Reviews on Environmental Health最新文献

This paper presents the results of modeling the distribution process of industrial emission components at specified distances from the emission source along the normal. The model uses a system of differential diffusion equations to compute the concentration profiles of aerosols, industrial gases, and fine particles in the atmosphere. In order to investigate the regularity of the emitter propagation into the atmosphere, a theory of impurity dispersion was developed. The model is constrained by the effect of particle interactions. The partial derivative equations are presented to calculate the concentrations of aerosols and fine particles under the turbulent airflow in the atmosphere, dispersion of inert impurities, and distribution of chemically active compounds. The adequacy of the mathematical model for a series of theoretical calculations was checked by contrasting the data of the atmospheric air monitoring for the cities of Almaty, Ust-Kamenogorsk, Pavlodar, Atyrau, Krasnodar, Chelyabinsk, Beijing, and Shanghai. Air monitoring data included PM10, SO₂, and NO₂ levels. The mathematical model solutions for the relative values of the emitter concentration in the direction along the normal of the pollution source at the surface were obtained. Graphical interpretation of the calculation results over the 0…200 m distance for time intervals ranging from 3 to 600 min was provided. According to the multiple factor cluster analysis, the critical values of SO₂ concentrations in Atyrau exceeded MPC in 26.2% of cases. The level of NO₂ for Shanghai was 15.6%, and those for PM10 concentrations in Almaty and Atyrau amounted to 16.4%. A comparison of theoretical values and results obtained from official sources showed arithmetic mean of 49.4 mg/m³ and maximum value of 823.0 mg/m³. Standard deviation comprised 48.9 mg/m³. Results were considered statistically significant at p≤0.005. The mathematical model developed in this study can be used to predict the status of atmospheric air.

Objectives: Environmental risk factors contribute to 24% of the global burden of disease from all causes in disability-adjusted life years (DALYs), and to 23% of all global deaths. Malaysia being an advanced developing country, there is a need to prioritise environmental health issues to enable environmental health practitioners to focus on the most significant and urgent environmental health concerns.

Content: This project was undertaken by a Thematic Working Group on Environmental Health Experts (TWG 10) under the Malaysian National Environmental Health Action Plan. Sixteen pre-selected environmental health issues were presented to a two focus group discussions among 20 environmental health and related professionals who then scored each issue on its magnitude and severity scale.

Summary: The total of these scores generated a list of priority environmental health issues for Malaysia. Children environmental health came out as the environmental health issue of the highest priority.

Outlook: We hope that this list of priority environmental health issues will be used for prioritising academic and professional manpower training, research funding allocation and planning for intervention programmes by various stakeholders.

Object: Arsenic as a chemical is found in rock, soil, air and used in various industries and their products, such as colors, hairs, and fertilizers. Humans may be exposed to arsenic mainly through food and drinking water. Due to its adverse health effects, its presence in drinking water has become a public health concern.

Methods: In this systematic review, we investigated the relationship between arsenic concentration in drinking water and the risk of kidney cancer in humans. For this reason, various electronic databases were searched from 1992 February to November 2021. In this review, three ecological studies, two case-control studies, and four cohort studies were investigated.

Results: High levels of arsenic (100 μg/L) have been reported in many countries such as southwest Taiwan, Niigata, Argentine, and northern Chile. A significant relationship was observed between kidney cancer incidence and its mortality rate with high arsenic levels in drinking water.

Conclusions: Despite the limitations in some previous studies, reviewing and comparing the data of different regions indicates a scientific relationship between kidney cancer incidence and high concentrations of arsenic in drinking water.

This study addresses a systematic review of the scientific literature to evaluate the most common advanced oxidation processes (AOP) for the removal of phthalate esters (PE) in aqueous matrices. Six AOP were reviewed for PE degradation such as processes based on photolysis, Fenton, ozonation and sulfate radicals ( ${\text{SO}}_4^{•-}$ ), combined AOP and other processes. The PE degradation efficiencies by AOP processes ranged from 40.3 to 100%. In the reviewed literature, an initial PE concentration within 0.04-250 mg/L was applied. The H₂O₂ concentrations used in the UV/H₂O₂ process and O₃ concentrations in ozonation-based processes ranged between 0.85-1,360.6 mg/L and 2-4,971 mg/L, respectively. Based on the reported results, the PE oxidation data fit well to the pseudo-first order kinetic model. A review of the studies revealed that many oxidant species are produced in the AOP, including hydroxyl radicals (^•OH), ${\text{SO}}_4^{•-}$ , superoxide radical anions ( ${\text{O}}_2^{-•}$ ), hydroperoxyl radicals (HO₂ ^•), hydrogen peroxide (H₂O₂), and singlet oxygen (O₂). Among these oxidants, ^•OH play a key role in the degradation of PE. However, ${\text{SO}}_4^{•-}$ are more effective and efficient than ^•OH since ${\text{SO}}_4^{•-}$ has a higher oxidation power (E = 2.5-3.1 V) compared to ^•OH radicals (E = 1.8-2.7 V). In different AOP processes, the aromatic rings of PE are destroyed by ^•OH and produce intermediates such as phthalic acid (C₆H₄(CO₂H)₂), benzoic acid ethyl ester (C₉H₁₀O₂), 2, 5-dihydroxybenzoic acid (C₇H₆O₄), formic acid (CH₂O₂), acetic acid (CH₃COOH), and oxalic acid (C₂H₂O₄), among some others. Until now, limited data have been reported on PE toxicity assessment. The reviewed literature has shown that AOP can be used effectively to degrade PE from aqueous matrices. However, this systematic study suggests focusing more on the evaluation of the toxicity of the effluent resulting from AOP for the decomposition of PE in future studies.

The gastrointestinal (GI) system has rapidly proliferating and differentiating cells, which make it one of the most radiosensitive organs in the body. Exposure to high dose of ionising radiation (IR) during radiotherapy may generate a variety of reactive oxygen species (ROS) and reactive nitrogen species (RNS) including radicals, cause some side effects such as nausea, vomiting, diarrhoea, pain, ulceration, mal-absorption etc. Irradiation disrupts GI system by damaging proliferating stem cells of the crypts that alters the histology and physiology of intestine. Radiation damage reflects the qualitative and quantitative changes in intestinal epithelial stem cells like enterocytes, enteroendocrine cells, goblet cells and Paneth cells. The damaging effects of radiation to bio-molecules and cellular structures can alter gene signalling cascades and grounds genomic instability, protein modifications, cell senescence and cell death. The signalling pathways of GI tract includes Wnt, BMP, Hedgehog, PTEN/PI3K and Notch plays an important role in self-renewal of intestinal stem cells (ISCs) and maintaining the balance between self-renewal and differentiation of ISCs. Various radiation countermeasures including radioprotectors and mitigators are under development phase globally but still not approved for clinical applications during any radiation emergencies. In view of above, present review highlights cellular and molecular interruptions of GI system due to acute and chronic GI radiation injury, role of radioprotectors in signalling cascade modulations in GI epithelium and involvement of ISC markers in radioprotection.