Effective reducing exposure to fine particulate matter (PM₂.₅) during commuting can help lower the risk of adverse health effects therefrom; however, few studies have examined the influence of different background levels of air pollution—particularly in China where PM₂.₅ concentrations are high globally. In this study, personal sampling was conducted to measure individual exposure during five different modes of commuting (bus, metro, car, bicycle and walking) in Shanghai, China. A total of 125 measurements were conducted for five days under haze and non-haze conditions, following which the corresponding doses of PM₂.₅ inhaled were estimated. The mean concentrations (±standard deviation, SD, 1-min averaging) of background PM₂.₅ were 155.9 (±98.7) μg/m³ during haze and 36.3 (±17.6) μg/m³ under the non-haze conditions. Under both conditions, active commuters were exposed to higher PM₂.₅ concentrations than those using motorized commuting modes (Wilcoxon test, p < 0.01). Moreover, driving with closed windows and air conditioning effectively reduces the PM₂.₅ concentrations in cars by 35 %–57 %. Cyclists inhaled the highest doses (539.8 ± 313.2 and 134.8 ± 71.3 μg/h under haze and non-haze conditions, respectively), whereas car drivers inhaled the lowest doses (28.8 ± 21.2 and 3.7 ± 2.6 μg/h under haze and non-haze conditions, respectively). Individual exposure to PM₂.₅ during commuting varied with the modes; the discrepancy between the latter depended largely on the ambient concentration. Our findings provided evidence that traffic-related air pollution contributed to daily pollutant exposure and highlighted the importance of taking personal protective measures while commuting, particularly during haze.

Cadmium (Cd) was an environmental pollutant, which could result in germ cell apoptosis in testes. Sertoli-germ cell communication was vital for germ cell development and maturity. However, little was known about the effect of Sertoli cell autophagy on Cd-induced germ cell apoptosis. Here, we used male Amh-Cre+/Atg5ᶠˡᵒˣ/ᶠˡᵒˣ (Atg5⁻/⁻) mice, loss of autophagy-related gene 5 (Atg5) in testicular Sertoli cells, to explore the obscure effects. Atg5⁻/⁻ and Wild-type (WT) mice were given with cadmium chloride (CdCl₂, 2.0 mg/kg) for 0–24 h. Our results showed that Cd triggered testicular germ cell apoptosis, as evidenced by the increment of TUNEL-labeled germ cells, cleaved caspase3 and cleaved poly (ADP-ribose) polymerase protein level. Additionally, Cd induced testicular autophagy, as determined by elevating the level of autophagy-related proteins, including Atg5, Atg7, LC3B-II, and the gathering of LC3 puncta. 3-methyladenine, a specific autophagy inhibitor, exacerbated Cd-caused germ cell apoptosis. Inversely, rapamycin, an autophagy inducer, relieved Cd-stimulated germ cell apoptosis. Interestingly, we found that autophagy in Sertoli cells was activated in Cd-treated WT mouse testes as evidenced by the increment of LC3 puncta surrounding SOX9, a specific Sertoli cell marker. More importantly, loss of autophagy in Sertoli cells aggravated Cd-triggered germ cell apoptosis. Taken together, these data indicate that autophagy in Sertoli cells alleviates Cd-triggered germ cell apoptosis in mouse testes.

A large number of toxicity studies report abnormalities in early life-stage (ELS) fish that are described here as a sublethal toxicity syndrome (TxSnFELS) and generally include a reduced heart rate, edemas (yolk sac and cardiac), and a variety of morphological abnormalities. The TxSnFELS is very common and not diagnostic for any chemical or class of chemicals. This sublethal toxicity syndrome is mostly observed at high exposure concentrations and appears to be a baseline, non-specific toxicity response; however, it can also occur at low doses by specific action. Toxicity metrics for this syndrome generally occur at concentrations just below those causing mortality and have been reported for a large number of diverse chemicals. Predictions based on tissue concentrations or quantitative-structure activity relationship (QSAR) models support the designation of baseline toxicity for many of the tested chemicals, which is confirmed by observed values. Given the sheer number of disparate chemicals causing the TxSnFELS and correlation with QSAR derived partitioning; the only logical conclusion for these high-dose responses is baseline toxicity by nonspecific action and not a lock and key type receptor response. It is important to recognize that many chemicals can act both as baseline toxicants and specific acting toxicants likely via receptor interaction and it is not possible to predict those threshold doses from baseline toxicity. We should search out these specific low-dose responses for ecological risk assessment and not rely on high-concentration toxicity responses to guide environmental protection. The goal for toxicity assessment should not be to characterize toxic responses at baseline toxicity concentrations, but to evaluate chemicals for their most toxic potential. Additional aspects of this review evaluated the fish ELS teratogenic responses in relation to mammalian oral LD50s and explored potential key events responsible for baseline toxicity.

Coking is a substantial source of carbonaceous aerosols in China, but the emission characteristics and pollution levels of coking-produced organic carbon (OC) and elemental carbon (EC) remain unknown, causing considerable uncertainty in emission estimates. In this study, the emission factors of OC (EFOC) and EC (EFEC) of typical coking plants in Shanxi, China, were measured. The measured EFEC and EFOC from fugitive emissions (7.43 and 9.54 g/t) were significantly higher than those from flue gas (1.67 and 3.71 g/t). The technological conditions of coke production affect the emissions of OC and EC. For example, the total emissions from coke plants that use 3.2-m-high coke ovens were greater than those from plants that use 4.3- and 6-m-high ovens. The EFOC and EFEC for plants conducting stamp charging were considerably higher than those for plants using top charging. The stable carbon isotopes of total carbon (δ¹³CTC), OC (δ¹³COC), and EC (δ¹³CEC) for fly ash during coking were −23.74‰ to −24.17‰, −23.32‰ to −23.87‰, and −23.84‰ to −24.14‰, respectively, and no clear isotopic fractionation was found during coke production. Different EC/OC ratios from different emission pathways and the carbon isotope signature of coke production should be considered when investigating the sources of carbonaceous aerosols. The total estimated EC and OC emissions from coke production in China were 3.93 and 5.72 Gg in 2017, and Shanxi, Hebei, and Shaanxi made the largest contributions.

Nitrogen in urban stormwater has been widely studied, and effective management of nitrogen pollution is critical for improving urban stormwater and receiving water quality. This requires an in-depth understanding of the transport process and source contribution to both dissolved and particulate nitrogen in stormwater from urban catchments. In this study, 123 stormwater runoff samples were collected from an urban catchment during different rainfall events. Dissolved and particulate nitrogen concentrations in roof runoff, road runoff, and sewer flow were analyzed. The concentration of dissolved nitrogen was higher in roof runoff than in road runoff and sewer flow. However, the concentration of particulate nitrogen was lower in roof runoff than in road runoff and sewer flow. Isotopic analysis and Bayesian mixing models showed that road runoff was the largest source contributor of both nitrate and particulate organic nitrogen (PON) in sewer flow discharged from the study catchment. In addition, road runoff contributed the majority of PON associated with coarse particles (>105 μm), whereas PON associated with fine particles (<105 μm) was primarily washed-off of sewer sediments. The results provided several suggestions for the management of nitrogen pollution in urban catchments. This study could help to fully understand the transport and sources of nitrogen pollution in urban stormwater and provide recommendations to the government for implementing appropriate stormwater management strategies to minimize stormwater pollution.

Microplastic pollution in marine environments and organisms has received a great deal of international attention. However, the long-term field studies of microplastics are rare. Here, we assessed annual variation in microplastic abundance in the Maowei Sea, a classic mariculture bay in southern China, and analyzed the long-term accumulation in oyster tissues. U-shaped time trends of microplastics in water were observed from January to December in 2018 in the estuarine region, inner bay, and mouth bay sites, representing an inverse relationship with the local rainfall patterns. The common microplastic particles in Maowei Sea are PET/PE fibers, and polystyrene foams, which are mainly related to textile pollution and fishery activities. After one year of continuous monitoring, we did not find accumulation of microplastics in the whole soft tissues of oyster after 10% KOH digestion. No significant correlation of microplastic abundances between water and oysters was observed. The microplastic abundance in oyster was correlated with some environmental variables (i.e. salinity, pH, nutrients and total organic carbon) of the surrounding water following Spearman correlation analysis. The microplastic levels in oysters could probably be influenced by the environmental variables.

As the ubiquitous active components in aquatic environments, low molecular weight organic acids (LMWOAs) have a large influence on the environmental behaviors of contaminants. This research was focused on the effect of different LMWOAs including 11 aliphatic acids and 7 aromatic acids on the photodegradation kinetics of tetracycline (TC), and the development of quantitative structure-activity relationship (QSAR) model. Results showed that TC photodegradation in the presence of LMWOAs fitted pseudo-first-order photolysis kinetics, and the observed photolysis rate constant (kobs) varied from 0.077 to 0.331 h⁻¹. The QSAR model was developed by partial-least-squares (PLS) with using a sequential approach with 25 theoretical molecular descriptors. Four descriptors including ELUMO-EHOMO, ELUMO, CCR and Qmax were found to mechanistically and statistically affect kobs.The high cross validated regression coefficient (Qcum2, 0.898) and high correlation coefficient (R², 0.908) indicated significantly goodness-of-fit and high robustness of the model. The predicted and observed values with high agreement in the defined applicability domain featured accuracy and feasibility of model. This work provided a robust predictive method for estimating the TC photodegradation in the presence of different structures of LMWOAs.

We assessed the contribution of transboundary air pollutants (TAPs) transported from China to Tokyo using the Pb₍₀.₅<Dₚ < ₁₎/Cu₍₂.₅<Dₚ < ₁₀₎ index. We conducted intensive observations over four seasons during 2014–2015 and analyzed ionic components and thirteen elements in size-segregated aerosols collected at the top of a 30-m-high tower in a hilly forested area of the Field Museum Tamakyuryo (FM Tama), in a western suburb of Tokyo. In order to evaluate if the Pb₍₀.₅<Dₚ < ₁₎/Cu₍₂.₅<Dₚ < ₁₀₎ ratio can be applied in Tokyo as the megacity, the annual average concentration of Pb at Cape Hedo, Kumamoto city, on the west side of Japan, was higher than that of Pb at Tokyo, on the east side; this result indicates that TAPs affect western Japan more than eastern Japan. We inferred the main source of Cu to be braking abrasion from cars at local scale on the basis of its enrichment factor and size distribution. From the Pb₍₀.₅<Dₚ < ₁₎/Cu₍₂.₅<Dₚ < ₁₀₎ ratio and sulfate concentration, we inferred that the highest contribution of TAPs to the total mass concentration in Tokyo occurred in spring, when TAPs accounted for 55%, 72%, and 53% of the total mass concentration in the 0.1 < Dp < 0.5, 0.5 < Dp < 1, and 1 < Dp < 2.5 fractions, respectively. These results can contribute to assessment of TAPs in Tokyo.

There has been a significant increase in the microplastic (MP) polluting the ocean in recent time which is regarded as toxic for living organisms. In this study, Fluorescent red polyethylene microspheres (FRPE) were administered intramuscularly to Litopenaeus vannamei juveniles at the concentration of 0.1, 0.2, 0.5 and 1.0 μg (g shrimp)⁻¹, and the survival rate was recorded. Analysis of the hepatopancreas for antioxidant enzyme activity and gene expression were done after seven days. Further tissue morphology and accumulation of FRPE was analysed. The results showed that FRPE at 0.5 and 1.0 μg (g shrimp)⁻¹ reduce the survival rate of L. vannamei. FRPE at 0.5 and 1.0 μg (g shrimp)⁻¹ reduced superoxide dismutase (SOD) activity; FRPE at different concentrations reduced catalase (CAT) activity; FRPE at 0.2, 0.5 and 1.0 μg (g shrimp)⁻¹ increased the lipid peroxide thiobarbituric acid (TBARS) content. FRPE at 0.1, 0.2, and 0.5 μg (g shrimp)⁻¹ significantly affect the performance of SOD and CAT genes; FRPE at 0.2 and 0.5 μg (g shrimp)⁻¹ significantly improves GPx gene performance; FRPE at 1.0 μg (g shrimp)⁻¹ significantly reduced the expression of GPx genes. Analysis of tissue morphology shows that FRPE cause muscle, midgut gland, and hepatopancreas, and gill damage at different concentrations. In the results of accumulation of microplastic, FRPE accumulated in gill tissue at 0.2 and 0.5 μg (g shrimp)⁻¹; FRPE accumulated in gill, muscle and hepatopancreas tissue at 1.0 μg (g shrimp)⁻¹. Based on the above results, FRPE at 0.5 and 1.0 μg (g shrimp)⁻¹ can regulate the antioxidant enzymes of L. vannamei, increase lipid peroxide content, cause tissue damage by accumulating in the tissues. The rate of survival decreased in L. vannamei, and the impact of FRPE at 1.0 μg (g shrimp)⁻¹ was significant.

Although abundant evidence has suggested that early-life antibiotic exposure was associated with adipogenesis later in life, limited data were available on the effect of intrauterine antibiotic exposure on infant growth and growth speed. Additionally, few studies have investigated the role of the neonatal gut microbiota in the above association. In this study, we examined the association between intrauterine cumulative antibiotic exposure and infant growth and explored the potential role of the neonatal gut microbiota in the association. 295 mother-child pairs from the Shanghai Maternal-Child Pairs Cohort (MCPC) study were included, and meconium samples and infant growth measurements were assessed. Z-scores of length-for-age, weight-for-age (weight-for-age), and body mass index (BMI)-for-age (BMI-for-age) were calculated. Eighteen common antibiotics were measured in meconium. Multivariable linear regression models were applied to test the interrelationships between antibiotic exposure, diversity indicators, and the relative abundance of selected bacterial taxa from phylum to genus levels from least absolute shrinkage and selection operator (LASSO) and infant growth indicators. The detection rates of the 18 antibiotics, except for chlortetracycline, penicillin, and chloramphenicol, were below 10 %. Penicillin was found to be positively associated with infant growth at birth and with growth speed from 2 to 6 months. The Pielou and Simpson indexes were negatively associated with meconium penicillin. Nominally significant associations between penicillin and the relative abundances of several bacterial taxa from the phyla Proteobacteria, Bacteroidetes, and Firmicutes were found. The Pielou and Simpson indexes were also found to be negatively associated with infant growth. Among taxa selected from LASSO regression, the relative abundances of the phyla Actinobacteria and Firmicutes and order Bifidobacteriales were found to be significantly associated with weight and BMI growth speeds from 2 to 6 months. In conclusion, intrauterine antibiotic exposure can affect infant growth. The neonatal gut microbiota might play a role in the abovementioned association.