elements on the Earth, such as iron, sulfate and phosphate. It has been documented that microbial genes associated with As biotransformation are widely present in As-rich environments. Nonetheless, their presence in natural environment with low As levels remains unclear. To address this issue, we investigated the abundance levels and diversities of aioA, arrA, arsC and arsM genes in estuarine sediments at low As levels across Southeastern China to uncover biogeographic patterns at a large spatial scale. Unexpectedly, genes involved in As biotransformation were characterized by high abundance and diversity. The functional microbial communities showed a significant decrease in similarity along the geographic distance, with higher turnover rates than taxonomic microbial communities based on the similarities of 16S rRNA genes. Further investigation with niche-based models showed that deterministic processes played primary roles in shaping both functional and taxonomic microbial communities. Temperature, pH, total nitrogen concentration, carbon/nitrogen ratio and ferric iron concentration rather than As content in these sediments were significantly linked to functional microbial communities, while sediment temperature and pH were linked to taxonomic microbial communities. We proposed several possible mechanisms to explain these results.

Continental-scale pollution of estuaries with antibiotic resistance genes.

Antibiotic resistance genes (ARGs) have moved from the environmental resistome into human commensals and pathogens, driven by human selection with antimicrobial agents. These genes have increased in abundance in humans and domestic animals, to become common components of waste streams. Estuarine habitats lie between terrestrial/freshwater and marine ecosystems, acting as natural filtering points for pollutants. Here, we have profiled ARGs in sediments from 18 estuaries over 4,000 km of coastal China using high-throughput quantitative polymerase chain reaction, and investigated their relationship with bacterial communities, antibiotic residues and socio-economic factors. ARGs in estuarine sediments were diverse and abundant, with over 200 different resistance genes being detected, 18 of which were found in all 90 sediment samples. The strong correlations of identified resistance genes with known mobile elements, network analyses and partial redundancy analysis all led to the conclusion that human activity is responsible for the abundance and dissemination of these ARGs. Such widespread pollution with xenogenetic elements has environmental, agricultural and medical consequences.

Heavy metal and organic contaminants in mangrove ecosystems of China: a review.

China's rapid economic growth has been accompanied by increasing environmental pollution. Mangrove ecosystems are now facing greater pollution pressures due to elevated chemical discharges from various land-based sources. Data on the levels of heavy metals and organic pollutants in mangrove compartments (sediments, plants, zoobenthos, and fish) in China over the past 20 years have been summarized to evaluate the current pollution status of the mangrove ecosystem. Overall, the Pearl River and Jiulong River estuaries were severely polluted spots. Concentrations of Cu, Zn, Cd, and Pb in mangrove sediments of Guangdong, Fujian, and Hong Kong were higher than those from Guangxi and Hainan. The pollution status was closely linked to industrialization and urbanization. The highest concentrations of polycyclic aromatic hydrocarbons (PAHs) were found in mangrove sediments from Hong Kong, followed by Fujian and Guangdong. Mangrove plants tend to have low-enriched ability for heavy metals and organic pollutants. Much higher levels of Pb, Cd, and Hg were observed in mollusks.

[Pollution characteristics and accumulation of antibiotics in typical protected vegetable soils].

The occurrence and distribution of 14 selected antibiotics in soils from 20 protected vegetable fields in Shandong province were investigated by ultrasonic extraction and UPLC-MS/MS. The results showed that antibiotics were detected in all the soil samples, the dominant antibiotics were tetracycline, oxytetracycline, chlortetracycline and doxycycline with 100% detection rate, the concentration of which in soil ranged from 2.11-139.16, 6.06-332.02, 1.82-391.31, 2.20-248.56 microg x kg(-1), respectively. The total concentration of four compounds sigma (TCs) ranged from 26.79-1010.11 microg x kg(-1), with an average of 274 microg x kg(-1). All the sulfonamides (SAs), quinolones (QNs) and macrolides antibiotics (MACs) were also detected, except for chloramphenicoles. The total concentration of QNs [sigma (QNs)] in soils ranged from 0-1017.06 microg x kg(-1) and the average concentration was 73.05 microg x kg(-1) with detection rate of 85%, and the individual concentrations of SAs and MACs were quite low in soils. The results also showed that the distibution and concentration of antibiotics in soils grown different vegetables were quite different. Notably, the individual concentrations of QNs (NFC, OFC) were 373.73 microg x kg(-1) and 643.34 microg x kg(-1), respectively, which far exceeded the trigger value of the ecological risk (100 microg x kg(-1)). Thus, more attention should be paid to antibiotics pollution in protected vegetable soils.

Particle size: a missing factor in risk assessment of human exposure to toxic chemicals in settled indoor dust.

For researches on toxic chemicals in settled indoor dust, selection of dust fraction is a critical influencing factor to the accuracy of human exposure risk assessment results. However, analysis of the selection of dust fraction in recent studies revealed that there is no consensus. This study classified and presented researches on distribution of toxic chemicals according to dust particle size and on relationship between dust particle size and human exposure possibility. According to the literature, beyond the fact that there were no consistent conclusions on particle size distribution of adherent fraction, dust with particle size less than 100 µm should be paid more attention and that larger than 250 µm is neither adherent nor proper for human exposure risk assessment. Calculation results based on literature data show that with different selections of dust fractions, analytical results of toxic chemicals would vary up to 10-fold, which means that selecting dust fractions arbitrarily will lead to large errors in risk assessment of human exposure to toxic chemicals in settled dust. Taking into account the influence of dust particle size on risk assessment of human exposure to toxic chemicals, a new methodology for risk assessment of human exposure to toxic chemicals in settled indoor dust is proposed and human exposure parameter systems to settled indoor dust are advised to be established at national and regional scales all over the world.

[Investigation of 14 selected antibiotics in sediments of the typical cross sections of Tiaoxi River].

The occurrence and distribution of 14 selected antibiotics in sediments of the typical cross sections of Tiaoxi River were analyzed by UPLC/MS/MS. The 14 antibiotics includes tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), doxycycline (DXC), sulfadiazine (SD), sulfamethoxazole (SMZ), sulfamethazine (SMX), norfloxacin (NFC), ofloxacin (OFC), enythromycin-H2O (ETM-H2O), roxithromycin (RTM), chloramphenicol (CPC), thiamphenical (TPC) and florfenicol (FFC). The results show that almost all sediment samples are unavoidably contaminated with antibiotics (detection frequency is more than 70%), and the dominant contaminants are TC, OTC, CTC and DXC, which range from 0.1 to 55.7, 0.7 to 276.6, 6.5 to 131.6 and 6.0 to 15.6 microg x kg(-1), respectively. The concentration of TC, OTC, CTC and DXC observed are as high as 1794.2, 9287.5, 1823.6, 1 149.5 microg x kg(-1) dry weight, in the sediments of the main stream around an outfall of a pig farm respectively. This implied that waste water discharge from animal husbandry was probably one of the main sources to the contamination of these antibiotics in the sediment of Tiaoxi River. Besides the four dominant antibiotics, sulfadiazineshould also be concerned due to its high concentration of 251.6 microg x kg(-1) in the sediment around the outfall of the pig farm.

[Characterizing the plant uptake factor of As, Cd and Pb for rice and wheat cereal].

The statistical characteristics of plant uptake factor (PUF) of As, Cd and Pb for rice/wheat cereal were analyzed and summarized based on collected data in China. The data were selected and distinguished between field investigation and glasshouse experiment in which metal salts were added to clean soils as grown media. Results showed that the PUF median and range of As, Cd and Pb for rice cereal were 0.026 (0.004-0.090), 0.150 (0.014-1.470), 0.005 (0.001-0.031) and 0.010 (0.003-0.033), 0.360 (0.056-1.700), 0.002 (0.001-0.019) for field investigation and salt added experiment respectively. The PUF median and range of As, Cd and Pb for wheat cereal were 0.010 (0.001-0.110), 0.190 (0.030-2.110), 0.017 (0.001-0.075) and 0.010 (0.003-0.028), 0.150 (0.055-0.730), 0.001 (0.001-0.014) for field investigation and salt added experiment respectively. Significant PUF distribution differences were found between field investigation and salt added experiment. PUF provided not exactly predictive ability of metal uptake by crops since the PUF values were influenced by a variety of factors including the soil contamination levels, basic soils characteristics, the cultivation of the crops and other environmental conditions. However, the ln (PUF) followed Gaussian distribution (R2 = 0.38-0.94) which is useful for general risk assessment and soil benchmark derivation of contaminated croplands. Use of these statistical models is restricted to the range of data they have been derived, as extrapolation outside this range is often unreliable. Soil properties and surrounding environment of the crops should also be in accordance with the conditions PUF derived.

[Prediction of PCBs uptake by vegetable in a representative area and evaluation of the human health risk by Trapp model].

Air, soil and vegetable samples were collected from an e-waste disassembly site and analyzed for characteristic contaminants PCBs. Based on the measured PCBs concentrations in soil and air, PCBs concentration in leafy vegetables was predicted by Trapp Model and the sources, composition of PCBs in vegetable and influencing factors were analyzed. By using human health risk assessment model of USEPA, risk to human health from consumption of vegetable that take up PCBs from environment was evaluated. The results showed that the Trapp Model could give good prediction of PCBs concentrations in leafy vegetables based on PCBs concentration in the soil and air. For instance, the measured sum of seven PCBs in vegetable was 51.2 microg x kg(-1) and the predicted value was 39.9 microg x kg(-1). So the predicted value agrees well with the measured value. The gaseous PCBs were the main source of PCBs in leafy vegetables, and the model predicting results indicated that the contribution rate was as high as 98.8%. The uptake pathway, n-octanol/water partition coefficient (K(ow)) and the n-octanol/air partition coefficient (K(oa)) of PCBs determine the concentration and composition of PCBs in vegetables. The duration needed for PCBs uptake to reach equilibrium was in good correlation with lgK(ow) and lgK(oa). Multiple linear regression analysis indicated that lgK(oa) was more important. Carcinogenic risk from consumption of PCBs contaminated vegetables was 10 000 times higher than that of gaseous PCBs, and the no-carcinogenic risk was increased by approximately 200 times. The main reasons are firstly the vegetables take up and accumulate more toxic PCBs with high-chloride substitutes and consequently the oral toxic factors of PCBs increase dramatically. Secondly, an adult takes 71 times more PCBs via consumption of vegetables than via inhalation of air.