Characterizing Black Carbon (BC) at regional background areas is important for better understanding its impact on climate forcing and health effects. The variability and sources of Equivalent Black Carbon (EBC) in PM₁₀ (atmospheric particles with aerodynamic diameter smaller than 10 μm) have been investigated during a 5-year measurement period at the National Atmospheric Observatory Košetice (NAOK), Czech Republic. Ground based measurements were performed from September 2012 to December 2017 with a 7-wavelength aethalometer (AE31, Magee Scientific). The contributions of fossil fuel (EBCff) and biomass burning (EBCbb) were estimated using the aethalometer model. Seasonal, diurnal and weekly variations of EBC were observed that can be related to the sources fluctuations and transport characteristic of pollutants predominantly associated with regional air masses recirculating over the Czech Republic and neighboring countries. The absorption Ångström exponent (α-value) estimated in summer (1.1 ± 0.2) was consistent with reported value for traffic, while the mean highest value (1.5 ± 0.2) was observed in winter due to increased EBCbb accounting for about 50% of the total EBC. This result is in agreement with the strong correlation between EBCbb and biomass burning tracers (levoglucosan and mannosan) in winter. During this season, the concentrations of EBCbb and Delta-C (proxy for biomass burning) reached a maximum in the evening when increasing emissions of wood burning in domestic heating devices (woodstoves/heating system) is expected, especially during the weekend. The diurnal profile of EBCff displays a typical morning peak during the morning traffic rush hour and shows a decreasing concentration during weekends due to lower the traffic emission.

Mercury (Hg) concentrations in Tilefish (Lopholatilus chamaeleonticeps) have been reported to be one of the highest of all fish species, resulting in advisories that, historically, have recommended zero consumption. The current study assesses Hg bioaccumulation in Tilefish targeted by the commercial fisheries operating off the coast of South Carolina, USA. We provide results for an under-sampled region and explore how life history potentially impacts Hg uptake in Tilefish. Mercury concentration in Tilefish muscle tissue ranged from 0.10 to 0.99 ppm, with a mean of 0.23 ppm (n = 63). The majority of Tilefish samples (95%) were within the “Good Choices” range for consuming at least one serving per week, with 62% being within the range considered best for eating two meals a week”, per suggestion by the US EPA and US FDA (2017). The present study of Tilefish from the western Atlantic further substantiates the importance of monitoring Hg in commercial fish species regionally.

Land use/Land cover (LULC) associated with Cryptosporidium sp. and Giardia sp. quantification and distribution can provide identification of the environmental circulation patterns of these parasites. The aim of this research was to relate the occurrence and circulation of these parasites to the LULC watershed with poor sanitation infrastructure and livestock as important economic activity. The study involved 11 municipalities in the state of São Paulo, located in southeastern Brazil. Sampling was carried out at the catchment sites of each water supply on a monthly basis, starting in December 2014 and lasting until November 2015, totalizing 128 samples. Protozoans were quantified according to the 1623.1 US. EPA Method. For watershed delimitation, the hydrographic network was extracted from the hydrology tool of ArcGIS 10.1. The frequency of occurrence of these pathogens and the high concentrations were evidenced in the municipality with the largest urban area (16.2%) and intense livestock activity (39%) near the catchment site. The municipality that showed the lowest frequency of occurrence presented the smallest urban area (0.87%) and absence of livestock activity near the catchment site. The high concentration of pathogens suggests a correlation between the impact on water supply networks and river basin degradation caused by urban activity and livestock.

This work aimed to investigate the metal accumulation characteristics as well as biogeochemical changes in the rhizosphere and root foraging strategies of this plant species. Previous reports suggested that Noccaea rotundifolia ssp. cepaeifolia is a Zn, Cd and Pb hyperaccumulator. We used hydroponic, rhizobox and split-pot experiments for studying metal accumulation and related rhizosphere processes. Although this species accumulated up to 1250 mg Pb kg⁻¹ and 27,000 mg Zn kg⁻¹ in shoots, translocation factors <1 do not meet the hyperaccumulation criteria. Substantial increases in Ca(NO₃)₂-extractable metals in the N. rotundifolia rhizosphere of a metal-spiked soil can be explained by proton release from N. rotundifolia roots to maintain the charge balance during excessive metal uptake; this was not observed for the non-spiked, moderately contaminated control soil. Specific rhizosphere mechanisms targeting the alleviation of metal toxicity in N. rotundifolia rhizosphere were not detected. Generally, N. rotundifolia had larger total root and shoot mass in soils with heterogeneous distribution of Zn and Pb relative to homogeneous treatments, associated with less root mass placed in metal-enriched patches. However, the avoidance strategy was not reflected by low shoot metal concentrations. Metal accumulation rates and translocation factors do not meet the criteria for hyperaccumulation. Changes of pH and DOC in N. rotundifolia rhizosphere were apparently not involved in targeted immobilisation or detoxification of Pb, Zn and Cd. Avoidance of metal-rich patches in soil is a major tolerance strategy of N. rotundifolia.

Microplastics are ubiquitous in marine environments. Sediments and marine organisms are recognized as the carriers and final destinations of microplastics. However, research on the concentration and abundance of microplastics in deep-sea sediments and organisms is limited. In this study, samples of sediments and organisms were collected from deep-sea locations of the western Pacific Ocean, with the depth ranging from 4601 m to 5732 m. Microplastics were extracted from the samples and analyzed by micro-Fourier-transform infrared spectroscopy. The average abundance of microplastics in the sediments was 240 items per kg dry weight of sediment. The microplastics were predominantly fibrous in shape (52.5%), blue in color (45.0%), and less than 1 mm in size (90.0%). The most commonly detected polymers were poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%). The concentrations of polychlorinated biphenyls (PCBs), which are representatives of persistent organic pollutants, in the pore water of sediment samples were also investigated. A significant correlation between the distribution of microplastics and the PCB concentrations in sediments was found (P = 0.016). Microplastics were also detected in deep-sea organisms (i.e., Crinoidea, Pheronematidae, Ophiuroidea, and Gammaridea) in the sampling region, with an abundance of 0–3 items per individual biological sample. This assessment of microplastics in deep-sea sediments and benthic organisms of the western Pacific Ocean confirms that microplastic pollution exists in the deep-sea ecosystems of this region.

Interactions between aromatic pollutants (APs) and porphyrin nucleus as physiological receptors have a significant effect on biological functions of porphyrin-based systems in organism. However, the details on the interaction at molecule level are still elusive. Herein, interaction mechanisms between two typical APs (methylene blue, MB and benzo[a]pyrene, B[a]P) and meso-tetra (4-carboxyphenyl) porphine (TCPP) as physiological receptors were systematically investigated. Adsorption behaviors of TCPP to B[a]P was dominated by pi-pi interaction, while interaction between TCPP and MB coupled with a multi-force field including hydrophobic, pi-pi, electrostatic, and H-bonding interactions. The relative contributions of these four forces obeyed an order: H-bonding > pi-pi > electrostatic > hydrophobic, regardless of the pH value and the initial concentration of MB. H-bonding assisted by hydrogen/hydroxide ion was the most influential force. According to the effect of pH and temperature, organisms exposed to cellular environment with high alkalinity and high temperature might uptake more APs molecules with chemical properties similar to MB and suffered greater health risks. In detail, APs might replace amino acid molecules surrounding porphyrin and change the distortion type of porphyrin molecule, and then affect biological functions of porphyrin and related proteins. This study facilitates a better understanding of potential toxicity of organisms in contaminated environment.

Aimed at effectively controlling coal dust pollution in the mining face of a coal mine, this study first conducted a theoretical analysis and then combined a spraying experiment and a numerical simulation to perform an in-depth examination of the atomizing characteristics and dust suppression performance of a coal cutter external spraying device. Based on the experimental spraying results, the optimal nozzle was determined to be a pressure round-mouth nozzle with an X-shaped core. The characteristics of the spray fields from nozzles of different calibers (1.6, 2.0 and 2.4 mm) at different spraying pressures (2, 4, 6 and 8 MPa) were then analyzed. It was found that the droplet concentration in the spray field increased with increasing spraying pressure and nozzle caliber. The droplet diameter was mainly dependent on the spraying pressure and varied more slowly with increased spraying pressure. At a spraying pressure of 8 MPa, the spray field formed could achieve effective dust suppression; specifically, the droplet concentration in the spray field was mostly more than 15 g/m³, and the droplet size was mainly distributed in the range of 30–100 μm. When using a 2.4 mm caliber nozzle, the dust concentration measured around the coal cutter operator was reduced to 87.21 mg/m³ under a spraying pressure of 8 MPa, suggesting adequate dust suppression.

1,3,5-Trimethylbeneze (TMB) is an important constituent of anthropogenic volatile organic compounds that contributes to the formation of secondary organic aerosol (SOA). A series of chamber experiments were performed to probe the effects of NOₓ and SO₂ on SOA formation from TMB photooxidation. The molecular composition of TMB SOA was investigated by ultra-high performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS). We found that the SOA yield increases notably with elevated NOₓ concentrations under low-NOₓ condition ([TMB]₀/[NOₓ]₀ > 10 ppbC ppb⁻¹), while an opposite trend is observed in high-NOₓ experiments ([TMB]₀/[NOₓ]₀ < 10 ppbC ppb⁻¹). The increase in SOA yield in low-NOₓ regime is attributed to the increase of NOₓ-induced OH concentrations. The formation of low-volatility species might be suppressed, thereby leading to a lower SOA yield in high-NOₓ conditions. Moreover, SOA formation was promoted in experiment with SO₂ addition. Multifunctional products containing carbonyl, acid, alcohol, and nitrate functional groups were characterized in TMB/NOₓ photooxidation, whereas several organosulfates (OSs) and nitrooxy organosulfates were identified in TMB/NOₓ/SO₂ photooxidation based on HR-Q-TOFMS analysis. The formation mechanism relevant to the detected compounds in SOA were proposed. Based on our measurements, the photooxidation of TMB in the presence of SO₂ may be a new source of OSs in the atmosphere. The results presented here also deepen the understanding of SOA formation under relatively complex polluted environments.

The residual characteristics and the adsorption-desorption behaviors of azoxystrobin (AZO) as well as the soil ecological effects in the individual repeated treatments of AZO and its combination with chlorothalonil (CTL), chlortetracycline (CTC) and ciprofloxacin (CIP) were systematically studied in organic manure (OM)-amended soil under laboratory conditions. The presence of CTL, CTC, and CIP, both individually and combined, decreased the sorption affinity of AZO with the Freundlich adsorption and desorption coefficient decreasing by 0.3–24.2%, and CTC and CIP exhibited greater adverse effects than CTL. AZO dissipated slowly and the residues significantly accumulated during ten repeated treatments. The dissipation of AZO was inhibited to different degrees in the combined treatments. Biolog analysis revealed that the soil microbial functional diversity in the OM-soil + AZO and OM-soil + AZO + CTL treatments was higher than that in the OM-soil treatment during the former three repeated treatments, but which was inhibited during the latter seven repeated treatments. The soil microbial functional diversity in the OM-soil + AZO + CTC, OM-soil + AZO + CIP and OM-soil + AZO + CTL + CTC + CIP treatments was inhibited during the ten repeated treatments compared with OM-soil treatment. Metagenomic results showed that all repeated treatments significantly increased the relative abundance of Actinobacteria, but significantly decreased that of Proteobacteria and Firmicutes during the ten repeated treatments. Furthermore, the relative abundance of soil dominant bacterial genera Rhodococcus, Mycobacterium and Arthrobacter in all the repeated treatments significantly increased by 1.5–1283.9% compared with the OM-soil treatment. It is concluded that coexistence of CTL, CTC and CIP, both individually and combined, with AZO can inhibit the dissipation of AZO, reduce the adsorption affinity of AZO on soil, and alter the soil microbial community structure and functional diversity.

We utilized volcanic CO₂ vents at Castello Aragonese off Ischia Island as a natural laboratory to investigate the effect of lowered pH/elevated CO₂ on the bioactivities of extracts from fleshy brown algae Sargassum vulgare C. Agardh. We analysed the carbohydrate levels, antioxidant capacity, antibacterial, antifungal, antiprotozoal, anticancer properties and antimutagenic potential of the algae growing at the acidified site (pH ∼ 6.7) and those of algae growing at the nearby control site Lacco Ameno (pH∼8.1). The results of the present study show that the levels of polysaccharides fucoidan and alginate were higher in the algal population at acidified site. In general, extracts for the algal population from the acidified site showed a higher antioxidant capacity, antilipidperoxidation, antibacterial, antifungal, antiprotozoal, anticancer activities and antimutagenic potential compared to the control population. The increased bioactivity in acidified population could be due to elevated levels of bioactive compounds of algae and/or associated microbial communities. In this snapshot study, we performed bioactivity assays but did not characterize the chemistry and source of presumptive bioactive compounds. Nevertheless, the observed improvement in the medicinal properties of S. vulgare in the acidified oceans provides a promising basis for future marine drug discovery.