Xenobiotic cannabinoids (phyto and synthetic) are highly lipophilic compounds and have been shown to accumulate within the particulate fraction of wastewater. Limited research has been conducted to investigate the occurrence of cannabinoids in sewage sludge and/or biosolids. The analysis of excreted cannabinoids from sewage sludge or biosolids can provide information about community health, as well as potentially long-term environmental impacts. In this study, a liquid-liquid extraction method was developed for the extraction and detection method for 50 cannabinoids by liquid chromatography-mass spectrometry, including the cannabis urinary biomarker 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH), Δ⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), and a variety of different generation synthetic cannabinoids and their respective metabolites. Method validation assessed criteria including linearity, selectivity, recovery, and matrix effects. The method was applied to samples collected from a conventional activated sludge reactor treatment facility from various stages of the treatment process. Three cannabinoids were abundant in primary sludge including THC, THC-COOH, and CBD, where THC was the most ubiquitous with concentrations up to 3200 μg kg⁻¹. Only THC and THC-COOH were detectable in aged biosolids. The detection of some cannabinoids in biosolids demonstrated that these compounds are stable throughout the treatment process.

Polycyclic aromatic hydrocarbons (PAHs) are petroleum components that, when dissolved in the aquatic environment, can disrupt normal animal physiological functions and negatively affect species populations. Gambusia yucatana is an endemic fish of the Yucatán Peninsula that seems to be particularly sensitive to the presence of PAHs dissolved in the water. Here, we examined PAH effects on gene expressions linked to endocrine disruption and biotransformation in this species. Specifically, we examined the expression of vitellogenin I (vtg1), vitellogenin II (vtg2), oestrogen receptor α (esr1), oestrogen receptor β (esr2), aryl hydrocarbon receptor (AhR) and the cytochrome P4503A (CYP3A) genes. We exposed G. yucatana to different concentrations of PAHs (3.89, 9.27, 19.51 μg/L) over a period of 72 h and found changes associated with reproduction, such as increases in hepatic expression of vtg, esr, AhR and CYP3A, mainly at concentrations of 9.27 and 19.51 μg/L. Our results also indicate that benzo[a]pyrene was probably the main PAH responsible for the observed effects. The genes examined here can be used as molecular markers of endocrine-disrupting compounds, as the PAHs, present in the environment, as gene expression increases could be observed as early as after 24 h. These biomarkers can help researchers and conservationists rapidly identify the impacts of oil spills and improve mitigation before the detrimental effects of environmental stressors become irreversible.

World’s food production relies on crops grown in irrigated land to feed an increasing population. In the long term, irrigation agriculture may cause environmental deterioration to the area (soil degradation, aquifer contamination) and its surroundings (greenhouse gas emission, eutrophication) to compromise crop production. Three irrigated areas in northern Mexico (Yaqui Valley, Delicias, Comarca Lagunera) were examined with respect to the challenges to achieve sustainability using reported values of nitrogen (N) along with the conventional aquifer depletion and water contamination parameters. N₂O emissions, measured in only the Yaqui Valley, amounted to up to 4.5% of applied N, and nitrate losses to about 18%. The water tables of these aquifers are dropping at rates of 0.4 m year⁻¹ (Delicias) to 1.5 m year⁻¹ (Comarca Lagunera). High NO₃⁻ concentrations in the Comarca Lagunera (66.2% of wells above 10 mg L⁻¹ NO₃–N) pose a threat to human health. Although lower than 10 mg L⁻¹ NO₃–N in most wells, NO₃⁻ levels in Delicias and Yaqui Valley are increasing with time, although more data are needed to confirm the trend. Overall, and although the efforts by farmers still focus on increasing crop yield, awareness of the advantage of implementing measures towards sustainability is on the rise.

The Itapemirim River is considered one of the most important water resources in the state of Espírito Santo, Brazil. However, environmental problems due to continuous anthropogenic contamination are threatening its potential use. This study assessed water quality by analyzing abiotic and toxicogenetic aspects of the water from four stations along the river. Samples were collected in both dry and rainy seasons. Most of the abiotic variables were below the threshold established by CONAMA Resolution No. 357/2005, and so were most of the metals. However, Al and Cu contents were above those allowed by legislation, ranging from 0.2 to 0.9 mg/L. Regarding toxicogenetic aspects, genotoxic effects were observed in meristematic cells of Allium cepa, in micronucleus test and comet assay of Oreochromis niloticus, and CHO-K1 cells. Mutagenic effects were significant at RI 02 (0.34), RI 03 (0.46), and RI 04 (0.12) stations on the first campaign in A. cepa F1 cells, compared to the negative control (0.0). The second campaign revealed the same results, but with the addition of samples from RI 01 (0.17) and RI 03 (0.18) showing mutagenicity in the micronucleus test with fish erythrocytes when compared to the negative control (0.3). Essentially, all the samples evaluated in both campaigns showed damage in A. cepa, O. niloticus, and CHO-K1 cells, thus demonstrating that the water quality of the Itapemirim River is compromised and requires action plans for its recovery.

The adverse effects of parabens raise concerns about their extensive use as preservatives in consumer products, especially in cosmetics. Until now, their distribution and excretion in humans have attracted little attention. Here, we quantified various agents including, for the first time, methyl-; ethyl-; n-propyl-; n-butyl-, and i-butylparaben (MeP, EtP, PrP, n-BuP, i-BuP); methyl- and ethyl-protocatechuate (OH-MeP and OH-EtP); hydroxybenzoic acid (4-HB); and 3,4-dihydroxybenzoic acid (3,4-DHB) in urine, serum, and seminal plasma samples from 50 healthy Chinese men in Beijing, China. Urine paraben concentrations were 1–2 orders of magnitudes higher than those in serum and seminal plasma. MeP and PrP were predominant and correlated with each other in the urine, serum, and seminal plasma. In urine, we observed a significant correlation between MeP and OH-MeP; EtP and OH-EtP; and 4-HB and 3,4-DHB concentrations. All these results provide new information on parabens as biomarkers for the assessment of exposure.

Various types of industries discharge their untreated contaminated water into the environment every year. This untreated water contains the pollutants that can negatively affect the environment and biosphere. Many methods are under practice at the moment to treat this wastewater. Among the variety of methods proposed and employed currently is the electrocoagulation (EC) method. This technique involves destabilizing the pollutants of the wastewater through the electric current flowing between the electrodes. The electrodes are mainly made of iron or aluminum. Over the past years, this technique has shown a great potential towards removal of different pollutant types from variety of wastewater. Like many other processes, the EC method is also governed and affected by various parameters such as pH, operation time, types of electrodes, and current density. It is important to keep these parameters under check and at the optimum desired value for the maximum pollutant removal. The optimum value depends upon the wastewater and the composition of the contaminants to be segregated. The present study reviews and compares the efficiency of EC with other methods in use so far. Compared to other methods, EC is shown to be energy efficient and reducing operation costs. The study also presents the challenges faced by this technique, such as electrode passivation, and the possible ways to deal with them in order to improve the overall performance effectiveness.

Betaine aldehyde dehydrogenase (BADH) transgenic maize has a capability to grow under drought and salt stress; the risk of planting BADH transgenic maize on symbiotic microorganisms remains problematic, however. A pot experiment was carried out to assess the impact of BADH transgenic maize BZ-136 on arbuscular mycorrhizal fungi (AMF) colonization in root and community structure in rhizosphere soil compared with that of parental maize Zheng58 in neutral and saline-alkaline soil. Microscope observation found that BZ-136 only had a significantly reduced effect on AMF colonization at the elongation stage (9–14%). High-throughput sequencing analysis revealed that the AMF taxonomic composition kept consistency at the genus level between transgenic BZ-136 and non-transgenic parental Zheng58. NMDS analysis verified the slight difference in community structure between BZ-136 and Zheng58 presented an agrotype-dependent pattern. AMF community indices showed that BZ-136 had a higher richness at the flowering stage in saline-alkaline soil and had a higher diversity at the mature stage in neutral soil. Heatmap analysis also illuminated AMF community structure of transgenic maize at species level was similar to that of non-transgenic maize. In summary, cropping transgenic BADH maize has minor or transient effects on AMF colonization and rhizospheric soil AMF community structure, while agrotype has a stronger effect on AMF community structure.

One of humanity’s most significant problems in the twenty-first century revolves around how to balance the mitigation of environmental pollution while achieving sustainable economic development. Despite increased awareness and dedication to climate change, the planet is still seeing a drastic decrease in the volume of pollutant emissions. This study explores the long-run and causal impact of economic growth, financial development, urbanization, and gross capital formation on Malaysia’s CO₂ emissions based on the STIRPAT framework. The current paper employs recently developed econometric techniques such as Maki co-integration, auto-regressive distribution lag (ARDL), fully modified OLS (FMOLS), dynamic ordinary least square (DOLS), and wavelet coherence and gradual shift causality tests to investigate these interconnections. The advantage of the gradual shift causality test is that it can capture the causality in the presence of a structural break(s). The findings from the Maki co-integration and ARDL bounds tests reveal evidence of cointegration among the variables. The ARDL test reveals that economic growth, gross capital formation, and urbanization exert a positive impact on CO₂ emissions. Furthermore, the wavelet coherence test reveals that there is a significant dependency between CO₂ emissions and economic growth, gross capital formation, and urbanization. The Toda Yamamoto and Gradual shift causality tests reveal that there is a (a) unidirectional causality from urbanization to CO₂ emissions, (b) unidirectional causality from economic growth to CO₂ emissions, and (c) unidirectional causality from gross capital formation to CO₂ emissions.

Reed is a common species in China’s estuarine wetlands, contains high carbon and low nitrogen, and its litters have potential to be reused as external carbon source to achieve denitrification efficiency enhancement in estuarine wetlands. In this study, leaching experiments of reed leaf and stem under estuarine wetland salinity were conducted, and a certain amount of reed litters was then added into simulated estuarine wetlands under 0‰ and 7‰ salinity respectively. It was observed that reed litters had a higher release of total organic carbon (TOC) under 7‰ salinity than 0‰ salinity, and reed leaf litters released more TOC than stem litters did. Meantime, it was found that salinity had a more significant effect on TOC leached from stems than from leaves. In simulated estuarine wetlands, NO₃⁻-N removal rates were found to be improved about 20% under 7‰ salinity and 25% under 0‰ salinity in average after the addition of mixed litters, and almost no additional improvement in NO₃⁻-N removal was found after leaf-only litter addition compared with mixed litter addition. Besides, mixed litter addition could work two weeks longer than leaf-only litter addition. Moreover, the microbial community change was analyzed by high-throughput sequencing and found that litter addition could increase the denitrification-related genera and then increased the NO₃⁻-N removal efficiency. For simulated estuarine wetland, reed litter addition could achieve better nitrogen removal efficiency.

Investment in capitals is sacrosanct to launch a country to a greater path of sustainable development. Notwithstanding, its deleterious impacts on environment are equally incontestable. In light of this stark reality, this paper examines the threshold effects of capital investments on carbon emissions in G20 economies over the period, 1992–2014, for which data are available. The study uses both exogenously determined and endogenously determined thresholds to uncover the relationship. While the former relies on median approach to determining the threshold on the one hand, the latter uses both the fixed effects panel threshold model proposed by (Hansen J Econ 93:345–368, 1999) and the bootstrap method by (Hansen Econometrica 68:575–603, 2000) to assess the statistical relevance of the threshold effects on the other hand. The results of the exogenously determined thresholds show higher statistical significant environmental impacts of capital investments at a median threshold of above 3.068 than when it is lesser. The findings of the latter approach indicate the relationship between capital investments and carbon emissions to be non-linear for the G20 countries. More specifically, this study establishes a single-threshold level of capital investment on carbon emissions for the group of countries. The threshold estimator of 3.434 is established at the 95% confidence interval. Beyond this point, the environmental impacts of capital investments are imaginable. On the policy front, keeping to the limit set by threshold effects would go a long way to stemming environmental pollution and mitigating climatic change impacts.