Volume 5 Number 4 April 2019

Analysis of Heavy Metal Pollution Based on Two-Dimensional Diffusion Model

Authors: Yunhui Zeng ; Wenhao Li ; Hongfei Guo ; Yilin Chen ; Xiaoqing Jiang ; Bingjie Yu
Pages: 87-92
This paper takes the propagation characteristics of heavy metals and the judgment of the location of pollution sources as the research objects, aiming to analyze the propagation characteristics of different heavy metals. Firstly, the Gaussian diffusion model is conducted to establish the propagation characteristics model of heavy metal pollutants in the atmosphere. Then, based on the law of conservation of mass and the law of two-dimensional diffusion, the two-dimensional diffusion model is adopted to establish the propagation characteristics model of heavy metals in soil moisture. According to these two models, the nonlinear differential equations are established respectively, revealing that the characteristics of the two propagation ways are related to space, time, diffusion coefficients, and other factors. Then, in the light of the propagation characteristics of different heavy metals, the least square method is applied to reduce the data calculation error and obtain the specific location of the pollution source. Finally, through establishing the three-dimensional diffusion model of heavy metal diffusion by introducing artificial control, speed and angle of prevailing wind direction, and other factors, the model is further optimized. The establishment of this model provides an important theoretical basis and guiding significance for the future study of heavy metal pollutants.

Knowledge, Attitude and Practice of Unintentional Injuries Among Old People in Urban Zunyi, Southwest China

Authors: Xue Wang ; Huiting Yu ; Chan Nie ; Chao Wang ; Xiuquan Shi
Pages: 81-86
Objective: To describe the KAP (knowledge, attitude and practice, KAP) and explore the influence factors for UIs (unintentional injuries, UIs) among the elderly (aged>﹦60 years) in urban districts of Zunyi, China. Methods: Using random cluster sampling method, a survey was conducted with questionnaires, to collect UIs and related KAP in the elderly and analyze its influencing factors. Results: The annual incidence of UIs (falls, burns, traffics, etc.) was 17.46% in some urban districts of Zunyi. Among them, 27.94% elderly regarded UI as a type of disease; the channels to acquire related knowledge through TV (79.05%), listening to others’ narration (56.83%), community publicity (26.03%), books or newspapers (22.86%) and internet (9.84%). While 76.51% of the elderly believed that UIs were preventable; 81.59% old people worried about UIs; 93.97% of the elderly chose to seek help when they suffered UIs; and 95.25% of elderly people followed traffic rules when crossing the road. In the case of gas use, 25.77% of the cases were checked and closed each time, 40% and 20% old people would check the time before taking the medicine, and purchasing food. Factors affecting the occurrence of UIs were age, heart disease (both P<0.05). Moreover, the living condition had an effect on “whether considering UIs as a kind of disease” (P=0.003). Conclusion: The KAP of UIs in the elderly is not optimistic, though most elderly people think the damage can be prevented; prevention on UIs related behavior needs to be enhanced. We should arouse the public to pay more attentions to keep elderly people far away UIs risk factors in this area.