1,2,4-Trimethylbenzene (Pseudocumene) Formation of Photochemical Smog and Contribution to Atmospheric Greenhouse Gases (GHGs)




Patel, Devang A.
Rich, Alisa A.


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Objective: To examine 1,2,4-Trimethylbenzene’s contribution to photochemical smog and affect cardiac and pulmonary disease. Introduction: 1,2,4-Trimethylbenzene, a chemical derivative of benzene, is an industrial solvent and easily volatilizes to the atmosphere. In the presence of other VOCs, it was found to contribute to formation of photochemical smog. Photochemical smog is known to exacerbate respiratory conditions, including asthma and may contribute to cardiac and pulmonary disease. This study examined 1,2,4-Trimethylbenzene in hydraulic fracturing fluids and produced water and its ability to contribute to atmospheric levels of GHGs and photochemical smog. Methods and Materials: A meta-analysis was performed and articles related to1,2,4-Trimethylbenzene evaluated. Databases searched include PubMed, Scopus, Web of Science, TOXNET and Science direct. Keywords 1,2,4-Trimethylbenzene, pseudocumene, Trimethylbenzene, atmospheric conversion, atmospheric degradation/reaction, hydraulic fracturing, and health effects. Published article dates ranged from 1994 – 2011. Inclusion criteria were chemical properties of 1,2,4-Trimethylbenzene, atmospheric degradation and reaction, and atmospheric sustainability, and health effects. Exclusion criteria were articles related to 1,2,4-Trimethylbenzene and water pollution, and animal toxicology studies. Articles meeting inclusion criteria were retrieved as full-text and examined. Results: This study confirmed high concentrations of 1,2,4-Trimethylbenzene in hydraulic fracturing fluids and produced water, and ability to aerosolize to the atmosphere from water and soil. Degradation of 1,2,4-TMB in the atmosphere by reactions with hydroxyl radicals are an indirect contributor to atmospheric GHG levels from hydroxyl radical scavenging, and may contribute to local/regional climate change. Slow atmospheric conversion of 1,2,4-TMB in the presence of ozone was found to occur with a half -life of more than 24 years, making it a candidate for long-range transportation. Conclusion: 1,2,4-Trimethylbenzene may be present in tanks and ponds in areas where hydraulic fracturing is occurring. The general public in close contact with these tanks and ponds may be exposed to 1,2,4-Trimethylbenzene in air and may experience adverse health effects.