A Lagrangian Tool for Simulating the Transport of Chemical Pollutants in the Arabian/Persian Gulf

A rapid-response Lagrangian model for the use in simulation of the transport of a chemical pollutant in the Arabian/Persian Gulf is described. The model is well suited to the provision of a fast response after an emergency due to an accident or a deliberate spill. It is easy to set up for any situation since only requires the modification of a few input files specifying the pollutant properties and release characteristics. Running times are short, even on a desktop PC, which makes it appropriate for a rapid assessment of a hypothetical accident occurring in the region. Baroclinic circulation was obtained from an HYCOM ocean model, and tides were calculated using a barotropic model. The interactions of pollutants with sediments (uptake/release processes) were described using a dynamic approach based on kinetic transfer coefficients and a stochastic numerical method. Some examples of model applications are shown, showing the influence of the geochemical behaviour of the pollutant in its distribution patterns.

Are PM2.5 in the Atmosphere of a Small City a Threat for Health?

A number of time series from two local PM2.5 monitoring stations were analyzed, for a small city, in North East Greece. They coincided with SARS-CoV-2 pandemic lockdowns and lifting restrictions. The aim of this analysis was to establish concentration exceedances and roughly apportion sources of the PM2.5 concentration problem. This was established by analyzing 24-h filter samples of trace elements using WD-XRF. It was found that the restrictions and their lifting did not significantly affect these concentrations. The main problems were assigned to emissions from biomass burning central heating and Saharan dust episodes. The study results indicate that even in small cities the air quality as far as PM2.5 is concerned can still be deleterious to the local population according to the WHO restricting levels but not according to the EU levels. The fact that PM2.5 is not a single chemical pollutant makes matters more complicated and renders such concentration upper levels, of little significance.

Contaminant acrylamide in food: toxicity, detection methods, mitigation measures and risk assessment for humans

Food safety is related to all aspects of human life, and the quality of food has a profound impact on people's lives and health. Acrylamide is a chemical pollutant produced by the Maillard reaction in baked goods such as potato chips, bread, and cookies. Studies have shown that acrylamide has neurotoxicity, carcinogenicity, reproductive toxicity, genotoxicity, and hepatosplenic toxicity in humans. However, the carcinogenicity of acrylamide in humans is still controversial, and it is unclear whether there is a significant correlation between human exposure to acrylamide and cancer incidence. This review aims to explore the latest research on the human health hazards of acrylamide and prevent or reduce the hazards of acrylamide to humans by detection methods, risk assessment, and mitigation measures to ensure people's food safety.

Organic Matter Causes Chemical Pollutant Dissipation Along With Adsorption and Microbial Degradation

Views on the entry of organic pollutants into the organic matter (OM) decaying process are divergent, and in part poorly understood. To clarify these interactions, pesticide dissipation was monitored in organic and mineral soils not adapted to contaminants for 241 days; in groundwater sediment slurries adapted to pesticides for 399 days; and in their sterilized counterparts with and without peat (5%) or compost-peat-sand (CPS, 15%) mixture addition. The results showed that simazine, atrazine and terbuthylazine (not sediment slurries) were chemically dissipated in the organic soil, and peat or CPS-amended soils and sediment slurries, but not in the mineral soil or sediment slurries. Hexazinone was chemically dissipated best in the peat amended mineral soil and sediment slurries. In contrast, dichlobenil chemically dissipated in the mineral soil and sediment slurries. The dissipation product 2,6-dichlorobenzamide (BAM) concentrations were lowest in the mineral soil, while dissipation was generally poor regardless of plant-derived OM, only algal agar enhanced its chemical dissipation. Based on sterilized counterparts, only terbutryn appeared to be microbially degraded in the organic soil, i.e., chemical dissipation of pesticides would appear to be utmost important, and could be the first response in the natural cleansing capacity of the environment, during which microbial degradation evolves. Consistent with compound-specific dissipation in the mineral or organic environments, long-term concentrations of pentachloroaniline and hexachlorobenzene were lowest in the mineral-rich soils, while concentrations of dichlorodiphenyltrichloroethane (DTT) and metabolites were lowest in the organic soils of old market gardens. OM amendments changed pesticide dissipation in the mineral soil towards that observed in the organic soil; that is OM accelerated, slowed down or stopped dissipation.

A Lagrangian Tool for Simulating the Transport of Chemical Pollutants in the Arabian/Persian Gulf

A rapid-response Lagrangian model for simulating the transport of a chemical pollutant in the Arabian/Persian Guls is described. The model is well suited to provide a fast response after an emergency due to an accident or a deliberate spill. Baroclinic circulation was obtained from HYCOM ocean model and tides were calculated using a barotropic model. The interactions of pollutants with sediments (uptake/release processes) were described using a dynamic approach based on kinetic transfer coefficients and a stochastic numerical method. Some examples of model applications are shown.

GC-mass determination for the biodegradative products of 2,6-dimethylpyridine using Dead-Sea bacterial isolate

Dead sea soil is known for its hypersaline environment and it is a promising location for isolating extremophilic bacteria with interesting metabolic features. In the current study, we isolated a gram-positive bacterium with the ability to degrade 2,6-dimethyl pyridine (2,6-DMP), also known as 2,6-lutidine, a chemical pollutant. The isolated bacteria were identified using the automated Microscan Walkaway system and the different biochemical reactions were determined. In minimal media using the 2,6-DMP as a sole carbon source, the bacterial isolate showed the ability to convert approximately 40 % of 2,6-DMP within 5 days. The GC-Mass analysis for the degradation products indicated that mono- and dihydroxylation for the pyridine ring and oxidation of one or both of the terminal methyl groups have occurred. Based on this finding, this isolated bacterial can further be utilized for bioremediation purposes.

In silico investigation of Methyl parathion and Diazinon with different Metabolic protein in Drosophila melanogaster

Chemical pollutant such as insecticide, pesticide and drugs are mainly used for agriculture, industry and economic development, which are well known for environment pollutant due to its toxicity and persistence in the nature. It can accumulate into the environment and continuously contaminate the food chain which causes threat to the health of consumer including human. Based on all these studies our investigation deals with the effects of two insecticides viz. methyl parathion and diazinon to non target organism like Drosophila melanogaster. In this study we have performed molecular modeling, docking and protein function analysis of different metabolic and physiological enzyme of Drosophila melanogaster such as acetylcholinesterase (AchE), Glutathione S-transferase D1(GST) and Protein kinase C (PKC) with these insecticides of six combinations (AchE + Diazinon, AchE + methyl parathion, GST+Diazinon, GST+Methyl parathion, PKC+Diazinon, PKC+Methyl parathion). Molecular docking results showing best binding affinity for GST+ Methyl parathion with binding energy of -4.79 kcal/mol. Overall, methyl parathion produces efficient binding toward all target protein when compare to diazinon. However, more detailed analysis need to be carried out to have an in-depth understanding of in vivo significance of these bimolecular interactions.

Hybrid emergency ventilation system for controlling inhaled contaminant dose in the case of chemical leakage

In factories where high-risk chemical pollutants are treated, it is essential to anticipate response measures in the event of chemical pollutant leakage to minimize adverse health effects on workers. When high-risk liquid chemical pollutants are assumed to be leaked inside enclosed spaces, it becomes crucial to predict the non-uniform concentration distributions in enclosed spaces and evaluate the health impacts and risks of short-time exposure to prevent large-scale accidents. Therefore, we have developed an emergency ventilation system for controlling the inhaled contaminant dose of factory workers. In this study, assuming a worst-case scenario liquid chemical pollutant leak in an enclosed factory space, the advantages and performance of a hybrid ventilation system that combines displacement and push–pull type ventilation systems were numerically investigated. Installation of wall materials that facilitate photocatalytic oxidation (PCO) reactions for background passive concentration control was also discussed. Based on the demonstrative numerical analyses for a realistic factory space, push–pull type ventilation system was confirmed to effectively suppress chemical pollutant diffusion in enclosed spaces with a low ventilation rate. Wall materials with the PCO mechanism had a certain contribution to the control of peak concentration.

Acute Toxicity of Hexavalent Chromium on Behavioural Parameters and Histopathology Damages in Freshwater Common Carp, Cyprinus carpio

Water sources of almost all regions in India are carrying the unbearable burden of dangerous pollutants. The release of waste products and anthropogenic wastes run-off has contributed to aquatic pollution. The environment has become a storehouse for chemical pollutant which infiltrate into the aquatic environment, including estuarine, thus immobilizing the aquatic biota, among the heavy metals. Chromium is a heavy metal which has both beneficial and harmful effect on organisms. It is highly toxic and carcinogenic. Many industries are disposing of chemical pollutants to the water. These disposals contain many chemicals, including Chromium. The purpose of this review was to check the accumulation and concentration of heavy metals in different organs of freshwater fishes that come in contact with the water contaminated with heavy metals. The subjected fish were exposed to Chromium (Cr) at the sub-lethal level at a concentration of 40mg/L in 96 hours. During the observation period, the fishes shown some behavioral changes like erratic swimming, slow motility, suffocation, and the scales become thin and decolorized. In the gill region, the gill filaments become swollen, and gill rackers become thick, and curling of lamellae was noticed, and it is caused due to the Chromium build-upon gills. At the region of the caudal fin, permanent bending of the tail was observed. The Chromium also affects other vital organs like the spleen and gut region. LC50 was found in 96 hours. The result indicates that Chromium is highly toxic and has deleterious effects on aquatic life. Humans are also affected by the intake of fishes for primary people of those areas where the leading food is fish.