Soil's Hidden Power: The Stable Soil Organic Carbon Pool Controls the Burden of Persistent Organic Pollutants in Background Soils.

Persistent organic pollutants (POPs) tend to accumulate in cold regions by cold condensation and global distillation. Soil organic matter is the main storage compartment for POPs in terrestrial ecosystems due to deposition and repeated air-surface exchange processes. Here, physicochemical properties and environmental factors were investigated for their role in influencing POPs accumulation in soils of the Tibetan Plateau and Antarctic and Arctic regions. The results showed that the soil burden of most POPs was closely coupled to stable mineral-associated organic carbon (MAOC). Combining the proportion of MAOC and physicochemical properties can explain much of the soil distribution characteristics of the POPs. The background levels of POPs were estimated in conjunction with the global soil database. It led to the proposition that the stable soil carbon pools are key controlling factors affecting the ultimate global distribution of POPs, so that the dynamic cycling of soil carbon acts to counteract the cold-trapping effects. In the future, soil carbon pool composition should be fully considered in a multimedia environmental model of POPs, and the risk of secondary release of POPs in soils under conditions such as climate change can be further assessed with soil organic carbon models.

Informal E -waste recycling in nine cities of Pakistan reveals significant impacts on local air and soil quality and associated health risks.

The global increase in electronic waste (e-waste) has led to a rise in informal recycling, emitting hazardous heavy metals (HMs) that threaten human health and ecosystems. This study presents the first comprehensive assessment of HM levels in dry deposition and soils at proximity of forty (40) informal e-waste recycling sites across Pakistan, between September 2020 to December 2021. Findings reveal that Zn (1410), Pb (410) and Mn (231) exhibited the higher mean deposition fluxes (µg/m2.day), derived from air samples, particularly in Karachi. Similarly, soils showed higher mean concentrations (µg/g dw) of Mn (477), Cu (514) and Pb (172) in Faisalabad, Lahore, and Karachi, respectively. HMs concentrations were found higher in winter or autumn and lower in summer. In addition, HM levels were significantly (p = 0.05) higher at recycling sites compared to background sites year-round, highlighting the e-waste recycling operations as the major source of their emissions. The Igeo index indicated moderate to extremely contaminated levels of Cu, Pb, Cd, and Ni in Karachi, Lahore and Gujranwala. Ingestion was found as a leading human exposure route, followed by dermal and inhalation exposure, with Pb posing the greatest health risk. The Cumulative Incremental Lifetime Cancer Risk (ILCR) model suggested moderate to low cancer risks for workers. Strategic interventions recommend mitigating health and environmental risks, prioritizing human health and ecosystem integrity in Pakistan's e-waste management.

Development of a novel DGT passive sampler for measuring polycyclic aromatic hydrocarbons in aquatic systems.

Polycyclic aromatic hydrocarbons (PAHs) are priority pollutants and need to be measured reliably in waters and other media, to understand their sources, fate, behaviour and to meet regulatory monitoring requirements. Conventional water sampling requires large water volumes, time-consuming pre-concentration and clean-up and is prone to analyte loss or contamination. Here, for the first time, we developed and validated a novel diffusive gradients in thin-films (DGT) passive sampler for PAHs. Based on the well-known DGT principles, the sampler pre-concentrates PAHs with typical deployment times of days/weeks, with minimal sample handling. For the first time, DGT holding devices made of metal and suitable for sampling hydrophobic organic compounds were designed and tested. They minimize sorption and sampling lag times. Following tests on different binding layer resins, a MIP-DGT was preferred - the first time applying MIP for PAHs. It samples PAHs independent of pH (3.9 -8.1), ionic strength (0.01 -0.5 M) and dissolved organic matter < 20 mg L-1, making it suitable for applications across a wide range of environments. Field trials in river water and wastewater demonstrated that DGT is a convenient and reliable tool for monitoring labile PAHs, readily achieving quantitative detection of environmental levels (sub-ng and ng/L range) when coupled with conventional GC-MS or HPLC. ENVIRONMENTAL IMPLICATIONS: PAHs are carcinogenic and genotoxic compounds. They are environmentally ubiquitous and must be monitored in waters and other media. This study successfully developed a new DGT passive sampler for reliable in situ time-integrated measurements of PAHs in waters at the ng/L level. This is the first time to use passive samplers for accurate measurements of hydrophobic organic contaminants in aquatic systems without calibration, a big step forward in monitoring PAHs. The application of this new sampler will enhance our understanding of the sources, fate, behavior and ecotoxicology of PAHs, enabling improved environmental risk assessment and management of these compounds.

Comprehensive Assessment of Environmental Emissions, Fate, and Risks of Veterinary Antibiotics in China: An Environmental Fate Modeling Approach.

China is one of the major global consumers of veterinary antibiotics. Insufficient recognition of emissions and environmental contamination hamper global efforts to prevent antibiotic resistance development. This pioneering study combined empirical data and modeling approaches to predict total 2010-2020 emissions of 80 veterinary antibiotics ranging from 23,110 to 40,850 tonnes/year, after 36-50% antibiotic removal by manure treatment. Following an initial increase of 10% from 2010 to 2015, emissions declined thereafter by 43%. While 85% of emissions discharged into soils, approximately 56%, 23%, and 18% of environmental residue were ultimately distributed in soils, freshwaters, and seawaters under steady-state conditions. In 2020, 657 (319-1470) tonnes entered the ocean from inland freshwaters. Median ∑antibiotics concentrations were estimated at 4.7 × 103 ng/L in freshwaters and 2.9 ng/g in soils, with tetracyclines and sulfonamides as the predominant components. We identified 44 veterinary antibiotics potentially posing high risks of resistance development in freshwaters, with seven exhibiting high risks in >10% of Chinese freshwater areas. Tetracyclines were the category with the most antibiotics exhibiting elevated risks; however, sulfamethylthiazole demonstrated the highest individual compound risk. The Haihe River Basin displayed the highest susceptibility overall. The findings offer valuable support for control of veterinary antibiotic contamination in China.

Evaluating the Current State of Epilepsy Care in the Province of Ontario.

There are numerous challenges pertaining to epilepsy care across Ontario, including Epilepsy Monitoring Unit (EMU) bed pressures, surgical access and community supports. We sampled the current clinical, community and operational state of Ontario epilepsy centres and community epilepsy agencies post COVID-19 pandemic. A 44-item survey was distributed to all 11 district and regional adult and paediatric Ontario epilepsy centres. Qualitative responses were collected from community epilepsy agencies. Results revealed ongoing gaps in epilepsy care across Ontario, with EMU bed pressures and labour shortages being limiting factors. A clinical network advising the Ontario Ministry of Health will improve access to epilepsy care.

Genetic Advancements in Infantile Epileptic Spasms Syndrome and Opportunities for Precision Medicine.

Infantile epileptic spasms syndrome (IESS) is a devastating developmental epileptic encephalopathy (DEE) consisting of epileptic spasms, as well as one or both of developmental regression or stagnation and hypsarrhythmia on EEG. A myriad of aetiologies are associated with the development of IESS; broadly, 60% of cases are thought to be structural, metabolic or infectious in nature, with the remainder genetic or of unknown cause. Epilepsy genetics is a growing field, and over 28 copy number variants and 70 single gene pathogenic variants related to IESS have been discovered to date. While not exhaustive, some of the most commonly reported genetic aetiologies include trisomy 21 and pathogenic variants in genes such as TSC1, TSC2, CDKL5, ARX, KCNQ2, STXBP1 and SCN2A. Understanding the genetic mechanisms of IESS may provide the opportunity to better discern IESS pathophysiology and improve treatments for this condition. This narrative review presents an overview of our current understanding of IESS genetics, with an emphasis on animal models of IESS pathogenesis, the spectrum of genetic aetiologies of IESS (i.e., chromosomal disorders, single-gene disorders, trinucleotide repeat disorders and mitochondrial disorders), as well as available genetic testing methods and their respective diagnostic yields. Future opportunities as they relate to precision medicine and epilepsy genetics in the treatment of IESS are also explored.

Development and validation of an in situ high-resolution technique for measuring antibiotics in sediments.

Important biogeochemical processes occur in sediments at fine scales. Sampling techniques capable of yielding information with high resolution are therefore needed to investigate chemical distributions and fluxes and to elucidate key processes affecting chemical fates. In this study, a high-resolution diffusive gradients in thin-films (DGT) technique was systematically developed and tested in a controlled sediment system to measure organic contaminants, antibiotics, for the first time. The DGT probe was used to resolve compound distributions at the mm scale. It also reflected the fluxes from the sediment pore-water and remobilization from the solid phase, providing more dynamic information. Through the fine scale detection, a reduction of re-supply was observed over time, which was concentration and location dependent. Compared to the Rhizon sampling method, antibiotic concentrations obtained by DGT probes were less than the pore-water concentrations, as DGT measures the labile fraction of the compounds. The DGT probe was also tested on an intact sediment core sampled from a lake in China and used to measure the distribution of labile antibiotics with depth in the core at the mm scale. ENVIRONMENTAL IMPLICATION: The abuse of antibiotics and widespread of their residues influences the ecosystem, induces the generation of super-bacteria, and finally poses threat to human health. Sediments adsorbs pollutants from the aquatic environment, while may also release them back to the environment. We systematically developed DGT probe approach for measuring antibiotics in sediment in situ in high resolving power, it provides information at fine scale to help us investigate biogeochemical processes take place in sediment and sediment-water interface.