Article
Engineering, Environmental
Sijia Liu, Weilin Huang, Jingjing Yang, Yu Xiong, Ziqing Huang, Jinling Wang, Tingting Cai, Zhi Dang, Chen Yang
Summary: Microplastics (MPs), resulting from the breakdown of plastic wastes, are widely distributed in the environment. Under ultraviolet (UV) radiation, the further fragmentation of MPs may lead to the formation of environmentally persistent free radicals (EPFRs). This study investigated the correlation between EPFRs concentrations and UV energy, using different types of plastics and UV light sources. The results showed that the structure of MPs and the level of UV energy influenced the generation of EPFRs. It was also observed that UVC radiation led to faster formation of free radicals compared to UVB and UVA. The study provides insights into the mechanisms of EPFRs formation on microplastic particles and highlights the broad impacts of EPFRs on the fate and transport of MPs in aquatic environments.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Pengfei Cheng, Xuqiang Zhao, Hassan El-Ramady, Tamer Elsakhawy, Michael Gatheru Waigi, Wanting Ling
Summary: The study revealed that metal oxides play a dual role in photocatalysis, both promoting the photodegradation of contaminants like triclosan and inhibiting it by competing with the contaminants for irradiation. Additionally, metal oxides were found to promote the formation of environmentally persistent free radicals (EPFRs), with EPFRs yields dependent on the concentration of metal oxides. This research provides new insights into the environmental impacts of metal oxides and the formation and fate of EPFRs in soil and aquatic environments.
Article
Environmental Sciences
Sikandar Azam, Vasily Kurashov, John H. Golbeck, Sekhar Bhattacharyya, Siyang Zheng, Shimin Liu
Summary: Coal dust is a major hazardous pollutant in coal mining environment and contains environmentally persistent free radicals (EPFRs). This study used EPR spectroscopy to analyze EPFRs characteristics in different types of nano-size coal dust and compared their stability and EPR parameters. EPFRs in coal were found to be stable and mostly comprised of oxygenated carbon centered or carbon and oxygen centered free radicals. EPFRs concentration in coal dust was proportional to carbon content and inversely related to g-values. The characteristics of EPFRs in coal dust were similar to those found in other environmental pollutants. It is recommended to study the role of EPFR-loaded coal dust in inhalation toxicity.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Engineering, Environmental
Shuting Liu, Guorui Liu, Lili Yang, Da Li, Minghui Zheng
Summary: This article summarizes the role of different metal compounds in the formation and stabilization of environmentally persistent free radicals (EPFRs). It emphasizes the importance of understanding EPFR characteristics and developing control strategies.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Heather L. Runberg, Brian J. Majestic
Summary: Environmentally persistent free radicals (EPFRs) are a type of pollutant found on fine atmospheric particulate matter (PM2.5), particularly those formed from combustion processes. EPFRs are organic radicals that can persist in the environment for days to years. Recent studies have shown increased interest in the toxicity of EPFRs, as they have the ability to form reactive oxygen species (ROS), but there is limited knowledge about how their characteristics change as PM2.5 ages in the atmosphere. In this study, newly produced hexane-generated soot was exposed to simulated sunlight, and changes in the EPFR characteristics were measured. The results showed no changes in EPFR characteristics due to sunlight exposure, but the ability of the soot to form hydroxyl radicals (OH) was greatly reduced by photoaging.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Li Wang, Danli Liang, Jiarong Liu, Lin Du, Eric Vejerano, Xiuhui Zhang
Summary: This study investigated the influence of acidic and basic pollutants on the formation of EPFRs using DFT and AIMD calculations. The findings showed that these pollutants can enhance the formation of EPFRs through different mechanisms. Acidic pollutants transfer hydrogen atoms to form EPFRs, while basic pollutants extract hydrogen atoms to form phenoxy EPFRs.
Article
Engineering, Environmental
Jinfeng Zhao, Guofeng Shen, Lin Shi, Hao Li, Di Lang, Lu Zhang, Bo Pan, Shu Tao
Summary: Residential biomass and coal burning are important emission sources for environmentally persistent free radicals (EPFRs). This study conducted a field campaign in rural China to evaluate the presence and characteristics of EPFRs generated from residential biomass and coal burning. The results showed that EPFRs emissions from crop residues burning were significantly higher than those from firewood and coal. Fuel type was found to be the primary factor controlling EPFR discharge. Biomass burning had higher EPFRs per particle compared to coal combustion. EPFRs had stronger relationships with carbonaceous components. EPFRs from biomass burning were mainly generated during the pyrolysis of fuels, while EPFRs from coal combustion were mainly associated with refractory organic compounds.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Huibin Guo, Yidan Wang, Kaixing Yao, Han Zheng, Xinji Zhang, Rui Li, Ning Wang, Haiyan Fu
Summary: This study investigates the characteristics and formation mechanism of environmentally persistent free radicals (EPFRs) in combustion particles after photoexcitation using electron paramagnetic resonance (EPR) spectroscopy. The results showed that secondary EPFRs can be generated after illumination, and their lifetime is approximately 1 day. Non-extractable substances were found to be the main contributors to secondary EPFRs, followed by extractable organics. The findings of this study have important implications for assessing the health risks of atmospheric particles.
ENVIRONMENT INTERNATIONAL
(2023)
Article
Environmental Sciences
Dyussenova Ainur, Qingcai Chen, Yuqin Wang, Hao Li, Hao Lin, Xuying Ma, Xin Xu
Summary: The impact of COVID-19 control measures on air quality has been significant, but there is limited research on the toxicity of atmospheric particulate matter during the epidemic. This study found that PM2.5 concentration decreased by 48% during the city lockdown (CLD) in Xi'an, China. The concentrations of other air pollutants and components also decreased, except for O-3 which increased during CLD. The concentration of environmentally persistent free radicals (EPFRs) in PM2.5 decreased by 12%, while oxidative potential (OP) slightly increased. The study suggests a need for further research on the health effects of EPFRs and OP, as well as the secondary processing of EPFRs and OP during lockdown periods.
ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Xia Guan, Lisa Truong, Slawomir M. Lomnicki, Robyn L. Tanguay, Stephania A. Cormier
Summary: EPFRs can induce developmental hazards in zebrafish embryos, with exposure to concentrations greater than 60 μg/mL of DCB-230 leading to high mortality. Additionally, TEMPOL shows a protective effect against the toxicity of EPFRs in zebrafish embryos.
Article
Environmental Sciences
Jinfeng Zhao, Lin Shi, Wenyan Duan, Hao Li, Peng Yi, Wenmei Tao, Guofeng Shen, Shu Tao, Bo Pan, Baoshan Xing
Summary: Emission factors (EFs) for environmentally persistent free radicals (EPFRs) in PM2.5 from burning of different solid fuels vary significantly, with crop residue identified as the main contributor to EPFRs emissions in China. Provinces with higher equivalent cigarette numbers of EPFRs in PM2.5 are mainly agricultural areas, where rural residents tend to use readily available fuels. Additionally, EPFRs in PM2.5 collected during a 2-month photoaging were found to be more stable in particles with higher organic carbon contents.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Hanhan Li, Zhen Zhao, Xiao-San Luo, Guodong Fang, Dong Zhang, Yuting Pang, Weijie Huang, Tariq Mehmood, Mingwei Tang
Summary: The presence of EPFRs in PM2.5 is potentially harmful to human health, especially during the cold season when exposure concentrations and cell toxicity are higher. Metals and carbon fractions are significantly correlated with the presence of EPFRs.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2022)
Article
Environmental Sciences
Zhansheng Li, Hongxia Zhao, Xintong Li, Tadiyose Girma Bekele
Summary: EPFRs are a class of hazardous pollutants that pose harmful effects on human health and exist in PM2.5 in Dalian, China. Coal combustion and vehicular exhaust are the primary sources of EPFRs, providing important evidence for controlling air pollution.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Engineering, Environmental
Kai Xiao, Zedong Wang, Yousong Zhou, Donglei Fu, Yongqiang Zhang, Zhihan Luo, Yichun Lin, Qingyue Wang, Juan Pei, Guofeng Shen
Summary: Environmental persistent free radicals (EPFRs) have raised concerns due to their potential adverse effects on human health. This study investigated the characteristics and formation mechanisms of EPFRs in road dust from different functional areas of an urban city. The results showed that EPFRs were enriched in finer dust particles and significantly correlated with total Fe, indicating different impacts of soluble and insoluble metals on EPFR formation. Health risk assessment revealed high potential risks through ingestion and dermal exposure to EPFRs in road dusts. Future research should focus on formation mechanisms and quantitative evaluation of health risks.
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
(2023)
Article
Environmental Sciences
Huijie Li, Hao Li, Ning Zuo, Yi Liu, Di Lang, Christian Steinberg, Bo Pan, Baoshan Xing
Summary: Environmentally persistent free radicals (EPFRs) have attracted extensive attention due to their potential toxicity. In this study, the direct toxicity of EPFRs was confirmed by comparing systems without EPFRs, and it was found that EPFRs-containing particles exhibited significant toxicity to Caenorhabditis elegans (C. elegans), while the parent chemical and intermediate degradation products did not. EPFRs mediated the generation of reactive oxygen species and increased gene expressions related to oxidative stress, biotransformation, energy homeostasis, survival, proliferation, cell and embryonic development in C. elegans.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
