RESUMO
The occurrence characteristics and ecological risk level of microplastics in the water and sediments of the Anhui section of Huaihe River Basin were analyzed via field sampling, stereomicroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), risk index (H), and pollution load index (PLI) model. The current situation of microplastics in the water and sediments of the basin was analyzed, and the ecological risk assessment of microplastics was conducted. The results showed that the detection rate of microplastics at each site in the basin was 100%. The average abundance of microplastics in surface water and sediments was (39800±3367) n·m-3 and (5078±447) n·kg-1, respectively. The average abundance of microplastics in the downstream was higher than that in the upstream and midstream. The particle size of microplastics in water and sediments was primarily 20-150 µm, accounting for 82.96% and 80.77%, respectively. The microplastics were primarily fiber (water 76.05%, sediment 84.53%), film (water 21.83%, sediment 15.43%), and debris (water 2.12%, sediment 0.04%). The microplastics in water and sediments were primarily transparent, accounting for 63.31% and 83.69%, respectively. Polyethylene (65.74% in water and 80.62% in sediment) and polypropylene (18.43% in water and 9.71% in sediment) were the major components of water and sediments. Microplastics were primarily derived from agricultural films, abandoned fishing gear and nets, and artificially abandoned plastic bags in ports. The microplastic risk index (H) model assessment revealed that the risk index of some sites was high, and the risk level of microplastics in the Anhui section of Huaihe River Basin was grade II. The pollution load index (PLI) model assessment revealed that the ecological risk of surface water and sediments in the basin was generally low.
RESUMO
Objective To study the preference relation between residence, sex, age and causes of accidental death of Chinese residents. Methods In this study, 72 residence-sex-age groups and 8 causes of accidental death were qualitatively and quantitatively analyzed by correspondence analysis using the official statistical yearbook issued from 2014 to 2018, and the preference values were calculated. Results Among the 576 pairs of correspondences between the residence-sex-age groups and causes of accidental death, 352 pairs （61.11%） showed a preference relation （preference value>0）. In terms of residence and sex, accidental death preference among Chinese residents was higher in rural areas than in urban areas, and males were higher than females. In terms of the causes of accidental death, the overall risk of accidental mechanical asphyxia and motor vehicle accidents was the highest among all age groups of Chinese residents. In terms of age, with the increase of age, the preference value of accidental death of Chinese residents showed a trend of first increasing and then decreasing. The comparative analysis results of the preference values of various causes of accidental death in different age groups showed that motor vehicle traffic accidents, accidental poisoning, death by crush and electric shock were more likely to occur in the working age group between 20 and 59 years old, accidental fall and fire were more likely to occur in the elderly group over 80 years old, and drowning and accidental mechanical asphyxia were more likely to occur in the minor group between 1 and 19 years old. Conclusion There are different preference relations between residence-sex-age groups and causes of accidental death in China. Therefore, effective control strategies and measures should be formulated for Chinese residents with preference for accidental death.
