Antarctic pristine environment is threatened by the presence of microplastics that occur in a variety of shapes and sizes, from fibers to irregular fragments. The aim of this study is to assess the abundance, distribution, and the characterization of the microfibers in zooplankton samples found in ocean waters in Admiralty Bay, Antarctica. The samples were collected at five points in Admiralty Bay during the XXIX Brazilian Antarctic Expedition in the austral summer of 2010–2011. A total of 603 microfibers were collected in 60 samples, with an average abundance of 2.40 (± 4.57) microfibers 100 m⁻³. Microfiber size ranging from ca. 10 to 22 μm in diameter of various lengths and colors (blue, red, black, and clear) was collected and characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Most of these microfibers were entangled in various different zooplankton species and were identified as polymers composed mostly by polyethyleneglycols, polyurethanes, polyethylene terephthalates, and polyamides. The presence of such microfibers may cause the loss of biodiversity in the Antarctic continent, and the results presented herein can contribute to a better understanding of the impact caused by them within the food chain and human health. Graphical Abstract ᅟ

Exposure to ambient air pollutants during pregnancy may be associated with numerous side health effects and adverse birth outcomes. Growing numbers of studies have explored a possible linkage between prenatal exposure to PM₂.₅ (particulate matter with aerodynamic diameter ≤ 2.5 μm) and impacts on fetal development. We aimed to conduct a systematic review based on published cohort studies to summarize evidence regarding the association between maternal PM₂.₅ exposure and birth outcomes, including birth weight, low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Eligible studies meeting the following criterion were selected: PM₂.₅ exposure during pregnancy and live birth singletons, certain presentation of sample sizes, and quantitative evaluation of the associations between exposure and outcomes. Among the 42 selected studies, 23 evaluated the impact of prenatal PM₂.₅ exposure on birth weight of infants while 12 of them provided a significantly negative association for exposure and birth weight. Twenty-one studies aimed to identify the possible relationship between maternal exposure and LBW and 8 studies proved significant associations. Among 18 studies that explored the correlation between prenatal exposure and PTB, 9 reached a consistent conclusion that gestational exposure would add to the risk of PTB. Nine studies assessed the impact of PM₂.₅ on SGA and 5 of them demonstrated a significant effect. So far, linkages between maternal PM₂.₅ exposure during varied gestational stages and multiple adverse birth outcomes have been observed in many studies. A summary of them will be meaningful for further research on maternal exposure and adverse birth outcomes.

Knowledge regarding the concentration levels resulting from the use of agricultural pesticides may indicate the nature of the controls necessary to reduce environmental and human health risks to an acceptable level. Therefore, the main goal of the present work was to assess the spatial and temporal occurrence of 35 pesticides in the River Sado estuary (Portugal) in 2017 and evaluate its environmental condition, as data for estuarine ecosystems is scarce. Since pesticides are very susceptible to matrix effects promoted by environmental samples, to attain the main goal, we developed a fast and almost solvent-free environmentally friendly method with a good performance for both estuarine surface water and sediment samples. Quantified residues were determined mostly during summer, in line with the pesticide application period. Five herbicides (alachlor, bentazon, metobromuron, metribuzin and triclopyr) were measured in the water before and after the production season, suggesting a long-term aquatic exposure. Sediment samples were less contaminated, since a lower number of quantified pesticides were found in the study area, in lower frequencies and lower concentrations. No potential high adverse effects of the use of agricultural pesticides were expected on the aquatic organisms of the Sado estuary, even considering the potential combination effect of pesticide mixtures.

Lignite fly ash (FA) and waste rocks (WRs) were mixed in three different ratios (1:1, 1:3 and 1:5) and studied to compare the effects of adding FA on acid mine drainage generation from coal mining WRs, leachability of elements and the potential occurrence of the secondary minerals. FA mixed with WRs showed significant differences in pH levels compared to previous research. The 1:1 mixture performed best of all the three mixtures in terms of pH and leachability of elements, mainly due to the higher proportion of FA in the mixture. The pH in the 1:1 mixtures varied between 3.3 and 5.1 compared to other mixtures (2.3–3.5). Iron and SO₄²⁻ leached considerably less from the 1:1 mixture compared to the others, indicating that the oxidation of sulphides was weaker in this mixture. Aluminium leached to a high degree from all mixtures, with concentrations varying from mg L⁻¹ to g L⁻¹. The reason behind this increase is probably the addition of FA which, due to acidic conditions and the composition of the FA, increases the availability of Al. For the same reason, high concentrations of Mn and Zn were also measured. Geochemical modelling indicates that the 1:1 mixture performs better in terms of precipitation of Al³⁺ minerals, whereas Fe³⁺ minerals precipitated more in mixtures containing less FA. These results suggest that, with time, the pores could possibly be filled with these secondary minerals and sulphate salts (followed by a decrease in sulphide oxidation), improving the pore water pH and decreasing the leachability of elements. Since grain size plays a crucial role in the reactivity of sulphides, there is a risk that the results from the leaching tests may have been influenced by crushing and milling of the WR samples.

Bacterial communities of mangrove sediments are well appreciated for their role in nutrient cycling. However, spatiotemporal variability in these communities over large geographical scale remains understudied. We investigated sediment bacterial communities and their metabolic potential in an intertidal mangrove forest of India, Bhitarkanika, using high-throughput sequencing of 16S rRNA genes and community-level physiological profiling. Bulk surface sediments from five different locations representing riverine and bay sites were collected over three seasons. Seasonality largely explained the variation in the structural and metabolic patterns of the sediment bacterial communities. Freshwater Actinobacteria were more abundant in monsoon, whereas γ-Proteobacteria demonstrated higher abundance in summer. Distinct differences in the bacterial community composition were noted between riverine and bay sites. For example, salt-loving marine bacteria affiliated to Oceanospirillales were more prominent in the bay sites than the riverine sites. L-asparagine, N-acetyl-D-glucosamine, and D-mannitol were the preferentially utilized carbon sources by bacterial communities. Bacterial community composition was largely governed by salinity and organic carbon content of the sediments. Modeling analysis revealed that the abundance of δ-Proteobacteria increased with salinity, whereas β-Proteobacteria displayed an opposite trend. Metabolic mapping of taxonomic data predicted biogeochemical functions such as xylan and chitin degradation, ammonia oxidation, nitrite reduction, and sulfate reduction in the bacterial communities suggesting their role in carbon, nitrogen, and sulfur cycling in mangrove sediments. This study has provided valuable clues about spatiotemporal heterogeneity in the structural and metabolic patterns of bacterial communities and their environmental determinants in a tropical mangrove forest.

The photocatalytic oxidation of urea on TiO₂ in water was compared with that in urine. Despite the presence of other organic compounds in urine, the oxidation efficiency of urea on TiO₂ in urine was higher than that in water. This enhanced oxidation of urea in urine is ascribed to the higher production of •OH (primary oxidant for urea degradation) by the adsorption of PO₄³⁻ (one constituent of urine) on the TiO₂ surface. Among the various anions in urine, only PO₄³⁻ was adsorbed on the surface of TiO₂. Both the production of •OH and the oxidation of urea were enhanced in the presence of PO₄³⁻. These results indicate that the enhanced •OH production by in situ surface phosphorylation is the reason for the increased oxidation of urea in urine. Surface platinization of TiO₂ enhanced the oxidation of urea in water. However, the oxidation efficiency of urea on Pt/TiO₂ in urine was lower than that in water. This behavior is due to the adsorption of PO₄³⁻ and SO₄²⁻ in urine on Pt deposits, which inhibits the adsorption of oxygen and the interfacial electron transfer to oxygen. The product distribution (i.e., the molar ratio of NO₃⁻ to NH₄⁺) in water was different from that in urine because the negatively charged surface of TiO₂ in urine attracts the positively charged area of carbamic acid (intermediate) and encourages its decomposition into NH₄⁺ and not into NO₃⁻.

Cadmium (Cd) contaminated rice has become a global food security issue. Hyperspectral remote sensing can do rapid and nondestructive monitoring of environmental stress in plant. To realize the nondestructive detection of Cd in brown rice before harvest, the leaf spectral reflectance of rice exposed to six different levels of Cd stress was measured during the whole life stages. In addition, the dry weight of rice grain and Cd concentrations in brown rice were measured after harvest. The impact of Cd stress on the quantity and the quality of rice grain and on the leaf reflectance of rice was analyzed, and hyperspectral estimation models for predicting the Cd content in brown rice during three growth stages were established. The results showed that rice plants can impact the quality of the brown rice seriously, even if the impact on the quantity was not significant. All the established models had the capability to estimate Cd concentrations in brown rice (R² > 0.598), and the best performance model, with the R² value of 0.873, was use first derivative spectrum of booting stage as variable. It was concluded that the hyperspectral of rice leaves provides a new insight to predict Cd concentration in brown rice before harvest.

An uncertainty in the relationship between aerosol optical depth (AOD) and fine particulate matter (PM₂.₅) comes from the uncertainty of AOD by aerosol models and the estimated surface reflectance, a mismatch in spatiotemporal resolution, integration of AOD and PM₂.₅ data, and data modeling. In this study, an integrated geographically temporally weighted regression (GTWR) and RANdom SAmple Consensus (RANSAC) models, which provide fine goodness-of-fit between observed PM₂.₅ and AOD data, were used for mapping of PM₂.₅ over Taiwan for the year 2014. For this, dark target (DT) AOD observations at 3-km resolution (DT₃K) only for high-quality assurance flag (QA = 3) were obtained from the scientific data set (SDS) “Optical_Depth_Land_And_Ocean”. AOD observations were also obtained from the merged DT and DB (deep blue) product (DTB₃K) which was generated using the simplified merge scheme (SMS), i.e., using an average of the DT and DB highest quality AOD retrievals or the available one. The GTWR model integrated with RANSAC can use the effective sampling and fitting to overcome the estimation problem of AOD-PM₂.₅ with the uncertainty and outliers of observation data. Results showed that the model dealing with spatiotemporal heterogeneity and uncertainty is a powerful tool to infer patterns of PM₂.₅ from a RANSAC subset samples. Moreover, spatial variability and hotspot analysis were applied after PM₂.₅ mapping. The hotspot and spatial variability of PM₂.₅ maps can give us a summary of the spatiotemporal patterns of PM₂.₅ variations.

Given the prevalence of skin cancer, sunscreens are recommended by dermatologists including the American Academy of Dermatology to protect skin from harmful ultraviolet rays. Unfortunately, this leads to an estimated 14,000 tons of sunscreen entering waterways each year. Many of the chemicals in sunscreens, such as oxybenzone and benzophenone-2, are indicated to have adverse effects on corals and other aquatic life. As an eco-conscious alternative, physical barrier sunscreens, such as non-nano-titanium dioxide (TiO₂), have been suggested as a replacement. This study examines the impact of a non-nano-TiO₂-based sunscreen over a nationally sold brand of sunscreen containing oxybenzone, on clownfish (Amphiprion ocellaris). Animals were evaluated for mortality, swimming behavior, and feeding behavior. Our data indicate that at an exposure level of 100 mg/L oxybenzone-containing sunscreen had a negative impact on mortality, leading to 25% death by the end of the 97-h testing period. Negative impacts on behavior were even more dramatic for the 100 mg/L oxybenzone-containing sunscreen, with 100% of the animals failing to feed over the first 49 h of testing and 100% of animals demonstrating abnormal swimming behavior over the entire testing period. By comparison, the non-nano-(TiO₂) sunscreen at 100 mg/L had little (6.7%) negative impact on mortality and feeding. While swimming behavior was disrupted during the first 25 h of testing (26.7% abnormal movement), animals recovered well over the remainder of the testing period (out to 97 h).

Lethal control remains an important approach to mitigating the impacts of predators on livestock and threatened fauna. This occurs in Australia, where wild dogs (Canis familiaris) and European red foxes (Vulpes vulpes) are commonly subjected to broad-scale poisoning programs. Ongoing refinement of lethal tools has led to the recent development of manufactured poison baits containing para-aminopropiophenone (PAPP). Canid pest ejectors (CPEs) have also been recently registered for use and are a target-specific poison delivery device; yet, there has been no confirmation that PAPP delivered via ejectors will provide similar efficacy to PAPP delivered via manufactured baits. We tested the efficacy of PAPP in ejectors on wild dogs (1000-mg dose) and foxes (400-mg dose). Time-to-death, physical signs of poisoning and other related factors were assessed. Ten of 11 (91%) wild dogs used in controlled trials died within 3 h after PAPP administration; the mean time to unconsciousness was 65 min and the mean time to death was 84 min. Three of four (75%) foxes also died within 3 h after PAPP administration; their mean time to unconsciousness was 78 min, and their mean time to death was 121 min. Carcasses of eight deceased wild dogs and one fox were found during field trials, with distances between the nearest triggered ejector and the deceased animal ranging from 30 to 200 m. The presence of de-oxygenated blood in all necropsied carcasses and photographic evidence of triggered ejectors unequivocally demonstrated that using powdered PAPP in ejectors produces rapid anoxia and death in both wild dogs and foxes. Although anxiety and accompanying behaviours were observed in wild dogs (but not foxes), the use of PAPP offers a humane, additional option for the control of wild canids.