This study investigates changes in air quality conditions during the restricted COVID-19 lockdown period in 2020 across 21 metropolitan areas in the Middle East and how these relate to surface urban heat island (SUHI) characteristics. Based on satellite observations of atmospheric gases from Sentinel-5, results indicate significant reductions in the levels of atmospheric pollutants, particularly nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO). Air quality improved significantly during the middle phases of the lockdown (April and May), especially in small metropolitan cities like Amman, Beirut, and Jeddah, while it was less significant in “mega” cities like Cairo, Tehran, and Istanbul. For example, the concentrations of NO₂ in Amman, Beirut, and Jeddah decreased by −56.6%, −43.4%, and −32.3%, respectively, during April 2020, compared to April 2019. Rather, there was a small decrease in NO₂ levels in megacities like Tehran (−0.9%) and Cairo (−3.1%). Notably, during the lockdown period, there was a decrease in the mean intensity of nighttime SUHI, while the mean intensity of daytime SUHI experienced either an increase or a slight decrease across these locations. Together with the Gulf metropolitans (e.g. Kuwait, Dubai, and Muscat), the megacities (e.g. Tehran, Ankara, and Istanbul) exhibited anomalous increases in the intensity of daytime SUHI, which may exceed 2 °C. Statistical relationships were established to explore the association between changes in the mean intensity and the hotspot area in each metropolitan location during the lockdown. The findings indicate that the mean intensity of SUHI and the spatial extension of hotspot areas within each metropolitan had a statistically significant negative relationship, with Pearson's r values generally exceeding - 0.55, especially for daytime SUHI. This negative dependency was evident for both daytime and nighttime SUHI during all months of the lockdown. Our findings demonstrate that the decrease in primary pollutant levels during the lockdown contributed to the decrease in the intensity of nighttime SUHIs in the Middle East, especially in April and May. Changes in the characteristics of SUHIs during the lockdown period should be interpreted in the context of long-term climate change, rather than just the consequence of restrictive measures. This is simply because short-term air quality improvements were insufficient to generate meaningful changes in the region's urban climate.

The present study provides an environmental risk assessment of the pharmaceutical mixtures detected in Brazilian surface waters, based on Toxic Units and Risk Quotients. Furthermore, the applicability of a previously proposed prioritization methodology was evaluated. The pharmaceuticals were classified according to their properties (occurrence, persistence, bioaccumulation, and toxicity) and the contribution of the prioritized compounds to the mixture risk was determined. The mixture risk quotients, based on acute and chronic toxicity data, often exceed 1, demonstrating a potential risk for the environment. While algae were most affected by acute effects, fish were the most sensitive organism to sublethal effects. The lipid regulator atorvastatin was the main driver for the mixture risk. Despite their lower occurrence, the antibiotics norfloxacin and enrofloxacin were critical compounds for the algae group. The prioritized pharmaceuticals contributed to more than 75% of the mixture risk in most of cases, indicating the applicability of prioritization approaches for risk management.

Air pollution is an important risk factor for autoimmune diseases, but its association with the recurrence of rheumatoid arthritis (RA) remains unclear so far. This study aimed to investigate the short-term association between traffic-related air pollutants and hospital readmissions for RA in Hefei, China. Data on daily hospital readmissions for RA and traffic-related air pollutants, including particulate matter (PM₂.₅ and PM₁₀), nitrogen dioxide (NO₂), and carbon monoxide (CO), from 2014 to 2018 were retrieved. A time-series approach using generalized linear regression model was employed. The analysis was further stratified by sex, age and season. A total of 1153 readmissions for RA were reported during the study period. A significant association between high-concentration PM₂.₅ (90th percentile) and RA readmissions was observed on lag1 (relative risk (RR) = 1.09, 95% confidence interval (CI): 1.01–1.19) and lasted until lag3 (RR = 1.06, 95%CI: 1.01–1.12). From lag2 to lag5, high-concentration NO₂ (90th percentile) was associated with increased risk of RA readmissions, with the highest RR observed at lag 4 (1.11, 95%CI: 1.05–1.17). Stratified analyses indicated that females and the elderly appeared to be more vulnerable to high-concentration PM₂.₅ and NO₂ exposure. High-concentration PM₂.₅ and NO₂ in cold seasons were consistently significantly associated with increased risk of RA readmissions. Exposure to high-concentration PM₂.₅ and NO₂ was associated with increased risk of RA readmissions. Protective measures against the exposure to high-concentration PM₂.₅ and NO₂ should be taken to reduce the recurrence risk in RA patients, especially in females, the elderly and during cold seasons.

In this study, the occurrence of aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN) and some of their metabolites were assessed in breast milk and urine of lactating women (N = 74) from Pirassununga, São Paulo, Brazil. Exposure estimations through urinary mycotoxin biomarkers was also performed. Samples were collected in four sampling times (May and August 2018, February and July 2019) and analyzed by liquid chromatography coupled to tandem mass spectrometry. Aflatoxin M₁ (AFM₁) was not detected in breast milk. However, two samples (3%) presented FB₁ at 2200 and 3400 ng/L, while 4 samples (5%) had OTA at the median level of 360 ng/L. In urine, AFM₁ and aflatoxin P₁ (AFP₁) were found in 51 and 11% of samples, respectively (median levels: 0.16 and 0.07 ng/mg creatinine, respectively). Urinary DON (median level: 38.59 ng/mg creatinine), OTA (median level: 2.38 ng/mg creatinine) and ZEN (median level: 0.02 ng/mg of creatinine) were quantified in 18, 8 and 10% of the samples, respectively. Mean probable daily intake (PDI) values based on urinary biomarkers were 1.58, 1.09, 5.07, and 0.05 μg/kg body weight/day for AFM₁, DON, OTA, and ZEN, respectively. Although a low mycotoxin occurrence was detected in breast milk, the PDI for the genotoxic AFs was much higher than those reported previously in Brazil, while PDI values obtained for OTA and DON were higher than recommended tolerable daily intakes. These outcomes warrant concern on the exposure of lactating women to these mycotoxins in the studied area.

Prorocentrum lima is a dinoflagellate that forms hazardous blooms and produces okadaic acid (OA), leading to adverse environmental consequences associated with the declines of zooplankton populations. However, little is known about the toxic effects and molecular mechanisms of P. lima or OA on zooplankton. Here, their toxic effects were investigated using the brine shrimp Artemia salina. Acute exposure of A. salina to P. lima resulted in lethality at concentrations 100-fold lower than densities observed during blooms. The first comprehensive results from global transcriptomic and metabolomic analyses in A. salina showed up-regulated mRNA expression of antioxidant enzymes and reduced non-enzyme antioxidants, indicating general detoxification responses to oxidative stress after exposure to P. lima. The significantly up-regulated mRNA expression of proteasome, spliceosome, and ribosome, as well as the increased fatty acid oxidation and oxidative phosphorylation suggested the proteolysis of damaged proteins and induction of energy expenditure. Exposure to OA increased catabolism of chitin, which may further disrupt the molting and reproduction activities of A. salina. Our data shed new insights on the molecular responses and toxicity mechanisms of A. salina to P. lima or OA. The simple zooplankton model integrated with omic methods provides a sensitive assessment approach for studying hazardous algae.

Rare earth elements (REEs) are generally defined as a homogenous group of elements with similar physical-chemical properties, encompassing Y and Sc and the lanthanides elements series. Natural REEs contents in soils depend on the parent material, the soil genesis processes and can be gradually added to the soil by anthropogenic activities. The REEs have been considered emerging pollutants in several countries, so the establishment of regulatory guidelines is necessary to avoid environmental contamination. In Brazil, REE soils data are restricted to some regions, and knowledge about them in the Amazon soils is scarce, although this biome covers more than 40% of the Brazilian territory. Thus, the objectives of this study were to determine the REE content in soils of two hydrographic basins (Solimões and Rio Negro) of the Amazon biome, establish their Quality Reference Values (QRV) and to investigate the existence of enrichment of REEs in urban soils. The ΣREE(Y + Sc) content of Solimões surface samples was 109.28 mg kg⁻¹ and the ΣREE(Y + Sc) content in the subsurface samples was 94.11 mg kg⁻¹. In soils of Rio Negro basin, the ΣREE(Y + Sc) was 43.95 15 mg kg⁻¹ surface samples and 38.40 mg kg⁻¹ in subsurface samples. The ΣREE(Y + Sc) in urban topsoils samples was 38.62 mg kg⁻¹. The REEs contents pattern in three studied areas are influenced in different amplitude by natural soil properties. The REEs content in urban topsoils were slightly higher than the Rio Negro pristine soils, but the ecological risk was low. QRVs recommend for Solimões soils ranged from 0.01 (Lu) to 145.6 mg kg⁻¹ (Ce) and for Rio Negro soils ranged from 0.05 (Lu) to 15.8 mg kg⁻¹ (Ce).

Knowledge of the toxic potential of polycyclic aromatic hydrocarbons (PAHs) has increased over time. Much of this knowledge is about the 16 United States - Environmental Protection Agency (US - EPA) priority PAHs; however, there are other US – EPA non-priority PAHs in the environment, whose toxic potential is underestimated. We conducted a systematic review of in vitro, in vivo, and in silico studies to assess the genotoxicity, mutagenicity, and carcinogenicity of 13 US - EPA non-priority parental PAHs present in the environment. Electronic databases, such as Science Direct, PubMed, Scopus, Google Scholar, and Web of Science, were used to search for research with selected terms without time restrictions. After analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, 249 articles, published between 1946 and 2020, were selected and the quality assessment of these studies was performed. The results showed that 5-methylchrysene (5-MC), 7,12-dimethylbenz[a]anthracene (7,12-DMBA), cyclopenta[cd]pyrene (CPP), and dibenzo[al]pyrene (Db[al]P) were the most studied PAHs. Moreover, 5-MC, 7,12-DMBA, benz[j]aceanthrylene (B[j]A), CPP, anthanthrene (ANT), dibenzo[ae]pyrene (Db[ae]P), and Db[al]P have been reported to cause mutagenic effects and have been being associated with a risk of carcinogenicity. Retene (RET) and benzo[c]fluorene (B[c]F), the least studied compounds, showed evidence of a strong influence on the mutagenicity and carcinogenicity endpoints. Overall, this systematic review provided evidence of the genotoxic, mutagenic, and carcinogenic endpoints of US - EPA non-priority PAHs. However, further studies are needed to improve the future protocols of environmental analysis and risk assessment in severely exposed populations.

Soil erosion contributes greatly to nonpoint source pollution (NSP). We built a coastal NSP risk calculation method (CNSPRI) based on the Revised Universal Soil Loss Equation (RUSLE) and geospatial methods. In studies on the formation and transport of coastal NSP, we analysed the pollution impacts on the sea by dividing subbasins into the sea and monitoring the pollutant flux. In this paper, a case study in the Yellow River Delta showed that the CNSPRI could better predict the total nitrogen (TN) and total phosphorus (TP) NSP risks. The value of the soil erodibility factor (K) was 0.0377 t h·MJ⁻¹·mm⁻¹, indicating higher soil erodibility levels, and presented an increased trend from the west to the east coast. The NSP risk also showed an increased trend from west to east, and the worst status was found near the Guangli River of the south-eastern region. The contributions of the seven influencing factors to CNSPRI presented an order of vegetation cover > rainfall erosivity > soil content > soil erodibility > flow > flow path > slope. The different roles of source and sink landscapes influenced the pollutant outputs on a subbasin scale. Arable land and saline-alkali land were the two land-use types with the greatest NSP risks. Therefore, in coastal zones, to reduce NSP output risks, we should pay more attention to the spatial distribution of vegetation cover, increase its interception effect on soil loss, and prioritize the improvement of saline-alkali land to reduce the amount of bare land.

Fomesafen (FSA) is widely used in soybean fields for weed control. However, the persisting characteristics of FSA in the agricultural soil or water may become a hidden danger causing environmental pollution and phytotoxicity to succession crops. In this study, the growth and physiological responses of rice to FSA were investigated. It was found that the growth of rice seedlings was obviously inhibited by FSA exposure especially at over 0.1 mg L⁻¹. To gain an insight into the molecular mechanisms for the potential ecotoxicology, four libraries of rice roots and shoots exposed to FSA were created and subjected to the global RNA-sequencing (RNA-Seq) combined with HRLC-Q-TOF-MS/MS analytical technologies to comprehensively characterize the biochemical processes and catalytic reactions involved in FSA metabolism in rice. Compared with those without FSA, 499 and 450 up-regulated genes in roots and shoots with FSA were detected. Many of them were closely correlated with the tolerance to environmental stress, detoxification of xenobiotics and molecular metabolism process including cytochrome P450, glutathione S-transferases and acetyltransferase. A total of eight metabolites and fourteen conjugates in the reactive pathways of hydrolysis, substitution, reduction, methylation, glycosylation, acetylation, and malonylation were characterized by HRLC-Q-TOF-MS/MS. The relationship between the metabolized derivatives of FSA and enhanced expression the corresponding enzymatic regulators was established. This study will help understand the mechanisms and pathways of FSA metabolism and inspire the further research on FSA degradation in the paddy crops and environmental or health risks.