| Statistics from Traffic Management Bureau, Ministry of Public Security show that with number of vehicles booming and frequency of vehicle usage increasing in recent years, traffic jams have become more and more common, and thus result in longer time drivers stay in the traffic microenvironment. The pollution, health hazards and control of air pollutants in the traffic microenvironment, especially the new semi-volatile organic contaminants(e.g. phthalic acid esters, or PAEs), have drawnresearchers’ widespread attention.This paper first introduces the properties, usage and toxicity of 15 kinds of PAEs, reviews literature of recent research progress on pollution of PAEs in indoor environment and summarizes related laws and regulations on limitation of PAEs content and health risks of exposure to PAEs in microenvironment.Secondly, we improve categories of PAEs pollutants research through investigation of common toxic PAEs. We optimize conditions of chromatogram analysis based on other people’s work and result illustrates that the optimized version consumes similar time and has advantages of fast response, high discrimination ability and stability. The method detection limit (MDL) range of our approach is between 19.32 ng/m3 and 41.29 ng/m3, and it satisfies the requirement of quantitive analysis in air samples from indoor and ourdoor environment The analysis method of PAEs in traffic microenvironment is determined.Thirdly, we study concentration level and characteristics of 15 kinds of PAEs in traffic microenvironment of 6 different ways of travel. Result reveals that private cars have the highest total PAEs exposure level, with buses, subway, electric cars and walking coming in a descending order. PAEs concentration level for these ways of travel are (ng/m3) 63505,50405,46057,43727,3113.8, and 1438.5 respectively. When it comes to travelling by buses, electric buses has the highest total PAEs exposure level, and buses with air conditioner, normal buses and school buses coming after. PAEs in urban area are higher than that in tourism area, but lower than that in suburb area. Also PAEs in peak traffic hours are higher than that in the rest of the day. This trend of peak hours can also be found when travelling by taxis and subway. When travelling on foot, pavements have higher PAEs exposure than footpaths.Last but not least, we adopt the most toxic DEHP as an example to analyze the amount of respiration for various group of people in traffic microenvironment and evaluate cancer risks for passengers and drivers of different ages and sexes to give reasonable suggestions for travel.According to the result, DEHP brings highest cancer risks to male passengers of age 2 to 3 and male drivers of age 18 to 21, regardless of ways of travelling. As for ways of travelling, walking has the lowest risk. We suggest that when travel for relatively short distance, walking is preferred, and you should choose subway when you travel for less than 12.23km, and otherwise you should take a taxi.The amount of gas-phase PAEs and particle-phase PAEs in traffic microenvironment are almost equal, while the ratio of gas-phase PAEs to particle-phase PAEs in room space is around 1.6. It can be seen that particle-phase PAEs take up higher percentage in traffic microenvrionment. When comparing total amount of six kinds of PAEs in different scenes, private cars have the highest level of PAEs concentration, with buses, taxis, subways and newly decorated rooms coming after that. The concentration level of PAEs in the aforementioned four vehicles are 2.5,2.0,1.9 and 1.8 times of that in newly decorated rooms, so a conclusion can be drawn from the result that PAEs pollution in traffic microenvironment is more severe and need to be dealt with seriously.This paper for the first time systematically studies concentration level, pollution characteristics and health hazards of air PAEs in traffic microenvironment. We also improve the characteristic database of PAEs in indoor air, and provide scientific basis and theoretical support for the study of PAEs in traffic microenvironment as well as the making oflaws and regulations on air PAEs control. |
PDF Full Text Request