Long-range transport (LRT) reportedly carries air pollutants and microorganisms to downwind areas. LRT can be of various types, such as dust storm (DS) and frontal pollution (FP); however, studies comparing their effects on bioaerosols are lacking. This study evaluated the effect of LRT on viral and bacterial concentrations in Northern Taiwan. When LRT occurred and possibly affected Taiwan from August 2013 to April 2014, air samples (before, during, and after LRT) were collected in Cape Fugui (CF, Taiwan’s northernmost point) and National Taiwan University (NTU). Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was applied to quantify influenza A virus. qPCR and qPCR coupled with propidium monoazide were, respectively, used to quantify total and viable bacteria. Types and occurrence of LRT were confirmed according to the changing patterns of meteorological factors and air pollution, air mass sources (HYSPLIT model), and satellite images. Two Asian DS and three FP cases were included in this study. Influenza A virus was detected only on days before and during FP occurred on January 3–5, 2014, with concentrations of 0.87 and 10.19 copies/m³, respectively. For bacteria, the increase in concentrations of total and viable cells during Asian DSs (17–19 and 25–29 November 2013) was found at CF only (from 3.13 to 3.40 and from 2.62 to 2.85 log copies/m³, respectively). However, bacterial levels at NTU and CF both increased during FP and lasted for 2 days after FP. In conclusion, LRT increased the levels of influenza A virus and bacteria in the ambient air of Northern Taiwan, particularly at CF. During and 2 days (at least) after LRT, people should avoid outdoor activities, especially in case of FP.

While polychlorinated biphenyl (PCB)-related risks have been reported at the cellular, organ, and individual levels in some marine mammals, studies quantifying the PCB-associated population-level effects are limited. Here, we combined chemical analysis and individual-based model simulation to investigate the impact of PCBs on the Indo-Pacific humpback dolphin (sub)population from the Pearl River Estuary (PRE). An annual PCB accumulation rate of 0.29 ± 0.07 mg/kg lipid per year was estimated based on the measured age-specific male data as males continue to accumulate PCBs throughout their lifetime, without depurating contaminant loads. Using the Taiwan Strait dolphin population with low PCBs as a baseline, we compare our model simulations in PRE population to estimate relative population impacts of PCBs and other stressors. When using the current vital rates of the PRE dolphins which have been affected by PCBs and other stressors (e.g., underwater noise, prey limitation, etc.), our simulations revealed a substantial decline (8.1%) in the annual population growth rate (λ) of PRE metapopulation compared to baseline over the next 100 years. At the estimated PCB accumulation rate, the PCB-mediated effects on calf survival and immunity would cause a slight decline (0.9%) in λ relative to baseline. Our findings suggest a relatively limited impact of PCBs on the long-term survival of PRE dolphins among all stressors. However, it should be noted that even under model simulations where dietary PCBs were eliminated, humpback dolphins would still need a long time to reduce their PCB burdens to a relatively “safe” level through biological cycling. Considering that the baseline vital rates might also have been affected by PCBs and other stressors, our results are considered relative rather than absolute. This study provides a starting point for quantifying population-level consequences of contaminant exposure on humpback dolphins, although more efforts are needed to perfect this type of analysis.

Microplastic contamination in ecosystems has emerged as an environmental issue of global significance. This research quantified microplastics in oysters from 22 sites along Taiwan coastlines. In total, 6630 microplastic items were found in 660 oysters of two genera (Crassostrea and Saccostrea). The average content of microplastics was 3.24 ± 1.02 items/g (wet weight), ranging from 0.63 ± 0.52 items/g to 37.94 ± 19.22 items/g. Over half of the microplastics were smaller than 100 μm, and the most common shape was fragments (67%), followed by fibers (29%). The dominant color was transparent (49.76%), followed by black (25.66%). Polymer types were identified using a μRaman microscope, and the major component was polyethylene terephthalate (PET) (69.54%). Microplastic contamination was higher overall in wild than in farmed oysters. In addition, the microplastic content of oysters from northeastern waters was significantly greater than that of other oysters; this result is similar to the findings of previous research on floating marine litter and beach cleaning data. The results indicated that the average content of microplastic in oysters along the Taiwan coastline was similar to that in oysters in adjacent regions. This study suggests that innovative technologies should be implemented for monitoring and removing pollution, tracking marine pollution origins, and improving accountability and that plastic limitation strategies should be strengthened.

The green turtle (Chelonia mydas) is listed as a globally endangered species and is vulnerable to anthropogenic threats, including environmental pollution. This study investigated the antimicrobial resistance of Gram-negative bacteria isolated from wild green turtles admitted to a sea turtle rehabilitation center in Taiwan. For this investigation, cloacal and nasal swab samples were collected from 28 green turtles between 2018 and 2020, from which a total of 47 Gram-negative bacterial isolates were identified. Among these, Vibrio spp. were the most dominant isolate (31.91%), and 89.36% of the 47 isolates showed resistance to at least one of 18 antimicrobial agents tested. Isolates resistant to one (6.38%), two (8.51%), and multiple (74.47%) antimicrobials were observed. The antimicrobial agents to which isolates showed the greatest resistance were penicillin (74.47%), followed by spiramycin, amoxicillin, and cephalexin. The antimicrobial-resistance profiles identified in this study provide useful information for the clinical treatment of sea turtles in rehabilitation facilities. The results of our study also imply that wild green turtles may be exposed to polluting effluents containing antimicrobials when the turtles traverse migratory corridors or forage in feeding habitats. To benefit sea turtle conservation, future research should focus on (1) how to prevent pollution from antimicrobials in major green turtle activity areas and (2) identifying sources of antimicrobial-resistant bacterial strains in coastal waters of Taiwan.

Perchlorate is an endocrine-disrupting chemical (EDC) that contaminate various foodstuffs. Exposure to perchlorate may cause severe health problems, mainly thyroid dysfunction. However, information on perchlorate contamination of consumer foods in Taiwan is limited. This study investigated perchlorate levels in 310 food samples belonging to 12 food groups collected from Taiwanese markets. A probabilistic risk assessment was conducted to assess the related exposure to Taiwanese people. Perchlorate was detected in 65% of the samples and high levels were identified in certain plant-origin, fruit, and processed food samples. A probabilistic approach was used to estimate daily dietary dose (Monte Carlo–estimated 95th percentile dietary exposure [MCS 95]) by using the Taiwan National Food Consumption database for 14 sex/age groups. The highest and lowest average daily doses (ADDs) were in the age groups of >65 years (MCS 95 = 3.60/3.90 [male/female] μg/kg bw/day) and 16–18 years (MCS 95 = 1.70/1.47 [M/F] μg/kg bw/day), respectively. The 95th percentile of the hazard index of exposure to perchlorate of all sex/age groups far exceeded the tolerable daily intake (0.3 μg/kg bw/day) and reference dose (0.7 μg/kg bw/day) set by the European Food Safety Authority and US EPA, respectively, but it was lower than the provisional maximum tolerable daily intake (10 μg/kg bw/day) suggested by the Joint FAO/WHO Expert Committee on Food Additives. The intake quantity and concentrations of perchlorate from vegetables, fruits, and whole grains are the critical contributors for the ADDs and integrated risk of dietary exposure to perchlorate. Long-term exposure through diets should be considered, instead of focusing on individual EDC during dietary risk assessment in specific populations. Furthermore, cumulative risks for exposure to multiple contaminants, particularly those causing thyroid adverse effects, may be higher than that from perchlorate exposure alone.

4-Nonylphenol (NP) and bisphenol A (BPA) are high-production and high-volume chemicals used to manufacture various commercial products. They are also ubiquitous contaminants that disrupt endocrine systems in wildlife and humans. We collected, from Taiwan cities with the highest food production, and analyzed, using high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS), 278 food samples for NP and BPA from 11 categories. We found background levels of 100% for NP and 72% for BPA in total samples. High levels of contamination (up to 918 and 49.4 μg/kg) were found in some foods of seafood and animal origin. We used a probabilistic approach to calculate daily dietary dose (Monte Carlo-estimated 95th percentile dietary exposure [MCS 95]) from the Taiwan National Food Consumption database for each sex- and age-specified population. For NP and BPA, the highest average daily dose (ADDs) were in the 4- to 6-year-old group (MCS 95 = 1.57/1.28 and 0.157/0.147 [Male/Female] μg/kg bw/day, respectively), and the lowest ADDs were in the ≥65-year-old group (MCS 95 = 0.674/0.581 and 0.054/0.045 [M/F] μg/kg bw/day, respectively). Based on the European Food Safety Authority (4 μg/kg bw/day for BPA) and Danish Institute of Safety and Toxicology guidelines (5 μg/kg bw/day for NP), the 95th percentile HQ of NP and BPA intake in different sex- and age-specified groups in Taiwan posed no risks through dietary exposure. The intake quantity and concentrations of grains, livestock, and seafood are important variables for the integrated risk of NP and BPA. In conclusion, a combination of multiple and long-term exposure via food consumption should be considered rather than individual endocrine-disrupting chemicals during dietary risk assessment in specific populations.The 95th percentile HQ of NP and BPA intake in different age and sex groups in Taiwan posed no risks through dietary exposure based on probabilistic and sensitive approach.

The presence of PM₂.₅ may affect the photodegradation of benzene in the natural atmosphere. On one hand, the photodegradation of benzene may be promoted with the increase in PM₂.₅ concentrations, owing to adsorption and catalysis effect of PM₂.₅ surface; On the other hand, PM₂.₅ can scatter or block ultraviolet light and lead to weakening the photochemical reactions in the atmospheric system. It is very difficult to prove which process is dominant in the real atmosphere due to the complexity of the atmosphere. Based on coupling detrended fluctuation analysis, the goal of this work is to reveal the role of PM₂.₅ in the photodegradation of benzene in real atmosphere over long time scales. The 9 years regular monitoring data from 2007 to 2016 in Puzi of Taiwan are analyzed. A new nonlinear parameter (PDB) is established to characterize the photodegradation degree of atmospheric benzene. Based on sliding window technique, the correlations between the temporal variation of PDB and PM₂.₅ are analyzed. The results show that there is a positive correlation between PDB and PM₂.₅ in daytime and little correlation between them in nighttime. It indicates that PM₂.₅ mainly plays the promoting effect on the photodegradation of atmospheric benzene. This is the first study to directly determine the role of PM₂.₅ in the photochemical behavior of atmospheric benzene based on long term field observation data. Moreover, the results suggest that the regional transport of PM₂.₅ could seriously affect the geochemistry cycle of some VOCs. This research provides a new analysis method to directly quantify the effect of PM₂.₅ on the photodegradation of VOCs in the real atmosphere. It is helpful for evaluating the role of PM₂.₅ in the complex photochemical system.

This study assessed the impact on air quality and health risk by long-range transported (LRT) PM2.5-10- and PM2.5-bound metals and PAHs in Taipei City, Taiwan. Several methods with receptor aerosol measurements were used to quantify the effect of LRT. The hybrid single particle lagrangian integrated trajectory model (HYSPLIT) was used in conjunction with the potential source contribution function (PSCF) to distinguish the LRT aerosols. By using a general linear model (GLM) with a marginal mean and positive matrix fraction (PMF), this study also evaluated the annual increased level of LRT (AIRLRT) for each source contribution to the concentration and the resultant health risk of particle-bound metals and polycyclic aromatic hydrocarbons (PAHs). The LRT influenced fine-sized metals and PAHs rather than coarse-sized ones. We found that the level of PM2.5-bound toxic metals (Pb, Cd, and As) and PAHs (Benzo[a]pyrene and dibenzo[a,e]pyrene) could increase by 90% under the influence of LRT in 2014, while an AIRLRT value of 25% for the PM2.5 mass concentration was observed. Overall, the excess cancer risk (ECR) resulting from PM2.5-bound metal and PAH exposures was 6.40 × 10−5 in relation to coal combustions (20.7%), traffic-related emissions (59.7%) and re-suspended aerosols (19.6%). Among these contributors, LRT-related metals and PAHs in PM2.5 accounted for 51% of the total ECR.

Control of organic matter, nutrients and disinfection byproduct formation is a major challenge for the drinking water treatment plants on Matsu Islands, Taiwan, receiving source water from the eutrophic reservoirs. A pilot entrapped biomass reactor (EBR) system was installed as the pretreatment process to reduce organic and nitrogen contents into the drinking water treatment plant. The effects of hydraulic retention time (HRT) and combination of preceding physical treatment (ultraviolet and ultrasound) on the treatment performance were further evaluated. The results showed that the EBR system achieved higher than 81%, 35%, 12% and 46% of reduction in chlorophyll a (Chl a), total COD (TCOD), dissolved organic carbon (DOC) and total nitrogen (TN), respectively under varied influent concentrations. The treatment performance was not significantly influenced by HRT and presence/absence of physical pretreatment and the effluent water quality was stable; however, removal efficiencies and removal rates of Chl a, TCOD and DOC showed strong correlation with their influent concentrations. Excitation–emission matrix (EEM) fluorescence spectroscopy identified fulvic-like and humic-like substances as the two major components of dissolved organic matter (DOM) in the reservoir, and decreased intensity of the major peaks in effluent EEM fluorescence spectra suggested the effective removal of DOM without production of additional amount of soluble microbial products in the EBR. Through the treatment by EBR, about 10% of reduction of total trihalomethane formation potential for the effluent could also be achieved. Therefore, the overall results of this study demonstrate that EBR can be a potential pretreatment process for drinking water treatment plants receiving eutrophic source water.