With the increasing number and volume of chemicals used in modern life, their adverse effects on human health and aquatic organisms have increased concerns as well. To formulate appropriate management plans, the amounts/volumes used and emitted of these chemicals must be regulated. However, no data are available on the use of most chemicals, particularly daily-use chemicals such as pharmaceuticals and personal care products (PPCPs). Herein, we tested eight activated sludge wastewater treatment plants (WWTPs) across Japan, each servicing populations of over 200,000, to investigate the emissions of 484 chemicals including 162 PPCPs. Twenty-four-hour composite samples were collected before and after the activated sludge component of treatment in each season of 2017. Targeted substances were solid-phase extracted and subsequently measured by LC-QTOF-MS-Sequential Window Acquisition of All Theoretical Fragment-Ion Spectra Acquisition. The mean number of the detected substances and their mean total concentrations in inflows (n=32) and outflows (n=32) were 87 and 92 and 108,517 and 31,537 ng L−1, respectively. Pharmaceuticals comprised 50% of the screened chemicals in the inflow. The median removal efficiency was 31.3%: 29.2% for pharmaceuticals and 20.2% for pesticides, which were similar to those in the literature. Cluster analysis showed that spatial differences among the WWTPs are larger than seasonal differences in the same WWTP. Regardless, we detected seasonal differences in the amounts of substances in the inflows: the amounts of sucralose, UV-filters, and insecticides were larger in summer than in winter, whereas those of ibuprofen and chlorpheniramine were larger in winter than in summer. The total inflow and outflow population equivalent loads estimated using wastewater volume, detected concentrations, and populations were 44.7 and 13.0 g 1,000 capita−1 d−1, respectively. The extrapolated total annual Japan-wide inflow and outflow loads were 2,079 and 671 tons y−1, respectively. Using the data obtained in this study, we identified 13 candidates of marker substances for estimating real-time population in a sewage treatment area and 22 candidates of marker substances for sewage contamination.
The neonicotinoid pesticides acetamiprid (ACE), clothianidin (CTD), dinotefuran (DIN), imidacloprid (IMI), nitenpyram (NTP), thiacloprid (THI), and thiamethoxam (TMX) are widely used in over 120 countries. These pesticides have been regulated in many jurisdictions, including the European Union (EU), the United States, and the United Kingdom, due to adverse effects on non-target organisms, whereas some of these pesticides are permitted in Japan. In the present study, we have 1) measured levels of these pesticides at 103 locations (n=672) across Gifu Prefecture, 2) analyzed the monthly trends and regionality using R and ArcGIS, and 3) created a predicted contamination map by an ordinary kriging analysis. The concentration levels of the seven neonicotinoid pesticides in surface waters were determined using liquid chromatography with tandem mass spectrometry (LC/MS/MS) and ranged from <2.0 to 530 ng/L during the ten-month period. In a total of 672 samples, the top three pesticides detected at high frequency were DIN (76.9%), CTD (48.4%), and IMI (19.6%). The concentration of the neonicotinoid pesticides in environmental waters varied with the time periods of application, physiochemical properties of the pesticides, land use, geological properties of the contamination sources, and other factors. Potential contamination sources were depicted in the predicted contamination maps by using ordinary kriging models, which showed that DIN and CTD are widely present in Gifu Prefecture. Monthly variance of the concentration of IMI differed in the two geological regions, due to differences in the time of application and agricultural products yield. The results of our study contribute to a better understanding of the contamination status of neonicotinoid pesticides by providing reference data (actual pesticide concentrations) as well as predicted contamination maps.
The notable challenges facing non-target environmental monitoring are the improvement of the reproducibility of extraction rates and the selection of internal standards for concentration correction. In the present study, a rapid and comprehensive analytical method, which we had developed in a previous study, greatly reduces the need for pretreatment. The method was applied to the actual measurement of river water. The water samples were divided into five sub-samples and analyzed by sorptive extraction using a magnetic stirrer coated with polydimethyl siloxane. Direct and whole sample extracts were determined by thermal desorption/comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry. Approximately 2,000 of the components were detected, and 80 of these components were selected for statistical evaluation in order to investigate the stability of the method and the ability to detect differences among samples. The effectiveness of this technique was confirmed by statistical methods, including the Kruskal-Wallis test, which is used to examine nonparametric multigroup comparisons and with which once can detect differences by comparing raw data obtained as precise mass measurements without the need to identify the substance itself. In brief, we show that changes in signal intensity of any unknown substance can be detected. We note that variations in data (retention time, mass spectrum, and signal intensity) affect the ability to detect differences. The accuracy of each therefore had to be improved to enable sensitive and precise detection.
In this study, we evaluated the long-term trend of atmospheric lead pollution in western Japan based on lead isotope ratios and Pb/Zn ratio as indicators of long-range transport of aerosols from the Asian continent. First, recent seasonal changes (May 2013–April 2015) in atmospheric lead concentration, lead isotope ratios, and Pb/Zn ratio were investigated in Hirado City on the Asian continent side of Japan. Each parameter increased during winter and decreased during summer. The increase during winter was due to the enhanced long-range transport of lead from the Asian continent based on the back-trajectory analysis and lead isotope ratios of aerosols in major cities of China. Then, the long-term trends (approximately after 1990) of lead concentration, lead isotope ratios, and Pb/Zn ratio during winter in several sites in western Japan were evaluated using the data from this study and literature. The lead concentration and Pb/Zn ratio tended to decrease over the years, whereas the lead isotope ratios in 2013–2015 were lower than the ratios before 2001. These long-term trends were attributable to the long-term changes in atmospheric emissions and sources of lead in China. Moreover, it is likely that the rapid increase in zinc emissions in China also contributed to the decreasing trend of Pb/Zn ratio over the years. This study confirmed that atmospheric lead pollution in western Japan has improved over the years owing to the decrease in the amounts of lead transported from the Asian continent.
Long-term trends of 207Pb/206Pb and Pb/Zn ratio during winter in western Japan, compared with those of lead emissions from anthropogenic sources in China (Li et al., 2012)
High-precision analytical methods to detect fumonisin B1 (FB1) in a limited range of biological samples have recently been reported. Here an analytical method for FB1 for use in a wider range of tissue and body fluid samples, such as the plasma, kidney, liver, urine, and bile was developed. Pigs were used in this investigation and administered with FB1 via osmotic pumps. Samples were extracted with a formic acid/acetonitrile/water mixture, purified on a phospholipid removal solid-phase extraction column, and analyzed by ultra-high performance liquid chromatography-electrospray ionization/tandem mass spectrometry (UHPLC-ESI/MS/MS). The mean recovery of FB1 in the plasma, kidney, liver, and urine ranged from 80%–115%, and the corresponding relative standard deviation (RSD) was below 10%. The matrix effects resulted in ionization suppression in the bile samples, but these effects were stable and constant, and could be accounted for; the mean recovery and RSD for the bile samples was 10% and <10%, respectively. Using this analytical method, FB1 was precisely detected in pigs and its levels decreased in the order of urine>bile>kidney=liver>plasma, which implied fast excretion. The detection and quantitation limits (1 and 3 ng g−1, respectively) alongside the other results indicated that this method was suitable for the analysis of FB1 in various types of biological samples.
We measured microplastics [(MPs): 10 μm–5 mm] in untreated and secondary-treated sewage, highway runoff, and estuarine water in Tokyo, Japan, during both dry and wet weather. MPs smaller than 200 μm were predominant, making up>60% of the total number, in all our water samples. The abundance of the MPs was 420 pieces/L in the influent and 8.7 pieces/L in the secondary effluent, indicating a removal efficiency of 98% during primary+secondary treatment. Of the measured polymers—polyethylene (PE), polypropylene, polystyrene, polyethyleneterephthalate (PET), polyethylene polypropylene copolymer, polyethylene polypropylene diene (PEPD), polyethylene vinyl acetate, and acrylonitrile styrene, PET was predominant in the sewage influent (88%) and effluent (49%) and its form was mostly fibrous, indicating contribution from laundry effluents. Highway runoff water samples contained high concentrations of MP (81–292 pieces/L). The highway runoff contained more PE (25%–49%) and PEPD (13%–30%) than PET (3%–12%) indicating contribution from debris from automobile tire wear and plastics weathered on the ground. MP concentrations in estuarine water samples were lower (1.4–2.3 pieces/L in dry weather), and PET was predominant, at 52%–77%, indicating a dominant contribution from sewage effluent. Following rainfall, MP concentrations in the estuarine water increased to 1.8–4.3 pieces/L, and PEPD, in particular, increased significantly, with a proportion of 43%–52%, indicating the contribution of MPs derived from street runoff. Although analyses of molecular markers of sewage, i.e., linear alkylbenzenes and coprostanol, confirmed the input of combined sewer overflow (CSO) to the estuarine water, we did not observe any significant increase in PET fiber MPs, indicating that there was no significant increase in the contribution of MPs from sewage including CSO to the estuarine waters after a rain event. This study highlights the importance of street runoff as a source of MPs in urban aquatic environments. Further investigation should be performed to quantitatively access the individual sources and processes.