Tarek Othman Said

Safety measures are desperately needed to lower the health dangers linked to contemporary pesticides. How successfully the current laws protect the environment and public health is one of the primary issues. The scientific community can help develop effective, empirically based policies and practices that protect the environment and public health, increase our understanding of the consequences of pesticides, and encourage their ethical use. Furthermore, in order to safeguard human health and preserve a pollution-free environment, international pesticide monitoring criteria frequently need to be modified in light of new scientific discoveries. To develop guidelines and rules for the creation of pesticides with fewer negative effects, many sectors, including manufacturers, government agencies, and non-governmental groups, should work together. Understanding these impacts can improve decision-making, reduce risks, enhance safety procedures, practice environmental stewardship, safeguard community health, and facilitate cooperation and communication among stakeholders. Numerous factors, such as consumer preferences, legislative changes, technological advancements, and a greater understanding of the significance of sustainable agriculture, are anticipated to influence pesticides in the future. In conclusion, it is critical to strike a balance between the necessity of pest management and the potential risks associated with pesticides.

This preliminary study looked at the concentrations, sources, and hazards of the persistent organochlorine pesticides in 71 sediment samples from the Shalatin area (Egyptian Red Sea coast). Conventional methods were used to study the persistent organochlorinated pesticide residue. The residues of 16 organochlorine pesticides were determined using the gas chromatograph-mass spectrometer-mass spectrometer (GC–MS/MS); selected reaction monitoring (SRM) technique. The total pesticide residue (ng g^–1, dry weight) extended from < DL-0.628; < DL-7.128; and < DL-8.256 ng g⁻¹ for hexachloro-cyclohexane (HCHs), dichloro-diphenyl-trichloro ethane (DDTs), and cyclodienes (CDs), respectively. DDD and DDE, metabolites of DDT, are abundant in the sediment samples, suggesting that the identified DDTs were ancient and not recently added to the Shalatin area due to the lack of potential sources of these metabolites such as rivers or agricultural activities near this area. The organochlorine pesticides in sediment samples are lower than those reported for other global regions. The source identification of organochlorine pesticides and the Eco-toxicological study were also investigated. The analysis of possible health and environmental issues showed that there were not many hazards to either people or animals in the area under study. The widespread use of organochlorine pesticides for non-agricultural and agricultural purposes is this study's leading cause of persistent pesticides.

Activated carbon (AC) derived from Date pits (DP) wastes was used as an eco-friendly and effective biosorbent for the removal of fluorene (FLU) from organic wastes. The maximum capacity of DP was 6.71 mg g⁻¹, compatible with the Freundlich model. FLU adsorption's chemisorption performance on DP was involved in following a superior linear fit for the pseudo-2nd-kinetic model. The maximum adsorption capacity from the pseudo-2nd order kinetic model fitted with the experimental findings and found to be 3.73 g, 2.62, 1.13, 0.955, 0.749, 0.591, and 0.665 mg g⁻¹ at 25, 3, 35, 4, 45, 5 and 55 °C, respectively. The negative value of the spontaneous nature of the adsorption corresponds to the exothermic nature however, + ΔS corresponds to an increase in the degree of freedom for FLU adsorption. The relatively high value of activation energy (Ea) demonstrates that the adsorption of FLU onto DP is classified as chemical adsorption, and found to be 84.8 kJ mol⁻¹. Also, the result of XRD shows that the prepared DP was re-used four times without substantially decreasing performance. In addition, it appears that AC prepared from DP is a promising adsorbent with a low cost for removing many organic pollutants.

The aim of present work is focused on determination of the residual concentrations of 16 PAHs and their health risk assessment in selected sectors of the street dust along Khamis-Mushait, Asir area. Objectives/backgrounds: With the recent rapid development of urbanization, polycyclic aromatic hydrocarbons (PAHs) in street dust pose serious problems to human health and ecological environment. Method: HPLC system (HPLC Nexera-i LC 2040 C 3D Plus Shimadzu Integrated) was used to perform the measurements following well-established USEPA 3550B method . Results: The average value of PAHs in Khamis-Mushait street dust was 2809.46 ng/g, ranging from 1250.41 to 4249.29 ng/g. Incinerator and industrial locations had the highest concentration of fossil PAHs, accounting for 69.62% of PAHs. The King Fahd Garden and Al-Hayat National Hospital regions had the highest concentrations of carcinogenic PAHs and combustion PAHs, which accounted for 41.70 and 27.46% of all PAHs, respectively. Naphthalene (NAP), acenaphthylene (ACY), and acenaphthene (ACE) were more effective range low. However, ACE was more effective range medium, and ACY, ACE, and DBA (dibenzo-anthracene) were more probable effect level. Furthermore, the effects of NAP, fluoranthene (FLT), pyrene (PYR), and benzo(a)pyren (BaP) were greater than the threshold effect level (TEL). For both kids and adults, the hazardous index (HI) was in the following order: ACE>ACY>NAP>PYR>fluorene (FLR)>FLT> benzo(ghi)perylene (BghiP)>phenanthrene (PHN)>ANT. However, total HI for noncancer risks for PAHs varied between 9.91´10-5 and 2.69´10-2 and from 9.22´10-4 to 2.50´10-1 for adults and children, respectively. Conclusion: Various approaches (geochemical indices, statistical analysis, and health risk assessment) were exploited to evaluate the levels of 16 PAHs in street dust from Abha and Khamis-Mushait City, Saudi Arabia. These values are considered safe level and insignificant to adults and children. In addition, ACE may pose risk based on acute and intermediate oral exposure. The following order from several sources was reported by the cluster analysis of dust samples: commercial>industrial>traffic.

The sorption investigation was applied using Hydroxyapatite (Hap650) for three recorded polycyclic aromatic hydrocarbons PAHs. These PAHs included: Naphthalene (NAP), Anthracene (ANT) and Chrysene (CHR) recorded in real street dust samples of Khamis-Mushait area. The sorption indicated that the uptake was 66.89, 69.49 and 19.67 mg/g, respectively after 120 min. For the adsorption of organic contaminants, this approach proved to be both affordable and effective. The impact of several parameters such as shaking time, sorbent weight, concentration and temperature was studied. In addition, multiple isotherm models were used to indicate an adsorption mechanism. The greatest R² values indicate that the Langmuir adsorption model is more applicable.

Polycyclic aromatic hydrocarbons (ΣPAHs) were varied from 1250.41-4249.29 ng/g, with an average value of 2809.46 ng/g in street dust of Khamis-Mushait. A maximum concentration of fossil PAHs (ΣFPAHs) was recorded at incinerator and industrial areas representing 69.62% of ΣPAHs. However, the maximum concentrations of carcinogenic PAHs (ΣCARC) and combustion PAHs (ΣCOMB) were recorded at King Fahd Garden and Al-Hayat National Hospital areas, representing 41.70% and 27.46% of ΣPAHs, respectively. Naphthalene (NAP), Acenaphthylene (ACY) and Acenaphthene (ACE) were > (effective range low (ERL). However, ACE was > effective range medium (ERM), ACY, ACE, DBA(dibenzo anthracene) were > Probable Effect Level (PEL). In addition, NAP, fluoranthene (FLT), pyrene (PYR) and benzo(a)pyren (BaP) were > threshold effect level (TEL). The Hazardous indices (HI) for both children and adults were in the following order: ACE > ACY > NAP > PYR > fluorene (FLR) > FLT > benzo(ghi)perylene (BghiP) > phenanthrene (PHN) > ANT. The total HI for non-cancer risks of PAHs exposure were 2.69×10^− 2 − 9.91×10^− 5 and 2.50x10^− 2 − 9.22×10^− 4 to adults and children, respectively. These values considered safe level and insignificant non-cancer risks to adults and children. In addition, ACE may pose risk based on acute and intermediate oral exposure. The cluster analysis of dust samples declared the following order for different sources: traffic > industrial > commercial.