Epigenetic transgenerational effects of PM2.5 collected from southern Taiwan on sperm functions and DNA methylation in mouse offspring.

During respiration, particulate matter with a diameter of 2.5 µm or less (PM2.5) suspended in the atmosphere enters the terminal alveoli and blood. PM2.5 particles can attach to toxic substances, resulting in health problems. Limited information is available regarding the effects of prenatal exposure to water-soluble PM2.5 (WS-PM2.5) and water-insoluble PM2.5 (WI-PM2.5) on male reproduction. In addition, whether exposure to these particles has transgenerational effects remains unknown. We investigated whether prenatal exposure to WS-PM2.5 and WI-PM2.5 disrupts sperm function in generations F1, F2, and F3 of male mice. Pregnant BALB/c mice were treated using intratracheal instillation on gestation days 7, 11, and 15 with 10 mg of a water extract or insoluble PM2.5. On postnatal day 105, epididymal sperm count, motility, morphology, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) production, the sperm chromatin DNA fragmentation index (DFI), and testicular DNA methyltransferase (Dnmt) levels were evaluated in all generations. Whole-genome bisulfite sequencing was used to analyze the DNA methylation status of generation F3. According to the results, exposure to WS-PM2.5 affected sperm morphology, ROS production, and mean DFI in generation F1; ROS production and mean DFI in generation F2; and sperm morphology and MMP in generation F3. Similarly, exposure to WI-PM2.5 affected sperm morphology, ROS production, mean DFI, %DFI, and Dnmt1 expression in generation F1; sperm morphology, MMP, and ROS production in generation F2; and sperm morphology, ROS, and %DFI in generation F3. Two hypermethylated genes, PRR16 and TJP2, were observed in the WS-PM2.5 and WI-PM2.5 groups, two hypomethylated genes, NFATC1 and APOA5, were observed in the WS-PM2.5 group, and two hypomethylated genes, ZFP945 and GSE1, were observed in the WI-PM2.5 group. Hence, prenatal exposure to PM2.5 resulted in transgenerational epigenetic effects, which may explain certain phenotypic changes in male reproduction.

Surface design of g-C3N4 quantum dot-decorated TiO2(001) to enhance the photodegradation of indoor formaldehyde by experimental and theoretical investigation.

Formaldehyde (CHOH), a common volatile organic compound, causes many adverse effects on human health. The highly exposed TiO2(001) facet possesses a high photodegradation efficiency of CHOH due to its excellent ability to trap photogenerated holes and high density of surface unsaturated Ti atoms (Ti5c) to bind CHOH. However, the rapid recombination of photoinduced electron-hole pairs of TiO2(001) limits the photodegradation efficiency. We adopted a strategy of decorating TiO2(001) with g-C3N4 quantum dots (QDs), exploiting the quantum effect of g-C3N4QDs and their combined staggered band structure. This decoration improves the photocatalytic activity of TiO2(001). Moreover, the chemical configuration of g-C3N4QDs/TiO2(001) and the combination mode between the g-C3N4QDs and TiO2(001) support were explored in detail using high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. Following the physiochemical characteristic results, the transport mechanism of photoinduced carriers was further analyzed by ultraviolet photoelectron spectroscopy (UPS), electron paramagnetic resonance (EPR), and Heyd-Scuseria-Ernzerh (HSE) exchange-correlation functional calculations. Finally, the performance and reaction mechanism of the photodegradation of CHOH by TiO2(001) and g-C3N4QDs/TiO2(001) were thoroughly investigated. The results show that the g-C3N4QDs were composed of an N-defect tri-s-triazine supported by TiO2(001) via a strong C-O-Ti chemical bond, which accelerated the separation of photoinduced carriers through a Z-scheme route. The photodegradation and mineralization efficiencies of CHOH were significantly promoted by 30% and 60% for g-C3N4QDs/TiO2(001) compared with those of TiO2(001). The photodegradation mechanism proceeded as CHOH - dioxymethylene - formate - carbonate - CO2. This study provides a surface engineering means to design highly active modified TiO2 for CHOH photodegradation.

Spatiotemporal distribution characteristics and potential sources of VOCs at an industrial harbor city in southern Taiwan: Three-year VOCs monitoring data analysis.

Kaohsiung City is the largest harbor city in Taiwan. The Linhai Special Industrial Complex (LSIC), which is the largest heavy industrial zone in Taiwan, and other industrial zones and storage station of petrochemicals are adjacent to the Kaohsiung Port. Volatile organic compounds (VOCs), which are discharged from industrial processes in this large industrial area, are likely to cause the poor ambient air quality and atmospheric visibility in Kaohsiung City. This study uses the continuous monitoring data of 54 VOCs during 2018-2020 at eight air quality monitoring stations in the industrialized city to evaluate the spatiotemporal distributions and seasonal variations of VOC concentrations. Principal component analysis and ratios of benzene, toluene, ethylbenzene and xylenes (BTEX) are used to track the potential sources of VOCs for different stations. The highest average concentration of total volatile organic compounds (TVOC) was observed in winter (32.54 ppb), while the lowest TVOC concentration was observed in summer (25.84 ppb), which is related to the prevailing wind directions of monsoons. Kaohsiung is located in the weak monsoon wake area, and air pollutants are easily accumulated in the winter. The southwest wind prevailing in summer results in good diffusion and frequent rainfalls. However, the Qijin station close to the seashore has the highest average TVOC concentration among the eight stations. The seasonal prevailing winds caused the average TVOC concentrations in summer (41.3 ppb) to be higher than that in winter (31.62 ppb) at the Qijin station. It was attributed to the fact that the Qijin Peninsula is vulnerable to VOC emissions from ship sailing in the Taiwan Strait, the processing and export zone, and the shipbuilding yards nearby the Kaohsiung Harbor. Comparing the BTEX ratios of Kaohsiung City with the data of Hong Kong, we found that VOCs were mainly from industrial emissions in Kaohsiung City, which were significantly different from Hong Kong that VOCs were mainly emitted from traffic emissions. Overall, VOCs in Kaohsiung City have been decreased from 2018 to 2020; however, according to the analytical results of ozone formation potential, toluene and m,p-xylenes are the most potential photochemical precursors for ozone formation. The government should enforce and regulate aromatic hydrocarbons from industrial emission sources to reduce the potential formation of ozone.

Repeated exposure to fine particulate matter constituents lead to liver inflammation and proliferative response in mice.

BACKGROUND: Fine particulate matter (particulate matter with aerodynamic diameter of ≦2.5 µm, PM2.5) exposure cause adverse health effects, including lung inflammation. Through intra-tracheal instillation of PM2.5 components, the study aimed to evaluate the inflammatory and proliferative effects on mice liver. PM2.5 samples were collected near an industrial complex at southern Taiwan. Mice were exposed to water extracts or insoluble particles by intra-tracheal instillation. Male C57BL/6 mice were divided into five groups: control, low dose insoluble particle exposure (LP), high dose insoluble particle exposure (HP), low dose water extract exposure (LW), and high dose water extract exposure (HW). Biochemical analysis, western blotting, histological examination, and immunohistochemistry were employed to evaluate the results. RESULT: Enrichment factor (EF) of metallic elements showed that the EFs of trace elements (Ti, V, Ni, Zn, Pb, Cr, and Cu) in PM2.5 were above 10. Hematoxylin and Eosin (H&E) staining of the liver tissue showed inflammatory infiltration in particle exposure group; hepatocyte ballooning degeneration and karyomegaly were seen in the water extract exposure group. Upregulation of inflammatory signaling, p65 and p50, and caspase-3 (an important effector involved in apoptosis) positive hepatocytes was significantly increased in the HP group, followed by an elevation in protein levels of growth arrest and DNA damage-inducible protein 153 (GADD153). Increased protein expression of proliferating cell nuclear antigen (PCNA) was noted in the LW and HW groups. An increase in phosphorylation of regulators of cell proliferation, Akt and extracellular signal-regulated kinase (ERK) 1/2, were detected in the LW and HW groups. CONCLUSION: The present study shows that the insoluble particle composition of PM2.5 induced inflammatory signaling and cytokines upregulation in the liver, accompanied with inflammatory cell and macrophage infiltration and an abnormal liver function. Exposure of water extract to PM2.5 induced signals of upregulated cellular proliferation, elevated markers of cell proliferation in liver, hepatocyte ballooning degeneration and karyomegaly.

In-situ measurement of greenhouse gas emissions from a coastal estuarine wetland using a novel continuous monitoring technology: Comparison of indigenous and exotic plant species.

This study investigated in-situ the seasonal and diurnal variation of emissions of greenhouse gases (GHGs) from both indigenous and exotic plant species and different environments in the Kaomei Estuary Wetland in central Taiwan with a self-designed non-dispersive infrared monitoring system. This study computed CO2 equivalent (CO2-e) emissions to identify their contribution to global warming. The net primary production and carbon sequestration were then estimated to determine the carbon budget of the coastal estuarine wetland. It concluded that the Kaomei Estuary Wetland functioned as a GHG source and a carbon sink. A significant diurnal variation of GHG emissions was observed, with generally lower daytime CO2 emissions than those at nighttime, while an opposite trend was observed for CH4 and N2O emissions. High solar radiation in the daytime enhanced the CO2 uptake by plant species via photosynthesis, and also accelerated the microbial activities in waters and soil/mud, both resulting in the decrease in atmospheric CO2 concentration. The highest GHG emissions were observed in summer, followed by fall, spring, and winter. Although the concentrations of GHG emissions from the coastal estuarine wetland were in the order as CO2>CH4>N2O, N2O has the highest impact on global warming. Biomass debris played an important role in carbon sequestration, which is stored in soils and muds and stimulated methanogenic bacteria to emit CH4. Tidal fluctuation and sewage discharge brought nitrogen-containing organics to the coastal estuarine wetland, resulting in high emission of N2O from nitrification and denitrification processes. Two vascular plants, Spartina alterniflora, and Phragmites australis emitted more GHGs than the other two plant species. However, the highest GHG emissions from the Kaomei Estuary Wetland was attributed to Bolboschoenus planiculmis due to its largest coverage area. The annual net primary production (NPP) varied mainly with vegetation coverage and season. The exotic Spartina alterniflora had the highest annual NPP compared to the indigenous plant species because of its high nutrient uptake from the soil/mud by its thriving roots.

Evidence for Fossil Fuel PM1 Accumulation in Marine Biota.

When fine particulates such as those with a diameter of approximately 1 µm (particulate matter, PM1) are released from fossil fuel combustion into the air, they warm the atmosphere and contribute to millions of premature deaths in humans each year. Considerable quantities of PM1 eventually enter the oceans as suspended particulates, yet subsequent removal mechanisms are poorly understood. In fact, the presence of PM1 in marine biota has never been reported. Since sea anemones are opportunistic suspension feeders, they are anticipated to incorporate and accumulate PM1 in their bodies. By histological examination, PM1 was detected in 21 of the 22 sea anemones collected from Taiwan and Southeast China, with a depth of intertidal zone to 1000 m. PM1, if present, was always detected in endodermal layers and had the same dominant color (i.e., black, brown, or green) in different species from the same site. The bioaccumulation factor of PM1 in sea anemones was approximately 5-7 orders of magnitude. Based on radioisotope 14C results, the contribution of fossil fuel source PM1 was 8-24%. Regardless of PM1's color, S and Fe were commonly detected by scanning electron microscopy and energy-dispersive spectrometry (SEM-EDS), suggesting anthropogenic sources. Furthermore, a maternal transfer of materials was suggested based on the existence of PM1 in sea anemone eggs and in brooding and released juveniles. The significance of PM1 accumulation by biota in aquatic ecosystems and the potential risk to living organisms via food webs warrant further investigation.

An overview of the development of vertical sampling technologies for ambient volatile organic compounds (VOCs).

Atmospheric volatile organic compounds (VOCs) are harmful to human health and the environment, and are precursors of other toxic air pollutants, e.g. ozone (O3) and secondary organic aerosols (SOAs). In recent years, due to scientific and technological advancements, vertical VOC profile in the atmosphere has been increasingly studied since it plays an essential role in the atmospheric research by providing multilevel three-dimensional data. Such information will improve the predictive ability of existing air quality models. This review summarizes the latest development of vertical VOC sampling technologies, highlighting the technical and non-technical challenges with possible solutions and future applications of vertical VOC sampling technologies. Further, other important issues concerning ambient VOCs have also been discussed, e.g. emission sources, VOC air samplers, VOC monitoring strategies, factors influencing airborne VOC measurement, the use of VOC data in air quality models and future smart city air quality management. Since ambient VOC levels can fluctuate significantly with altitude, technologies for vertical VOC profiling have been developed from building/tower-based measurements and tethered balloons to aircrafts, unmanned aerial vehicles (UAVs) and satellites in order to improve the temporal-spatial capacity and accuracy. Between the existing sampling methods, so far, UAVs are capable of providing more reliable VOC measurements and better temporal-spatial capacities. Heretofore, their disadvantages and challenges, e.g. sampling height, sampling time, sensitivity of the sensors and interferences from other chemical species, have limited the application of UAV for vertical VOC profiling.

Analysis of carbon sink effects for saline constructed wetlands vegetated with mangroves to treat mariculture wastewater and sewage.

In this study, two saline mangrove artificial wetlands, Datang Saline Constructed Wetland (DSCW) created for treating mariculture wastewater and sewage, vegetated with Avicennia marina, and Mangrove Wetland Park (MWP) created for mangrove conservation, vegetated with Rhizophora stylosa, were selected for assessment of carbon sequestration and carbon budget based on measuring greenhouse gas (GHG) emissions and net primary productivities. The average GHG flux and net carbon sequestration flux as carbon dioxide equivalent (CO2 eq.) were measured. The results showed that the GHG flux emitted from DSCW and MWP were 2,128 and 2,148 g CO2 eq./m2-yr, respectively, while the flux of net sequestered carbon was 2,909 and 3,178 g CO2 eq./m2-yr, respectively, which achieved carbon budget values of -676 and -230 g CO2 eq./m2-yr, respectively, exhibiting carbon source effects. Some amounts of N2O, with a high global warming potential of 265, emitted from both artificial wetland systems might cause high GHG flux as CO2 eq. emitted from the wetland systems. It was concluded that both the nitrogenous contents and environmental conditions suitable for microbial production of N2O might be the main factors to change the wetland systems from carbon sinks to carbon sources.

Vertical stratification of volatile organic compounds and their photochemical product formation potential in an industrial urban area.

High emissions of volatile organic compounds (VOCs) from the petrochemical industry and vehicle exhaust may contribute to high ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP). In this study, the vertical profiles of VOCs were created for the southern Taiwan industrial city of Kaohsiung. Vertical air samples were collected up to 1000 m using an unmanned aerial vehicle (UAV). In Renwu District, VOC distribution was affected by the inversion layer up to 200 m height. Total VOCs (36-327 ppbv), OFP (66-831 ppbv) and SOAFP (0.12-5.55 ppbv) stratified by height were the highest values at 300 m. The VOCs originated from both local and long-distance transport sources. These findings can be integrated into Kaohsiung's future air quality improvement plans and serve as a reference for other industrialized areas worldwide.

Investigating the differences between receptor and dispersion modeling for concentration prediction and health risk assessment of volatile organic compounds from petrochemical industrial complexes.

Receptor and dispersion models both provide important information to help understand the emissions of volatile organic compounds (VOCs) and develop effective management strategies. In this study, differences between the predicted concentrations of two models and the associated impacts on the estimated health risks due to different theories behind two models were investigated. Two petrochemical industrial complexes in Kaohsiung city of southern Taiwan were selected as the sites for this comparison. Although the study compares the approaches by applying the methods to this specific area, the results are expected to be adopted for other areas or industries. Ninety-nine VOC concentrations at eight monitoring sites were analyzed, with the effects of diurnal temperature and seasonal humidity variations being considered. The Chemical Mass Balance (CMB) receptor model was used for source apportionment, while the Industrial Source Complex (ISC) dispersion model was used to predict the VOC concentrations at receptor sites. In the results of receptor modeling, 54% ± 11% and 49% ± 20% of the monitored concentrations were contributed by process emissions in two complexes, whereas the numbers increased to 78% ± 41% and 64% ± 44% in the results of dispersion modeling. Significant differences were observed between two model predictions (p < 0.05). The receptor model was more reproducible given the smaller variances of its results. The effect of seasonal humidity variation on two model predictions was not negligible. Similar findings were observed given that the cancer and non-cancer risks estimated by the receptor model were lower but more reproducible. The adverse health risks estimated by the dispersion model exceeded and were 75.3%-132.4% of the values estimated by using the monitored data, whereas the percentages were lowered to the range from 27.4% to 53.8% when the prediction was performed by using the receptor model. As the results of different models could be significantly different and affect the final health risk assessment, it is important to carefully choose an appropriate model for prediction and to evaluate by monitoring to avoid providing false information for appropriate management.

Spatiotemporal variation and inter-transport of atmospheric speciated mercury between Kaohsiung Harbor and neighboring urban areas.

This study investigated the spatiotemporal variation, gas-particle partition, and source resolution of atmospheric speciation mercury (ASM) in Kaohsiung Harbor and neighboring Metro Kaohsiung. Four sampling sites were selected to determine the pollution characteristics and inter-transport of ASM between the port and urban areas. The yearly average GEM, GOM, and PBM concentrations were 7.13 ± 2.2 ng/m3, 331 ± 190 pg/m3, and 532 ± 301 pg/m3, respectively. Notably, GEM emerged as the predominant ASM species (85-94%), primarily originating from anthropogenic emissions from the harbor area and nearby industrial complex. The study revealed a distinct seasonal variation in ASM concentrations in the Kaohsiung Area in the following order: winter > fall > spring > summer. Concerning spatial distribution, ASM concentrations in the port areas were generally higher than those in the urban areas. This disparity was chiefly attributed to the influence of the prevailing winds, local sources, and atmospheric dispersion. Backward trajectory simulation revealed that polluted air masses blown from the northeast in winter and spring, moving along the western in-land part of Taiwan Island, were likely influenced by local sources and long-range transport (LRT). In summer, air pollutants originating from the south were likely transported from the coastal industrial sources. During fall, air masses blown from the western offshore waters transported air pollutants from Kaohsiung Harbor to neighboring Metro Kaohsiung. The results obtained from principle component analysis (PCA) indicated that primary sources in the port areas included ship emissions, vehicular exhausts, and nearby industrial complex, which align with the primary source factors identified by positive matrix factorization (PMF), which were mobile sources and coal-fired industrial boilers. Meanwhile, mobile sources and sulfur-containing fuel/waste combustion were identified as the primary sources in the urban areas.

Deseasonalized trend of ground-level ozone and its precursors in an industrial city Kaohsiung, Taiwan.

Mitigating ground-level ozone (GLO) remains challenging due to its highly nonlinear formation process. Thus, understanding GLO pollution trends is crucial for developing effective control strategies, especially Kaohsiung industrial city, Taiwan. Based on the long-term monitoring data set of 2011-2022, temporal analysis reveals that monthly mean GLO peaks in autumn (40.66 ± 5.10 ppb), carbon monoxide (CO) and major precursors such as nitrogen oxides (NOx), nonmethane hydrocarbons (NMHC) reach their highest levels in winter. The distinct seasonal variation of air pollutants in Kaohsiung is primarily influenced by the unique blocking effect of the mountainous area under the northeasterly wind, as the city is situated downwind, causing high GLO levels during autumn due to the accumulation of stagnant air hindering the dispersion of pollutants. Over the 12 years (2011-2022), the deseasonalized trend analysis was conducted with p < 0.001, revealing a stabilization trend of GLO (+0.04 ppb/yr) from a previous sharp increase. The observed improvement is credited to a drastic decrease in total oxidants (Ox) at -0.63 ppb/yr due to significantly reducing their precursors. Furthermore, the effectiveness of precursor reduction is also supported by GLO daily maximum profile changes. While high GLO events (>120 ppb) decrease, days within midrange (60-80 ppb) rise from 24.4% to 33.3%. A notable difference emerges when comparing daytime and nighttime GLO. While daytime GLO decreased at -0.22 ppb/yr, nighttime GLO increased at +0.34 ppb/yr. Weakened nocturnal titration effects accounted for the nighttime increase. The distinct spatial variations in GLO trends on a citywide scale underscore that areas with complicated industrial activities may not benefit from a continuing reduction of precursors compared to less-polluted areas. The findings of this study hold significant implications for improving GLO control strategies in heavily industrialized city and provide valuable information to the general public about the current state of GLO pollution.

Temporal variations and chemical characteristics of marine PM2.5 at Dongsha Islands, South China Sea: Three-year measurement.

The study of long-range transport effects on marine fine particles (PM2.5), particularly in remote sites such as the Dongsha Islands, is pivotal for advancing our understanding of air pollution dynamics on a regional scale and for formulating effective environmental policies. PM2.5 concentrations were examined over three consecutive years and grouped based on their transport routes. The backward trajectory simulation revealed that high PM2.5 concentrations were observed in the West Channel, originating from North and Central China, the Korean Peninsula, and the Japanese Islands, opposed to the East Channel. High PM2.5 concentrations, commonly observed in winter and spring, were mainly attributed to the Asian Northeastern Monsoons. Water-soluble inorganic ions constituted the major components, accounting for 37.8-48.7% of PM2.5, and followed by metal elements (15.5-20.0%), carbons (7.5-13.3%), levoglucosan (0.01-0.17%), and organic aerosols (0.2-2.2%). Secondary inorganic aerosols as the dominant source accounted for 8.3-24.7% of PM2.5, while sea salts were the secondary major contributor. High levoglucosan contribution (3.8-7.2%) in winter and spring was attributed to biomass burning, mainly from the Indochina Peninsula. Chemical mass balance receptor modeling resolved that major sources of PM2.5 were secondary sulfate, sea salts, fugitive dust, and industrial boilers. This study concluded that the long-range transport of PM2.5 gradually increased since fall, contributing 52.1-74.3%, highlighting its substantial impact on PM2.5 in all seasons except summer.

Identification of potential source regions and long-range transport routes/channels of marine PM2.5 at remote sites in East Asia.

Long-range transport (LRT) of air masses in East Asia and their impacts on marine PM2.5 were explored. Situated in the leeward region of East Asia, Taiwan Island marked by its elevated Central Mountain Range (CMR) separates air masses into two distinct air currents. This study aims to investigate the transport of PM2.5 from the north to the leeward region. Six transport routes (A-F) were identified and further classified them into three main channels (i.e. East, West, and South Channels) based on their transport routes and potential sources. Green Island (Site GR) and Hengchun Peninsula (Site HC) exhibited similarities in their transport routes, with Central China, North China, and Korean Peninsula being the major source regions of PM2.5, particularly during the Asian Northeastern Monsoons (ANMs). Dongsha Island (Site DS) was influenced by both Central China and coastal regions of East China, indicating Asian continental outflow (ACO) as the major source of PM2.5. The positive matrix factorization (PMF) analysis of PM2.5 resolved that soil dust, sea salts, biomass burning, ship emissions, and secondary aerosols were the major sources. Northerly Channels (i.e. East and West Channels) were primarily influenced by ship emissions and secondary aerosols, while South Channel was dominated by oceanic spray and soil dust. The results of W-PSCF and W-CWT analysis indicated that three remote sites experienced significant contributions from Central China in the highest PM2.5 concentration range (75-100%). In contrast, PM2.5 in the 0-25% and 25-50% ranges primarily originated from the open seas, with ship emissions being the prominent source. It suggested that northern regions with heavy industrialization and urbanization have impacts on high PM2.5 concentrations, while open seas are the main sources of low PM2.5 concentrations.

Impacts of ship emissions and sea-land breeze on urban air quality using chemical characterization, source contribution and dispersion model simulation of PM2.5 at Asian seaport.

Fine particulate matter (PM2.5) emitted from marine transportation, bulk materials handling at the docks, and dust dispersion has garnered increased attention, particularly in the interface between port and urban areas. This study explored the inter-transport of PM2.5 between Kaohsiung Harbor and neighboring Metro Kaohsiung. Chemical analyses of PM2.5 samples from four sites include water-soluble ions, metallic elements, carbons, anhydrosugars, and organic acids to establish PM2.5's chemical fingerprints. The CALPUFF air dispersion model is employed to simulate the spatiotemporal distribution of PM2.5 in Kaohsiung Harbor and adjacent urban areas. A clear seasonal and diurnal variation of PM2.5 concentrations and chemical composition was observed in both harbor and urban areas. The high correlation of nighttime PM2.5 levels between the port and urban areas suggests inter-transport phenomena. Sea salt spray, ship emissions, secondary aerosols, and heavy fuel-oil boilers exhibit higher levels in the port area than in the urban area. In Metro Kaohsiung, mobile sources, fugitive dust, and waste incinerators emerge as major PM2.5 contributors. Furthermore, sea breeze significantly influences PM2.5 dispersion from Kaohsiung Harbor to Metro Kaohsiung, particularly in the afternoon. The average contribution of PM2.5 from ships' main engines in Kaohsiung Harbor ranges from 2.9% to 5.3%, while auxiliary engines contribute 3.8%-8.3% of PM2.5 in Metro Kaohsiung.

Chemical fingerprints and source resolution of atmospheric fine particles in an industrial harbor based on one-year intermittent field sampling data.

This study investigated the spatiotemporal variation, chemical characteristics, and source resolution of PM2.5 in an East Asian seaport adjacent to industrial complex and urban area. Three representative harbor sites were selected to simultaneously sample 24-h PM2.5 once every 13 days in four seasons. A significant seasonal variation was observed with the highest and the lowest PM2.5 concentration in February (winter) and May (summer), respectively. High contribution of secondary inorganic aerosols (SIAs) showed that SO2 and NOx emitted from neighboring combustion sources burning coal and heavy fuel oil (HFO) were the major precursors forming secondary inorganic PM2.5. High ratios of V/Ni and V/Cu were observed in summer (June~August) since the prevailing west and southwest winds from outer port carried ship emissions to inter port. The correlation of chemical fingerprints (V, Ni, V/Ni, Zn, nss-SO42-, OC) and the number of ships were high at the Zhung-He Site and moderate at the Qi-Ho Site. The Cl-, Na+, V, Ni, nss-SO42-, OC, and V/Ni of PM2.5 were co-influenced by ship missions and oceanic spray in the Kaohsiung Harbor. The influences were relatively higher for winds blown from the harbor areas than those blown from the industrial areas. Oppositely, the Fe, Mn, Cr, Cu, Ca, Zn, and Al in PM2.5 were higher for winds blown from the industrial areas than those from the harbor areas. The CMB receptor modelling resolved that the major sources of PM2.5 were industrial missions, secondary aerosols, mobile sources, ship emissions, oceanic spray, fugitive dust, biomass burning, and organic carbon. Similar to Busan (South Korea), Brindisi (Italy), Lampedusa (Italy), and Barcelona (Spain), the contributions of ship emissions in the Kaohsiung Harbor were in the range of 7.4-7.8 %. Meanwhile, Kaohsiung Harbor was highly influenced by emissions from industrial areas and urban areas.

Long-range transport of atmospheric speciated mercury from the eastern waters of Taiwan Island to northern South China Sea.

This study explored the temporospatial distribution, gas-particle partition, and pollution sources of atmospheric speciated mercury (ASM) from the eastern offshore waters of the Taiwan Island (TI) to the northern South China Sea (SCS). Both gaseous and particulate mercury were simultaneously sampled at three remote sites in four seasons. The average concentrations of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate bound mercury (PBM) were 2.05 ± 0.45 ng/m3, 19.17 ± 5.39 pg/m3, and 0.11 ± 0.06 ng/m3, respectively. The concentrations of GEM and PBM in the cold seasons were higher than those in the warm seasons, but those of GOM had an opposite trend. In terms of gas-solid partition, ASM was apportioned as 91.3-97.3% of GEM and 2.7-8.7% of GOM and PBM. The average concentrations of GEM, GOM, and PBM at the Green Island (GI) were 2.21 ± 0.47 ng/m3, 22.31 ± 5.35 pg/m3, and 0.12 ± 0.06 ng/m3; those at the Kenting Peninsula (KT) were 2.11 ± 0.43 ng/m3, 20.57 ± 4.38 pg/m3, and 0.11 ± 0.06 ng/m3; and those at the Dongsha Islands (DS) were 1.84 ± 0.40 ng/m3, 15.19 ± 3.58 pg/m3, and 0.08 ± 0.05 ng/m3, respectively. Overall, the spatial distribution of ASM concentrations showed the order as: GI > KT > DS. Air masses blown mainly from the West Pacific Ocean (WPO) and SCS in summer showed the lowest ASM concentrations. Oppositely, high ASM concentrations were commonly observed in spring and winter when polluted air masses were blown by Asian Northeastern Monsoons (ANMs). The transport routes of polluted air masses were originated mainly from North China, Central China, Northeast China, Korea and Japan, and mostly passed through the urban and industrial regions in the northeastern Asian countries.

Volatile organic compounds in ambient air of a major Asian port: spatiotemporal variation and source apportionment.

This study investigated the spatiotemporal variation and source characteristics of volatile organic compounds (VOCs) in Kaohsiung Harbor, one of the busiest ports in the world. The VOCs' potential to form ozone (O3) and secondary organic aerosols (SOAs) was also examined. The temporal variation was studied in February, May, July, and November of 2020, while the spatial distribution was investigated in the export processing zone (KEPZ) and at the two port entrances (E1 and E2). The most polluted month in the harbor was November (37.7 ± 12.6 ppbv), while the most polluted site was the industrial area (KEPZ). A significant positive correlation was found between VOCs and O3 (r = 0.985). Meanwhile, a moderate positive correlation (r = 0.449) was observed between VOCs and secondary organic aerosol formation potential (SOAFP), mainly affected by the concentration of toluene in the study area. The diagnostic ratios indicated that the air parcels in the site were "fresh," and three possible ambient sources of VOC were identified by the positive matrix factorization (PMF): industrial emissions (53.6%), freight transport emissions (29.6%), and others (17.7%). The study highlights the current state of VOCs and their potential sources in the port city of Kaohsiung, which can be used to enhance the strategies for regulating and controlling industrial activities and improving air pollution control measures to reduce VOC emissions.

Emission characteristics of naphthalene from ship exhausts under global sulfur cap.

The global sulfur limit regulation mandates the use of 0.5 % low sulfur fuel oil (LSFO) to reduce emissions of sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter (PM). However, the addition of naphthalene (Nap) to LSFO to stabilize its quality has led to an increase in polycyclic aromatic hydrocarbons (PAHs), with Nap being the main pollutant. This study investigates the effects of Nap in ship exhaust by analyzing the emission concentrations of volatile organic compounds (VOCs) and Nap in the exhaust of 16 ships, including 2 container ships, 6 bulk carriers, 1 tanker, 2 ferries, 3 fishing vessels, and 2 harbor crafts, based on USEPA method TO-15A. The results show that the percentage of Nap emissions in the exhaust gases of the 16 ship engines ranged from 77 % to 97 % of the total volatile organic compound (TVOC). The Nap concentration in the exhaust of fishing vessels, tanker, and harbor craft exceeded the occupational exposure limit of 50,000 µg/m3, with fishing vessels having the highest TVOC and Nap concentrations. The enhanced Nap emission in the air degrades air quality in port cities and poses an obvious potential public health risk. While the benefits of the global sulfur cap are being secured, additional efforts should be made to reduce the undetected side effects. Alternative stabilizers of LSFO should be considered, or Nap emission control should be boosted to mitigate the potential negative impact on harbor air quality.

Chemical characteristics and spatiotemporal variation of marine fine particles for clustered channels of air masses transporting toward remote background sites in East Asia.

This study investigated the chemical characteristics, spatiotemporal distribution, and source apportionment of marine fine particles (PM2.5) for clustered transport channels/routes of air masses moving toward three remote sites in East Asia. Six transport routes in three channels were clustered based on backward trajectory simulation (BTS) in the order of: West Channel > East Channel > South Channel. Air masses transported toward Dongsha Island (DS) came mainly from the West Channel, while those transported toward Green Island (GR) and Kenting Peninsula (KT) came mostly from the East Channel. High PM2.5 commonly occurred from late fall to early spring during the periods of Asian Northeastern Monsoons (ANMs). Marine PM2.5 was dominated by water-soluble ions (WSIs) which were predominated by secondary inorganic aerosols (SIAs). Although the metallic content of PM2.5 was predominated by crustal elements (Ca, K, Mg, Fe, and Al), enrichment factor clearly showed that trace metals (Ti, Cr, Mn, Ni, Cu, and Zn) came mainly from anthropogenic sources. Organic carbon (OC) was superior to elemental carbon (EC), while OC/EC and SOC/OC ratios in winter and spring were higher than those in other two seasons. Similar trends were observed for levoglucosan and organic acids. The mass ratio of malonic acid and succinic acid (M/S) was commonly higher than unity, showing the influences of biomass burning (BB) and secondary organic aerosols (SOAs) on marine PM2.5. We resolved that the main sources of PM2.5 were sea salts, fugitive dust, boiler combustion, and SIAs. Boiler combustion and fishing boat emissions at the site DS had higher contribution than those at the sites GR and KT. The highest/lowest contribution ratios of cross-boundary transport (CBT) were 84.9/29.6% in winter and summer, respectively.