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The occurrence of triphenyltin (TPT) compounds, a highly toxic antifouling biocide, has been documented in marine environments and organisms all over the world. While some studies showed that marine mammals can be used as sentinel organisms to evaluate the pollution status of emerging contaminants in the environment because of their long lifespans and high trophic levels, information regarding the contamination status of TPT in marine mammal species has been limited over the past decade. More importantly, the primary bioaccumulation pathway of TPT in these long-lived apex predators and the corresponding marine food web is still uncertain. Therefore, this study aimed to evaluate the contamination statuses of TPT in two marine mammal species, namely the finless porpoise and the Indo-Pacific humpback dolphin, and assess the trophic magnification potential of TPT along the food webs of these two species, using stable isotope analysis, and chemical analysis with gas chromatography-mass spectrometry. The results showed that TPT is the predominant residue in majority of the analyzed individuals of two marine mammals, with concentrations ranging from 426.2 to 3476.6 ng/g wet weight in their muscle tissues. Our results also demonstrated an exponential increase in the concentration of TPT along the marine food web, indicating that trophic magnification occurs in the respective food webs of the two marine mammals. The range of trophic magnification factors of TPT in the food webs of finless porpoise and Indo-Pacific humpback dolphin was 2.51-3.47 and 2.45-3.39, respectively. These results suggest that high trophic organisms may be more vulnerable to the exposure of TPT-contaminated environments due to the high trophic magnification potential, and thus ecological risk of these compounds ought to be assessed with the consideration of their bioaccumulation potentials in these marine mammals., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A cross-sectional study was designed to understand the impacts of "hikikomori" lifestyle on physical health. A total of 104 eligible hikikomori cases were recruited from the social services network of Hong Kong with a mean age of 19.02 ± 3.62 (ranged 13-31) year-old, and had completed the set of questionnaires and a series of anthropometric and physical health measurements. Despite SF36 score of 84.0 indicated good physical functioning in general, participants were lived sedentarily with high incidence of hypertension at 15.4% and prehypertension at 31.7%. Occurrence of hypertension and prehypertension in cases living as hikikomori >6 months were 3 times and 1.5 times higher than those newly onset cases, respectively. The blood pressure levels were correlated with age and all obesity index parameters measured including waist circumference and body mass index. Results also observed a shift of body weight from underweight to overweight and obesity along the hikikomori duration. Half of the hypertensive cases involved the elevation of systolic blood pressure, which suggested higher odds of cardiovascular complications. In conclusion, the hikikomori lifestyle could be a risk behavior that may harm the younger generation physically by promoting obesity and hypertension and probably other chronic illnesses., Competing Interests: The authors declare no conflict of interest.