title: A Multifaceted Analysis of Migration, Distribution, Exchange Dynamics, and Health Risks of Typical Xenoestrogens at Surface Water and Atmosphere in Suzhou
Creators: name: Wang, Minhao
Publisher: name: University of Liverpool Repository
Year: 2028

description: Xenoestrogens, also known as environmental estrogens, are ubiquitous in the environment and belong to a subset of endocrine disruptors that interfere with the normal functioning of endocrine systems, leading to various health issues. Xenoestrogens can be classified as natural estrogens, synthetic estrogens, and industrial chemicals exhibiting estrogenic properties. Among these, plasticisers, a leading type of xenoestrogen, are industrial chemicals commonly applied in manufacturing processes and utilised as additives in plastic products. Phthalates (PAEs), bisphenols (BPs), alkylphenols (APs) and organophosphate (OPEs) are four common types of plasticisers that are prevalent in water and the atmosphere. Human activities significantly influence the xenoestrogen levels in atmospheric particulate matter and water. The Taihu Lake Basin in Suzhou represents a crucial freshwater ecosystem vulnerable to contamination from diverse anthropogenic sources. The region's rapid urbanisation and industrialisation contribute to substantial environmental pollution. Despite being an emerging atmospheric organic pollutant, research on xenoestrogen in the Taihu Lake Basin remains relatively inadequate. Xenoestrogens are considered trace environmental pollutants, with certain meteorological factors influencing its concentration. The primary source of xenoestrogens in inland lakes is believed to be atmospheric transportation. Understanding the sources and fate of xenoestrogens requires thoroughly investigating their air-water exchange process. Previous studies on this exchange in inland waters have been limited, and there is evidence suggesting that differences in population demographics may lead to variations in the health impacts of the same air pollutants.
The primary objective of this study is to conduct a comprehensive analysis of xenoestrogen in the Taihu Lake Basin, focusing on source contribution, environmental distribution, interface exchange, and associated public health and ecological risk. The research initially examines the migration under various situations and dietary exposure risk of PAEs xenoestrogen from food package materials. Subsequently, the study evaluates the spatial distribution and potential risks of xenoestrogens in surface water. Data synthesis was performed on the air-water exchange flux reported in the previous literature. The study further compares the observed air-water exchange flux in the Xietang River and East Taihu Lake to assess changes in xenoestrogen in the air-water exchange. Furthermore, a two-year long-term monitoring effort reveals the temporal distribution of xenoestrogen in the atmospheric particulate matter smaller than 2.5 micrometres (PM2.5) within the Suzhou urban area (specifically the campus of Xi'an Jiaotong-Liverpool University (XJTLU)). The study also investigated factors influencing xenoestrogen concentration and conducted a health assessment in response to the presence of xenoestrogens in both water and air.
In Chapter 2, an assessment was conducted on the spatial distribution and potential risks of xenoestrogens found in surface water within the Taihu Lake Basin. The analysis also included the examination of heavy element concentrations and physicochemical parameters of water samples to establish relationships between heavy elements, physicochemical parameters, and xenoestrogens, as well as to identify potential sources of these pollutants. Xenoestrogens were detected at concentrations ranging from 0.001 to 208.67 ng·L-1, with the highest levels attributed to Bisphenol A (BPA). In comparison, concentrations of estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) were comparatively lower. Certain regions exhibited a potentially high risk of estrogenic activity, especially for BPA, highlighting the importance of regular monitoring of xenoestrogens to mitigate potential risks in the future. Analysis of the correlation between xenoestrogens, physicochemical parameters, and heavy element content indicated a significant positive correlation (p&lt;0.05) between total chromium content in water bodies and xenoestrogens levels. The study also proposed potential management strategies for xenoestrogens, offering actionable plans for relevant stakeholders. 
In Chapter 3, a study was conducted to explore the monthly distribution, seasonal variation, potential source and human health effects of Dibutyl Phthalate (DBP), Di (2-Ethylhexyl) phthalate (DEHP) and Diisobutyl phthalate (DIBP), BPA and Nonylphenol (NP) and 4-tert-Octylphenol (4-t-OP) in PM2.5 at a monitoring site on the campus of XJTLU. The concentrations of six target xenoestrogens were measured in 122 atmospheric samples collected once a week. BPA was found to be the predominant xenoestrogen across the campus, with concentrations peaking at 126.52 ± 0.67 ng·m-3. During the spring and summer of 2022, there was a significant increase in DBP and DEHP concentrations (p&lt;0.05). The average concentrations of BPA were significantly (p&lt;0.05) higher in winter compared to summer in 2022. A significant correlation (|R|&gt;0.4, p&lt;0.05) was observed between temperature and the presence of BPA and DEHP, while atmospheric pressure was also found to impact the concentration of BPA in PM2.5. Applying the weighted potential source contribution function (WPSCF) and weighted concentration-weighted trajectory (WCWT) identified Suzhou and its surrounding regions as potential sources of xenoestrogens. The non-dietary non-carcinogenic (hazard index (HI) &lt;1) and carcinogenic risk (ILCR&lt;10-6) for all residents did not exceed the threshold limit. Overall, infants and young children were identified as more susceptible to exposure risks associated with xenoestrogens of PM2.5.
In Chapter 4, a data synthesis study was conducted to evaluate the global air-water exchange and dry deposition flux of PAEs and OPEs xenoestrogens. The aim was to identify the factors that affect this exchange process, which is crucial for understanding the atmospheric transport and environmental fate of xenoestrogens. The research involved a comprehensive review of existing literature and statistical data analysis. The findings showed that the air-water exchange and dry deposition flux of various xenoestrogens differ due to their distinct chemical properties, such as molecular weight, water solubility, and vapour pressure. Additionally, climatic conditions were found to influence the air-water exchange of xenoestrogens, particularly the impact of wind speed on the dry deposition of OPEs. However, dry deposition may not significantly contribute to the air-water exchange process in specific regions like the Great Lakes of the United States. Further investigations are needed to explore additional mechanisms related to influencing factors and to emphasise research on inland surface water systems.
In Chapter 5, an investigation was conducted on the distribution, air-water exchange, and non-dietary health risks associated with xenoestrogens in water and PM2.5 samples collected from the Xietang River and East Taihu Lake. The mean concentrations of total xenoestrogens in surface water and PM2.5 were determined to be 40.30 ± 7.19 ng·L-1 and 460.13 ± 31.87 ng·m-3 (East Taihu Lake), 536.69 ± 99.62 ng·L-1 and 63.93 ± 3.82 ng·m-3 (Xietang River), respectively. By utilising a two-film model, the air-water exchange flux was calculated, with BPA exhibiting the widest range among all xenoestrogens from -1.33×109 ng·m-2·d-1 to 2.88×106 ng·m-2·d-1 near East Taihu Lake and -1.98×109 ng·m-2·d-1 to 1.97×109 ng·m-2·d-1 near Xietang River. Various xenoestrogens displayed different air-water exchange directions. DBP shows the highest dry deposition fluxes of 9373.26 ± 611.59 ng·m-2·d-1 near East Taihu Lake and 478.97 ± 48.00 ng·m-2·d-1 near Xietang River. The study also assessed the non-dietary exposure risk of six xenoestrogens in PM2.5 for adults, concluding that no non-cancer risks were identified, with a hazard index below 1. Additionally, DEHP is also within an acceptable level of carcinogenic risk (Incremental Lifetime Cancer Risk (ILCR)&lt;10-6). These results underscore the importance of developing and implementing xenoestrogen management policies in the Taihu Lake Basin.
In Chapter 6, this case study focuses on takeaway food packaging as a potential source of xenoestrogen, quantifying the levels of PAE xenoestrogen present in takeaway food packaging and analysing the migration amounts under various conditions. A comprehensive evaluation of the health impact of PAEs was conducted to assess the extent of daily human exposure to these chemicals. The results revealed that five PAEs (DEHP, Butyl benzyl phthalate (BBP), Diethyl phthalate (DEP), Dimethyl phthalate (DMP) and DBP) were detectable in the n-Hexane extract of plastic food packaging materials at room temperature. Elevated levels of PAEs were correlated with increased temperature or when in contact with an oily food simulant solvent. The levels of PAEs in dietary exposure did not exceed the concentration that could pose a risk to human health, as determined by the dietary exposure assessment. This study highlighted a significant connection between the release of xenoestrogens and human health. Consequently, further detailed investigations into the distribution of xenoestrogen in water and atmosphere were conducted in this study, along with assessments of their impact on human health and the ecosystem.
Chapter 7 provides a synthesis of significant findings of the study and some policy management suggestions for xenoestrogens, and also proposes several potential directions for future research on xenoestrogens. In this research, xenoestrogens are detected in the atmosphere and surface water within Taihu Lake Basin, exhibiting migration and exchange across various mediums. Anthropogenic sources are considered the primary pollution source and the main driving force of dispersion. Food packaging materials are one primary potential source. Although the health risks associated with xenoestrogen are generally considered to be low based on this study, the potential risks associated with long-term exposure and their impact on specific vulnerable populations should not be ignored. To effectively manage the environmental and health risks of xenoestrogens, policymakers need to adopt multi-layered management measures. Measures such as biomonitoring, alternative development, public education, and labelling transparency will help reduce public exposure. Collaboration between government, researchers, and industry is key to ensuring effective management of xenoestrogens. To enhance research in relevant fields, it is recommended to initial efforts on the development of real-time monitoring technologies. Subsequently, laboratory-based simulation studies could be conducted to investigate the environmental fate of xenoestrogens. Additionally, novel adsorbent materials are suggested to enhance removal efficiency. Finally, a molecular toxicology approach could be employed to explore the specific mechanism of impact of xenoestrogens on the health of diverse populations.