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Air quality
Published in Stephen Battersby, Clay's Handbook of Environmental Health, 2023
PAHs (polycyclic aromatic hydrocarbons) – Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds that comprise two or more aromatic rings, including both naturally occurring and human-made chemicals. PAHs are widely distributed in the atmosphere. They have low vapour pressures and are found at ambient temperatures in air as gases or often absorbed onto particles of soot. They are relatively insoluble in water but dissolve readily in fats and oils and can accumulate through food chains. They are generated by incomplete burning of fuels, particularly solid fuels.
Exploitation of Silver Nanoparticles in Bioremediation
Published in Ram Naresh Bharagava, Sandhya Mishra, Ganesh Dattatraya Saratale, Rijuta Ganesh Saratale, Luiz Fernando Romanholo Ferreira, Bioremediation, 2022
Punabati Heisnam, Abhinash Moirangthem, Yengkhom Disco Singh, Pranab Dutta, Chabungbam Victoria Devi, B.N. Hazarika
Moreover, biological methods are also reliable in ‘bottom-up approach’, which provides an important alternate pathway for the green synthesis of nanomaterials. The microorganisms include bacteria, fungi, enzymes and plant extracts that can be used for the synthesis of metal nanoparticles such as silver. PAHs (polycyclic aromatic hydrocarbons) are an organic contaminant (e.g. phenanthrene, pyrene and naphthalene) mainly caused by unfinished fossil fuel burning, old storage tanks seepage, spilling of oils, domestic waste, etc. The PAHs can remain for a longer period of time in the environment and are unmanageable, so they produce harmful organic pollutants that cause mutant disorders and that are carcinogenic in nature. Culturing of pure bacteria in contaminated paths helps in the degradation and uptake of PAHs.
Bioremediation of Polycyclic Aromatic Hydrocarbons (PAHs): An Overview
Published in M.H. Fulekar, Bhawana Pathak, Bioremediation Technology, 2020
Heavy metals are of major concern and present at a high ratio in contaminated sites (Thavamani et al., 2011). PAHs frequently occur with heavy metals at contaminated sites, which may cause hindrance during the biodegradation of PAH compounds (Thavamani et al., 2013). High concentrations of these metals can damage cell membranes and prevent enzymatic activity (Bruins et al., 2000). Isolation of metal-tolerant PAH compounds for degrading microorganisms is achievable to avoid metal inhibition during PAH degradation. Microbial degradation of phenanthrene co-contaminated with zinc in soil has been found to be somewhat restricted (Lloyd and Lovely, 2001).
Polycyclic aromatic hydrocarbons (PAHs): Updated aspects of their determination, kinetics in the human body, and toxicity
Published in Journal of Toxicology and Environmental Health, Part B, 2023
Fernando Barbosa, Bruno A. Rocha, Marília C. O. Souza, Mariana Z. Bocato, Lara F. Azevedo, Joseph A. Adeyemi, Anthony Santana, Andres D. Campiglia
Epidemiological data demonstrated a marked association between PAH exposure and cancer occurrence. Cohort studies between 1977 and 2017 showed a high-risk ratio for lung cancer among subjects occupationally exposed to PAHs, especially those in coal/coke and iron/steel industries (Singh et al. 2018). Sediment samples from a former industrial site (superfund site) noted that most of the PAHs were carcinogenic, which poses a significant adverse health risk (Gearhart-Serna et al. 2018). The risks of humans developing various forms of cancers including breast, cervical, ovarian, uterine, endometrial, and lung cancers through exposure to PAHs have been widely reported in the literature (Korsh et al. 2015; Moorthy, Chu, and Carlin 2015; Therachiyil et al. 2022). Although previous studies predominantly focused on BaP as the most suitable indicator of PAH-induced cancer incidences, more than 16 other PAHs have also been linked to cancer incidences in humans A single intraperitoneal (ip) injection of PAHs in A/J mice induced PAH-DNA adducts and high levels of gene mutations that initiated lung tumors (Nesnow et al. 1995). The intra-pulmonary instillation of Wistar rats with 10- or 20 mg/kg of BaP resulted in epithelial tracheal pleomorphism indicative of adenocarcinoma formation (Da Silva et al. 2007).
Profiling and occupational health risk assessment study on coal ashes in terms of polycyclic aromatic hydrocarbons (PAHs)
Published in Journal of Environmental Science and Health, Part A, 2022
Abhrajyoti Tarafdar, Alok Sinha
The samples were collected in triplets and an arithmetic mean with standard deviation was used to express the concentration of each PAH component. The perception of soil contamination by PAHs from coal ashes is essential to understand the expanse of carcinogenic exposure on the local inhabitants. Exposure to a certain PAH can be a potential cause of cancer. This potency can be acquired by computing its equivalent concentration to Benzo[a]pyrene (BaPeq), as Benzo[a]pyrene (BaP) is known to be the most carcinogenic and the most studied PAH compound.[30] For 60 distinct PAHs, the IARC Monographs Program has examined experimental evidence.[31] Among these 60 PAHs, BaP is regarded as carcinogenic to people (Group 1). To calculate the BaPeq of individual species, the toxic equivalent factor (TEF)[32] of a provided species relative to BaP was used. The total BaPeq was calculated as, where,
Evaluation of PAHs concentration and cancer risk assessment on human health in a roadside soil: A case study
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Shanti Priya Ghosh, Subodh Kumar Maiti
The PAHs analysis on extracted soil was performed by using a High-Performance Liquid Chromatography (HPLC), attached with UV detector (254 NM) (Dionex UHPLC Ultimate 3000) and Hypersil Green PAH column (Dim. 150 mm ×3 mm, particle size. 5 μm, Thermo Scientific). The mobile phase was a gradient mode of acetonitrile/water Milli-Q (50:50 v/v with the flow rate: 1.5ml/min, and run time was 25 min for a chromatography cycle of 13 PAHs complete separation). The Calibration of the instrument, verification and repeatability was carried out with quality assurance. To check cross contamination or loss of the analysis, two blanks were processed. PAHs standard solution was prepared by diluting with mixture of acetonitrile/water (50:50, v/v). The calibration was performed by injecting active amount of the five-level PAHs standard solution of the range 0.25–2.0 mg/l and concentrations were 0.25, 0.5, 1.0, 1.5 and 2.0 mg/l. The calibration curves followed Beer’s law into the investigation range of PAHs injected in the column. The concentration of each PAHs compound was calculated by using the calibration factors and the peak area (SEPARATIONS 1996).