Study On Environmental Health Effects Of Public Bicycles

Public transport is an important way to solve the problem that the existing resources cannot meet the growing traffic demand.Public Bicycles is an important supplement to public transport to extending its services radius.Public Bicycles has been developing rapidly in the past 10 years,especially in China.More than 400 cities,including Nanjing city have built Public Bicycles in China with more than 80%bikes of the world s total.Environmental health effects of Publie Bicycles also attract wide attention.On the one hand,air pollution,has been proved harm for our health,is the most serious environmental problems in China.On the other hand,pollution exposure changes of the Public Bicycles users,reduction of the car usage and pollutants emission introduced by Public Bicycles are closely related to environmental health.Therefore,not only the public concern this topic,but also more and more researchers are spending time on this study.Many studies have assessed the environmental health effects of shift from the other transport mode to Public Bicycles,and most results show that the benefits are far greater than the risks.However,most of existing studies have two key limitations.The first limitation is that the pattern of transport mode substitution,the starting point of the whole study,is determined based on assumption,which cannot conduct the accurate result of the actual situation.The second one is that there is none study focus on China,therefore the results of existing studies would be inaccurate when applied to China.To address these problems,we assess the environmental health effects of Public Bicycles in Nanjing city in 2015 based on the actual pattern of Public Bicycles usage.The actual usage data come from the Nanjing Public Bicycle Co.,Ltd.,and the data of transport mode substitution come from our questionnaire survey,conducted in September to November 2016,with 461 valid questionnaires returned.The existing studies find that there are 4 main pathways through which Public Bicycles affect environmental health.Pathways includes 1)the health effects of physical activity in Public Bicycles users;2)the health effects of air pollution exposure on users and general population;3)the effects of traffic accidents;and 4)the health effects of noise.Based on the realistic conditions and the availability of the existing studies,we just consider the pathway 1 and 2 in our study.Firstly,we find that if Public Bicycles is not available,29.93%of all respondents would choose bus,24.51%choose metro,3.90%choose taxi,2.39%choose car,35.14%choose walking and 4.12%choose private bike to make the particular trip made by Public Bicycles.Secondly,we assess the atmospheric environment impacts of Public Bicycles.The results show that Public Bicycles in Nanjing introduces 13.65 tons of CO,1.10 tons of NOx,1.29 tons of VOC,6.84 kilograms of particulate matter and 626 tons of CO2 emissions reductions in 2015.However,these are too small to affect the air quality.Finally,we assess the environmental health impact of Public Bicycles users.We find that if the users shift to use bike 13 minutes per day from buses,subways,the average PM2.5 exposure concentration would increase about 4 ?g/m3 in Nanjing,mainly because of the exposure time increasing and the respiration rate increasing;And if shift from walking,it will reduce 1 ?g/m3.Totally,17.48 deaths were avoided due to increased physical activity,while 3.21 deaths were caused by changes of air pollution exposure in Nanjing in 2015.The benefits are much smaller than other hypothetical scenarios,suggesting that other hypothetical scenarios may overestimate the environmental health benefits of Public Bicycles.The results of this study show that the environmental health benefits of Public Bieycles exceed health risks under the certain conditions in China.In the context of environmental health,Publie Bicycles is a favorable option for policymakers and its'users.