Nanoparticles (NPs) are causing threats to the environment. In this review, we examined how hematite (Fe2O3) and cobalt oxide (Co2O3) nanoparticles impact the species of freshwater green algae Chlorella vulgaris (C. vulgaris). We exposed laboratory cultures to five initial concentrations of nanoparticles and measured impacts on species in 24, 48, 72, 96, 120, and 144 hours in Karun River water at 20-25°C. Our results indicated that Fe2O3 and Co2O3 NPs significantly (dependent on concentration) reduced the chlorophyll a, b, and carotenoid contents of algae C. vulgaris compared to the control group (P <0.05). Also, due to the combination of these two nanoparticles, Co2O3 (50 Fe2O3 +100 Co2O3) has a more negative effect on algae chlorophyll change. According to the data, the exposure concentration was also found to be a more effective factor in the Chlorophyll content in algae species as compared to the exposure time. Our study suggests this nanoparticle has potential to affect aquatic life and ecosystem properties of freshwater habitats.

1, 3-Butadiene (BD) is primarily used for the production of synthetic rubbers and polymers, which are found in many industrial and consumer products. BD is suspected to be both carcinogenic and genotoxic to humans. This study aims to compare occupational exposure limits (OELs) based on BDâs carcinogenic effects using threshold and non-threshold methods in industrial settings. A review of published literature was carried out to find the most suitable in vivo carcinogenic data. Selection criteria included the number of dose levels considering more than three dose level and chronic exposure through the lung route. Studies of the National Toxicology Program (NTP) and Melnick et al. met the criteria for this study. The U.S. Environmental Protection Agency (EPA)âs BMD software, version 3.2.0, was utilized to estimate BMDL10. In the threshold approach, OELs were calculated using BMDL10 divided by uncertainty factors. The margin of exposure (MOE) method was used as a non-threshold approach. In the threshold approach, an OELI of 2.3 ppm and 3.8 ppm was estimated in males and females, respectively. In the non-threshold approach, the OELII of 0.008 ppm and 0.014 ppm was calculated for males and females, respectively, which were substantially lower than those found using the threshold method. Examining and comparing the results of this study to the threshold limit values (TLVs) and carcinogenic risk values determined by the EPA revealed that the threshold values are closer to the safe workplace concentrations (concentrations where no carcinogenic effects have been detected). Consequently, the use of non-threshold approaches results in an inaccurate estimation of carcinogenic risk.

Cadmium (Cd) and lead (Pb) are known to enhance immune cell damages and to decrease cellular immunity, promoting higher susceptibility to infectious diseases. Selenium (Se) is an essential element involved in immunity and reactive oxygen species scavenging. This study aimed at evaluating how Cd and Pb and low nutritional (Se) quality modulate immune response to a bacterial lipopolysaccharide (LPS) challenge in wood mice (Apodemus sylvaticus). Mice were trapped near a former smelter in northern France in sites of High or Low contamination. Individuals were challenged immediately after capture or after five days of captivity, fed a standard or a Se-deficient diet. Immune response was measured with leukocyte count and plasma concentration of TNF-α, a pro-inflammatory cytokine. Faecal and plasma corticosterone (CORT), a stress-hormone involved in anti-inflammatory processes, was measured to assess potential endocrine mechanisms. Higher hepatic Se and lower faecal CORT were measured in free-ranging wood mice from High site. LPS-challenged individuals from High site showed steeper decrease of circulating leukocytes of all types, higher TNF-α concentrations, and a significant increase of CORT, compared to individuals from Low site. Challenged captive animals fed standard food exhibited similar patterns (decrease of leukocytes, increase of CORT, and detectable levels of TNF-α), with individuals from lowly contaminated site having higher immune responses than their counterparts from highly polluted site. Animals fed Se-deficient food exhibited lymphocytes decrease, no CORT variation, and average levels of TNF-α. These results suggest (i) a higher inflammatory response to immune challenge in free-ranging animals highly exposed to Cd and Pb, (ii) a faster recovery of inflammatory response in animals lowly exposed to pollution when fed standard food than more exposed individuals, and (iii) a functional role of Se in the inflammatory response. The role of Se and mechanisms underlying the relationship between glucocorticoid and cytokine remain to be elucidated.

The interaction of aerosols and the planetary boundary layer (PBL) plays an important role in deteriorating urban air quality. Aerosols from different sources may have different effects on regulating PBL structures owing to their distinctive dominant compositions and vertical distributions. To characterize the complex feedback of aerosols on PBL over the Beijing megacity, multiple approaches, including in situ observations in the autumn and winter of 2016–2019, backward trajectory clusters, and large-eddy simulations, were adopted. The results revealed notable distinctions in aerosol properties, vertical distributions and thermal stratifications among three types of air masses from the West Siberian Plain (Type-1), Central Siberian Plateau (Type-2) and Mongolian Plateau (Type-3). Low loadings of 0.28 ± 0.26 and 0.15 ± 0.08 of aerosol optical depth (AOD) appeared in the Type-1 and Type-2, accompanied by cool and less stable stratification, with a large part (80%) of aerosols concentrated below 1500 m. For Type-3, the AOD and single scattering albedo (SSA) were as high as 0.75 ± 0.54 and 0.91 ± 0.05, demonstrating severe pollution levels of abundant scattering aerosols. Eighty percent of the aerosols were constrained within a lower height of 1150 m owing to the warmer and more stable environment. Large-eddy simulations revealed that aerosols consistently suppressed the daytime convective boundary layer regardless of their origins, with the PBL height (PBLH) decreasing from 1120 m (Type-1), 1160 m (Type-2) and 820 m (Type-3) in the ideal clean scenarios to 980 m, 1100 m and 600 m, respectively, under polluted conditions. Therefore, the promotion of absorbing aerosols below the residual layer on PBL could be greatly hindered by the suppression effects generated by both absorbing aerosols in the upper temperature inversion layer and scattering aerosols. Moreover, the results indicated the possible complexities of aerosol-PBL interactions under future emission-reduction scenarios and in other urban regions.

Because of the high production rates, low recycling rates, and poor waste management of plastics, an increasing amount of plastic is entering the aquatic environment, where it can provide new ecological niches for microbial communities and form a so-called plastisphere. Recent studies have focused on the one-way impact of plastic substrata or biofilm communities. However, our understanding of the two-way interactions between plastics and biofilms is still limited. This review first summarizes the formation process and the co-occurrence network analysis of the aquatic plastisphere to comprehensively illustrate the succession pattern of biofilm communities and the potential consistency between keystone taxa and specific environmental behavior of the plastisphere. Furthermore, this review sheds light on mutual interactions between plastics and biofilms. Plastic properties, environmental conditions, and colonization time affect biofilm development. Meanwhile, the biofilm communities, in turn, influence the environmental behaviors of plastics, including transport, contaminant accumulation, and especially the fragmentation and degradation of plastics. Based on a systematic literature review and cross-referencing from these disciplines, the current research focus, and future challenges in exploring aquatic plastisphere development and biofilm-plastic interactions are proposed.

Some weather events like drought, increased precipitation, and warming exert substantial impact on the terrestrial C and N cycling. However, it remains largely unclear about the effect of extreme weather events (extreme drought, heavy rainfall, extreme heat, and extreme cold) on terrestrial C and N cycling. This study aims to analyze the responses of pools and fluxes of C and N in plants, soil, and microbes to extreme weather events by conducting a global meta-analysis of 656 pairwise observations. Results showed that extreme weather events (extreme drought, heavy rainfall, and extreme heat) decreased plant biomass and C flux, and extreme drought and heavy rainfall decreased the plant N pool and soil N flux. These results suggest that extreme weather events weaken the C and N cycling process in terrestrial ecosystems. However, this study did not determine the impact of extreme cold on ecosystem C and N cycling. Additional field experiments are needed to reveal the effects of extreme cold on global C and N cycling patterns.

Although microplastics (MPs) are ubiquitous in agricultural soil, little is known about the effects of MPs combined with pesticides on soil organisms and their biogenic transport through the soil profile. In this study, we conducted mesocosm experiments to observe the effects of microplastics (polyethylene (LDPE-MPs) and biodegradable microplastics (Bio-MPs)) and chlorpyrifos (CPF) on earthworm (Lumbricus terrestris) mortality, growth and reproduction, as well as the biogenic transport of these contaminants through earthworm burrows. The results showed that earthworm reproduction was not affected by any treatment, but earthworm weight was reduced by 17.6% and the mortality increased by 62.5% in treatments with 28% Bio-MPs. Treatments with 28% LDPE-MPs and 7% Bio-MPs combined with CPF showed greater toxicity while the treatment with 28% Bio-MPs combined with CPF showed less toxicity on earthworm growth as compared to treatments with only MPs. The treatments with 1250 g ha−1 CPF and 28% Bio-MPs significantly decreased the bioaccumulation of CPF in earthworm bodies (1.1 ± 0.2%, w w−1), compared to the treatment with CPF alone (1.7 ± 0.4%). With CPF addition, more LDPE-MPs (8%) were transported into earthworm burrows and the distribution rate of LDPE-MPs in deeper soil was increased. No effect was observed on the transport of Bio-MPs. More CPF was transported into soil in the treatments with LDPE-MPs and Bio-MPs, 5% and 10% of added CPF, respectively. In addition, a lower level of the CPF metabolite 3,5,6-trichloropyridinol was detected in soil samples from the treatments with MPs additions than without MP additions, indicating that the presence of MPs inhibited CPF degradation. In conclusion, Bio-MPs caused significant toxicity effects on earthworms and the different types of MPs combined with CPF affected earthworms differently, and their transport along the soil profile. Thus, further research is urgently needed to understand the environmental risks of MPs and MP-associated compounds in the soil ecosystem.

Climate impacts of elevated temperatures and more severe and frequent weather extremes like heatwaves are globally becoming discernible on nature. While a mechanistic understanding is pivotal for ecosystem management, stressors like pesticides may interact with warming, leading to unpredictable effects on freshwater ecosystems. These multiple stressor studies are scarce and experimental designs often lack environmental realism. To investigate the multiple stressor effects, we conducted a microcosm experiment for 48 days comprising benthic macroinvertebrates, zooplankton, phytoplankton, macrophytes, and microbes. The fungicide carbendazim (100 μg/L) was investigated combined with temperature scenarios representing elevated temperatures (+4 °C) or heatwaves (+0 to +8 °C), both applied with similar energy input on a daily fluctuating ambient temperature (18 °C ± 1.5 °C), which served as control. Measurements showed the highest carbendazim dissipation in water under heatwaves followed by elevated and ambient temperatures. Average carbendazim concentrations were about 50% in water and 16% in sediment of the nominal concentration. In both heated cosms, zooplankton community dynamics revealed an unexpected shift from Rotifera to Cladocera and Copepoda nauplii, indicating variations in their thermal sensitivity, tolerance and resilience. Notably, warming and heatwaves shaped community responses similarly, suggesting heat intensity rather than distribution patterns determined the community structure. Heatwaves led to significant early and longer-lasting adverse effects that were exacerbated over time with Cladocera and Copepoda being most sensitive likely due to significant carbendazim interactions. Finally, a structural equation model demonstrated significant relationships between zooplankton and macrophytes and significantly negative carbendazim effects on zooplankton, whereas positive on macroinvertebrate abundances. The relationship between macroinvertebrate feeding and abundance was masked by significantly temperature-affected microbial leaf litter decomposition. Despite the thermal tolerance of zooplankton communities, our study highlights an increased pesticide threat under temperature extremes. More intense heatwaves are thus likely to cause significant alterations in community assemblages which will adversely affect ecosystem's processes and functions.

The Zayandeh-Rood River (Isfahan Province, Iran) is of vital importance as a water source for various purposes, but it is facing adverse effects from human activities. This study focused on the surface sediment of 21 stations along the river to assess the concentration of potentially toxic elements (PTEs) and their environmental risk using the Geoaccumulation Index (Igeo), Enrichment Factor (EF), Pollution Load Index (PLI), and Potential Ecological Risk Index (RI). The mean concentration of the PTEs (mg/kg) was ranked as follows: Cd (0.34)< As (9.73)< Pb (10.95)< Co (11.91)< Cu (31.14)< Ni (31.90)< Zn (61.33)< Cr (96.95)< V (125.09)< Mn (707.76). Positive correlation coefficients were found among all the PTEs, while their relationships with the sediment physicochemical characteristics varied considerably, indicating that various interacting factors might influence the deposition and mobility of PTEs in the river. The river was classified as having moderate to low contamination (Igeo index) and minimal-to-moderate enrichment (EF index) except for Cd and As which exhibited extremely high enrichment and strong pollution in the upstream zone, where agricultural activities dominate. Therefore, managing agricultural practices and reducing the excessive use of PTE-containing pesticides and insecticides should be a primary focus to protect the Zayandeh-Rood River from further contamination.

The purpose of this study was to evaluate the environmental and health risk of PM2.5 microns in district 10 of Tehran. Initially, data related to the year 2019 were collected and analyzed through pollutant measurement at the regional level. Based on Kriging's interpolation the corresponding raster was produced and classified according to the minimum and maximum range. Finally, according to the air quality index, the level of importance of health safety was classified and the relevant map was prepared. Through the IO technique, the location layer of sensitive and vulnerable land uses and the carbon monoxide contaminant zoning layer were mapped. Results showed that District 10 of Tehran with the average concentration of 42µg/m3 is the most polluted area in terms of this contaminant in Tehran. Also, most of the PM2.5 pollutants belong to the northern, southern and western half of the region. Also, December was the most polluted month of the year with an average concentration of 56μg/m3. From the point of view of the air quality index based on the type of pollutants, the area had 104 days of unhealthy and unhealthy days for sensitive groups. Environmental and health risk assessment of these pollutants indicates that according to William Fine method, the risk number is 105, which indicates the average risk level. Therefore, it requires corrective and emergency risk control measures.