China
Africa
Explore chapters and articles related to this topic
Effects of Pollutants
Published in Mary K. Theodore, Louis Theodore, Introduction to Environmental Management, 2021
Mary K. Theodore, Louis Theodore
“Carcinogens,” which are often polycyclic hydrocarbons inducing cancer in susceptible individuals, are present in the exhaust emissions of the internal combustion engine, be it diesel or gasoline. Two major carcinogens are benzopyrene, which is a strong cancer-inducing agent, and benzanthracene, which is a weak one. They are essentially non-VOCs associated with solids or polymeric substances in the air. These compounds are not very stable, and they are destroyed at varying rates by other air pollutants and by sunlight. However, as a result of industrialization and urbanization, these substances are discharged into the atmosphere in significant quantities, reportedly causing a steady increase in the frequency of human lung cancer in the world [5].
Field-Scale Remediation of Crude Oil–Contaminated Desert Soil Using Various Treatment Technologies
Published in Ram Chandra, R.C. Sobti, Microbes for Sustainable Development and Bioremediation, 2019
Subhasis Das, Veeranna A. Channashettar, Nanthakumar Kuppanan, Banwari Lal
Crude oil is a complex mixture of an indefinite number of individual chemical compounds, and the properties of these compounds differ depending on many factors, such as source, geological history, age, migration, and alteration of crude oil. The PHCs in crude oil contain a complex mixture of four fractions: saturates, aromatics, resins (N, S, O), and asphaltene (Balba et al., 1998). The saturate fractions are straight chain alkanes (all normal alkanes), branched alkanes (isoalkanes), and cycloalkanes (naphthenes). The aromatic fractions contain volatile monoaromatic hydrocarbon (benzene, toluene, xylene etc.), polyaromatic hydrocarbon (PAH) (three-ring compounds—anthracene, phenanthrene; four-ring compounds—tetracene, chrysene, triphenylene; five-ring compounds—pentacene, benzopyrene, corannulene, benzopyrene; six-ring compound—coronene; and seven-ring compounds—ovalene and benzofluorene), naphthenoaromatics, and aromatic sulfur compounds (Figure 7.1). The resin and asphaltene fractions consist of polar molecules containing nitrogen, sulfur, and oxygen. Resins are amorphous in nature and dissolved in oil, whereas asphaltenes are of a big colloidal shape and dispersed in oil. It is notable that PAH fractions associated with oil contamination, as well as known carcinogens, are suspected. The most toxic PAH compound is benzopyrene.
A critical review of environmental exposure, metabolic transformation, and the human health risks of synthetic musks
Published in Critical Reviews in Environmental Science and Technology, 2023
Na Luo, Yanpeng Gao, Xiaoyi Chen, Mei Wang, Xiaolin Niu, Guiying Li, Taicheng An
The potential carcinogenicity of SMs has also been reported. The predicted health risks results showed that MX and MT had strong mutagenicity up to 0.96 and 0.83 (Figure 5). The number of tumors was three times higher in mice fed 0.075% or 0.15% MX than in blank controls (Taylor et al., 2014). SMs have also been detected in the breast fat tissue of breast cancer patients, but the concentrations were not significantly different between malignant and benign tumors (Li et al., 2019). SMs inhibited the growth of six human tumor cell lines by inducing apoptosis through various pathways, such as the interleukin family, tumor necrosis factor, and MAPK/P53/JAK-STAT signaling pathway (Xu and Cao 2016). MX was reported to induce human normal stem L02 cells to abnormally proliferate through the transforming growth factor (TGF)-β signaling pathway, leading to malignant transformation and tumor formation (Zhang, Huang, et al., 2017). Additionally, the carcinogenic mutagenicity of SMs had a synergistic enhancement effect. When MK was added to HepG2 cells before induction with benzopyrene, they could synergistically act with benzopyrene to enhance the mutagenic effect of benzopyrene on HepG2 cells (Mersch-Sundermann et al., 2001). Another possible way of promoting tumorigenesis is that SMs could inhibit multidrug effector transporter activity, resulting in the reduced ability of cells to remove exogenous substances (including potent carcinogens). Thus, the residence time of these harmful substances could be longer (Cunha et al., 2017; Luckenbach and Epel 2005).
Concentrations, seasonal trends, sources, health risk and subchronic toxicity to the respiratory and immune system of PAHs in PM2.5 in Xi'an
Published in Journal of Environmental Science and Health, Part A, 2023
Xiang-ni Wang, Hui-juan Wang, Yan Ma, Jin-ren Liu, Yue Hao, Cai-qin Ma, Na Liu, Yi-xin Cui, Xing-min Shi, Fu-liang Gong, Xi-li Wu
Sixteen priority PAHs namely benzo(a)anthrancene (BaA), benzopyrene (BaP), benzo[b]fluoranthene (BbF), benzo[K]fluoranthene (BkF), benzopyrene (BghiP), acenaphthene (Ace), acenaphthylene (Acy), anthracene (Ant), fluoranthene (Fl), dibenzanthracene (DahA), phenanthrene (Phe), naphthalene (NaP), pyrene (Py), chrysene (Chr), fluorene (Flu), indeno[123-cd]pyrene (IcdP) were extracted by soxhlet extraction method. The filter membrane was placed in the Soxhlet extract and concentrated three times after 5 mL of hexane was added. The concentrated sample extract was added to the column, and the sample-concentrating vial was washed with 3 mL hexane for three times, and the washing solution was added to the column together with 10 mL hexane eluent to wash the clean-up column with the adsorbed sample. After infiltration for 5 min, the valve of the column was released to receive more eluate until all eluate flowed out. The eluate was concentrated to 0.5–1.0 mL, 3 mL of acetonitrile was added, the mixed liquid was concentrated to about 1 mL, and finally the volume was accurately fixed to 1.0 mL for measurement. Prepared samples were stored under refrigeration at 4 °C and analyzed within 30 days. Finally, they were analyzed and quantified with high performance liquid chromatography (HPLC).
Effects of Carbon Dioxide and Water Vapor Addition on Benzene and PAH Formation in a Laminar Premixed CH4/O2/Ar Flame
Published in Combustion Science and Technology, 2019
Yuxin Wu, Fengshan Liu, Yunlan Sun, Baozhong Zhu
The first reaction mechanism was formulated by Chernov et al. (2014) to describe the growth and oxidation of aromatic compounds in methane, ethylene, and ethane flames. This mechanism was originally developed by Slavinskaya and Frank (2009) for simulation of laminar methane and ethane premixed flames and was further modified with updated reactions and added pathways associated with PAH formation based on literature reviews (Butler, 2001; Fournet et al., 1999; Laskin and Lifshitz, 1998; Narayanaswamy et al., 2010; Raj et al., 2009; Robinson and Lindstedt, 2011). This mechanism describes the formation and growth of PAHs up to benzopyrene (C20H12) and consists of 102 chemical species and 829 reactions. It has been validated for simulations of methane flames with PAH formation by comparing numerical results with experimental data (Slavinskaya and Frank, 2009).