Hestermartinsen5832

Rural sewers are applied widely to collect rural sewage and biofilm characteristics in rural sewers may be different with municipal sewers. Apoptosis inhibitor The succession of bacteria communities, sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) need to be studied since rural sewers have a potential risk of sulfide and methane accumulation. In this study, lab-scale rural sewer facilities were established to analyze the characteristics of sewer biofilm and the generation of sulfide and methane. The results indicate that the variation tendency of biofilm thickness in rural sewers was different with municipal sewers. Time-based bacterial succession existed in rural sewer biofilms and the predominant genus was changed from Acinetobacter (approximately 19.10%) to Pseudomonas (approximately 12.61%). SRB (mean 1.49 × 106dsrA copies/cm2) were abundant than MA (mean 2.57 × 105mcrA copies/cm2) while MA were eliminated gradually in rural sewer biofilms. The tendency of sulfide and methane generation was similar with the number variation of SRB and MA, indicating sulfide accumulation might be more serious trouble than methane accumulation in a long-run rural sewer. Overall, this study deeply analyzed the succession of rural sewer biofilms and found that MA and methane were automatically inhibited in rural sewers.Per- and poly-fluoroalkyl substances (PFAS) raised increasing concerns over the past years due to their persistence and global distribution. Understanding their occurrence in the environment and their disruptive effect on the physiology of humans and wildlife remains a major challenge in ecotoxicological studies. Here, we investigate the occurrence of several carboxylic and sulfonic PFAS in 105 individuals of three seabird species (27 great black-backed gull Larus marinus; 44 lesser black-backed gull Larus fuscus graellsii; and 34 European herring gull Larus argentatus) from South western France. We further estimated the relationship between plasma concentrations of PFAS and i) the body condition of the birds and ii) plasma concentrations of thyroid hormone triiodothyronine (TT3). We found that great and lesser black-backed gulls from South Western France are exposed to PFAS levels comparable to highly contaminated species from other geographical areas, although major emission sources (i.e. related to industrial activities) are absent in the region. We additionally found that PFAS are negatively associated with the body condition of the birds in two of the studied species, and that these results are sex-dependent. Finally, we found positive associations between exposure to PFAS and TT3 in the great black-backed gull, suggesting a potential disrupting mechanism of PFAS exposure. Although only three years of data have been collected, we investigated PFAS trend over the study period, and found that great black-backed gulls document an increasing trend of plasma PFAS concentration from 2016 to 2018. Because PFAS might have detrimental effects on birds, French seabird populations should be monitored since an increase of PFAS exposure may impact on population viability both in the short- and long-term.Heavy metals (HMs) are constantly released into the environment during the production and use of batteries. Battery manufacturing has been ongoing for over six decades in the "Battery Industrial Capital" (located in Xinxiang City) of China, but the potential exposure pathways of residents in this region to HMs remain unclear. To clarify the exposure pathways and health risk of human exposure to HMs, hand wipe samples (n=82) and fingernail samples (n=36) were collected from residents (including young children (0-6 years old), children (7-12 years old) and adults (30-60 years old)) living around battery factories. The total concentrations of the target HMs (Zn, Mn, Cu, Pb, Ni, Cr, Cd, Co) in hand wipes ranged from 133 to 8040 μg/m2, and those in fingernails ranged from 9.7-566 μg/g. HM levels in the hand wipe and fingernail samples both decreased with age, and higher HM levels were observed for males than females. The HM composition profiles in these two matrices represented a high degree of similarity, with Zn as the predominant element, and thus, oral ingestion and dermal exposure via dust were expected to be the most important HM exposure pathways for residents in this region. The non-carcinogenic risks (HQs) from dermal and oral ingestion exposure to Cd, Cr, and Pb were higher than those of the other five elements for all three populations, and the HQderm of Cd for young children was 2.1 (HQoral=0.6). Moreover, the hazard index (HI) values of ∑8HMs for young children (HItotal=5.2, HIoral=2.0, HIdermal=3.2) and children (HItotal=1.6, HIoral=1.3, HIdermal=0.3) exceeded the safe threshold (1.0). Therefore, young children and children should be prioritized for protection from HM pollution, and more attention should be paid to young children's dermal exposure to Cd in this region.Effects of ozone (O3) on maize have been increasingly studied, but only few studies have focused on the combined impacts of O3 and nitrogen (N) on this important crop with C4 carbon (C) fixation. In this study, a maize cultivar with the largest acreage in China was exposed to two O3 treatments (NF ambient air O3 concentration; NF60 NF plus 60 ppb O3) and four N levels (farmers' N practice 240 kg N ha-1 yr-1; 150%, 50% and 25% of farmers' N practice). Generally, O3 and N significantly influenced biomass, N and C, but did not change their allocation to kernel. There were significant interactions between O3 and N in stem biomass, C concentration and uptake, and leaf biomass and C uptake, with significant O3 effects mainly occurring at N120 and N240. Based on the coefficient of determination (R2), root CN ratio rather than the most commonly used leaf CN ratio was the best trait to indicate maize productivity. Furthermore, O3 significantly increased the regression slopes between root CN ratio and kernel N uptake, kernel C uptake and plant N uptake, strengthened the correlation of CN ratio and kernel C uptake, and weakened the correlation of CN ratio and hundred-kernels weight. These suggest that O3 pollution can change the relationship of CN ratio and productivity in maize. The weak correlation between kernel harvest index (HI) and N harvest index (NHI) indicated that future breeding researches should consider how to improve the coupling between biomass and N-related nutrition allocations in crop edible parts. Our results not only are helpful to accurately estimate O3 impacts on maize with consideration of N but also provide a new insight into the relationship between plant traits and its productivity under O3 pollution.