Appropriately characterizing spatiotemporal individual mobility is important in many research areas, including epidemiological studies focusing on air pollution. However, in many retrospective air pollution health studies, exposure to air pollution is typically estimated at the subjects’ residential addresses. Individual mobility is often neglected due to lack of data, and exposure misclassification errors are expected. In this study, we demonstrate the potential of using location history data collected from smartphones by the Google Maps application for characterizing historical individual mobility and exposure. Here, one subject carried a smartphone installed with Google Maps, and a reference GPS data logger which was configured to record location every 10 s, for a period of one week. The retrieved Google Maps Location History (GMLH) data were then compared with the GPS data to evaluate their effectiveness and accuracy of the GMLH data to capture individual mobility. We also conducted an online survey (n = 284) to assess the availability of GMLH data among smartphone users in the US. We found the GMLH data reasonably captured the spatial movement of the subject during the one-week time period at up to 200 m resolution. We were able to accurately estimate the time the subject spent in different microenvironments, as well as the time the subject spent driving during the week. The estimated time-weighted daily exposures to ambient particulate matter using GMLH and the GPS data logger were also similar (error less than 1.2%). Survey results showed that GMLH data may be available for 61% of the survey sample. Considering the popularity of smartphones and the Google Maps application, detailed historical location data are expected to be available for large portion of the population, and results from this study highlight the potential of these location history data to improve exposure estimation for retrospective epidemiological studies.

As the frequency, intensity, and duration of heatwaves increases, emergency health serviceutilization, including ambulance service, has correspondingly increased across the world. The negative effects of air pollution on health complicate these adverse health effects. This research work is the first known study to analyze the joint effects of heatwaves and air quality on the ambulance service in Western Australia (WA). The main objective is to investigate the potential joint effects of heatwaves and air quality on the ambulance service for vulnerable populations in the Perth metropolitan area. A time series design was used. Daily data on ambulance callouts, temperature and air pollutants (CO, SO₂, NO₂, O₃, PM₁₀ and PM₂.₅) were collected for the Perth metropolitan area, WA from 2006 to 2015. Poisson regression modeling was used to assess the association between heatwaves, air quality, and ambulance callouts. Risk assessments on age, gender, socio-economic status (SES), and joint effects between heatwaves and air quality on ambulance callouts were conducted. The ambulance callout rate was higher during heatwave days (14.20/100,000/day) compared to non-heatwave days (13.95/100,000/day) with a rate ratio of 1.017 (95% confidence interval 1.012, 1.023). The ambulance callout rate was higher in males, people over 60 years old, people with low SES, and those living in coastal areas during period of heatwaves. Exposure to CO, SO₂, O₃ and PM₂.₅ increased risk on ambulance callouts and exposure to NO₂ showed joint effect with heatwave and increased risk of ambulance callouts by 3% after adjustment of all other risk factors. Ambulance callouts are an important indicator for evaluating heatwave-related emergency morbidity in WA. As the median concentrations of air pollutants in WA were lower than the Australian National Standards, the interactive effects of heatwaves and air quality on ambulance service need to be further examined, especially when air pollutants exceed the standards.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants with a number of them being carcinogenic. One of the approaches to assess human exposure to PAHs is to measure their urinary metabolites, monohydroxyl polycyclic aromatic hydrocarbons (OH-PAHs), with a method allowing for high throughput and short turn-around time. We developed a method to quantify nine urinary OH-PAHs by using supported liquid phase extraction (SLE) and isotope dilution gas chromatography tandem mass spectrometry (GC-MS/MS). SLE demonstrated advantages over the traditionally used liquid-liquid extraction techniques. The target analytes with spiked deuterated and ¹³C-labeled internal standards were extracted from urine by SLE after enzymatic cleavage of the glucuronide and sulfate conjugates. The extracted analytes were then derivatized with N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), and analyzed by GC-MS/MS. Six solvent mixtures were evaluated as the SLE extraction solvent, and pentane:chloroform (7:3, v/v) was selected due to its best overall analytical performance. Method detection limits for the 9 analytes ranged from 2.3 to 13.8 pg/mL. Precision and accuracy were satisfactory. SLE and internal isotope labeled standard combination reduced matrix effect effectively. This new method using SLE sample preparation techniques coupled with GC-MS/MS proves applicable to urinary measurements for PAH exposure studies for general population.

Neonicotinoids and the closely related insecticide classes sulfoximines and butenolides have recently attracted growing concerns regarding their potential negative effects on non-target organisms, including pollinators such as bees. Indeed, it is becoming increasingly clear that these effects may occur at much lower levels than those considered to be safe for humans. To properly assess the ecological and environmental risks posed by neonicotinoids, appropriate sampling and analytical procedures are needed. Here, we used honey as reliable environmental sampler and developed an unprecedentedly sensitive method based on QuEChERS and UHPLC-MS/MS for the simultaneous determination of the nine neonicotinoids and related molecules currently present on the market (acetamiprid, clothianidin, dinotefuran, flupyradifurone, imidacloprid, nitenpyram, sulfoxaflor, thiacloprid and thiamethoxam). The method was validated and provided excellent levels of precision and accuracy over a wide concentration range of 3–4 orders of magnitude. Lowest limits of quantification (LLOQs) as low as 2–20 pg/g of honey depending on the analytes were reached. The method was then applied to the analysis of 36 honey samples from various regions of the World which had already been analysed for the five most common neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) in a previous study. This allowed us to determine the long-term stability (i.e. up to 40 months) of these molecules in honey, both at room temperature and −20 °C. We found that the five pesticides were stable over a period of several years at −20 °C, but that acetamiprid and thiacloprid partially degraded at room temperature. Finally, we also measured the levels of dinotefuran, nitenpyram, sulfoxaflor and flupyradifurone and found that 28% of the samples were contaminated by at least one of these pesticides.

Rorippa globosa (Turcz.) Thell. is known as Cd hyperaccumulator, however neither hyperaccumulation nature, nor affecting factors like the effect of Cd compounds entering soil from different sources, or of specific soil amendments, are not yet satisfactorily clarified. In the pot culture experiment, Cd accumulation by R. globosa from soils spiked with 3 and 9 mg Cd kg⁻¹ in the form of Cd(NO₃)₂, CdCl₂, CdBr₂, CdI₂, CdSO₄, CdF₂, Cd(OH)₂, CdCO₃, Cd₃(PO₄)₂, CdS and effect of soil amendment with glutathione (GSH) were investigated. Accumulation capacity of R. globosa for Cd appeared to reflect its extractability in soils and was about two-fold bigger for high soluble compounds than for low-soluble ones. At that, the differences between the accumulation of Cd originating from high soluble compound group did not exceed 20%, while the differences within the low soluble compound group were insignificant (p < 0.05). The analysis of Cd uptake, uptake factor (UF), enrichment factor (EF) and translocation factor (TF) patterns revealed that Cd hyperaccumulating properties of R. globosa are based on the high water/nutrients demand and strong tolerance to Cd, although weak protection against Cd uptake by root system was also observed. Amendment with GSH enhanced Cd availability to plant and its uptake from soil, but exerted no effect on Cd translocation in plants. In the light of the results, the use of R. globosa for phytoremediation of moderately polluted agricultural lands as forecrop or aftercrop, and the GSH-assisted phytoremediation of highly polluted post-industrial sites seem to be viable options.

Hydrogen gas (H₂) has been shown as an important factor in plant tolerance to abiotic stresses, but the underlying mechanisms remain unclear. In the present study, the effects of H₂ and its interaction with nitric oxide (NO) on alleviating cadmium (Cd) stress in Brassica campestris seedlings were investigated. NO donor (SNP) or hydrogen-rich water (HRW) treatment showed a significant improvement in growth of Cd-stressed seedlings. Cd treatment upregulated both endogenous NO and H₂ (36% and 66%, respectively), and the increase of H₂ was prior to NO increase. When treated with NO scavenger (PTIO) or NO biosynthesis enzyme inhibitors (L-NAME and Gln), HRW-induced alleviation under Cd stress was prevented. Under Cd stress, HRW pretreatment significantly enhanced the NO accumulation, and together up-regulated the activity of NR (nitrate reductase) and expression of NR. HRW induced lower reactive oxygen species (ROS), higher AsA content, enhanced activity of POD (peroxidase) and SOD (superoxide dismutase) in seedling roots were inhibited by PTIO, L-NAME and Gln. Through proteomic analysis, the level of 29 proteins were changed in response to H₂ and NO-induced amelioration of Cd stress. Nearly half of them were involved in oxidation-reduction processes (about 20%) or antioxidant enzymes (approximately 20%). These results strongly indicate that in Cd-stressed seedlings, pretreatment with HRW induces the accumulation of H₂ (biosynthesized or permeated), which further stimulates the biosynthesis of NO through the NR pathway. Finally, H₂ and NO together enhance the antioxidant capabilities of seedlings in response to Cd toxicity.

The Minamata Convention entered into force in 2017 with the aim to phase-out the use of mercury (Hg) in manufacturing processes such as the chlor-alkali or vinyl chloride monomer production. However, past industrial use of Hg had already resulted in extensive soil pollution, which poses a potential environmental threat. We investigated the emission of gaseous elemental mercury (Hg0) from Hg polluted soils in settlement areas in the canton of Valais, Switzerland, and its impact on local air Hg concentrations. Most soil Hg was found as soil matrix-bound divalent Hg (HgII). Elemental mercury (Hg0) was undetectable in soils, yet we observed substantial Hg0 emission (20–1392 ng m−2 h−1) from 27 soil plots contaminated with Hg (0.2–390 mg Hg kg−1). The emissions of Hg0 were calculated for 1274 parcels covering an area of 8.6 km2 of which 12% exceeded the Swiss soil remediation threshold of 2 mg Hg kg−1. The annual Hg0 emission from this area was approximately 6 kg a−1, which is almost 1% of the total atmospheric Hg emissions in Switzerland based on emission inventory estimates. Our results show a higher abundance of Hg resistance genes (merA) in soil microbial communities with increasing soil Hg concentrations, indicating that biotic reduction of HgII is likely an important pathway to form volatile Hg0 in these soils. The total soil Hg pool in the top 20 cm of the investigated area was 4288 kg; hence, if not remediated, these contaminated soils remain a long-term source of atmospheric Hg, which is prone to long-range atmospheric transport.

Although evidence suggests the ubiquity of microplastics in the marine environment, our knowledge of its occurrence within remote habitats, such as the deep sea, is scarce. Furthermore, long term investigations of microplastic abundances are even more limited. Here we present a long-term study of the ingestion of microplastics by two deep-sea benthic invertebrates (Ophiomusium lymani and Hymenaster pellucidus) sampled over four decades. Specimens were collected between the years 1976–2015 from a repeat monitoring site >2000 m deep in the Rockall Trough, North East Atlantic. Microplastics were identified at a relatively consistent level throughout and therefore may have been present at this locality prior to 1976. Considering the mass production of plastics began in the 1940s - 50s our data suggest the relatively rapid occurrence of microplastics within the deep sea. Of the individuals examined (n = 153), 45% had ingested microplastics, of which fibres were most prevalent (95%). A total of eight different polymer types were isolated; polyamide and polyester were found in the highest concentrations and in the majority of years, while low-density polystyrene was only identified in 2015. This study provides an assessment of the historic occurrence of microplastics on the deep seafloor and presents a detailed quantification and characterisation of microplastics ingested by benthic species. Furthermore these data advance our knowledge on the long-term fate of microplastic in marine systems.

At present, the study of microplastic sources is in a relatively preliminary stage due to the complexity of microplastic features in the environment. Based on a literature review, we developed a source-specific classification system for the quantitative analysis of microplastic sources. The classification system includes ten types of microplastics based on morphology and composition and can identify their main sources and the associated probabilities. To reflect the complexity of types and sources in the regional combination of microplastics, we first propose a microplastic diversity index (D1-D’(MP)). We use the South China Sea as an example to carry out quantitative source analysis and calculate the diversity index. Eight types of microplastics were found, mainly consisting of maritime coatings (type “Gran_coat”) (33.0%) and synthetic fibers (type “Fib_thin”) (29.6%). We also found that the diversity increased with offshore distance. In addition, we partitioned surface microplastics globally according to a two-dimensional microplastic abundance-diversity index. We believe that these indicators can effectively reflect pollution status and ultimately lead to different types of control measures. In the future, additional indicators for the characterization of microplastics must be included in the classification system to establish a one-to-one source analysis system for microplastic characteristics and source apportionment. In general, our study may provide new insights into the establishment of more accurate and quantitative source apportionment techniques and effective pollution control.

Methylene blue (MB) is a dye pollutant commonly present in textile wastewater. We investigate and critically evaluate the applicability of BaTiO3/GO composite for photodegradation of MB in synthetic wastewater under UV–vis irradiation. To enhance its performance, the BaTiO3/GO composite is varied based on the BaTiO3 weight. To compare and evaluate any changes in their morphologies and crystalline structures before and after treatment, BET (Brunauer–Emmett–Teller), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) tests are conducted, while the effects of reaction time, pH, dose of photocatalyst and initial MB concentration on its photodegradation by the composite are also investigated under identical conditions. The degradation pathways and removal mechanisms of MB by the BaTiO3/GO are elaborated. It is evident from this study that the BaTiO3/GO composite is promising for MB photodegradation through ·OH. Under optimized conditions (0.5 g/L of dose, pH 9.0, and 5 mg/L of MB concentration), the composite with 1:2 dose ratio of BaTiO3/GO has the highest MB degradation rate (95%) after 3 h of UV vis irradiation. However, its treated effluents still could not comply with the discharge standard limit of less than 0.2 mg/L imposed by national environmental legislation. This suggests that additional biological treatments are still required to deal with the remaining oxidation by-products of MB, still present in the wastewater samples such as 3,7-bis (dimethyl-amino)-10H-phenothiazine 5-oxide.